Science.gov

Sample records for original constellation points

  1. Origins of the "Western" Constellations

    NASA Astrophysics Data System (ADS)

    Frank, Roslyn M.

    The development of the 48 Greek constellations is analyzed as a complex mixture of cognitive layers deriving from different cultural traditions and dating back to different epochs. The analysis begins with a discussion of the zodiacal constellations, goes on to discuss the stellar lore in Homer and Hesiod, and then examines several theories concerning the origins of the southern non-zodiacal constellations. It concludes with a commentary concerning the age and possible cultural significance of stars of the Great Bear constellation in light of ethnohistorical documentation, folklore, and beliefs related to European bear ceremonialism.

  2. The origin of the constellations

    NASA Astrophysics Data System (ADS)

    Roy, Archie E.

    The problem of the origin of the stellar constellations familiar to western astronomers from ancient times is discussed in an attempt to answer the classical detective story questions: Who? When? Why? and Where? The available astronomical, literary and archaeological evidence is examined to suggest a possible solution.

  3. The Origin of Our Constellations.

    ERIC Educational Resources Information Center

    Ridpath, Ian

    1990-01-01

    Reviewed is the history of the naming of the constellations which appear in the sky. The roles of many ancient peoples through the astronomers of the eighteenth century up to the adoption of the official list of 88 constellations produced in 1922 by the International Astronomical Union are discussed. (CW)

  4. On the origin of the zodiacal constellations

    NASA Astrophysics Data System (ADS)

    Gurshtein, Alex A.

    A reconstruction of the evolution of the zodiacal constellations is made, based on the Indoeuropean and Sumero-Akkadian religio-cultural data, including artifacts such as cult statuettes, cuneiform tablets, cylinder seals and boundary stones. It is argued that the development of the twelve houses of the zodiac in three groups of four over some six millennia was dictated by the changes made by precession in the positions of the vernal and autumnal equinoxes and the winter and summer solstices.

  5. Origins of the ancient constellations: II. The Mediterranean traditions

    NASA Astrophysics Data System (ADS)

    Rogers, J. H.

    1998-04-01

    The classical map of the sky, with the 48 Greek constellations, was derived from at least two different pre-Greek traditions. One tradition comprised the 12 signs of the zodiac, with several associated animal constellations, all of which developed over ~3200-500 BC in Mesopotamia in a religious or ritual tradition. These were taken over by the Greeks around 500 BC. However the other Babylonian constellations, their farming-calendar tradition, were not adopted. The other tradition was not Mesopotamian; it comprised large constellations which appear to date from ~2800 BC, probably from the Mediterranean region, devised for the navigators of ships. They include huge bears and serpents which marked the celestial pole and equator at that time, and probably the four anonymous giants which we know as Hercules, Ophiuchus, Bootes, and Auriga, as well as some of the large southern 'marine' constellations. The origins of some other constellations, including the Perseus tableau and various animals, are unknown; they may have been new creations of the Greeks. The Greeks assembled the classical sky-map from these different sources between 540-370 BC, but many of the familiar legends were only applied to the constellations later.

  6. A New Synthesis for the Origin of the Greek Constellations

    NASA Astrophysics Data System (ADS)

    Schaefer, B. E.

    2005-08-01

    The Greek constellations constitute one of the longest enduring intellectual properties of humanity. While various papers attribute the origin of the constellations to many diverse possibilities, main stream historians view the origin as largely being in Mesopotamia after around 1350 BC with transmission to the Greeks around 500 BC or so. The evidence for this synthesis is cuneiform and iconographic records that first mention constellations from roughly 1350-500 BC. My recent research on precessional dating has added much detail to this old synthesis. The earliest surviving written description of the Greek constellations is Aratus' Phaenomenon, which is a copy of Eudoxus' lost book of the same name. Hipparchus' Commentary also extensively quotes from Eudoxus. With 172 observations from Eudoxus, I derive a precessional date of 1130 ± 80 BC and a latitude of 36.0 ± 0.9 degrees north. Further, the positioning of the southern void amongst the Greek constellations yields a date of 690 BC (with an uncertainty of 2-4 centuries) and a latitude of 33 degrees (with an uncertainty of 1-3 degrees) for the six southernmost constellations. The earliest surviving description of the Mesopotamian constellations is the MUL.APIN tablet series, with the oldest dated example from the 8th century BC. My precessional calculation gives a date of 1100 BC and a latitude of 33 north. I also see that Eudoxus and MUL.APIN share a substantial number of observations. In all, some Assyrian observer(s) between 33-36 degrees north latitude around the time of 1300-1000 BC apparently invented many of the constellations adopted by the Greeks and made a database of observations later repeated by MUL.APIN, Eudoxus, Aratus, and Hipparchus. But this is not the whole story, as this only accounts for 19 Greek constellations which are identical in stars and representation with the Mesopotamian sky. An additional 12 Greek constellations have the same star groups as the Babylonians yet have completely

  7. Code Single Point Positioning Using Nominal GNSS Constellations (Future Perception)

    NASA Astrophysics Data System (ADS)

    Farah, A. M. A.

    Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation, namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning from different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, GLONASS and Galileo) using different combinations. This study presents results of code single point positioning for five stations using the three constellations and different combinations.

  8. Precise Point Positioning Using Triple GNSS Constellations in Various Modes

    PubMed Central

    Afifi, Akram; El-Rabbany, Ahmed

    2016-01-01

    This paper introduces a new dual-frequency precise point positioning (PPP) model, which combines the observations from three different global navigation satellite system (GNSS) constellations, namely GPS, Galileo, and BeiDou. Combining measurements from different GNSS systems introduces additional biases, including inter-system bias and hardware delays, which require rigorous modelling. Our model is based on the un-differenced and between-satellite single-difference (BSSD) linear combinations. BSSD linear combination cancels out some receiver-related biases, including receiver clock error and non-zero initial phase bias of the receiver oscillator. Forming the BSSD linear combination requires a reference satellite, which can be selected from any of the GPS, Galileo, and BeiDou systems. In this paper three BSSD scenarios are tested; each considers a reference satellite from a different GNSS constellation. Natural Resources Canada’s GPSPace PPP software is modified to enable a combined GPS, Galileo, and BeiDou PPP solution and to handle the newly introduced biases. A total of four data sets collected at four different IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the International GNSS Service Multi-GNSS Experiment (IGS-MGEX) network are used to correct the GPS, Galileo, and BeiDou measurements in the post-processing PPP mode. A real-time PPP solution is also obtained, which is referred to as RT-PPP in the sequel, through the use of the IGS real-time service (RTS) for satellite orbit and clock corrections. However, only GPS and Galileo observations are used for the RT-PPP solution, as the RTS-IGS satellite products are not presently available for BeiDou system. All post-processed and real-time PPP solutions are compared with the traditional un-differenced GPS-only counterparts. It is shown that combining the GPS, Galileo, and BeiDou observations in the post-processing mode improves the PPP convergence

  9. Precise Point Positioning Using Triple GNSS Constellations in Various Modes.

    PubMed

    Afifi, Akram; El-Rabbany, Ahmed

    2016-01-01

    This paper introduces a new dual-frequency precise point positioning (PPP) model, which combines the observations from three different global navigation satellite system (GNSS) constellations, namely GPS, Galileo, and BeiDou. Combining measurements from different GNSS systems introduces additional biases, including inter-system bias and hardware delays, which require rigorous modelling. Our model is based on the un-differenced and between-satellite single-difference (BSSD) linear combinations. BSSD linear combination cancels out some receiver-related biases, including receiver clock error and non-zero initial phase bias of the receiver oscillator. Forming the BSSD linear combination requires a reference satellite, which can be selected from any of the GPS, Galileo, and BeiDou systems. In this paper three BSSD scenarios are tested; each considers a reference satellite from a different GNSS constellation. Natural Resources Canada's GPSPace PPP software is modified to enable a combined GPS, Galileo, and BeiDou PPP solution and to handle the newly introduced biases. A total of four data sets collected at four different IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the International GNSS Service Multi-GNSS Experiment (IGS-MGEX) network are used to correct the GPS, Galileo, and BeiDou measurements in the post-processing PPP mode. A real-time PPP solution is also obtained, which is referred to as RT-PPP in the sequel, through the use of the IGS real-time service (RTS) for satellite orbit and clock corrections. However, only GPS and Galileo observations are used for the RT-PPP solution, as the RTS-IGS satellite products are not presently available for BeiDou system. All post-processed and real-time PPP solutions are compared with the traditional un-differenced GPS-only counterparts. It is shown that combining the GPS, Galileo, and BeiDou observations in the post-processing mode improves the PPP convergence

  10. Origins of the ancient constellations: I. The Mesopotamian traditions

    NASA Astrophysics Data System (ADS)

    Rogers, J. H.

    1998-02-01

    In the sky-map of ancient Babylon, constellations had two different roles, and thus developed into two overlapping traditions. One set of constellations represented the gods and their symbols; the other set represented rustic activities and provided a farming calendar. Many constellations were shared by the two traditions, but in some regions of sky there were alternative divine and rustic figures. These figures developed in stages from ~3200 BC to ~500 BC. Of the divine set, the most important (although the last to be finalised) were the twelve zodiacal signs, plus several associated animals (the serpent, crow, eagle, and fish), which were all transmitted to the classical Greek sky-map that we still use today. Conversely, the rustic constellations of workers and tools and animals were not transmitted to the West. However, a few of them may have survived in Bedouin Arab sky-maps of the first millennium AD.

  11. Rannyaya istoriya Mesopotamskikh sozvezdij (k probleme proiskhozhdeniya sozvezdij) %t The early history of Mesopotamian constellations (to the problem of the constellations origin

    NASA Astrophysics Data System (ADS)

    Kurtik, G. E.

    This paper considers the early written and iconographic sources of the end of the 4th-beginning of the 2nd millennia B.C. which can shed light on the problem of the origin of Mesopotamian constellations. We were interested, first of all, with two questions: (1) whether it is possible to make a conclusion on the basis of the sources that the constellations were already distinguished in Mesopotamia in the appropriate period, and, if-yes, (2) what constellation or group of constellations is there the question about? In most cases the conclusion turns out to be either negative or uncertain because the sources allow ambiguous, sometimes opposite senses, interpretations.

  12. Precise point positioning with quad-constellations: GPS, BeiDou, GLONASS and Galileo

    NASA Astrophysics Data System (ADS)

    Cai, Changsheng; Gao, Yang; Pan, Lin; Zhu, Jianjun

    2015-07-01

    Multi-constellation GNSS precise point positioning (PPP) first became feasible back to 2007 but with only two constellations, namely GPS and GLONASS. With the availability of more satellites and precise orbit and clock products from BeiDou and Galileo, it is possible now to investigate PPP with four constellations, namely GPS, BeiDou, GLONASS and Galileo. This research aims at investigating the quad-constellation PPP for position determination and analyzing its positioning performance. A quad-constellation PPP model is developed to simultaneously process the observations from all the four GNSS systems. The developed model is also applicable to the PPP processing with observations from single, dual or triple constellations. The analysis on PPP accuracy and convergence time is conducted based on data processing results from both static and kinematic tests of single-constellation and multi-constellations. The three-hour static positioning results indicate that the BeiDou-only PPP accuracy is worse than the GPS-only PPP. The RMSs of position errors for BeiDou-only PPP are 5.2 cm, 2.7 cm and 8.3 cm in east, north and up directions while the ones for GPS-only PPP are 3.9 cm, 1.6 cm and 5.7 cm. The GPS/BeiDou PPP improves the positioning accuracy by 28%, 6% and 7% and reduces the convergence time by 26%, 13% and 14% over the GPS-only PPP in three coordinate components, respectively. The GPS/GLONASS PPP achieves slightly better performance than the GPS/BeiDou PPP. The triple-constellation PPP further increases the positioning accuracy and decreases the convergence time over the dual-constellation PPP. The improvement of positioning performance is not significant after adding Galileo due to currently limited number of satellites. Similar to the static positioning, the quad-constellation kinematic PPP also significantly improves the positioning performance in contrast with single-constellation and dual-constellations. The time varying characteristics of the time differences

  13. Multi-point Magnetic Field Observations of Field-Aligned Currents from Swarm Constellation Mission

    NASA Astrophysics Data System (ADS)

    Le, Guan; Chi, Peter; Lühr, Hermann; Gjerloev, Jesper; Stolle, Claudia; Park, Jaeheung; Rauberg, Jan

    2015-04-01

    In this paper, we report the results of case studies of multi-point magnetic field measurements of field-aligned currents (FACs) from Swarm constellation mission to understand their temporal characteristics and hemispheric asymmetry. For science operations (since April, 2014), the three spacecraft were placed in slightly different polar orbits: Swarm B spacecraft in a higher altitude orbit (507km x 512km) and Swarm A and C side-by-side in lower altitude orbits (459km x 462km). In the beginning of the science operational phase, the longitudinal separations of the orbital planes were small, and Swarm A/C pair and Swarm B were nearly out of phase in the orbit. This unique orbit configuration provides opportunities to study some new features of FACs. Specifically, the Swarm satellites make multiple crossings of a FAC region within a few hours. Such data enable us to study temporal variations in several time scales, from 1 minute up to about 3 hours. Furthermore, the three satellites make nearly simultaneous observations of FACs in northern and southern hemispheres, which provide us an opportunity to study the hemispheric asymmetry.

  14. On biases in precise point positioning with multi-constellation and multi-frequency GNSS data

    NASA Astrophysics Data System (ADS)

    El-Mowafy, A.; Deo, M.; Rizos, C.

    2016-03-01

    Various types of biases in Global Navigation Satellite System (GNSS) data preclude integer ambiguity fixing and degrade solution accuracy when not being corrected during precise point positioning (PPP). In this contribution, these biases are first reviewed, including satellite and receiver hardware biases, differential code biases, differential phase biases, initial fractional phase biases, inter-system receiver time biases, and system time scale offset. PPP models that take account of these biases are presented for two cases using ionosphere-free observations. The first case is when using primary signals that are used to generate precise orbits and clock corrections. The second case applies when using additional signals to the primary ones. In both cases, measurements from single and multiple constellations are addressed. It is suggested that the satellite-related code biases be handled as calibrated quantities that are obtained from multi-GNSS experiment products and the fractional phase cycle biases obtained from a network to allow for integer ambiguity fixing. Some receiver-related biases are removed using between-satellite single differencing, whereas other receiver biases such as inter-system biases are lumped with differential code and phase biases and need to be estimated. The testing results show that the treatment of biases significantly improves solution convergence in the float ambiguity PPP mode, and leads to ambiguity-fixed PPP within a few minutes with a small improvement in solution precision.

  15. Point pattern match-based change detection in a constellation of previously detected objects

    DOEpatents

    Paglieroni, David W.

    2016-06-07

    A method and system is provided that applies attribute- and topology-based change detection to objects that were detected on previous scans of a medium. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, detection strength, size, elongation, orientation, etc. The locations define a three-dimensional network topology forming a constellation of previously detected objects. The change detection system stores attributes of the previously detected objects in a constellation database. The change detection system detects changes by comparing the attributes and topological consistency of newly detected objects encountered during a new scan of the medium to previously detected objects in the constellation database. The change detection system may receive the attributes of the newly detected objects as the objects are detected by an object detection system in real time.

  16. Accuracy improvement techniques in Precise Point Positioning method using multiple GNSS constellations

    NASA Astrophysics Data System (ADS)

    Vasileios Psychas, Dimitrios; Delikaraoglou, Demitris

    2016-04-01

    The future Global Navigation Satellite Systems (GNSS), including modernized GPS, GLONASS, Galileo and BeiDou, offer three or more signal carriers for civilian use and much more redundant observables. The additional frequencies can significantly improve the capabilities of the traditional geodetic techniques based on GPS signals at two frequencies, especially with regard to the availability, accuracy, interoperability and integrity of high-precision GNSS applications. Furthermore, highly redundant measurements can allow for robust simultaneous estimation of static or mobile user states including more parameters such as real-time tropospheric biases and more reliable ambiguity resolution estimates. This paper presents an investigation and analysis of accuracy improvement techniques in the Precise Point Positioning (PPP) method using signals from the fully operational (GPS and GLONASS), as well as the emerging (Galileo and BeiDou) GNSS systems. The main aim was to determine the improvement in both the positioning accuracy achieved and the time convergence it takes to achieve geodetic-level (10 cm or less) accuracy. To this end, freely available observation data from the recent Multi-GNSS Experiment (MGEX) of the International GNSS Service, as well as the open source program RTKLIB were used. Following a brief background of the PPP technique and the scope of MGEX, the paper outlines the various observational scenarios that were used in order to test various data processing aspects of PPP solutions with multi-frequency, multi-constellation GNSS systems. Results from the processing of multi-GNSS observation data from selected permanent MGEX stations are presented and useful conclusions and recommendations for further research are drawn. As shown, data fusion from GPS, GLONASS, Galileo and BeiDou systems is becoming increasingly significant nowadays resulting in a position accuracy increase (mostly in the less favorable East direction) and a large reduction of convergence

  17. Crater Constellation

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Cup; abbrev. Crt, gen. Crateris; area 282 sq. deg.) A southern constellation which lies to the south-west of Virgo, and culminates at midnight in mid-March. It represents the cup of the god Apollo in Greek mythology (see Corvus). Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

  18. Egyptian Constellations

    NASA Astrophysics Data System (ADS)

    Lull, José; Belmonte, Juan Antonio

    The ancient Egyptians had a wide range of constellations, which populated the skies of ancient Egypt (see Chap. 133, "Orientation of Egyptian Temples: An Overview", 10.1007/978-1-4614-6141-8_146) for more than three millennia, whose knowledge has come to us through lists of stars and other representations which have mainly appeared in a dozen of coffins, a few clepsydrae, and a good set of astronomical ceilings. Hence, by making very simple assumptions and using the information provided by the ancient Egyptian sky-watchers, it is possible to uncover a great part of the ancient Egyptian firmament. This celestial tapestry was populated by the images of animals, symbols, and divinities that were most significant in understanding the Egyptian interpretation of the cosmos.

  19. Origins of the Human Pointing Gesture: A Training Study

    ERIC Educational Resources Information Center

    Matthews, Danielle; Behne, Tanya; Lieven, Elena; Tomasello, Michael

    2012-01-01

    Despite its importance in the development of children's skills of social cognition and communication, very little is known about the ontogenetic origins of the pointing gesture. We report a training study in which mothers gave children one month of extra daily experience with pointing as compared with a control group who had extra experience with…

  20. Origins of the human pointing gesture: a training study.

    PubMed

    Matthews, Danielle; Behne, Tanya; Lieven, Elena; Tomasello, Michael

    2012-11-01

    Despite its importance in the development of children's skills of social cognition and communication, very little is known about the ontogenetic origins of the pointing gesture. We report a training study in which mothers gave children one month of extra daily experience with pointing as compared with a control group who had extra experience with musical activities. One hundred and two infants of 9, 10, or 11 months of age were seen at the beginning, middle, and end of this one-month period and tested for declarative pointing and gaze following. Infants'ability to point with the index finger at the end of the study was not affected by the training but was instead predicted by infants' prior ability to follow the gaze direction of an adult. The frequency with which infants pointed indexically was also affected by infant gaze following ability and, in addition, by maternal pointing frequency in free play, but not by training. In contrast, infants' ability to monitor their partner's gaze when pointing, and the frequency with which they did so, was affected by both training and maternal pointing frequency in free play. These results suggest that prior social cognitive advances, rather than adult socialization of pointing per se, determine the developmental onset of indexical pointing, but socialization processes such as imitation and adult shaping subsequently affect both infants' ability to monitor their interlocutor's gaze while they point and how frequently infants choose to point. PMID:23106736

  1. Methods and apparatuses for signaling with geometric constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2012-01-01

    Communication systems are described that use signal constellations, which have unequally spaced (i.e. geometrically shaped) points. In many embodiments, the communication systems use specific geometric constellations that are capacity optimized at a specific SNR. In addition, ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes d.sub.min, are also described. Capacity measures that are used in the selection of the location of constellation points include, but are not limited to, parallel decode (PD) capacity and joint capacity.

  2. Constellation Coverage Analysis

    NASA Technical Reports Server (NTRS)

    Lo, Martin W. (Compiler)

    1997-01-01

    The design of satellite constellations requires an understanding of the dynamic global coverage provided by the constellations. Even for a small constellation with a simple circular orbit propagator, the combinatorial nature of the analysis frequently renders the problem intractable. Particularly for the initial design phase where the orbital parameters are still fluid and undetermined, the coverage information is crucial to evaluate the performance of the constellation design. We have developed a fast and simple algorithm for determining the global constellation coverage dynamically using image processing techniques. This approach provides a fast, powerful and simple method for the analysis of global constellation coverage.

  3. 48 CFR 52.247-46 - Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... when price evaluation for shipments from various shipping points is contemplated: Shipping Point(s... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Shipping Point(s) Used in... Text of Provisions and Clauses 52.247-46 Shipping Point(s) Used in Evaluation of F.o.b. Origin...

  4. The Magnetospheric Multiscale Constellation

    NASA Astrophysics Data System (ADS)

    Tooley, C. R.; Black, R. K.; Robertson, B. P.; Stone, J. M.; Pope, S. E.; Davis, G. T.

    2016-03-01

    The Magnetospheric Multiscale (MMS) mission is the fourth mission of the Solar Terrestrial Probe (STP) program of the National Aeronautics and Space Administration (NASA). The MMS mission was launched on March 12, 2015. The MMS mission consists of four identically instrumented spin-stabilized observatories which are flown in formation to perform the first definitive study of magnetic reconnection in space. The MMS mission was presented with numerous technical challenges, including the simultaneous construction and launch of four identical large spacecraft with 100 instruments total, stringent electromagnetic cleanliness requirements, closed-loop precision maneuvering and pointing of spinning flexible spacecraft, on-board GPS based orbit determination far above the GPS constellation, and a flight dynamics design that enables formation flying with separation distances as small as 10 km. This paper describes the overall mission design and presents an overview of the design, testing, and early on-orbit operation of the spacecraft systems and instrument suite.

  5. Capacity Maximizing Constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  6. Mega-constellations Issues

    NASA Astrophysics Data System (ADS)

    Bastida Virgili, Benjamin; Krag, Holger

    2016-07-01

    Space traffic has always been subject to considerable fluctuations. In the past, these fluctuations have been mainly driven by geopolitical and economic factors. During the last years there has been a considerable increase due to the use of cubesats by non-traditional space operators, and due to a significant change of mission scopes and mission orbits in Low Earth Orbit (LEO). In the near future, however, many indications point to a further increase in the space traffic in LEO. This increase is mainly driven by a cheaper access to space, also triggered by the miniaturisation of spacecraft systems. An acceleration of this trend is expressed by the announcement of large constellations in LEO with the purpose to provide broadband internet communication, allowing to minimise the required infrastructure on Earth. The number of artificial objects in orbit continues to increase and, with it, a key threat to space sustainability. In response, space agencies have identified a set of mitigation guidelines aimed at enabling space users to reduce the generation of space debris by, for example, limiting the orbital lifetime of their spacecraft and of launcher stages after the end of their mission to 25 years in LEO. However, several recent studies have shown that, today, current guidelines for the LEO protected zone are insufficiently applied by space systems of all sizes. Under these conditions, a step increase in the launch rate is a potential concern for the environment, in particular if the current End of Life (EOL) behaviour prevails in the future. Even in a perfect behaviour w.r.t. the 25 year lifetime rule, the new traffic might lead to unrecoverable environment trends. Furthermore, the requirement for reliability of the disposal function is of 90%, however, weighted with the reliability of the entire system. A failure rate of 10%, in general, was found to be acceptable under current space traffic conditions. This might not be sustainable when the LEO launch rates

  7. 48 CFR 52.247-46 - Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Evaluation of F.o.b. Origin Offers. 52.247-46 Section 52.247-46 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.247-46 Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers. As prescribed in 47.305-3(b)(4)(ii), insert the following provision in f.o.b. origin...

  8. 48 CFR 52.247-46 - Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Evaluation of F.o.b. Origin Offers. 52.247-46 Section 52.247-46 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.247-46 Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers. As prescribed in 47.305-3(b)(4)(ii), insert the following provision in f.o.b. origin...

  9. 48 CFR 52.247-46 - Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Evaluation of F.o.b. Origin Offers. 52.247-46 Section 52.247-46 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.247-46 Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers. As prescribed in 47.305-3(b)(4)(ii), insert the following provision in f.o.b. origin...

  10. 48 CFR 52.247-46 - Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Evaluation of F.o.b. Origin Offers. 52.247-46 Section 52.247-46 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.247-46 Shipping Point(s) Used in Evaluation of F.o.b. Origin Offers. As prescribed in 47.305-3(b)(4)(ii), insert the following provision in f.o.b. origin...

  11. Star Numbers and Constellations.

    ERIC Educational Resources Information Center

    Francis, Richard L.

    1993-01-01

    A number for which the number of digits categorizes the number is called a star number. A set of star numbers having a designated property is called a constellation. Discusses nature and cardinality of constellations made up of star square, star prime, star abundant, and star deficient numbers. Presents five related problems for exploration. (MDH)

  12. On the Origins of Pointing in Infancy: A Pilot Study.

    ERIC Educational Resources Information Center

    Butterworth, George; Adamson-Macedo, Elvidina

    Observations were made of the incidence of pointing behavior among infants differing in age when a radio-controlled truck entered the room in which mother and infant were seated. Infants' reactions over 5 to 6 minutes were recorded on videotape. Recordings were analyzed to establish the incidence of pointing, handedness of pointing, whether…

  13. GPM Constellation with Clock

    NASA Video Gallery

    In this animation the orbit paths of the NASA partner satellites of the GPM constellation fill in blue as the instruments pass over Earth. Rainfall appears light blue for light rain, yellow for mod...

  14. Macedonian Folk Constellations

    NASA Astrophysics Data System (ADS)

    Cenev, G.

    2008-10-01

    Ethno-astronomical researches started to be performed on the territory of the Republic of Macedonia in 1982 and since then they are constantly carried out. Information gathered directly from the elderly inhabitants of around 130 villages all over the country, enlighten the folk presentation of sky, division of the stars and constellations, but also provided a vast scope of myths, beliefs and rituals linked to the sky, stars, and constellations. More in-depth analyses of the gathered data lead to the reconstruction of the ancient stars map of the Macedonian people. Due to the fact that in the past people recognized only two seasons, most of the stars and constellations are presented on the so-called winter and summer sky. People were also familiar with the part of the sky around the Polaris and knew about the constellations that did not rise and set, but are special part of the folk sky map. The mentioned study provides a comparative analysis of the folk constellations known among the Macedonian people and folk constellations know among the others, mos tly neighbouring people living on the Balkan Peninsula.

  15. The BRITE Nanosatellite Constellation Mission

    NASA Astrophysics Data System (ADS)

    Schwarzenberg-Czerny, Alexander; Weiss, Werner; Moffat, Anthony; Zee, Robert E.; Rucinski, Slavek; Mochnacki, Stefan; Matthews, Jaymie; Breger, Michel; Kuschnig, Rainer; Koudelka, Otto; Orleanski, Piotr; Pamyatnykh, Alexei; Pigulski, Andrzej; Grant, Cordell

    BRITE Constellation, short for "BRIght Target Explorer Constellation," is a group of six seven-kilogram nanosatellites from Austria, Poland and Canada carrying three-centimeter aperture optical telescopes. The purpose of the mission is to photometrically measure low-level oscilla-tions and temperature variations in the sky's 286 stars brighter than visual magnitude 3.5, with unprecedented precision and time sampling not achievable through terrestrial-based methods. These stars turn out, for the most part, to be among the most luminous -either massive stars during their whole lifetimes or medium-mass stars at the very end of their nuclear burning phases. Such stars dominate the ecology of the Universe and the current massive ones are believed to represent the lower mass-range of the first stars ever formed (although long gone from the local Universe). Astronomers are eager to measure the variable behavior of lumi-nous stars in order to explore their inner workings in a unique way. BRITE Constellation will investigate the role that stellar winds play in setting up future stellar life cycles, and will measure pulsations to probe the histories and ages of luminous stars through asteroseismology. The three-axis pointing performance (1 arcminute RMS stability) of each BRITE satellite is a significant advancement by the University of Toronto's Space Flight Laboratory over any-thing that has ever flown before on a nanosatellite, and is a critical element that enables the high precision photometry mission. The University of Vienna and FFG/ALR (Austria's space agency) are financing the development of two satellites and development is nearing completion. The Polish Academy of Sciences is preparing two additional satellites. The Canadian Space Agency is also expected to fund two satellites in the constellation. This paper will summarize the science objectives of the mission and describe the progress to date.

  16. On the origin of planetary-scale tipping points.

    PubMed

    Lenton, Timothy M; Williams, Hywel T P

    2013-07-01

    Tipping points are recognised in many systems, including ecosystems and elements of the climate system. But can the biosphere as a whole tip and, if so, how? Past global tipping points were rare and occurred in the coupled planetary-scale dynamics of the Earth system, not in the local-scale dynamics of its weakly interacting component ecosystems. Yet, evolutionary innovations have triggered past global transformations, suggesting that tipping point theory needs to go beyond bifurcations and networks to include evolution. PMID:23777818

  17. Ancient Chinese constellations

    NASA Astrophysics Data System (ADS)

    Xu, Junjun

    2011-06-01

    China, a country with a long history and a specific culture, has also a long and specific astronomy. Ancient Chinese astronomers observed the stars, named and distributed them into constellations in a very specific way, which is quite different from the current one. Around the Zodiac, stars are divided into four big regions corresponding with the four orientations, and each is related to a totem, either the Azure Dragon, the Vermilion Bird, the White Tiger or the Murky Warrior. We present a general pattern of the ancient Chinese constellations, including the four totems, their stars and their names.

  18. CarbonSat Constellation

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Tobehn, Carsten; Ernst, Robert; Bovensmann, Heinrich; Buchwitz, Michael; Burrows, John P.; Notholt, John

    1 Carbon dioxide (CO2) and methane (CH4) are the most important manmade greenhouse gases (GHGs) which are driving global climate change. Currently, the CO2 measurements from the ground observing network are still the main sources of information but due to the limited number of measurement stations the coverage is limited. In addition, CO2 monitoring and trading is often based mainly on bottom-up calculations and an independent top down verification is limited due to the lack of global measurement data with local resolution. The first CO2 and CH4 mapping from SCIAMACHY on ENVISAT shows that satellites add important missing global information. Current GHG measurement satellites (GOSAT)are limited either in spatial or temporal resolution and coverage. These systems have to collect data over a year or even longer to produce global regional fluxes products. Conse-quently global, timely, higher spatial resolution and high accuracy measurement are required for: 1. A good understanding of the CO2 and CH4 sources and sinks for reliable climate predic-tion; and 2. Independent and transparent verification of accountable sources and sinks in supporting Kyoto and upcoming protocols The CarbonSat constellation idea comes out the trade off of resolution and swath width during CarbonSat mission definition studies. In response to the urgent need to support the Kyoto and upcoming protocols, a feasibility study has been carried out. The proposed solution is a constellation of five CarbonSat satellites in 614km LTAN 13:00, which is able to provide global, daily CO2 and CH4 measurement everywhere on the Earth with high spatial resolution 2 × 2 km and low uncertainty lt;2ppm (CO2) and lt;8ppb (CH4). The unique global daily measurement capability significantly increases the number of cloud free measurements, which enables more reliable services associated with reduced uncertainty, e.g. to 0.15ppm (CO2) per month in 10km and even more timely products. The CarbonSat Constellation in

  19. Origin of acoustic emission produced during single point machining

    SciTech Connect

    Heiple, C.R,.; Carpenter, S.H.; Armentrout, D.L.

    1991-01-01

    Acoustic emission was monitored during single point, continuous machining of 4340 steel and Ti-6Al-4V as a function of heat treatment. Acoustic emission produced during tensile and compressive deformation of these alloys has been previously characterized as a function of heat treatment. Heat treatments which increase the strength of 4340 steel increase the amount of acoustic emission produced during deformation, while heat treatments which increase the strength of Ti-6Al-4V decrease the amount of acoustic emission produced during deformation. If chip deformation were the primary source of acoustic emission during single point machining, then opposite trends in the level of acoustic emission produced during machining as a function of material strength would be expected for these two alloys. Trends in rms acoustic emission level with increasing strength were similar for both alloys, demonstrating that chip deformation is not a major source of acoustic emission in single point machining. Acoustic emission has also been monitored as a function of machining parameters on 6061-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, lead, and teflon. The data suggest that sliding friction between the nose and/or flank of the tool and the newly machined surface is the primary source of acoustic emission. Changes in acoustic emission with tool wear were strongly material dependent. 21 refs., 19 figs., 4 tabs.

  20. Origins of nonlocality near the neutrality point in graphene.

    PubMed

    Renard, Julien; Studer, Matthias; Folk, Joshua A

    2014-03-21

    We present an experimental study of nonlocal electrical signals near the Dirac point in graphene. The in-plane magnetic field dependence of the nonlocal signal confirms the role of spin in this effect, as expected from recent predictions of the Zeeman spin Hall effect in graphene, but our experiments show that thermo-magneto-electric effects also contribute to nonlocality, and the effect is sometimes stronger than that due to spin. Thermal effects are seen to be very sensitive to sample details that do not influence other transport parameters. PMID:24702396

  1. The Family Constellation Scale.

    ERIC Educational Resources Information Center

    Lemire, David

    The Family Constellation Scale (FC Scale) is an instrument that assesses perceived birth order in families. It can be used in counseling to help initiate conversations about various traits and assumptions that tend to characterize first-born, middle-born children, youngest-born, and only children. It provides both counselors and clients insights…

  2. On satellite constellation selection

    SciTech Connect

    Canavan, G.H.

    1991-05-01

    Analytical estimates can be used to produce and discuss optimal constellations. They are in close agreement with phase-space estimates and exact solutions. They suggest that distributions of inclined orbits could reduce satellite numbers by factors of 2--3 while improving uniformity. 4 refs., 2 figs.

  3. Commanding Constellations (Pipeline Architecture)

    NASA Technical Reports Server (NTRS)

    Ray, Tim; Condron, Jeff

    2003-01-01

    Providing ground command software for constellations of spacecraft is a challenging problem. Reliable command delivery requires a feedback loop; for a constellation there will likely be an independent feedback loop for each constellation member. Each command must be sent via the proper Ground Station, which may change from one contact to the next (and may be different for different members). Dynamic configuration of the ground command software is usually required (e.g. directives to configure each member's feedback loop and assign the appropriate Ground Station). For testing purposes, there must be a way to insert command data at any level in the protocol stack. The Pipeline architecture described in this paper can support all these capabilities with a sequence of software modules (the pipeline), and a single self-identifying message format (for all types of command data and configuration directives). The Pipeline architecture is quite simple, yet it can solve some complex problems. The resulting solutions are conceptually simple, and therefore, reliable. They are also modular, and therefore, easy to distribute and extend. We first used the Pipeline architecture to design a CCSDS (Consultative Committee for Space Data Systems) Ground Telecommand system (to command one spacecraft at a time with a fixed Ground Station interface). This pipeline was later extended to include gateways to any of several Ground Stations. The resulting pipeline was then extended to handle a small constellation of spacecraft. The use of the Pipeline architecture allowed us to easily handle the increasing complexity. This paper will describe the Pipeline architecture, show how it was used to solve each of the above commanding situations, and how it can easily be extended to handle larger constellations.

  4. The Relationship between Marital Adjustment and Sibling Constellation.

    ERIC Educational Resources Information Center

    Bloser, Edward Charles

    The conflict in research that exists between the relationship of marital adjustment and sibling constellation is examined here. The belief that the combination of birth order and gender (sibling constellation) is important, is not only a part of folk wisdom but it is a continuing point of view in the literature of marital and family therapy. Data…

  5. Origins of Nonlocality Near the Neutrality Point in Graphene

    NASA Astrophysics Data System (ADS)

    Folk, Joshua

    Nonlocal measurements are an effective experimental tool for probing non-charge characteristics of carriers using a (charge) transport measurement. For example, nonlocal signals in a Hall bar geometry can indicate spin currents, or valley currents, or heat currents flowing through a sample without an accompanying charge current. We present an experimental study of nonlocal electrical signals near the Dirac point in graphene, with the goal of disentangling the various types of current that might give rise to nonlocality. The in-plane magnetic field dependence of the nonlocal signal confirms the role of spin in this effect, as expected from predictions of the Zeeman spin Hall effect in graphene, but our experiments show that thermo-magneto-electric effects also contribute to nonlocality, and the effect is sometimes stronger than that due to spin.

  6. BRITE-Constellation

    NASA Astrophysics Data System (ADS)

    Weiss, W. W.; Moffat, A., Kudelka, O.

    2008-12-01

    BRITE-Constellation, a project developed since 2003 by researchersxE2x88x97 at Canadian and Austrian Universities presently consists of UniBRITE and BRITE-Austria/TUG-SAT1, which are two 20 cm cube nanosatellites. Each will fly a 30 mm aperture telescope with a CCD camera equipped with either a red (550 to 700 nm) or a blue (390 to 460 nm) filter, to perform high-precision two-color photometry of the brightest stars in the sky ( ≤ 4th mag) for up to several years. Stars of up to two magnitudes fainter will be observed simultaneously with reduced accuracy in an on-board photometric mode. Depending on the orbit and the position of the BRITE targets the photometry can be obtained contiguously during many orbits for many months, with gaps during individual orbits, or only for certain periods of the year. The primary science goals are studies of massive and luminous stars in our neighbourhood, representing objects which dominate the ecology of our Universe, and of evolved stars (giants) to probe the future development of our Sun. The wide field cameras (24◦ ) will also obtain data from other scientifically interesting stars to investigate their stellar structure and evolution. All of this is enabled by innovative technology currently developed in collaboration between Canada and Austria. A launch of UniBRITE and BRITE-Austria in 2009 is envisioned and an expansion proposal of the BRITE-Constellation by two dditional spacecrafts of the same construction, to be funded by the Canadian Space Agency (CSA), is currently under review. A comprehensive description of scientific and technical aspects of BRITE-Constellation is being prepared for publication in Communications in Asteroseismology. The BRITE- Constellation web site can be found at www.brite-constellation.at. A first Announcement of Opportunity for submitting BRITE-Constellation observing proposals was issued at http://ams.astro.univie.ac.at/BRITE AO/BRITE AO.html

  7. Brite-Constellation: A status report

    NASA Astrophysics Data System (ADS)

    Kaiser, A.; Kuschnig, R.; Weiss, W. W.; BRITE-Constellation Team

    2012-12-01

    The BRITE-Constellation, short for ``BRIght Target Explorer" Constellation, is a group of six nanosatellites from Austria, Poland and Canada carrying thirty millimeter aperture optical telescopes with a CCD camera. The goal of the mission is to photometrically measure low-level oscillations and temperature variations of the brightest stars in the sky down to a visual magnitude of 4.0, with unprecedented precision and time coverage not achievable from ground in two colors. The improved three-axis pointing performance which is a critical element that makes this high precision photometry mission feasible is a recent development by the University of Toronto's Space Flight Laboratory. The University of Vienna and the FFG/ALR (Austria's space agency) are financing the development of two satellites. The Polish Academy of Sciences is funding two additional satellites as well as the Canadian Space Agency resulting in six components for the constellation.

  8. Constellation Commodities Studies Summary

    NASA Technical Reports Server (NTRS)

    Dirschka, Eric

    2011-01-01

    Constellation program was NASA's long-term program for space exploration. The goal of the commodities studies was to solicit industry expertise in production, storage, and transportation required for future use and to improve efficiency and life cycle cost over legacy methods. Objectives were to consolidate KSC, CCAFS and other requirements; extract available industry expertise; identify commercial opportunities; and establish synergy with State of Florida partnerships. Study results are reviewed.

  9. Anthropometric Requirements for Constellation

    NASA Technical Reports Server (NTRS)

    Raulu, Sudhakar; Margerum, Sarah; Dory, Jonathan; Rochlis, Jennifer

    2009-01-01

    This slide presentation reviews the requirement from an Anthropometric standpoint for the development of the Constellation's programs hardware, specifically the Orion crew exploration vehicle. The NASA JSC Anthropometry and Biomechanics Facility (ABF) provides anthropometry, strength, mobility, and mass properties requirements; gathers, interprets, manages and maintains the flight crew anthropometry database; and participates and provides input during crew selection. This is used to assist in requirements for vehicle and space suit design and for crew selection.

  10. Autonomous interplanetary constellation design

    NASA Astrophysics Data System (ADS)

    Chow, Cornelius Channing, II

    According to NASA's integrated space technology roadmaps, space-based infrastructures are envisioned as necessary ingredients to a sustained effort in continuing space exploration. Whether it be for extra-terrestrial habitats, roving/cargo vehicles, or space tourism, autonomous space networks will provide a vital communications lifeline for both future robotic and human missions alike. Projecting that the Moon will be a bustling hub of activity within a few decades, a near-term opportunity for in-situ infrastructure development is within reach. This dissertation addresses the anticipated need for in-space infrastructure by investigating a general design methodology for autonomous interplanetary constellations; to illustrate the theory, this manuscript presents results from an application to the Earth-Moon neighborhood. The constellation design methodology is formulated as an optimization problem, involving a trajectory design step followed by a spacecraft placement sequence. Modeling the dynamics as a restricted 3-body problem, the investigated design space consists of families of periodic orbits which play host to the constellations, punctuated by arrangements of spacecraft autonomously guided by a navigation strategy called LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation). Instead of more traditional exhaustive search methods, a numerical continuation approach is implemented to map the admissible configuration space. In particular, Keller's pseudo-arclength technique is used to follow folding/bifurcating solution manifolds, which are otherwise inaccessible with other parameter continuation schemes. A succinct characterization of the underlying structure of the local, as well as global, extrema is thus achievable with little a priori intuition of the solution space. Furthermore, the proposed design methodology offers benefits in computation speed plus the ability to handle mildly stochastic systems. An application of the constellation design

  11. Chinese Constellations and Star Maps

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochun

    Star observations can be traced back to as early as the twenty-third century BC in ancient China. By the fifth century BC, the Chinese had named the 28 asterisms that formed the basic reference points for the Chinese equatorial coordinate system. By the first century BC, the Chinese had developed a unique system of constellations that reflected Chinese cosmological ideas with the central theme of the correlation between Heaven and Man. Star charts have been discovered on tomb ceilings dating back to Han times. But most of them are illustrative in their presentation of stars. The Dunhuang star maps from the ninth century, the star maps in the Xin yixiang fa yao of the eleventh century, and the Suzhou Astronomical Planisphere of the thirteenth century are examples of precise star maps from ancient China.

  12. Constellation Training Facility Support

    NASA Technical Reports Server (NTRS)

    Flores, Jose M.

    2008-01-01

    The National Aeronautics and Space Administration is developing the next set of vehicles that will take men back to the moon under the Constellation Program. The Constellation Training Facility (CxTF) is a project in development that will be used to train astronauts, instructors, and flight controllers on the operation of Constellation Program vehicles. It will also be used for procedure verification and validation of flight software and console tools. The CxTF will have simulations for the Crew Exploration Vehicle (CEV), Crew Module (CM), CEV Service Module (SM), Launch Abort System (LAS), Spacecraft Adapter (SA), Crew Launch Vehicle (CLV), Pressurized Cargo Variant CM, Pressurized Cargo Variant SM, Cargo Launch Vehicle, Earth Departure Stage (EDS), and the Lunar Surface Access Module (LSAM). The Facility will consist of part-task and full-task trainers, each with a specific set of mission training capabilities. Part task trainers will be used for focused training on a single vehicle system or set of related systems. Full task trainers will be used for training on complete vehicles and all of its subsystems. Support was provided in both software development and project planning areas of the CxTF project. Simulation software was developed for the hydraulic system of the Thrust Vector Control (TVC) of the ARES I launch vehicle. The TVC system is in charge of the actuation of the nozzle gimbals for navigation control of the upper stage of the ARES I rocket. Also, software was developed using C standards to send and receive data to and from hand controllers to be used in CxTF cockpit simulations. The hand controllers provided movement in all six rotational and translational axes. Under Project Planning & Control, support was provided to the development and maintenance of integrated schedules for both the Constellation Training Facility and Missions Operations Facilities Division. These schedules maintain communication between projects in different levels. The Cx

  13. Methods and Apparatuses for Signaling with Geometric Constellations in a Raleigh Fading Channel

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2015-01-01

    Communication systems are described that use signal constellations, which have unequally spaced (i.e., `geometrically` shaped) points. In many embodiments, the communication systems use specific geometric constellations that are capacity optimized at a specific SNR (signal to noise ratio). In addition, ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes d (sub min) (i.e. minimum distance between constellations) are also described. Capacity measures that are used in the selection of the location of constellation points include, but are not limited to, parallel decode (PD) capacity and joint capacity.

  14. Methodology and Method and Apparatus for Signaling with Capacity Optimized Constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2016-01-01

    Design Methodology and Method and Apparatus for Signaling with Capacity Optimized Constellation Abstract Communication systems are described that use geometrically PSK shaped constellations that have increased capacity compared to conventional PSK constellations operating within a similar SNR band. The geometrically shaped PSK constellation is optimized based upon parallel decoding capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel. In numerous embodiments, the communication uses adaptive rate encoding and the location of points within the geometrically shaped constellation changes as the code rate changes.

  15. Constellations and Networks

    NASA Astrophysics Data System (ADS)

    Greenwald, R. A.

    2013-12-01

    Constellations and Networks Prior to the late 1970's, most satellites probing the Earth's upper atmosphere, ionosphere, and magnetosphere and most ground-based experiments measuring the upper atmosphere and ionosphere provided uncoordinated, localized measurements of different regions of the Earth's near-space environment with the objective of determining their basic properties. These measurements showed that the magnetosphere was divided into a number of regions, each containing plasmas with different properties and varying concentrations of energetic particles. By the mid 1970's, this discovery phase of the various regions of the Earth's magnetosphere had essentially been completed. The next step was to understand how the various plasma domains of the magnetosphere and ionosphere were coupled into a complex plasma system and how energy flowed through this system from the solar wind to the upper atmosphere. To achieve this goal, satellite missions sponsored by NASA, ESA, and ISAS became more complex beginning with ISEE and extending to ISTP, Cluster, and many others. Specifically, the research effort evolved into coordinated multipoint measurements provided by constellations of spacecraft, all with on-board propulsion and station-keeping capability. During the same period, other scientific funding agencies in many countries supplemented the satellite-based research effort with the development of ground-based instrumentation networks capable of remote sensing the ionosphere and upper atmosphere. These networks provide measurements that complement the satellite data sets by providing large-scale contextual views of the state of the ionosphere and magnetically conjugate determinations of important physical parameters such as ionospheric electric fields and current systems. In this paper I discuss several of these ground-based networks and highlight research areas where they have made important contributions to satellite constellation missions as well as other topic

  16. Origin of electrical signals for plasma etching end point detection: Comparison of end point signals and electron density

    SciTech Connect

    Sobolewski, Mark A.; Lahr, David L.

    2012-09-15

    Electrical signals are used for end point detection in plasma etching, but the origin of the electrical changes observed at end point is not well understood. As an etch breaks through one layer and exposes an underlayer, the fluxes and densities of etch products and reactants in the gas phase will change. The resulting perturbation in gas composition may alter the plasma electron density, which in turn may affect the electrical signals. Alternatively, changes in substrate electrical properties or surface properties, such as work function or emitted electron yield, may be involved. To investigate these effects, experiments were performed in a radio-frequency (rf)-biased, inductively coupled reactor, during CF{sub 4}/Ar plasma etching of silicon dioxide films on silicon substrates. A complete set of electrical parameters, for the bias as well as the inductive source, was measured and compared. The most useful end point signal was found to be the fundamental rf bias impedance, which decreases when the oxide is removed. A simultaneous increase in plasma electron density was measured by a wave cutoff probe. Analytical sheath models indicate that the measured change in electron density accounts for nearly all of the impedance decrease. The change in electron density can in turn be explained by the effects of etch products or reactants on gas composition. In contrast, electrons emitted from the wafer surface play at most a minor role in the changes in electron density and impedance observed at end point.

  17. SATCOM constellation power simulation

    SciTech Connect

    Capulli, J.; Badke, B.; Davis, G.

    1995-12-31

    Three basic variables directly impact the power and energy generated by the SATCOM satellite constellation and its individual Space Vehicles (SVs). They are (1) telecommunications traffic patterns, (2) network resource management controllables, and (3) system hardware and software performance. This power simulation has verified the robustness of the telecommunications architecture. It has validated the onboard resource allocation process from an SV and network level power and energy perspective. The analyses have led to development of operational procedures that prevent SV node outages, and maximize network telecommunication traffic capacity. The program objective is to optimize overall system operation, availability and quality of service. Achieving this goal requires a thorough understanding of the Electrical Power Subsystem and its interfaces. The EPS simulation model analyzes network level performance by evaluating requirement compliance in the expected operating environments. Specifically, the simulation tool evaluates different design approaches and network operational strategies from a power and energy perspective. As a result, optimal load management solutions will be implemented both on-board the SV and via ground station directed resource allocation strategies.

  18. The THEMIS Constellation

    NASA Astrophysics Data System (ADS)

    Harvey, P.; Taylor, E.; Sterling, R.; Cully, M.

    2008-12-01

    The Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission is the fifth NASA Medium-class Explorer (MIDEX), launched on February 17, 2007 to determine the trigger and large-scale evolution of substorms. The mission employs five identical micro-probes (termed “probes”), which have orbit periods of one, two and four days. Each of the Probes carries five instruments to measure electric and magnetic fields as well as ions and electrons. Each probe weighs 134 kg including 49 kg of hydrazine fuel and measures approximately 0.8×0.8×1.0 meters ( L× W× H) and operates on an average power budget of 40 watts. For launch, the Probes were integrated to a Probe Carrier and separated via a launch vehicle provided pyrotechnic signal. Attitude data are obtained from a sun sensor, inertial reference unit and the instrument Fluxgate Magnetometer. Orbit and attitude control use a RCS system having two radial and two axial thrusters for roll and thrust maneuvers. Its two fuel tanks and pressurant system yield 960 meters/sec of delta-V, sufficient to allow Probe replacement strategies. Command and telemetry communications use an S-band 5 watt transponder through a cylindrical omni antenna with a toroidal gain pattern. This paper provides the key requirements of the probe, an overview of the probe design and how they were integrated and tested. It includes considerations and lessons learned from the experience of building NASA’s largest constellation.

  19. Report of the Constellations Panel

    NASA Technical Reports Server (NTRS)

    Bents, D. J.; Vontiesenhausen, G.; Lundquist, C. A.; Swan, P.; Mayer, H. L.; Mangano, M. J.; Bergamasui, S.; Bevilacqua, F.; Williams, F.; Rum, G.

    1985-01-01

    The purpose of a constellation is to provide a mode of distributing space systems in a method that could be advantageous and not eliminating the consolidation/aggregation advantages. The applicability of stabilization concepts to various orbital conditions was defined.

  20. BRITE-Constellation: Nanosatellites for precision photometry of bright stars

    NASA Astrophysics Data System (ADS)

    Weiss, W. W.; Moffat, A. F. J.; Schwarzenberg-Czerny, A.; Koudelka, O. F.; Grant, C. C.; Zee, R. E.; Kuschnig, R.; Mochnacki, St.; Rucinski, S. M.; Matthews, J. M.; Orleański, P.; Pamyatnykh, A. A.; Pigulski, A.; Alves, J.; Guedel, M.; Handler, G.; Wade, G. A.; Scholtz, A. L.; Scholtz

    2014-02-01

    BRITE-Constellation (where BRITE stands for BRIght Target Explorer) is an international nanosatellite mission to monitor photometrically, in two colours, brightness and temperature variations of stars brighter than V ~ 4, with precision and time coverage not possible from the ground. The current mission design consists of three pairs of 7 kg nanosats (hence ``Constellation'') from Austria, Canada and Poland carrying optical telescopes (3 cm aperture) and CCDs. One instrument in each pair is equipped with a blue filter; the other, a red filter. The first two nanosats (funded by Austria) are UniBRITE, designed and built by UTIAS-SFL (University of Toronto Institute for Aerospace Studies-Space Flight Laboratory) and its twin, BRITE-Austria, built by the Technical University Graz (TUG) with support of UTIAS-SFL. They were launched on 25 February 2013 by the Indian Space Agency, under contract to the Canadian Space Agency. Each BRITE instrument has a wide field of view (~ 24 degrees), so up to 15 bright stars can be observed simultaneously in 32 × 32 sub-rasters. Photometry (with reduced precision but thorough time sampling) of additional fainter targets will be possible through on-board data processing. A critical technical element of the BRITE mission is the three-axis attitude control system to stabilize a nanosat with very low inertia. The pointing stability is better than 1.5 arcminutes rms, a significant advance by UTIAS-SFL over any previous nanosatellite. BRITE-Constellation will primarily measure p- and g-mode pulsations to probe the interiors and ages of stars through asteroseismology. The BRITE sample of many of the brightest stars in the night sky is dominated by the most intrinsically luminous stars: massive stars seen at all evolutionary stages, and evolved medium-mass stars at the very end of their nuclear burning phases (cool giants and AGB stars). The Hertzsprung-Russell diagram for stars brighter than mag V=4 from which the BRITE-Constellation sample

  1. Our Pittsburgh Constellation

    NASA Astrophysics Data System (ADS)

    Turnshek, Diane

    2015-08-01

    Riding on the Pittsburgh mayor’s keen interest in astronomy and the ongoing change of 40,000 city lights from mercury and sodium vapor to shielded LEDs, we organized a series of city-wide celestial art projects to bring attention to the skies over Pittsburgh. Light pollution public talks were held at the University of Pittsburgh’s Allegheny Observatory and other colleges. Earth Hour celebrations kicked off an intensive year of astronomy outreach in the city. Lights went out on March 28, 2015 from 8:30 to 9:30 pm in over fifty buildings downtown and in Oakland (the “Eds and Meds” center, where many Pittsburgh universities and hospitals are located). Our art contest was announced at the De-Light Pittsburgh celebration at the Carnegie Science Center during Astronomy Weekend. “Our Pittsburgh Constellation” is an interactive Google map of all things astronomical in the city. Different colored stars mark locations of planetariums, star parties, classes, observatories, lecture series, museums, telescope manufacturers and participating art galleries. Contest entrants submitted artwork depicting their vision of the constellation figure that incorporates and connects all the “stars” in our custom city map. Throughout the year, over a dozen artists ran workshops on painting star clusters, galaxies, nebulae, comets, planets and aurorae with discussions of light pollution solutions and scientific explanations of what the patrons were painting, including demonstrations with emission tubes and diffraction grating glasses. We will display the celestial art created in this International Year of Light at an art gallery as part of the City’s Department of Innovation & Performance March 2016 Earth Hour gala. We are thankful for the Astronomical Footprint grant from the Heinz Endowments, which allowed us to bring the worlds of science and art together to enact social change.

  2. Measurement and modeling of bentazone in the river Main (Germany) originating from point and non-point sources.

    PubMed

    Bach, M; Letzel, M; Kaul, U; Forstner, S; Metzner, G; Klasmeier, J; Reichenberger, S; Frede, H G

    2010-06-01

    A Water Framework Directive pilot project combines measured data and model approaches to calculate fluxes and mass balance of the pesticide bentazone in an 81 km section of the river Main (Germany). During the study period (six weeks in spring 2004) the observed bentazone inflow and outflow in the river section amounted to 52.8 and 53.1 kg, respectively; the maximum concentrations reached 220 and 290 ng l(-1). Based on sampling of seven sewage treatment plants a specific loss of 0.87 g bentazone per farm was calculated. Extrapolation to the entire sub-basin results in 2.6 kg bentazone in total as point source contribution from farms. Diffuse input into the surface water network occurred after an intensive rainfall event on May 7th. Total bentazone load was simulated with the pesticide emission model DRIPS to be 23.2 kg. One third of this load was estimated to be degraded by photolysis before reaching the main waterway, the river Main. The ATV water quality model was applied to predict the concentration profile of bentazone in river Main between Schweinfurt and Würzburg with reasonable results. The difference between total measured and modeled fluxes amounted to 1.5 kg corresponding to 2% of the overall input. The combined approach of monitoring and modeling appears to be a valuable strategy to quantify the relevance of point and non-point sources and to focus effective mitigation measures to the most relevant origins within a river basin. PMID:20546837

  3. System Constellations as a Tool Supporting Organisational Learning and Change Processes

    ERIC Educational Resources Information Center

    Birkenkrahe, Marcus

    2008-01-01

    Originally developed in the context of family therapy, system constellations are introduced using an organisational learning and system theoretical framework. Constellations are systemic group interventions using a spatial representation of the system elements. They correspond to deutero-learning processes and use higher-order systemic thinking.…

  4. Methodology and Method and Apparatus for Signaling With Capacity Optimized Constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2014-01-01

    Communication systems are described that use geometrically shaped constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. In several embodiments, the geometrically shaped is optimized based upon a capacity measure such as parallel decoding capacity or joint capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel. In numerous embodiments, the communication uses adaptive rate encoding and the location of points within the geometrically shaped constellation changes as the code rate changes.

  5. Constellation Lessons Learned Executive Summary

    NASA Technical Reports Server (NTRS)

    Thomas, L. Dale; Neubek, Deb

    2011-01-01

    This slide presentation reviews the lessons learned from the Constellation Program (CxP) and identified several factors that contributed to the inability of the CxP to meet the cost and schedule commitments. The review includes a significant section on the context in which the CxP operated since new programs are likely to experience the same constraints.

  6. Single point off-center helium ignitions as origin of some Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Forcada, Ramon; Garcia-Senz, Domingo; José, Jordi

    The explosion of a helium layer accreted on top of a white dwarf, leading to the subsequent explosion of the star (while the accreting dwarf is still below the Chandrasekhar mass limit) is an alternative model for some subluminous Type Ia supernovae explosions. In this communication we present two preliminary hydrodynamical simulations concerning these so- called Sub-Chandrasekhar mass models for Type Ia supernovae, calculated in two dimensions. In the first calculation we have assumed one single detonation travelling through the helium layer which, after a while, induces the detonation of the carbon layer at the antipodes of the original ignition point. In the second case we assumed the prompt detonation of the carbon just beneath the ignition point. A comparison between these two models is presented.

  7. The power of inexpensive satellite constellations

    NASA Astrophysics Data System (ADS)

    Dyrud, Lars P.; La Tour, Rose; Swartz, William H.; Nag, Sreeja; Lorentz, Steven R.; Hilker, Thomas; Wiscombe, Warren J.; Papadakis, Stergios J.

    2014-06-01

    Two thematic drivers are motivating the science community towards constellations of small satellites, the revelation that many next generation system science questions are uniquely addressed with sufficient numbers of simultaneous space based measurements, and the realization that space is historically expensive, and in an environment of constrained costs, we must innovate to ―do more with less‖. We present analysis that answers many of the key questions surrounding constellations of scientific satellites, including research that resulted from the GEOScan community based effort originally intended as hosted payloads on Iridium NEXT. We present analysis that answers the question how many satellites does global system science require? Perhaps serendipitously, the analyses show that many of the key science questions independently converge towards similar results, i.e. that approximately 60+ satellites are needed for transformative, as opposed to incremental capability in system science. The current challenge is how to effectively transition products from design to mass production for space based instruments and vehicles. Ideally, the lesson learned from past designs and builds of various space products should pave the way toward a better manufacturing plan that utilizes just a fraction of the prototype`s cost. Using the commercial products industry implementations of mass customization as an example, we will discuss about the benefits of standardization in design requirements for space instruments and vehicles. For example, the instruments (payloads) are designed to have standardized elements, components, or modules that interchangeably work together within a linkage system. We conclude with a discussion on implementation plans and the new paradigms for community and international cooperation enabled by small satellite constellations.

  8. Light Water Reactor Sustainability Constellation Pilot Project FY11 Summary Report

    SciTech Connect

    R. Johansen

    2011-09-01

    Summary report for Fiscal Year 2011 activities associated with the Constellation Pilot Project. The project is a joint effor between Constellation Nuclear Energy Group (CENG), EPRI, and the DOE Light Water Reactor Sustainability Program. The project utilizes two CENG reactor stations: R.E. Ginna and Nine Point Unit 1. Included in the report are activities associate with reactor internals and concrete containments.

  9. The replication origin decision point is a mitogen-independent, 2-aminopurine-sensitive, G1-phase event that precedes restriction point control.

    PubMed Central

    Wu, J R; Gilbert, D M

    1997-01-01

    At a distinct point during G1 phase (the origin decision point [ODP]), Chinese hamster ovary (CHO) cell nuclei experience a transition (origin choice) that is required for specific recognition of the dihydrofolate reductase (DHFR) origin locus by Xenopus egg extracts. We have investigated the relationship between the ODP and progression of CHO cells through G1 phase. Selection of the DHFR origin at the ODP was rapidly inhibited by treatment of early G1-phase cells with the protein kinase inhibitor 2-aminopurine (2-AP). Inhibition of the ODP required administration of 2-AP at least 3 h prior to phosphorylation of the retinoblastoma tumor suppressor protein (Rb) and the restriction point (R point). Cells deprived of either serum or isoleucine from metaphase throughout early G1 phase acquired the capacity to replicate in Xenopus egg extract (replication licensing) and subsequently passed through the ODP on the same schedule as cells cultured in complete growth medium. After growth arrest at the R point with hypophosphorylated Rb protein, serum- or isoleucine-deprived cells experienced a gradual loss of replication licensing. However, recognition of the DHFR origin by Xenopus egg cytosol remained stable in growth-arrested cells until the point at which all nuclei had lost the capacity to initiate replication. These results provide evidence that the ODP requires a mitogen-independent protein kinase that is activated after replication licensing and prior to R-point control. PMID:9234688

  10. Influence of Ethnicity, Gender and Answering Mode on a Virtual Point-to-Origin Task

    PubMed Central

    Kitson, Alexandra; Sproll, Daniel; Riecke, Bernhard E.

    2016-01-01

    In a virtual point-to-origin task, participants seem to show different response patterns and underlying strategies for orientation, such as “turner” and “non-turner” response patterns. Turners respond as if succeeding to update simulated heading changes, and non-turners respond as if failing to update their heading, resulting in left-right hemisphere errors. We present two other response patterns, “non-movers” and “spinners,” that also appear to result in failures to update heading. We have three specific goals in mind: (1) extend previous findings of higher turner rates with spatial language response mode using a point-to-origin task instead of a triangle completion task; (2) replicate the gender effect of males more likely responding as turners; (3) examine ethnicity influence. Designed as a classroom study, we presented participants (N = 498) with four passages through a virtual star field. Participants selected the direction pointing to the origin from four multiple-choice items. Response mode was either pictograms or written language, chosen to compare with similar studies and see if these response modes have an effect on virtual orientation behavior. Results show a majority of participants (48.35%) classified as non-turners, 32.93% turners, 15.57% as non-movers, and 3.14% as spinners. A multinomial regression model reached 49% classification performance. Written spatial language, compared to pictograms, made turner response patterns more likely; this effect was more pronounced for Chinese participants and among females, but not male Caucasians. Moreover, higher turner numbers for written spatial language extends Avraamides findings of higher turner numbers when participants turned their bodies toward the origin but not when they responded verbally. Using pictorial response mode (i.e., top-down picture of a head) may have increased cognitive load because it could be considered more embodied. It remains to be seen how we can reduce the reference

  11. Influence of Ethnicity, Gender and Answering Mode on a Virtual Point-to-Origin Task.

    PubMed

    Kitson, Alexandra; Sproll, Daniel; Riecke, Bernhard E

    2016-01-01

    In a virtual point-to-origin task, participants seem to show different response patterns and underlying strategies for orientation, such as "turner" and "non-turner" response patterns. Turners respond as if succeeding to update simulated heading changes, and non-turners respond as if failing to update their heading, resulting in left-right hemisphere errors. We present two other response patterns, "non-movers" and "spinners," that also appear to result in failures to update heading. We have three specific goals in mind: (1) extend previous findings of higher turner rates with spatial language response mode using a point-to-origin task instead of a triangle completion task; (2) replicate the gender effect of males more likely responding as turners; (3) examine ethnicity influence. Designed as a classroom study, we presented participants (N = 498) with four passages through a virtual star field. Participants selected the direction pointing to the origin from four multiple-choice items. Response mode was either pictograms or written language, chosen to compare with similar studies and see if these response modes have an effect on virtual orientation behavior. Results show a majority of participants (48.35%) classified as non-turners, 32.93% turners, 15.57% as non-movers, and 3.14% as spinners. A multinomial regression model reached 49% classification performance. Written spatial language, compared to pictograms, made turner response patterns more likely; this effect was more pronounced for Chinese participants and among females, but not male Caucasians. Moreover, higher turner numbers for written spatial language extends Avraamides findings of higher turner numbers when participants turned their bodies toward the origin but not when they responded verbally. Using pictorial response mode (i.e., top-down picture of a head) may have increased cognitive load because it could be considered more embodied. It remains to be seen how we can reduce the reference frame conflict

  12. NASA Project Constellation Systems Engineering Approach

    NASA Technical Reports Server (NTRS)

    Dumbacher, Daniel L.

    2005-01-01

    NASA's Office of Exploration Systems (OExS) is organized to empower the Vision for Space Exploration with transportation systems that result in achievable, affordable, and sustainable human and robotic journeys to the Moon, Mars, and beyond. In the process of delivering these capabilities, the systems engineering function is key to implementing policies, managing mission requirements, and ensuring technical integration and verification of hardware and support systems in a timely, cost-effective manner. The OExS Development Programs Division includes three main areas: (1) human and robotic technology, (2) Project Prometheus for nuclear propulsion development, and (3) Constellation Systems for space transportation systems development, including a Crew Exploration Vehicle (CEV). Constellation Systems include Earth-to-orbit, in-space, and surface transportation systems; maintenance and science instrumentation; and robotic investigators and assistants. In parallel with development of the CEV, robotic explorers will serve as trailblazers to reduce the risk and costs of future human operations on the Moon, as well as missions to other destinations, including Mars. Additional information is included in the original extended abstract.

  13. Optimized orbits for the constellation of Space Station polar platforms

    NASA Technical Reports Server (NTRS)

    Chase, Robert; Mundt, Michael

    1989-01-01

    The orbital configuration of the Eos polar-platform constellation is examined to determine if baseline orbital parameters are appropriately specified to meet the mission task of measuring global oceanic mesoscale variability. Using the Nyquist sampling theorem, spatial and temporal measurement requirements are first established for the constellation. Based upon these requirements, the optimum solution indicates that a total of five spacecraft equipped with nadir-pointing altimeters, or two multibeam-equipped platforms, would be required to meet the mesoscale mapping task. Additional analyses were performed on both one- and and two-platform configurations as well as the complete four-platform Eos constellation. The results of these calculations show that the preferred scenario would be to equip all four Eos polar platforms with multibeam altimeters.

  14. Laser satellite constellations for strategic defense - an analytic model

    SciTech Connect

    Parmentola, J.A.; Milton, A.F.

    1987-10-01

    Using mainly geometric reasoning, an analytic model is constructed that predicts the required characteristics of an orbiting constellation of laser battle stations, each of which is designed to destroy ballistic missiles during their boost phase. The geometry of the constellation configuration and some general aspects of the coverage problem are discussed. The determination of the absentee ratio falls into two main categories that depend upon whether the Soviet ICBM threat is concentrated at a single location or whether it is distributed as it is now. A point-threat model and a distributive threat model are considered, the determination of the respective kill rates for these models is discussed, and the scaling properties of the laser constellation with respect to a change in the quantitative nature of the two types of ICBM threats are considered.

  15. The Constellation-X Observatory

    NASA Technical Reports Server (NTRS)

    Weaver, Kimberly

    2003-01-01

    The Constellation X-ray mission will revolutionize X-ray spectroscopy and will provide a key component of NASA's '!Beyond Einstein" program. Over the past 35 years, X-ray astronomy has grown from infancy to near-maturity and is now an indispensable astrophysical tool. Constellation-X will transform this field from the exploratory spectroscopic era of Chandra and XMM to an era of fully comprehensive spectroscopic studies. The mission will consist of four 1.6-meter X-ray telescopes orbiting the Earth/Sun system. By providing a factor of 100 increase in throughput over previous missions, as well as high spectral resolution and a broad energy bandpass, Constellation-X will obtain high quality spectra for all classes of X-ray sources over a wide range of luminosity and redshift. It will study the warping of space and time near black holes, determine the distribution of ordinary matter, dark matter and dark energy, and probe detailed physical processes that occur at temperatures, densities and pressures far beyond those achievable in Earth-bound laboratories.

  16. Science with Constellation-X

    NASA Technical Reports Server (NTRS)

    Hornschemeier, Ann (Editor); Garcia, Michael (Editor)

    2005-01-01

    NASA's upcoming Constellation-X mission, one of two flagship missions in the Beyond Einstein program, will have more than 100 times the collecting area of any previous spectroscopic mission operating in the 0.25-40 keV bandpass and will enable high-throughput, high spectral resolution studies of sources ranging from the most luminous accreting supermassive black holes in the Universe to the disks around young stars where planets form. This booklet, which was assembled during early 2005 using the contributions of a large team of Astrophysicists, outlines the important scientific questions for the decade following this one and describes the areas where Constellation-X is going to have a major impact. These areas include the exploration of the space-time geometry of black holes spanning nine orders of magnitude in mass and the nature of the dark energy and dark matter which govern the expansion and ultimate fate of the Universe. Constellation-X will also explore processes referred to as "cosmic feedback" whereby mechanical energy, radiation, and chemical elements from star formation and black holes are returned to interstellar and intergalactic medium, profoundly affecting the development of structure in the Universe, and will also probe all the important life cycles of matter, from stellar and planetary birth to stellar death via supernova to stellar endpoints in the form of accreting binaries and supernova remnants.

  17. [Variations in the position and point of origin of the vermiform appendix].

    PubMed

    Delić, Jasmin; Savković, Admedina; Isaković, Eldar

    2002-01-01

    There were investigated variations of appendix vermiformis in the place of origin and position. The investigations were carried out on 50 human preparations of adults of both sexes, unintentional choice. The position and relation between intestinum caecum and appendix vermiformis were determined by forensic medical and pathoanatomical autopsy. Place of origin of appendix vermiformis, from wall of intestinum caecum is determined by anatomical dissection. Intestinum caecum has a variable shape and it occurs in two forms: conical, which dominates (56%) and square (44%). It has constant position in fossa iliaca dextra in 100% of 50 investigated cases. Appendix vermiformis is fully variable organ as for position and the place of origin from the wall of intestinum caecum. Dominantly (52%) it has rising position, and two subtypes are present: retrocecal (more expressed-38%) related to the retrocolic subtype (14%). Very frequent position of appendix vermiformis is a falling one (32%), in which pelvic position is more frequent (26%) related to descendent position (6%). Appendix vermifirmis is located subcaecaly in 8% of total number of investigated cases, found in three subtypes. It is found out that ostium appendicis vermiformis has a variable position in the wall of intestinum caecum. It is predominantly placed in the middle of the lower pole of the intestinum caecum (58%), in medial wall it is present in 32%, of all investigated, and in the lateral wall in the least number case 10%. The results of these investigations point out how important is to know variable anatomies of appendix vermiformis, for the clinical image of acute appendicitis is undoubtedly caused by the variable anatomical relations. PMID:11917693

  18. Vestigial phragmocone in the gladius points to a deepwater origin of squid (Mollusca: Cephalopoda)

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Alexander I.; Bizikov, Vyacheslav A.; Fuchs, Dirk

    2012-03-01

    The microstructure of the gladius cone was investigated in six species of nektonic squid: shallow-water Loligo gahi (Loliginidae), pelagic eurybathic Illex argentinus, Todarodes pacificus, Dosidicus gigas (Ommastrephidae), and deepwater Onykia ingens (Onychoteuthidae) and Gonatus antarcticus (Gonatidae) using state-of-the-art microscopy. Apart from L. gahi, all other species had septa-like layers in the gladius cone, which for the first time were investigated in detail and compared with those in extinct Cretaceous belemnites Hibolithes sp. and Pachyteuthis sp., and spirulid Cyrtobelus sp. It was found that the organic layers of the gladius cone in recent squid can be homologized with the organic components of the shell in fossil phragmocone-bearing coleoids. The septa-like layers in modern gladius cones therefore represent a vestigial phragmocone composed of organic septal rudiments of the ancestral phragmocone that has lost the siphuncle and gas-filled chambers. The well-developed rostrum in onychoteuthids and small rostrum of the gladius in ommastrephids and gonatids can be seen as homologous with the belemnoid rostrum, which may indicate a close phylogenetic relationship between belemnites and at least some squid. Possible evolutionary pathways of the reduction of the functional phragmocone in squid ancestors are discussed. Several features such as the loss of shell calcification, deep water speciation, and the structure of the equilibrium organ point to a deep-water origin of squids.

  19. Relative motion and visibility evaluation in GNSS constellation: A projection method

    NASA Astrophysics Data System (ADS)

    Lin, Jinmao; Wang, Yueke; Zhou, Yongbin; Yang, Jun

    2016-04-01

    Using crosslinks to network the satellites in a GNSS constellation has been regarded as one of the most important trends for the GNSS modernisation. The motion and visibility of the satellites w.r.t. each other in the constellation have to be evaluated as an prerequisite to many tasks, especially to the inter-satellite network design, measurement scheduling and pointing-related issues. Thus far, very few analytical studies have been done on this issue for GNSS constellations. In this paper, a projection method is proposed to evaluate the relative motion and visibility. By projecting the relative trajectory orthogonally onto the orbital plane of the base satellite, it is much easier to study the geometric characteristics of the relative motion and the effect of constellation parameters and field-of-view constraint on the relative visibility. Given that GNSS constellations are designed based on Walker constellation, the relative motion pattern is explored algorithmically with index mapping techniques and the always visible relationship is visually modelled using a graph which in most cases shows a symmetry structure when the vertices are placed in a proper order. As demonstration of our method, a thorough experimental validation on the nominal GPS, GLONASS, Galileo and BeiDou-M constellation is proposed. The result explicitly reveals that the relative motion and visibility varies according to the parameters of the constellations.

  20. Best Practices for Operations of Satellite Constellations

    NASA Technical Reports Server (NTRS)

    Howard, Joseph; Oza, Dipak; Smith, Danford S.

    2006-01-01

    This paper presents the best practices used by several commercial and government operators of satellite constellations. These best practices were identified through a series of seminars and discussions held at NASA Goddard Space Flight Center (GSFC). The best practices are arrived through many years of experience and improvements made in the operations procedures and the operational systems with the primary drivers as mission safety and cost effectiveness. This paper discusses the operational aspects associated with how different organizations manage complexities of constellation operations. For the purposes of this paper, satellite constellations are groups of similar spacecraft with more than one spacecraft needed to fully accomplish the constellation's mission

  1. Constellation X-Ray Mission and Support

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.; Grady, Jean (Technical Monitor)

    2002-01-01

    This is the Third Annual Report of work performed by the Smithsonian Astrophysical Observatory (SAO) for NASA Goddard Space Flight Center (GSFC) under Cooperative Agreement NCC5-3681. The Agreement is entitled 'Constellation X-ray Mission Study and Support.' Work performed through January 31, 2001 was reported in a supplement to the Second Annual Report. That supplemental report was submitted in order to obtain funding subsequent to March 2001 which has, as the result of prior funding actions, become the de facto beginning of the funding year under the Agreement. This report covers the balance of the third year of the Agreement from February 1, 2001 through September 30, 2001. The Agreement as currently configured runs for two more years. When funding is significantly different from the originally approved amounts, SAO submits a revised budget. One such revision was submitted last year and was the basis for funding a portion of the work reported here. This report summarizes the main areas of SAO activity. Most of the work has been performed jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). Consequently, we do not claim that such activities were carried out exclusively by SAO. Rather, we describe SAO participation in these efforts. Under the Agreement, SAO performed work in seven major areas of activity. These areas related to: (1) Constellation X-ray Mission Facility Definition Team and Study Management; (2) Science Support; (3) Spectroscopy X-ray Telescope (SXT); (4) Systems Engineering; (5) Travel; and (6) In-house Management and Coordination.

  2. Multisatellite constellation configuration selection for multiregional highly elliptical orbit constellations

    NASA Technical Reports Server (NTRS)

    Matossian, Mark G.

    1994-01-01

    The Archimedes Project is a joint effort of the European Space Agency (ESA) and the National Space Development Agency of Japan (NASDA). The primary goal of the Archimedes project is to perform a technical feasibility analysis and preliminary design of a highly inclined multisatellite constellation for direct broadcast and mobile communications services for Europe, Japan and much of North America. This report addresses one aspect of this project, specifically an analysis of continuous satellite coverage using multiregional highly elliptical orbits (M-HEO's). The analysis methodology and ensuing software tool, named SPIFF, were developed specifically for this project by the author during the summer of 1992 under the STA/NSF Summer Institute in Japan Program at Tsukuba Space Center.

  3. 41 CFR 302-7.6 - What are the authorized origin and destination points for the transportation of HHG and PBP&E?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... origin and destination points for the transportation of HHG and PBP&E? 302-7.6 Section 302-7.6 Public..., PAPERS, AND EQUIPMENT (PBP&E) General Rules § 302-7.6 What are the authorized origin and destination points for the transportation of HHG and PBP&E? The authorized origin and destination points for...

  4. 41 CFR 302-9.142 - What will I be reimbursed if I transport a POV from a point of origin that is different from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reimbursed if I transport a POV from a point of origin that is different from the authorized point of origin... STORAGE OF A PRIVATELY OWNED VEHICLE Transportation Pov Transportation at Time of Assignment § 302-9.142 What will I be reimbursed if I transport a POV from a point of origin that is different from...

  5. 41 CFR 302-9.142 - What will I be reimbursed if I transport a POV from a point of origin that is different from the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reimbursed if I transport a POV from a point of origin that is different from the authorized point of origin... STORAGE OF A PRIVATELY OWNED VEHICLE Transportation Pov Transportation at Time of Assignment § 302-9.142 What will I be reimbursed if I transport a POV from a point of origin that is different from...

  6. Science-Enabling MicroSpacecraft Constellations for Mars

    NASA Astrophysics Data System (ADS)

    Mauritz, A.; Patel, B.

    2000-07-01

    By leveraging commercially-developed spacecraft constellation technology, a wide variety of Mars missions can be accomplished ranging from single microspacecraft missions costing less than 50 million to constellations of microspacecraft that provide distributed remote sensing capabilities. Remote sensing missions that require global coverage of Mars can be conducted by constellations of microspacecraft. These microspacecraft provide focused science at low risk. As an additional benefit, these microspacecraft could easily be modified to provide the communication and navigation infrastructure necessary for other complimentary surface science missions. Orbital Sciences Corporation has extensive experience developing and operating microspacecraft constellations. The figures illustrate microspacecraft designs applicable to a wide variety of Mars missions. Based on the highly proven Microstar bus, this spacecraft is capable of dedicated or shared launches on a number of launch vehicles including Pegasus, Taurus, Delta II, Delta III, and Ariane 5. Missions enabled by these microspacecraft include constellation-based scientific remote sensing, communications relay, navigation, and distributed aperture sensing. Additionally, this bus can support singular missions focused on probe delivery, remote sensing, or remote monitoring of, and data collection from land-based elements conducting Mars in situ science. The spacecraft bus utilizes a common set of low mass, low power avionics successfully demonstrated on 38 MicroStar spacecraft currently in operation. By optimizing mechanical designs around specific launch vehicles and payloads, this bus offers a robust means by which to realize many missions. Depending on launch vehicle capability, this bus can support payloads weighing up 70 kg with average payload power requirements in excess of 50W. These proven spacecraft platforms provide an affordable means by which to execute exciting science missions at low risk. A figure is

  7. ISHM Implementation for Constellation Systems

    NASA Technical Reports Server (NTRS)

    Figueroa, Fernando; Holland, Randy; Schmalzel, John; Duncavage, Dan; Crocker, Alan; Alena, Rick

    2006-01-01

    Integrated System Health Management (ISHM) is a capability that focuses on determining the condition (health) of every element in a complex System (detect anomalies, diagnose causes, prognosis of future anomalies), and provide data, information, and knowledge (DIaK) "not just data" to control systems for safe and effective operation. This capability is currently done by large teams of people, primarily from ground, but needs to be embedded on-board systems to a higher degree to enable NASA's new Exploration Mission (long term travel and stay in space), while increasing safety and decreasing life cycle costs of systems (vehicles; platforms; bases or outposts; and ground test, launch, and processing operations). This viewgraph presentation reviews the use of ISHM for the Constellation system.

  8. Autonomy Architectures for a Constellation of Spacecraft

    NASA Technical Reports Server (NTRS)

    Barrett, Anthony

    2000-01-01

    Until the past few years, missions typically involved fairly large expensive spacecraft. Such missions have primarily favored using older proven technologies over more recently developed ones, and humans controlled spacecraft by manually generating detailed command sequences with low-level tools and then transmitting the sequences for subsequent execution on a spacecraft controller. This approach toward controlling a spacecraft has worked spectacularly on previous missions, but it has limitations deriving from communications restrictions - scheduling time to communicate with a particular spacecraft involves competing with other projects due to the limited number of deep space network antennae. This implies that a spacecraft can spend a long time just waiting whenever a command sequence fails. This is one reason why the New Millennium program has an objective to migrate parts of mission control tasks onboard a spacecraft to reduce wait time by making spacecraft more robust. The migrated software is called a "remote agent" and has 4 components: a mission manager to generate the high level goals, a planner/scheduler to turn goals into activities while reasoning about future expected situations, an executive/diagnostics engine to initiate and maintain activities while interpreting sensed events by reasoning about past and present situations, and a conventional real-time subsystem to interface with the spacecraft to implement an activity's primitive actions. In addition to needing remote planning and execution for isolated spacecraft, a trend toward multiple-spacecraft missions points to the need for remote distributed planning and execution. The past few years have seen missions with growing numbers of probes. Pathfinder has its rover (Sojourner), Cassini has its lander (Huygens), and the New Millenium Deep Space 3 (DS3) proposal involves a constellation of 3 spacecraft for interferometric mapping. This trend is expected to continue to progressively larger fleets. For

  9. Simulating the Liaison Navigation Concept in a Geo + Earth-Moon Halo Constellation

    NASA Technical Reports Server (NTRS)

    Fujimoto, K.; Leonard, J. M.; McGranaghan, R. M.; Parker, J. S.; Anderson, R. L.; Born, G. H.

    2012-01-01

    Linked Autonomous Interplanetary Satellite Orbit Navigation, or LiAISON, is a novel satellite navigation technique where relative radiometric measurements between two or more spacecraft in a constellation are processed to obtain the absolute state of all spacecraft. The method leverages the asymmetry of the gravity field that the constellation exists in. This paper takes a step forward in developing a high fidelity navigation simulation for the LiAISON concept in an Earth-Moon constellation. In particular, we aim to process two-way Doppler measurements between a satellite in GEO orbit and another in a halo orbit about the Earth-Moon L1 point.

  10. Constellations: A New Paradigm for Earth Observations

    NASA Technical Reports Server (NTRS)

    Kelly, Angelita C.; Volz, Stephen M.; Yuhas, Cheryl L.; Case, Warren F.

    2009-01-01

    The last decade has seen a significant increase in the number and the capabilities of remote sensing satellites launched by the international community. A relatively new approach has been the launching of satellites into heterogeneous constellations. Constellations provide the scientists a capability to acquire science data, not only from specific instruments on a single satellite, but also from instruments on other satellites that fly in the same orbit. Initial results from the A-Train (especially following the CALIPSO/CloudSat launch) attest to the tremendous scientific value of constellation flying. This paper provides a history of the constellations (particularly the A-Train) and how the A-Train mission design was driven by science requirements. The A-Train has presented operational challenges which had not previously been encountered. Operations planning had to address not only how the satellites of each constellation operate safely together, but also how the two constellations fly in the same orbits without interfering with each other when commands are uplinked or data are downlinked to their respective ground stations. This paper discusses the benefits of joining an on-orbit constellation. When compared to a single, large satellite, a constellation infrastructure offers more than just the opportunities for coincidental science observations. For example, constellations reduce risks by distributing observing instruments among numerous satellites; in contrast, a failed launch or a system failure in a single satellite would lead to loss of all observations. Constellations allow for more focused, less complex satellites. Constellations distribute the development, testing, and operations costs among various agencies and organizations for example, the Morning and Afternoon Constellations involve several agencies within the U.S. and in other countries. Lastly, this paper addresses the need to plan for the long-term evolution of a constellation. Agencies need to have

  11. 77 FR 11168 - In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; Nine Mile Nuclear Station...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... hearing was published in the Federal Register on July 7, 2011 (76 FR 39910). No comments or hearing... Exelon Corporation; Constellation Energy Group, Inc.; Nine Mile Nuclear Station, LLC; Nine Mile Point... Ventures), and Constellation Energy Nuclear Group, LLC (CENG), acting on behalf of itself, and the...

  12. Autonomy Architectures for a Constellation of Spacecraft

    NASA Technical Reports Server (NTRS)

    Barrett, Anthony

    2000-01-01

    Until the past few years, missions typically involved fairly large expensive spacecraft. Such missions have primarily favored using older proven technologies over more recently developed ones, and humans controlled spacecraft by manually generating detailed command sequences with low-level tools and then transmitting the sequences for subsequent execution on a spacecraft controller. This approach toward controlling a spacecraft has worked spectacularly on previous missions, but it has limitations deriving from communications restrictions - scheduling time to communicate with a particular spacecraft involves competing with other projects due to the limited number of deep space network antennae. This implies that a spacecraft can spend a long time just waiting whenever a command sequence fails. This is one reason why the New Millennium program has an objective to migrate parts of mission control tasks onboard a spacecraft to reduce wait time by making spacecraft more robust. The migrated software is called a "remote agent" and has 4 components: a mission manager to generate the high level goals, a planner/scheduler to turn goals into activities while reasoning about future expected situations, an executive/diagnostics engine to initiate and maintain activities while interpreting sensed events by reasoning about past and present situations, and a conventional real-time subsystem to interface with the spacecraft to implement an activity's primitive actions. In addition to needing remote planning and execution for isolated spacecraft, a trend toward multiple-spacecraft missions points to the need for remote distributed planning and execution. The past few years have seen missions with growing numbers of probes. Pathfinder has its rover (Sojourner), Cassini has its lander (Huygens), and the New Millenium Deep Space 3 (DS3) proposal involves a constellation of 3 spacecraft for interferometric mapping. This trend is expected to continue to progressively larger fleets. For

  13. The CEOS constellation for land surface imaging

    NASA Astrophysics Data System (ADS)

    Bailey, G. Bryan; Berger, Michael; Jeanjean, Hervé; Gallo, Kevin P.

    2007-10-01

    A constellation of satellites that routinely and frequently images the Earth's land surface in consistently calibrated wavelengths from the visible through the microwave and in spatial detail that ranges from submeter to hundreds of meters would offer enormous potential benefits to society. A well-designed and effectively operated land surface imaging satellite constellation could have great positive impact not only on the quality of life for citizens of all nations, but also on mankind's very ability to sustain life as we know it on this planet long into the future. The primary objective of the Committee on Earth Observation Satellites (CEOS) Land Surface Imaging (LSI) Constellation is to define standards (or guidelines) that describe optimal future LSI Constellation capabilities, characteristics, and practices. Standards defined for a LSI Constellation will be based on a thorough understanding of user requirements, and they will address at least three fundamental areas of the systems comprising a Land Surface Imaging Constellation: the space segments, the ground segments, and relevant policies and plans. Studies conducted by the LSI Constellation Study Team also will address current and shorter-term problems and issues facing the land remote sensing community today, such as seeking ways to work more cooperatively in the operation of existing land surface imaging systems and helping to accomplish tangible benefits to society through application of land surface image data acquired by existing systems. 2007 LSI Constellation studies are designed to establish initial international agreements, develop preliminary standards for a mid-resolution land surface imaging constellation, and contribute data to a global forest assessment.

  14. The CEOS constellation for land surface imaging

    USGS Publications Warehouse

    Bailey, G.B.; Berger, M.; Jeanjean, H.; Gallo, K.P.

    2007-01-01

    A constellation of satellites that routinely and frequently images the Earth's land surface in consistently calibrated wavelengths from the visible through the microwave and in spatial detail that ranges from sub-meter to hundreds of meters would offer enormous potential benefits to society. A well-designed and effectively operated land surface imaging satellite constellation could have great positive impact not only on the quality of life for citizens of all nations, but also on mankind's very ability to sustain life as we know it on this planet long into the future. The primary objective of the Committee on Earth Observation Satellites (CEOS) Land Surface Imaging (LSI) Constellation is to define standards (or guidelines) that describe optimal future LSI Constellation capabilities, characteristics, and practices. Standards defined for a LSI Constellation will be based on a thorough understanding of user requirements, and they will address at least three fundamental areas of the systems comprising a Land Surface Imaging Constellation: the space segments, the ground segments, and relevant policies and plans. Studies conducted by the LSI Constellation Study Team also will address current and shorter-term problems and issues facing the land remote sensing community today, such as seeking ways to work more cooperatively in the operation of existing land surface imaging systems and helping to accomplish tangible benefits to society through application of land surface image data acquired by existing systems. 2007 LSI Constellation studies are designed to establish initial international agreements, develop preliminary standards for a mid-resolution land surface imaging constellation, and contribute data to a global forest assessment.

  15. Constellation choosing based on multi-dimensional sphere packing technique

    NASA Astrophysics Data System (ADS)

    Jinghe, Li; Guijun, Hu; Kashero, Enock; Zhaoxi, Li

    2016-09-01

    In this paper we address the sphere packing lattice points selection problem being used as constellation points in high-dimensional modulation. We propose a new type of points selection method based on threshold theory. Theoretically, this method improves the transmission performance of high-dimensional signal modulation systems. We find that the BER of a 4D modulation signal using the threshold value points selection method reduces. We also compared random and distant points selection methods in a BER of 10-3 and obtained a reduced SNR of about 2 db. At a 10-3 BER, a 8D modulation signal with points selected using the threshold selection methods obtained a reduced SNR of about 3 db. At a 10-3 BER, a 16D modulation signal with points selected using the threshold selection methods obtained a reduced SNR of about 3.5 db.

  16. Distortion-insensitive correlation constellation detection

    NASA Astrophysics Data System (ADS)

    Casey, Charles; Hassebrook, Laurence G.; Crane, Eli; Davidson, Aaron

    2011-04-01

    There are applications that require detection of multiple features which remain consistent in shape locally, but may change position with respect to one another globally. We refer to these feature sets as multi-feature constellations. We introduce a multi-level correlation filter design which uses composite feature detection filters, which on one level detect local features, and then on the next level detect constellations of these local feature responses. We demonstrate the constellation filter method with sign language recognition and fingerprint matching.

  17. The 50 Constellation Priority Sites

    NASA Technical Reports Server (NTRS)

    Noble, S.; Joosten, K.; Eppler, D.; Gruener, J.; Mendell, W.; French, R.; Plescia, J.; Spudis, P.; Wargo, M.; Robinson, M.; Lucey, P.

    2009-01-01

    The Constellation program (CxP) has developed a list of 50 sites of interest on the Moon which will be targeted by the LRO narrow angle camera. The list has also been provided to the M team to supplement their targeting list. This list does not represent a "site selection" process; rather the goal was to find "representative" sites and terrains to understand the range of possible surface conditions for human lunar exploration to aid engineering design and operational planning. The list compilers leveraged heavily on past site selection work (e.g. Geoscience and a Lunar Base Workshop - 1988, Site Selection Strategy for a Lunar Outpost - 1990, Exploration Systems Architecture Study (ESAS) - 2005). Considerations included scientific, resource utilization, and operational merits, and a desire to span lunar terrain types. The targets have been organized into two "tiers" of 25 sites each to provide a relative priority ranking in the event of mutual interference. A LEAG SAT (special action team) was established to validate and recommend modifications to the list. This SAT was chaired by Dr. Paul Lucey. They provided their final results to CxP in May. Dr. Wendell Mendell will organize an on-going analysis of the data as they come down to ensure data quality and determine if and when a site has sufficient data to be retired from the list. The list was compiled using the best available data, however, it is understood that with the flood of new lunar data, minor modifications or adjustments may be required.

  18. Approach to the origin of turbulence on the basis of two-point kinetic theory

    NASA Technical Reports Server (NTRS)

    Tsuge, S.

    1974-01-01

    Equations for the fluctuation correlation in an incompressible shear flow are derived on the basis of kinetic theory, utilizing the two-point distribution function which obeys the BBGKY hierarchy equation truncated with the hypothesis of 'ternary' molecular chaos. The step from the molecular to the hydrodynamic description is accomplished by a moment expansion which is a two-point version of the thirteen-moment method, and which leads to a series of correlation equations, viz., the two-point counterparts of the continuity equation, the Navier-Stokes equation, etc. For almost parallel shearing flows the two-point equation is separable and reduces to two Orr-Sommerfeld equations with different physical implications.

  19. Origins.

    ERIC Educational Resources Information Center

    Online-Offline, 1999

    1999-01-01

    Provides an annotated list of resources dealing with the theme of origins of life, the universe, and traditions. Includes Web sites, videos, books, audio materials, and magazines with appropriate grade levels and/or subject disciplines indicated; professional resources; and learning activities. (LRW)

  20. Constellation Space Suit System Development Status

    NASA Technical Reports Server (NTRS)

    Ross, Amy; Aitchison, Lindsay; Daniel, Brian

    2007-01-01

    The Constellation Program has initiated the first new flight suit development project since the Extravehicular Mobility Unit (EMU) was developed for the Space Shuttle Program in the 1970s. The Constellation suit system represents a significant challenge to designers in that the system is required to address all space suit functions needed through all missions and mission phases. This is in marked contrast to the EMU, which was designed specifically for micro-gravity space walks. The Constellation suit system must serve in all of the following scenarios: launch, entry and abort crew survival; micro-gravity extravehicular activity (EVA); and lunar (1/6th-gravity) surface EVA. This paper discusses technical efforts performed from May 2006 through February 2007 for the Constellation space suit system pressure garment.

  1. Multiple Autonomous Discrete Event Controllers for Constellations

    NASA Technical Reports Server (NTRS)

    Esposito, Timothy C.

    2003-01-01

    The Multiple Autonomous Discrete Event Controllers for Constellations (MADECC) project is an effort within the National Aeronautics and Space Administration Goddard Space Flight Center's (NASA/GSFC) Information Systems Division to develop autonomous positioning and attitude control for constellation satellites. It will be accomplished using traditional control theory and advanced coordination algorithms developed by the Johns Hopkins University Applied Physics Laboratory (JHU/APL). This capability will be demonstrated in the discrete event control test-bed located at JHU/APL. This project will be modeled for the Leonardo constellation mission, but is intended to be adaptable to any constellation mission. To develop a common software architecture. the controllers will only model very high-level responses. For instance, after determining that a maneuver must be made. the MADECC system will output B (Delta)V (velocity change) value. Lower level systems must then decide which thrusters to fire and for how long to achieve that (Delta)V.

  2. Cross Calibration of the Afternoon Constellation's

    NASA Video Gallery

    The name "A-Train" comes from the formation of international, Earth-observing satellites known as the Afternoon Constellation, which operate in a Sun-synchronous orbit at an altitude of 705 km. The...

  3. Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution.

    PubMed

    Fujioka, R S

    2001-01-01

    The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely

  4. 78 FR 32385 - Exelon Generation Company, LLC; CER Generation II, LLC; Constellation Mystic Power, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ... Energy Regulatory Commission Exelon Generation Company, LLC; CER Generation II, LLC; Constellation Mystic Power, LLC; Constellation NewEnergy, Inc.; Constellation Power Source Generation, Inc.; Criterion Power..., CER Generation II, LLC, Constellation Mystic Power, LLC, Constellation NewEnergy, Inc.,...

  5. 41 CFR 302-9.104 - What may I do if there is no port or terminal at the point of origin and/or destination?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... is no port or terminal at the point of origin and/or destination? 302-9.104 Section 302-9.104 Public... Transportation General § 302-9.104 What may I do if there is no port or terminal at the point of origin and/or destination? If there is no port or terminal at the point of origin and/or destination, your agency will...

  6. Analysis of a Constellation Lab Cooperative Learning Activity

    NASA Astrophysics Data System (ADS)

    Gauthier, A. J.

    2001-12-01

    A cooperative learning activity was designed for use in the undergraduate laboratory course Introduction to Astronomical Observation. This group exercise enhances the student's learning of constellations and will hopefully increase retention of the material throughout the semester. It also serves as an "ice-breaker" during the first week of lab, promoting student involvement and vested interest in the course. To gain some insight into the student mind, a survey was conducted to evaluate the usefulness and overall opinion of this method. The students who completed the survey had previously been enrolled in a pre-requisite astronomy course that also required a constellation lab. In this previous course they "learned" the constellations from an instructor and a flashlight beam, studied them on their own, and then promptly took a quiz. Both methods are analyzed from an instructional designer's point of view and suggestions for future activities are presented. The preliminary results and accompanying activity will be discussed in poster and hand-out medium.

  7. Origin of melting point depression for rare gas solids confined in carbon pores

    NASA Astrophysics Data System (ADS)

    Morishige, Kunimitsu; Kataoka, Takaaki

    2015-07-01

    To obtain insights into the mechanism of the melting-point depression of rare gas solids confined in crystalline carbon pores, we examined the freezing and melting behavior of Xe and Ar confined to the crystalline pores of ordered mesoporous carbons as well as compressed exfoliated graphite compared to the amorphous pores of ordered mesoporous silicas, by means of X-ray diffraction. For the Xe and Ar confined to the crystalline carbon pores, there was no appreciable thermal hysteresis between freezing and melting. Furthermore, the position of the main diffraction peak did not change appreciably on freezing and melting. This strongly suggests that the liquids confined in the carbon pores form a multilayered structure parallel to the smooth walls. For the Xe and Ar confined to the amorphous silica pores, on the other hand, the position of the main diffraction peak shifted into higher scattering angle on freezing suggested that the density of the confined solid is distinctly larger than for the confined liquid. Using compressed exfoliated graphite with carbon walls of higher crystallinity, we observed that three-dimensional (3D) microcrystals of Xe confined in the slit-shaped pores melted to leave the unmelted bilayers on the pore walls below the bulk triple point. The lattice spacing of the 3D microcrystals confined is larger by ˜0.7% than that of the bilayer next to the pore walls in the vicinity of the melting point.

  8. Origin of melting point depression for rare gas solids confined in carbon pores

    SciTech Connect

    Morishige, Kunimitsu Kataoka, Takaaki

    2015-07-21

    To obtain insights into the mechanism of the melting-point depression of rare gas solids confined in crystalline carbon pores, we examined the freezing and melting behavior of Xe and Ar confined to the crystalline pores of ordered mesoporous carbons as well as compressed exfoliated graphite compared to the amorphous pores of ordered mesoporous silicas, by means of X-ray diffraction. For the Xe and Ar confined to the crystalline carbon pores, there was no appreciable thermal hysteresis between freezing and melting. Furthermore, the position of the main diffraction peak did not change appreciably on freezing and melting. This strongly suggests that the liquids confined in the carbon pores form a multilayered structure parallel to the smooth walls. For the Xe and Ar confined to the amorphous silica pores, on the other hand, the position of the main diffraction peak shifted into higher scattering angle on freezing suggested that the density of the confined solid is distinctly larger than for the confined liquid. Using compressed exfoliated graphite with carbon walls of higher crystallinity, we observed that three-dimensional (3D) microcrystals of Xe confined in the slit-shaped pores melted to leave the unmelted bilayers on the pore walls below the bulk triple point. The lattice spacing of the 3D microcrystals confined is larger by ∼0.7% than that of the bilayer next to the pore walls in the vicinity of the melting point.

  9. Origin of melting point depression for rare gas solids confined in carbon pores.

    PubMed

    Morishige, Kunimitsu; Kataoka, Takaaki

    2015-07-21

    To obtain insights into the mechanism of the melting-point depression of rare gas solids confined in crystalline carbon pores, we examined the freezing and melting behavior of Xe and Ar confined to the crystalline pores of ordered mesoporous carbons as well as compressed exfoliated graphite compared to the amorphous pores of ordered mesoporous silicas, by means of X-ray diffraction. For the Xe and Ar confined to the crystalline carbon pores, there was no appreciable thermal hysteresis between freezing and melting. Furthermore, the position of the main diffraction peak did not change appreciably on freezing and melting. This strongly suggests that the liquids confined in the carbon pores form a multilayered structure parallel to the smooth walls. For the Xe and Ar confined to the amorphous silica pores, on the other hand, the position of the main diffraction peak shifted into higher scattering angle on freezing suggested that the density of the confined solid is distinctly larger than for the confined liquid. Using compressed exfoliated graphite with carbon walls of higher crystallinity, we observed that three-dimensional (3D) microcrystals of Xe confined in the slit-shaped pores melted to leave the unmelted bilayers on the pore walls below the bulk triple point. The lattice spacing of the 3D microcrystals confined is larger by ∼0.7% than that of the bilayer next to the pore walls in the vicinity of the melting point. PMID:26203042

  10. Haplotypes in the Dystrophin DNA Segment Point to a Mosaic Origin of Modern Human Diversity

    PubMed Central

    Ziętkiewicz, Ewa; Yotova, Vania; Gehl, Dominik; Wambach, Tina; Arrieta, Isabel; Batzer, Mark; Cole, David E. C.; Hechtman, Peter; Kaplan, Feige; Modiano, David; Moisan, Jean-Paul; Michalski, Roman; Labuda, Damian

    2003-01-01

    Although Africa has played a central role in human evolutionary history, certain studies have suggested that not all contemporary human genetic diversity is of recent African origin. We investigated 35 simple polymorphic sites and one Tn microsatellite in an 8-kb segment of the dystrophin gene. We found 86 haplotypes in 1,343 chromosomes from around the world. Although a classical out-of-Africa topology was observed in trees based on the variant frequencies, the tree of haplotype sequences reveals three lineages accounting for present-day diversity. The proportion of new recombinants and the diversity of the Tn microsatellite were used to estimate the age of haplotype lineages and the time of colonization events. The lineage that underwent the great expansion originated in Africa prior to the Upper Paleolithic (27,000–56,000 years ago). A second group, of structurally distinct haplotypes that occupy a central position on the tree, has never left Africa. The third lineage is represented by the haplotype that lies closest to the root, is virtually absent in Africa, and appears older than the recent out-of-Africa expansion. We propose that this lineage could have left Africa before the expansion (as early as 160,000 years ago) and admixed, outside of Africa, with the expanding lineage. Contemporary human diversity, although dominated by the recently expanded African lineage, thus represents a mosaic of different contributions. PMID:14513410

  11. New interpretation of the ancient constellations

    NASA Astrophysics Data System (ADS)

    Dementev, M. S.

    New method of study of the ancient constellations and mythes is discussed. It is based on the comparison of two maps - the sky and the Earth. The Stellar map is built in an equatorial system of coordinates, the geografic map - in the Mercator's projection and of the same scale. The former map is put on the laster one. The constellation of Pleiades (seven daughter of Atlant) is placed on the meridian of Atlant (Western coast of Africa). If the Stellar map is constructed for a epoch J-3000 (3000 years up to B.C.) then we could found the following. The constellations Andromeda (the daughter of the Ethiopian tsar), Cetus, Perseus and Cassiopeia (mother of Andromeda) are projected on the centre, south and west of Ancient Ethiopia and Mediterranean Sea, respectively. That is all the constellations fall to the places, where events described in mythes occured. A constellation Cepheus (Arabian name is "Burning") covers the Caucasus. Possibly, before a epoch J-1000 this group of stars was connected with Prometheus. It is known Prometheus was chained to the Caucasian rock because of stealing of a fire. Ancient Chineses divided the sky in other way. They called "The Heavenly Town" the area of sky consisting of stars in Herculis, Aquilae and Ophiuchi. Parts of the mentioned constellation were called as a provinces in Ancient China. If the Heavenly Town locate near the Ancient China then the Greek constellations (Andromeda, Perseus and Cetus) will appear over Africa. Three important conclusions follow from this: (i) the geography of the Earth is reflected on the sky; (ii) the ancient astronomers were investigating a connection between the sky and Earth; (iii) the ancient peoples exchanged by the information about a construction of the world.

  12. Science Opportunities Enabled by NASA's Constellation System: Interim Report

    NASA Technical Reports Server (NTRS)

    2008-01-01

    In 2004 NASA initiated studies of advanced science mission concepts known as the Vision Missions and inspired by a series of NASA roadmap activities conducted in 2003. Also in 2004 NASA began implementation of the first phases of a new space exploration policy, the Vision for Space Exploration. This implementation effort included development of a new human-carrying spacecraft, known as Orion, and two new launch vehicles, the Ares I and Ares V rockets.collectively called the Constellation System. NASA asked the National Research Council (NRC) to evaluate the science opportunities enabled by the Constellation System (see Preface) and to produce an interim report on a short time schedule and a final report by November 2008. The committee notes, however, that the Constellation System and its Orion and Ares vehicles have been justified by NASA and selected in order to enable human exploration beyond low Earth orbit, and not to enable science missions. This interim report of the Committee on Science Opportunities Enabled by NASA s Constellation System evaluates the 11 Vision Mission studies presented to it and groups them into two categories: those more deserving of future study, and those less deserving of future study. Although its statement of task also refers to Earth science missions, the committee points out that the Vision Missions effort was focused on future astronomy, heliophysics, and planetary exploration and did not include any Earth science studies because, at the time, the NRC was conducting the first Earth science decadal survey, and funding Earth science studies as part of the Vision Missions effort would have interfered with that process. Consequently, no Earth science missions are evaluated in this interim report. However, the committee will evaluate any Earth science mission proposal submitted in response to its request for information issued in March 2008 (see Appendix A). The committee based its evaluation of the preexisting Vision Missions studies

  13. On the origin of deletions and point mutations in Duchenne muscular dystrophy: most deletions arise in oogenesis and most point mutations result from events in spermatogenesis.

    PubMed Central

    Grimm, T; Meng, G; Liechti-Gallati, S; Bettecken, T; Müller, C R; Müller, B

    1994-01-01

    We present the results of a study of the rate and origin of mutations in Duchenne muscular dystrophy (DMD). Depending on the type of mutation (deletion/duplication or point mutation) present in the patient, there are widely varying ratios of male to female mutation rates. In deletions, the male mutation rate is only 30% of the female one. In non-deletional/non-duplicational mutations (presumably containing a high proportion of point mutations) the male mutation rate is at least 2.2 as high as the female one and probably much higher. Allowing for the presence of autosomal recessive phenocopies we find that k in non-deletional/non-duplicational mutations is 40.3. These findings mean that the vast majority of deletions arise in oogenesis, while most point mutations stem from spermatogenesis. Previous investigations have shown that in other diseases and genes, most notably haemophilia B and A, but also the ZFY and ZFX genes, the male mutation rate for point mutations tends to be higher than the female one. Our results can be seen as a confirmation of this for the special case of DMD. The influence on risk figures is considerable. As an example, the risk of the mother of an isolated case of DMD without an apparent structural anomaly of the gene of being a carrier increases from 67% to at least 76%. Given the estimate of 40.3 for k, allowing for the presence of autosomal recessive phenocopies mentioned above, it increases even further to 98%. However, as confidence intervals are still large, more data are needed to improve the estimates. Germinal mosaicism in this context is discussed. PMID:8014964

  14. Structural origin underlying the effect of cooling rate on solidification point

    NASA Astrophysics Data System (ADS)

    Li, Chen-Hui; Han, Xiu-Jun; Luan, Ying-Wei; Li, Jian-Guo

    2015-11-01

    Solidification behaviors of liquid aluminum at different cooling rates were examined via classical molecular dynamics simulation with an embedded atom method potential. The results demonstrate that solidification point decreases with increasing cooling rate. To explain this phenomenon, solid-like cluster in liquid was analyzed by the structural analysis method of bond order parameters. The results reveal that the size of the largest solid-like cluster in deeply undercooled liquid decreases with the increase of cooling rate, which can provide a structural interpretation to the above phenomenon. Project supported by the National Basic Research Program of China (Grant No. 2011CB012900), the National Natural Science Foundation of China (Grant No. 51171115), the Natural Science Foundation of Shanghai City, China (Grant No. 10ZR1415700), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100073120008), the Program for New Century Excellent Talents in Universities of China. This work is partially supported by Alexander von Humboldt Foundation.

  15. On the origin of dislocation loops in irradiated materials: A point of view from silicon

    NASA Astrophysics Data System (ADS)

    Claverie, Alain; Cherkashin, Nikolay

    2016-05-01

    Numerous dislocation loops are often observed in irradiated and nuclear materials, affecting many physical properties. The understanding of their origin and of their growth mechanism remains unclear rendering all modeling efforts elusive. In this paper, we remind the knowledge which has been gained during the last 20 years on the formation and growth of extrinsic dislocations loops in irradiated/implanted silicon. From the compilation of a large number of experimental results, a unified picture describing the thermal evolution of interstitial defects, from the di-interstitial stable at room temperature, to "magic-size" clusters then to rod-like defects and finally to large dislocation loops of two types has emerged. All these defects grow by Ostwald ripening, i.e. by interchanging the interstitial atoms they are composed of, and transform from one to the other driven by the resulting reduction of the defect formation energy. A model has been proposed and is now integrated into process simulators which quantitatively describes the thermal evolution of all these defects, based on pertinent formation energies. The influence of the proximity of free surfaces or other recombining interfaces can be integrated, allowing simulating the possible dissolution of defects. It is suggested that, beyond silicon, the same type of scenario may take place in many materials. Dislocation loops are just one, easily detectable among many, type of defects which forms during the growth of self-interstitials. They do not nucleate but result from the growth and transformation of smaller defects.

  16. Integration of Point Clouds Originated from Laser Scaner and Photogrammetric Images for Visualization of Complex Details of Historical Buildings

    NASA Astrophysics Data System (ADS)

    Altuntas, C.

    2015-02-01

    Three-dimensional (3D) models of historical buildings are created for documentation and virtual realization of them. Laser scanning and photogrammetry are extensively used to perform for these aims. The selection of the method that will be used in threedimensional modelling study depends on the scale and shape of the object, and also applicability of the method. Laser scanners are high cost instruments. However, the cameras are low cost instruments. The off-the-shelf cameras are used for taking the photogrammetric images. The camera is imaging the object details by carrying on hand while the laser scanner makes ground based measurement. Laser scanner collect high density spatial data in a short time from the measurement area. On the other hand, image based 3D (IB3D) measurement uses images to create 3D point cloud data. The image matching and the creation of the point cloud can be done automatically. Historical buildings include more complex details. Thus, all details cannot be measured by terrestrial laser scanner (TLS) due to the blocking the details with each others. Especially, the artefacts which have complex shapes cannot be measured in full details. They cause occlusion on the point cloud model. However it is possible to record photogrammetric images and creation IB3D point cloud for these areas. Thus the occlusion free 3D model is created by the integration of point clouds originated from the TLS and photogrammetric images. In this study, usability of laser scanning in conjunction with image based modelling for creation occlusion free three-dimensional point cloud model of historical building was evaluated. The IB3D point cloud was created in the areas that could not been measured by TLS. Then laser scanning and IB3D point clouds were integrated in the common coordinate system. The registration point clouds were performed with the iterative closest point (ICP) and georeferencing methods. Accuracy of the registration was evaluated by convergency and its

  17. 41 CFR 302-9.207 - What will I be reimbursed if I transport my POV from a point of origin or to a destination that...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOR TRANSPORTATION AND EMERGENCY STORAGE OF A PRIVATELY OWNED VEHICLE Return Transportation of a POV From a Post of Duty § 302-9.207 What will I be reimbursed if I transport my POV from a point of origin... reimbursed if I transport my POV from a point of origin or to a destination that is different from...

  18. 41 CFR 302-9.207 - What will I be reimbursed if I transport my POV from a point of origin or to a destination that...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOR TRANSPORTATION AND EMERGENCY STORAGE OF A PRIVATELY OWNED VEHICLE Return Transportation of a POV From a Post of Duty § 302-9.207 What will I be reimbursed if I transport my POV from a point of origin... reimbursed if I transport my POV from a point of origin or to a destination that is different from...

  19. Diverse origins of Arctic and Subarctic methane point source emissions identified with multiply-substituted isotopologues

    NASA Astrophysics Data System (ADS)

    Douglas, P. M. J.; Stolper, D. A.; Smith, D. A.; Walter Anthony, K. M.; Paull, C. K.; Dallimore, S.; Wik, M.; Crill, P. M.; Winterdahl, M.; Eiler, J. M.; Sessions, A. L.

    2016-09-01

    Methane is a potent greenhouse gas, and there are concerns that its natural emissions from the Arctic could act as a substantial positive feedback to anthropogenic global warming. Determining the sources of methane emissions and the biogeochemical processes controlling them is important for understanding present and future Arctic contributions to atmospheric methane budgets. Here we apply measurements of multiply-substituted isotopologues, or clumped isotopes, of methane as a new tool to identify the origins of ebullitive fluxes in Alaska, Sweden and the Arctic Ocean. When methane forms in isotopic equilibrium, clumped isotope measurements indicate the formation temperature. In some microbial methane, however, non-equilibrium isotope effects, probably related to the kinetics of methanogenesis, lead to low clumped isotope values. We identify four categories of emissions in the studied samples: thermogenic methane, deep subsurface or marine microbial methane formed in isotopic equilibrium, freshwater microbial methane with non-equilibrium clumped isotope values, and mixtures of deep and shallow methane (i.e., combinations of the first three end members). Mixing between deep and shallow methane sources produces a non-linear variation in clumped isotope values with mixing proportion that provides new constraints for the formation environment of the mixing end-members. Analyses of microbial methane emitted from lakes, as well as a methanol-consuming methanogen pure culture, support the hypothesis that non-equilibrium clumped isotope values are controlled, in part, by kinetic isotope effects induced during enzymatic reactions involved in methanogenesis. Our results indicate that these kinetic isotope effects vary widely in microbial methane produced in Arctic lake sediments, with non-equilibrium Δ18 values spanning a range of more than 5‰.

  20. APM for a Constellation Intersatellite Link - EM Qualification and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Hartel, Frank; Kozilek, Horst

    2016-01-01

    For an Intersatellite Link (ISL) of a future constellation program, a study phase was initiated by ESA to design a mechanism for Radio Frequency communication. Airbus DS Friedrichshafen (ADSF) proposed a design based on the Antenna Pointing Mechanism (APM) family with modifications that met the stated needs of the constellation. A qualification program was started beginning in September 2015 to verify the launch and thermal loads and the equipment performance (Radio Frequency, Pointing, Microvibration and Magnetic Moment). Technical challenges identified with the Engineering Model will be discussed within this paper.

  1. The NASA Constellation Program Procedure System

    NASA Technical Reports Server (NTRS)

    Phillips, Robert G.; Wang, Lui

    2010-01-01

    NASA has used procedures to describe activities to be performed onboard vehicles by astronaut crew and on the ground by flight controllers since Apollo. Starting with later Space Shuttle missions and the International Space Station, NASA moved forward to electronic presentation of procedures. For the Constellation Program, another large step forward is being taken - to make procedures more interactive with the vehicle and to assist the crew in controlling the vehicle more efficiently and with less error. The overall name for the project is the Constellation Procedure Applications Software System (CxPASS). This paper describes some of the history behind this effort, the key concepts and operational paradigms that the work is based upon, and the actual products being developed to implement procedures for Constellation

  2. Science with the constellation-X observatory

    SciTech Connect

    Valinia, Azita; White, Nicholas; Tananbaum, Harvey

    1999-04-27

    The Constellation X-ray Mission is a high throughput X-ray facility emphasizing observations at high spectral resolution (E/{delta}E{approx}300-3000), and broad energy bandpass (0.25-40 keV). Constellation-X will provide a factor of nearly 100 increase in sensitivity over current high resolution X-ray spectroscopy missions. It is the X-ray astronomy equivalent of large ground-based optical telescopes such as the Keck Observatory and the ESO Very Large Telescope. When observations commence toward the end of next decade, Constellation-X will address many fundamental astrophysics questions such as: the formation and evolution of clusters of galaxies; constraining the baryon content of the Universe; determining the spin and mass of supermassive black holes in AGN; and probing strong gravity in the vicinity of black holes.

  3. The Earth Science Afternoon Constellation Contingency Procedures

    NASA Technical Reports Server (NTRS)

    Case, Warren F.; Richon, Karen

    2005-01-01

    The Earth Science Afternoon Constellation comprises NASA missions Aqua, Aura, CloudSat and the Orbiting Carbon Observatory (OCO), the joint NASA/CNES mission CALIPSO and the CNES mission PARASOL. Both NASA and CNES offices are responsible for ensuring that contingency plans or other arrangements exist to cope with contingencies within their respective jurisdictions until the conclusion of all Afternoon Constellation operations. The Mission Operations Working Group, comprised of members from each of the missions, has developed the high-level procedures for maintaining the safety of this constellation. Each contingency situation requires detailed analyses before any decisions are made. This paper describes these procedures, and includes defining what constitutes a contingency situation, the pertinent parameters involved in the contingency analysis and guidelines for the actions required, based on the results of the contingency analyses.

  4. Status of Constellation Pressure Garment Development

    NASA Technical Reports Server (NTRS)

    Ross, Amy; Aitchison, Lindsay; Daniel, Brian

    2009-01-01

    The Constellation Program requires the development of a space suit system to meet new requirements for launch, entry, and abort crew survival functions, microgravity intravehicular and extravehicular activities, and lunar surface exploration. This paper summarizes recent work and the current status of the NASA Constellation Space Suit Element Pressure Garment and Crew Survival Subsystem (PG/CS). The emphasis of the work by the PGS/CS team has been in the areas of feasibility studies toward PGS/CS architecture definition, risk mitigation, and requirements development. Included are results from component level engineering studies, testing in the Orion Vehicle and Orion seat mockups, microgravity testing on the Reduced Gravity Aircraft, occupant protection sled testing, analyses and studies, and their implications on Constellation PG/CS subsystem.

  5. Evolvable Lunar Navigation and Communication Constellations

    NASA Astrophysics Data System (ADS)

    Hamera, Kathryn E.; Mosher, T.

    2008-05-01

    Several international space agencies have announced plans for future lunar exploration missions, including orbiters, rovers, and the eventual build-up of a lunar outpost. Each of these missions will have certain communication and navigation requirements. Some missions will explore parts of the lunar environment that are not directly visible to the Earth, and a lunar relay element will be necessary to provide critical communication and navigation support. Previous research has shown the advantages of using halo orbits for a lunar relay. Halo orbit insertion costs are less than those for geostationary orbit, station-keeping costs are minimal, and the Earth is visible for 100% of the spacecraft's orbital period. An example constellation was designed to show the feasibility of a halo orbit constellation. The methodologies used to construct the example constellation can be tailored to design halo orbit constellations to meet the coverage needs of any lunar mission. Additionally, the halo orbits are selected such that low energy-transfers may be used to transfer spacecraft between halo orbits for very small maneuver costs. This follow-on research demonstrates the capability of the constellation to evolve and reconfigure through the use of low-energy transfers. Using low-energy transfers, multiple space agencies can utilize the same lunar relay constellation by reconfiguring the spacecraft to provide optimal coverage for different missions at different times. This research was funded by a grant from NASA's Exploration System Mission Directorate to the Colorado Space Grant Consortium and a Graduate Student Research Fellowship from the National Science Foundation.

  6. Optimizing Spacecraft Placement for Liaison Constellations

    NASA Technical Reports Server (NTRS)

    Chow, C. Channing; Villac, Benjamin F.; Lo, Martin W.

    2011-01-01

    A navigation and communications network is proposed to support an anticipated need for infrastructure in the Earth-Moon system. Periodic orbits will host the constellations while a novel, autonomous navigation strategy will guide the spacecraft along their path strictly based on satellite-to-satellite telemetry. In particular, this paper investigates the second stage of a larger constellation optimization scheme for multi-spacecraft systems. That is, following an initial orbit down-selection process, this analysis provides insights into the ancillary problem of spacecraft placement. Two case studies are presented that consider configurations of up to four spacecraft for a halo orbit and a cycler trajectory.

  7. BRITE-Constellation: Science Operations Concept

    NASA Astrophysics Data System (ADS)

    Kuschnig, R.

    2008-01-01

    The BRITE-Constellation currently consists of two nano-satellites: BRITE-AUSTRIA and Uni-BRITE. Both are in principle of identical build with one exception, the respective telescopes will be designed for two different bandpasses one constrained to RED (555-690nm) and the other to BLUE (400-450nm) wavelengths. In general both satellites will collect data from the same stars during any particular observing run. A proposal to build and launch an additional pair of spacecrafts to complement the constellation is currently under review. This article describes the organization structure, the main operations tasks and the software tools to conduct the mission.

  8. Automating Operational and Science Analysis Processes with the Autonomous Sciencecraft Constellation

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Greeley, R.; Baker, V.; Williams, K. K.; Dohm, J.; Castano, R.; Mjolsness, E.; Roden, J.; Stough, T.; Chien, S.

    2002-01-01

    The Autonomous Sciencecraft Constellation-Techsat 21 mission is a NASA New Millennium Program mission selected for flight in 2004. ASC will autonomously perform science analyses of X-band radar data, while in Earth orbit. Additional information is contained in the original extended abstract.

  9. Some notes on the Inka constellations

    NASA Astrophysics Data System (ADS)

    Pacheco, Elluz; Flores, Soraya; Salazar, Erwin

    2011-06-01

    The research carried out so far on the identification of constellations in the Inka civilisation is far from exhaustive, as there is both a great difficulty in obtaining the data and much heterogeneity in the information gathered. A brief presentation is given here.

  10. Human Rating Requirements for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Berdich, Debbie

    2009-01-01

    This slide presentation reviews the human system integration (HSI) process in achieving human ratings for NASA Constellation Program (CxP). The NASA Procedural Requirements (NPR) document that defines the Human Ratings Requirements is NPR 8705.2B. An example of the human rating requirements flow down is given in the handling qualities for space craft control.

  11. Optimizing space constellations for mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Roussel, T.; Taisant, J.-P.

    1993-01-01

    Designing a mobile satellite system entails many complex trade-offs between a great number of parameters including: capacity, complexity of the payload, constellation geometry, number of satellites, quality of coverage, etc. This paper aims at defining a methodology which tries to split the variables to give rapidly some first results. The major input considered is the traffic assumption which would be offered by the system. A first key step is the choice of the best Rider or Walker constellation geometries - with different numbers of satellites - to insure a good quality of coverage over a selected service area. Another aspect to be addressed is the possible altitude location of the constellation, since it is limited by many constraints. The altitude ranges that seem appropriate considering the spatial environment, the launch and orbit keeping policy and the feasibility of the antenna allowing sufficient frequency reuse are briefly analyzed. To support these first considerations, some 'reference constellations' with similar coverage quality are chosen. The in-orbit capacity needed to support the assumed traffic is computed versus altitude. Finally, the exact number of satellite is determined. It comes as an optimum between a small number of satellites offering a high (and costly) power margin in bad propagation situation and a great number of less powerful satellites granting the same quality of service.

  12. Relationships between Social Cognition and Sibling Constellations.

    ERIC Educational Resources Information Center

    Goebel, Barbara L.

    1985-01-01

    First and second born college students (N=178) responded to measures of four social cognition factors. Multivariate analysis of variance identified relationships of social cognition factors with five sibling constellation components: subject's sex, subject's birth order (first or second), adjacent first or second born sibling's sex, spacing…

  13. Capabilities of lightsat constellation for operational altimetry

    NASA Astrophysics Data System (ADS)

    Aguttes, J. P.; Bellaiche, G.

    1992-08-01

    An overview is given of mission tradeoffs involved in lightsat constellations for operational altimetry. Typical mission requirements for a light satellite system and system constraints are discussed. A typical operational performance of a light satellite system is briefly described, and the lightsat as a tool for international cooperation is addressed.

  14. Combined constellations GPS and Galileo systems

    NASA Astrophysics Data System (ADS)

    Januszewski, Jacek

    As for the users of satellite navigation systems the actual slogan is GPS and Galileo the advantages and disadvantages of different combined constellations of these systems must be taken into account. The distributions (in per cent) of the numbers of satellites visible by the observer at different latitudes situated in open and restricted (urban canyon) area for different masking elevation angles (Hmin) for two combined constellations GPS + Galileo systems (I - 29 GPS satellites + 27 Galileo satellites, II - 29 GPS + 30 Galileo) are presented in this paper. In addition to it the detailed distributions for the observer at latitudes 50-60° for other constellations & elevation angles are demonstrated. For the first constellation the difference between the number of GPS satellites visible by the observer above horizon (Hmin = 0°) at latitudes 50-60° and the number of Galileo satellites visible by the same observer at the same time can be equal each number between plus 7 and minus 7. This fact must be taken into account in the production and the determination of the number of channel of GPS-Galileo integrated receivers.

  15. Connect the Dots and Pinhole Constellations.

    ERIC Educational Resources Information Center

    Kominski, John

    1991-01-01

    Identifies a variety of methods to introduce constellations and asterisms to students in the classroom and planetarium prior to their study of the night sky. Materials used include transparencies, oatmeal boxes, photographic slides, and tracing paper. Exercises incorporate storytelling and prediction of location, movement, and seasonal patterns of…

  16. Life Support Technology Challenges for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Carrasquillo, Robyn; Bagdigian, Robert; Ewert, Michael

    2007-01-01

    The presentation is for the ECLSS session of the Constellation Technology Exchange Conference and is to describe what new technology challenges the Constellation mission presents for the ECLSS, in order to communicate these needs with industry.

  17. Origines de la nomenclature astrale

    NASA Astrophysics Data System (ADS)

    Duchesne-Guillemin, J.

    Within a survey of the Indo-European, Sumero-Babylonian, Greek, Arabic, and modern origins of the names of the constellations, stars, planets, satellites, asteroids, etc., an explanation is offered of the Omega sign used in Greek horoscopes for the lunar nodes but already appearing on Babylonian reliefs. Its origin is traced back to the Sumerian constellations of the Yoke, later called the Dragon.

  18. ML-oriented NDA carrier synchronization for general rotationally symmetric signal constellations

    NASA Astrophysics Data System (ADS)

    Moeneclaey, Marc; Dejonghe, Geert

    1994-08-01

    In this contribution we point out that the nondecision-aided (NDA) carrier synchronizer, maximizing the low E(sub s)/N(sub o) limit of the likelihood function averaged over a general 2(pi) /N-rotationally symmetric signal constellation, reduces to the familiar timing-aided Nth power synchronizer. Whereas in the case of M-PSK the tracking error variance of this NDA ML synchronizer is known to converge to the Cramer-Rao bound (CRB) with increasing E(sub s)/N(sub o), we show that for other rotationally symmetric constellations (such as QAM) the tracking error variance is substantially larger than the CRB.

  19. Investigating GAIM-GM's Capability to Sense Ionospheric Irregularities via Walker Satellite Constellations

    NASA Astrophysics Data System (ADS)

    McClung, B.

    2015-12-01

    GAIM-GM is a modularized physics based data assimilation model, that ingests data from multiple data sources. One data source is slant total electron content (TEC) from a ground station network to satellites, and along the occultation path between multiple satellites. This study examines GAIM-GM's capability to sense a scintillation feature in the ionosphere, overlaid on an IFM electron density grid, from simulated satellite constellations ingesting the slant TEC values into GAIM-GM. Satellite constellations were developed in an extension of Matlab, called STK. A real ground station network generated from IGS was ingested into STK to calculate access times to the satellite constellation and use the access data to compute the slant TEC values on the perturbed IFM grid. It was discovered that a Walker constellation would give the most frequent revisit time to the scintillation feature, which co-rotates with the Earth, capturing both the day and nightside ionosphere throughout the evaluation period (96 hrs). The size of the feature was varied along with the number of satellites in the Walker constellation. 25 different scenarios with these parameters varied were created to determine the sensitivity of GAIM-GM to sense the feature. A simple heuristic algorithm was applied comparing the truth data, in this case the perturbed IFM grid, to the GAIM-GM output in each scenario across the entire grid, and for those grid points within the feature.

  20. Radio occultation constellation deployment via impulses along the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Michael Yu.; Trofimov, Sergey P.; Chang, Hao-Chi

    2013-01-01

    The problem of radio occultation (RO) constellation deployment is examined. Of particular interest here is to study the feasibility of using passively stabilized small satellites. We consider a pair of satellites supplied with a passive magnetic attitude control system. The capsule containing two satellites is launched into a parking orbit and stabilized along the geomagnetic field direction. Then the satellites are pushed apart by a separation spring at some point of orbit. If necessary for braking, one or two thrusters may be placed along the stabilized axis of each satellite. Optimization of the separation point and velocity along with the ΔV required for possible braking thrust is carried out in accordance with some specific demands of RO missions. Atmospheric drag and Earth oblateness are taken into account as perturbations. It is shown that, depending on a mission scenario, the separation with either one braking thrust or no thrusts at all is preferable.

  1. Spatial Sense and Perspective: A 3-D Model of the Orion Constellation

    NASA Astrophysics Data System (ADS)

    Heyer, I.; Slater, T. F.; Slater, S. J.

    2012-08-01

    Building a scale model of the Orion constellation provides spatial perspective for students studying astronomy. For this activity, students read a passage from literature that refers to stars being strange when seen from a different point of view. From a data set of the seven major stars of Orion they construct a 3-D distance scale model. This involves the subject areas of astronomy, mathematics, literature and art, as well as the skill areas of perspective, relative distances, line-of-sight, and basic algebra. This model will appear from one side exactly the way we see it from Earth. But when looking at it from any other angle the familiar constellation will look very alien. Students are encouraged to come up with their own names and stories to go with these new constellations. This activity has been used for K-12 teacher professional development classes, and would be most suitable for grades 6-12.

  2. Global Coverage from Ad-Hoc Constellations in Rideshare Orbits

    NASA Technical Reports Server (NTRS)

    Ellis, Armin; Mercury, Michael; Brown, Shannon

    2012-01-01

    A promising area of small satellite development is in providing higher temporal resolution than larger satellites. Traditional constellations have required specific orbits and dedicated launch vehicles. In this paper we discuss an alternative architecture in which the individual elements of the constellation are launched as rideshare opportunities. We compare the coverage of such an ad-hoc constellation with more traditional constellations. Coverage analysis is based on actual historical data from rideshare opportunities. Our analysis includes ground coverage and temporal revisits for Polar, Tropics, Temperate, and Global regions, comparing ad-hoc and Walker constellation.

  3. Autonomy Architectures for a Constellation of Spacecraft

    NASA Technical Reports Server (NTRS)

    Barrett, Anthony

    2000-01-01

    This paper describes three autonomy architectures for a system that continuously plans to control a fleet of spacecraft using collective mission goals instead of goals of command sequences for each spacecraft. A fleet of self-commanding spacecraft would autonomously coordinate itself to satisfy high level science and engineering goals in a changing partially-understood environment-making feasible the operation of tens of even a hundred spacecraft (such as for interferometer or magnetospheric constellation missions).

  4. The GeoEye Satellite Constellation

    NASA Technical Reports Server (NTRS)

    Dial, Gene; Cole, Aaron; Lutes, James; McKune, John; Martinez, Mike; Rao, R. S.; Taylor, Martin

    2007-01-01

    The GeoEye Constellation consists of: a) IKONOS and OrbView-3 for high resolution; b) GeoEye with higher resolution 1Q2007; c) RESOUCESAT-1 for global crop assessment; d) OrbView-2 for ocean research and fish. IKONOS performance in 2005 included stable image quality, radiometry and geometric accuracy. reliability is 80% to 2008. Demonstrated capacity for high-volume, quick-response collection and production.

  5. Constellation X-Ray Mission and Support

    NASA Technical Reports Server (NTRS)

    Grady, Jean (Technical Monitor); Tananbaum, H.

    2002-01-01

    This Fourth Annual Report summarizes work performed by the Smithsonian Astrophysical Observatory (SAO) for NASA Goddard Space Flight Center (GSFC) under Cooperative Agreement NCC5-368. The Agreement is entitled Constellation X-ray Mission Study and SAO continues to perform work under the overall direction of Dr. Harvey Tananbaum, the SAO Principal Investigator for the program. Mr. Robert Rasche is the SAO Program Manager and is responsible for day-to-day program management at SAO and coordination with GSFC. The report summarizes the main areas of SAO activity. Most of the work has been done jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). We describe SAO participation in these efforts. As is appropriate to a Cooperative Agreement, SAO continued to work with GSFC in an integrated team mode. SAO was involved in the overall mission management, technology development, scientific direction, and mission definition. While formal overall management responsibility resides with GSFC, scientific lead and subordinate responsibilities continue to be shared by GSFC and SAO. The work performed by SAO is consistent with the SAO proposal 'Constellation X-ray Mission Study and Optics Development' dated September 1997, which was the basis for establishing the Cooperative Agreement under which SAO is currently funded. Over time, the scope of the effort has expanded somewhat to accommodate the needs of the project. Work, except for meeting support and high priority program tasks, has been at a level of effort. Priorities and work progress have been closely coordinated with the Constellation-X Project Formulation Manager at GSFC. Funding limitations constrained the work accomplished during this period. Nonetheless, a significant amount of work was accomplished. Under the Agreement, SAO performed work in seven major areas of activity. These areas related to: Constellation X-ray Mission Facility Definition Team and Study Management; Science Support; Spectroscopy X

  6. NASA's Constellation Program: Milestones Towards the Frontier

    NASA Technical Reports Server (NTRS)

    Hanley, Jeffrey M.; Thomas, Lawrence D.; Rhatigan, Jennifer L.; Boatright, Tony J.

    2009-01-01

    This slide presentation reviews the status and progress made in the Constellation Program's work towards the goal of lunar and Martian exploration flights. It includes views of the various components of the program, and reviews the status of the engine tests, and the development of the Ares I-X towards test launch, the Orion Crew Module, the launch abort system, and the ground operations facilities.

  7. Constellation X-Ray Mission and Support

    NASA Astrophysics Data System (ADS)

    Tananbaum, H.

    2002-01-01

    This report is a supplement to the Third Annual Report summarizing work performed by the Smithsonian Astrophysical Observatory (SAO) for NASA Goddard Space Flight Center (GSFC) under Cooperative Agreement NCC5-3681. The Agreement is entitled 'Constellation X-ray Mission Study and Support.' This supplementary report covers the period from October 1, 2001 through January 10, 2002. The report has been prepared and submitted to ensure that the Constellation-X Project Office at GSFC has current performance information needed to evaluate a proposed modified budget for FY02. That proposed budget is being submitted separately. SAO continues to perform work under the overall direction of Dr. Harvey Tananbaum, the SAO Principal Investigator for the program. Mr. Robert Rasche is the SAO Program Manager and is responsible for day-to-day program management at SAO and coordination with GSFC. The report summarizes the main areas of SAO activity. Most of the work has been done jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). We describe SAO participation in these efforts. Under the Agreement, SAO performed work in seven major areas of activity. These areas related to: (1) Constellation X-ray Mission Facility Definition Team and Study Management; (2) Science Support; (3) Spectroscopy X-ray Telescope (SXT); (4) Systems Engineering; (5) Travel in Support of the Work Effort; and (6) In-house Management and Coordination.

  8. Optimization of satellite constellation reconfiguration maneuvers

    NASA Astrophysics Data System (ADS)

    Appel, Leonid; Guelman, Moshe; Mishne, David

    2014-06-01

    Constellation satellites are required to perform orbital transfer maneuvers. Orbital transfer maneuvers, as opposed to orbital correction maneuvers, are seldom performed but require a substantial amount of propellant for each maneuver. The maneuvers are performed in order to obtain the desired constellation configuration that satisfies the coverage requirements. In most cases, the single-satellite position is immaterial; rather the relative position between constellation multiple-satellites is to be controlled. This work deals with the solution to the coupled optimization problem of multiple-satellite orbital transfer. The studied problem involves a coupled formulation of the terminal conditions of the satellites. The solution was achieved using functional optimization techniques by a combined algorithm. The combined algorithm is based on the First Order Gradient and Neighboring-Extremals Algorithms. An orbital transfer optimization tool was developed. This software has the ability to consider multiple satellites with coupled terminal conditions. A solution to the multiple-satellite orbital transfer optimization problem is presented. A comparison of this solution to the uncoupled case is presented in order to review the benefits of using this approach. It is concluded that the coupled transfer maneuver solution approach is more computationally efficient and more accurate. Numerical solutions for a number of representative cases are presented.

  9. The Constellation-X Science Case

    NASA Astrophysics Data System (ADS)

    Hornschemeier, Ann E.; White, N.; Tananbaum, H.; Garcia, M.; Petre, R.; Bookbinder, J.

    2006-09-01

    Constellation-X presents a great leap forward in collecting area over current X-ray observatories and will enable high signal-to-noise studies of X-ray sources that are currently too faint for Chandra and XMM-Newton. Thus Constellation-X remains a high-priority mission in reviews by the National Academies and is the next major X-ray observatory under development by NASA. Con-X will carry out high spectral resolution studies of AGN, which currently require heroic megasecond-class observations with Chandra and XMM, in observations as short as 50 ks. Con-X will be able to track material in accretion disks around supermassive black holes on a light-crossing timescale and will study AGN out to at least redshift 6. The imaging (non-dispersive) spectroscopy capability of the mission will be critical to studying extended sources such as clusters of galaxies and supernova remnants. Con-X studies of clusters of galaxies will allow a crucial means of studying dark matter properties and also of studying dark energy. This talk will cover recent updates to the Constellation-X science case considering the new, proposed Con-X Lite approach. We will also discuss the process whereby the high energy astrophysics community may continue to influence the science case for the mission.

  10. 41 CFR 302-9.206 - What should I do if there is no port or terminal at my authorized point of origin or authorized...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOR TRANSPORTATION AND EMERGENCY STORAGE OF A PRIVATELY OWNED VEHICLE Return Transportation of a POV From a Post of Duty § 302-9.206 What should I do if there is no port or terminal at my authorized point... there is no port or terminal at my authorized point of origin or authorized destination when I...

  11. 41 CFR 302-9.206 - What should I do if there is no port or terminal at my authorized point of origin or authorized...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOR TRANSPORTATION AND EMERGENCY STORAGE OF A PRIVATELY OWNED VEHICLE Return Transportation of a POV From a Post of Duty § 302-9.206 What should I do if there is no port or terminal at my authorized point... there is no port or terminal at my authorized point of origin or authorized destination when I...

  12. End-of-Mission Planning Challenges for a Satellite in a Constellation

    NASA Technical Reports Server (NTRS)

    Boain, Ronald J.

    2013-01-01

    At the end of a mission, satellites embedded in a constellation must first perform propulsive maneuvers to safely exit the constellation before they can begin with the usual end-of-mission activities: deorbit, passivation, and decommissioning. The target orbit for these exit maneuvers must be sufficiently below the remaining constellation satellites such that, once achieved, there is no longer risk of close conjunctions. Yet, the exit maneuvers must be done based on the spacecraft's state of health and operational capability when the decision to end the mission is made. This paper focuses on the recently developed exit strategy for the CloudSat mission to highlight problems and issues, which forced the discarding of CloudSat's original EoM Plan and its replacement with a new plan consistent with changes to the spacecraft's original operational mode. The analyses behind and decisions made in formulating this new exit strategy will be of interest to other missions in a constellation currently preparing to update their End-of-Mission Plan.

  13. Automating Trend Analysis for Spacecraft Constellations

    NASA Technical Reports Server (NTRS)

    Davis, George; Cooter, Miranda; Updike, Clark; Carey, Everett; Mackey, Jennifer; Rykowski, Timothy; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Spacecraft trend analysis is a vital mission operations function performed by satellite controllers and engineers, who perform detailed analyses of engineering telemetry data to diagnose subsystem faults and to detect trends that may potentially lead to degraded subsystem performance or failure in the future. It is this latter function that is of greatest importance, for careful trending can often predict or detect events that may lead to a spacecraft's entry into safe-hold. Early prediction and detection of such events could result in the avoidance of, or rapid return to service from, spacecraft safing, which not only results in reduced recovery costs but also in a higher overall level of service for the satellite system. Contemporary spacecraft trending activities are manually intensive and are primarily performed diagnostically after a fault occurs, rather than proactively to predict its occurrence. They also tend to rely on information systems and software that are oudated when compared to current technologies. When coupled with the fact that flight operations teams often have limited resources, proactive trending opportunities are limited, and detailed trend analysis is often reserved for critical responses to safe holds or other on-orbit events such as maneuvers. While the contemporary trend analysis approach has sufficed for current single-spacecraft operations, it will be unfeasible for NASA's planned and proposed space science constellations. Missions such as the Dynamics, Reconnection and Configuration Observatory (DRACO), for example, are planning to launch as many as 100 'nanospacecraft' to form a homogenous constellation. A simple extrapolation of resources and manpower based on single-spacecraft operations suggests that trending for such a large spacecraft fleet will be unmanageable, unwieldy, and cost-prohibitive. It is therefore imperative that an approach to automating the spacecraft trend analysis function be studied, developed, and applied to

  14. A Genuine Jahn-Teller System with Compressed Geometry and Quantum Effects Originating from Zero-Point Motion.

    PubMed

    Aramburu, José Antonio; García-Fernández, Pablo; García-Lastra, Juan María; Moreno, Miguel

    2016-07-18

    First-principle calculations together with analysis of the experimental data found for 3d(9) and 3d(7) ions in cubic oxides proved that the center found in irradiated CaO:Ni(2+) corresponds to Ni(+) under a static Jahn-Teller effect displaying a compressed equilibrium geometry. It was also shown that the anomalous positive g∥ shift (g∥ -g0 =0.065) measured at T=20 K obeys the superposition of the |3 z(2) -r(2) ⟩ and |x(2) -y(2) ⟩ states driven by quantum effects associated with the zero-point motion, a mechanism first put forward by O'Brien for static Jahn-Teller systems and later extended by Ham to the dynamic Jahn-Teller case. To our knowledge, this is the first genuine Jahn-Teller system (i.e. in which exact degeneracy exists at the high-symmetry configuration) exhibiting a compressed equilibrium geometry for which large quantum effects allow experimental observation of the effect predicted by O'Brien. Analysis of the calculated energy barriers for different Jahn-Teller systems allowed us to explain the origin of the compressed geometry observed for CaO:Ni(+) . PMID:27028895

  15. Lagrange L4/L5 points and the origin of our Moon and Saturn's moons and rings.

    PubMed

    Gott, J Richard

    2005-12-01

    The current standard theory of the origin of the Moon is that the Earth was hit by a giant impactor the size of Mars causing ejection of debris from its mantle that coalesced to form the moon; but where did this Mars-sized impactor come from? Isotopic evidence suggests that it came from 1 AU radius in the solar nebula, and computer simulations are consistent with its approaching Earth on a zero-energy parabolic trajectory. How could such a large object form at 1 AU in a quiescent disk of planetesimals without having already collided with the Earth at an earlier epoch before having the chance to grow large? Belbruno and Gott propose that the giant impactor could have formed in a stable orbit from debris at the Earth's Lagrange point L(5) (or L(4)). It would grow quietly by accretion at L(5) (or L(4)), but eventually gravitational perturbations by other growing planetesimals would kick it out into a horseshoe orbit and finally into a chaotic creeping orbit, which Belbruno and Gott show would, with high probability, hit the Earth on a near zero-energy parabolic trajectory. We can see other examples of this phenomenon occurring in the solar system. Asteroid 2002AA29 is in a horseshoe orbit relative to the Earth that looks exactly like the horseshoe orbits that Belbruno and Gott found for objects that had been perturbed from L(4)/L(5). The regular moons of Saturn are made of ice and have the same albedo as the ring particles (ice chunks, plus some dust). We (J. R. Gott, R. Vanderbei, and E. Belbruno) propose that the regular icy moons of Saturn (out to the orbit of Titan), which are all in nearly circular orbits, formed out of a thin disk of planetesimals (ice chunks) rather like the rings of Saturn today only larger in extent. In such a situation formation of objects at L(4)/L(5) might be expected. Indeed, Saturn's moon Dione is accompanied by moons (Helene and Polydeuces) at both L(4) and L(5) Lagrange points, and Saturn's moon Tethys is also accompanied by moons

  16. Constellation X-Ray Observatory Unlocking the Mysteries of Black Holes, Dark Matter and Life Cycles of Matter in the Universe

    NASA Technical Reports Server (NTRS)

    Weaver, Kim; Wanjek, Christopher

    2004-01-01

    This document provides an overview of the Contellation X-Ray Observatory and its mission. The observatory consists of four x-ray telescopes borne on a satellite constellation at the Earth-Sun L2 point.

  17. GPM Constellation Reconfiguration and Mission Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2006-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission that uses combined active and passive remote sensing techniques to improve global precipitation measurements derived from dedicated and operational passive microwave sensors. GPM is a science mission with integrated applications goals to (1) advance the knowledge of precipitation physics and the global water cycle variability, and (2) improve weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of global precipitation and innovative application methods. The GPM Mission is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), with opportunities for additional domestic and international partners in satellite constellation buildup and ground validation activities. The GPM concept is centered on employing a dualfrequency precipitation radar and a microwave radiometer with high-frequency capabilities on a core satellite to serve as a physics observatory and calibration standard to provide a consistent framework for unifying precipitation measurements from a heterogeneous constellation of passive microwave sensors. Building on the siccess of TRMM, GPM extends combined radadradiometer precipitation measurements into the mid and high latitudes, with new science foci on improved capabilities for light-rain and snowfall measurements, as well as more accurate precipitation retrievals over land. With recent studies indicating that AMSU-B rainfall estimates are comparable in quality to those derived from conically-scanning radiometers over land, it is envisioned that cross-track microwave sounders with high-frequency channels on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS), NPOESS Preparatory Project (NPP), NOAA-N', and MetOp satellites can play a significant role in augmenting conically-scanning microwave radiometers to achieve better

  18. Electrical Arc Ignition Testing for Constellation Program

    NASA Technical Reports Server (NTRS)

    Sparks, Kyle; Gallus, Timothy; Smith, Sarah

    2009-01-01

    NASA Johnson Space Center (JSC) Materials and Processes Branch requested that NASA JSC White Sands Test Facility (WSTF) perform testing for the Constellation Program to evaluate the hazard of electrical arc ignition of materials that could be in close proximity to batteries. Specifically, WSTF was requested to perform wire-break electrical arc tests to determine the current threshold for ignition of generic cotton woven fabric samples with a fixed voltage of 3.7 V, a common voltage for hand-held electrical devices. The wire-break test was developed during a previous test program to evaluate the hazard of electrical arc ignition inside the Extravehicular Mobility Unit [1].

  19. Constellation Architecture and System Margins Strategy

    NASA Technical Reports Server (NTRS)

    Muirhead, Brian

    2008-01-01

    NASA's Constellation Program (CxP) is responsible for the definition, design, development, and operations of the flight, ground, and mission operations elements being developed by the United States for the human exploration of the Moon, Mars, and beyond. This paper provides an overview of the latest CxP technical architecture baseline, driving requirements, and reference missions for initial capability to fly to the International Space Station (ISS) and to the Moon. The results of the most recent design decisions and analyses supporting the architecture, including the Ares I, Ares V, Orion crew exploration vehicle, and the Altair lunar lander will be presented.

  20. The Constellation-X Reflection Grating Spectrometer

    NASA Technical Reports Server (NTRS)

    Allen, Jean C.

    2006-01-01

    The Reflection Grating Spectrometer on the Constellation-X mission will provide high sensitivity, high-resolution spectra in the soft x-ray band. The RGS performance requirements are specified as a resolving power of greater than 300 and an effective area of greater than 1000 sq cm across most of the 0.25 to 2.0 keV band. These requirements are driven by the science goals of the mission. We will describe the performance requirements and goals, the reference design of the spectrometer, and examples of science cases where we expect data from the RGS to significantly advance our current understanding of the universe.

  1. NASA Constellation Distributed Simulation Middleware Trade Study

    NASA Technical Reports Server (NTRS)

    Hasan, David; Bowman, James D.; Fisher, Nancy; Cutts, Dannie; Cures, Edwin Z.

    2008-01-01

    This paper presents the results of a trade study designed to assess three distributed simulation middleware technologies for support of the NASA Constellation Distributed Space Exploration Simulation (DSES) project and Test and Verification Distributed System Integration Laboratory (DSIL). The technologies are the High Level Architecture (HLA), the Test and Training Enabling Architecture (TENA), and an XML-based variant of Distributed Interactive Simulation (DIS-XML) coupled with the Extensible Messaging and Presence Protocol (XMPP). According to the criteria and weights determined in this study, HLA scores better than the other two for DSES as well as the DSIL.

  2. Angular Resolution of Multi-Lisa Constellations

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Gong, Xue-Fei

    2010-04-01

    In this article, we present a detailed derivation of the angular resolution of arbitrary sets of LISA (Laser Interferometer Space Antenna) constellations with a toy model for gravitational wave signals, and further generalized to more complicated cases with slowly varying gravitational wave signals of well-defined frequency at any time instant. For future space-borne LISA-like gravitational wave detectors, our results may serve as a conservative quick estimate of the detector's angular resolution and hopefully moreover a reference for the configuration designs.

  3. The Constellations of the Zodiac: Astronomy for Low Vision and Blind People

    NASA Astrophysics Data System (ADS)

    Garcia, B.; Cicero, A.; Farrando, M.; Bruno, P.

    2006-08-01

    One thinks, in general, there exist areas of the knowledge to which it is not possible to be acceded if one of the senses is diminished. Nevertheless, the reality is far from this false concept: it is not necessary to hear to compose music, nor to see to come near to the starred sky. This book has the purpose to introduce to the readers with visual difficulties the amazing world of astronomy, by means of the transmission of basic concepts of positional astronomy (cardinal points, Earth movements, apparent movement of the celestial sphere), with special emphasis in: movement of precession, the concept of stellar magnitude, its representation in celestial charts, and relation to mythology. On the other hand, the figures associated with the 13 constellations in the region of the plane of the ecliptic are described. The texts and the images are displayed in two formats: for visually diminished people, one worked on the basis of the original engravings of the Uranographia by Hevelius (1690). These were adapted and simplified for their better understanding, and a recommended font size. For blind people, we use tactile feature for the figures and Braille for the text.

  4. The strengths of constellation missions when exploring our atmosphere

    NASA Astrophysics Data System (ADS)

    Ridley, A. J.; Ruf, C. S.; Posselt, D. J.; Rose, R.; Provost, D.

    2014-12-01

    A few constellation mission have been flow by NASA, ESA, DoD and different companies. While some of these missions are with large satellites, such as ESA's Cluster mission, others are with smaller satellites, such as NASA's Themis mission. CubeSats and MicroSats are obviously smaller than monolithic satellites, and are therefore much more constrained in mass, power, volume and data throughput. They are also cheaper and can be launched in constellations or as secondary payloads. Constellations can provide measurements over larger areas and better sampling in time than single satellites in low Earth orbit, which is one of their main advantages. In this presentation, we focus on the CYGNSS constellation mission, which will measure the winds over the ocean. We show how the the mission will be deployed, the constellation measurement strategy, coverage statistics, and repeat times. We will also discuss other constellation missions that have flown or are being planned.

  5. The Origin of Sterol Biosynthesis: A Time-Point for the Evolution of Eukaryotes and the Presence of O2

    NASA Astrophysics Data System (ADS)

    Pearson, A.; Budin, M.; Brocks, J. J.

    2003-12-01

    The evolution of sterol biosynthesis is of critical interest to geoscientists as well as to evolutionary biologists. The first enzyme in the pathway, squalene monooxygenase (Sqmo), requires molecular oxygen (O2), suggesting that this process post-dates the evolution of Cyanobacteria. Additionally, the presence of steranes in ancient rocks marks the suggested time-point of eukaryogenesis(1). Sterol biosynthesis is viewed primarily as a eukaryotic process, and the frequency of its occurrence in bacteria long has been a subject of controversy. In this work, 19 protein gene sequences for Sqmo from eukaryotes were compared to all available complete and partial prokaryotic genomes. Twelve protein gene sequences representing oxidosqualene cyclase (Osc), the second enzyme of the sterol biosynthetic pathway, also were examined. The only unequivocal matches among the bacteria were the alpha-proteobacterium, Methylococcus capsulatus, in which sterol biosynthesis already is known, and the planctomycete, Gemmata obscuriglobus. The latter species contains the most abbreviated sterol pathway yet identified in any organism. Experiments show that the major sterols in Gemmata are lanosterol and its uncommon isomer, parkeol. In bacteria, the sterol biosynthesis genes occupy a contiguous coding region and may represent a single operon. Phylogenetic trees show that the sterol pathway in bacteria and eukaryotes has a common ancestry. Gemmata may retain the most ancient remnants of the pathway's origin, and it is likely that sterol biosynthesis in eukaryotes was acquired through gene transfer from bacteria. However, this work indicates that no known prokaryotes could produce the 24-ethyl steranes found in Archaean rocks(1). Therefore these compounds remain indicative of the presence of both eukaryotes and O2 at 2.7 Ga. 1. J. J. Brocks, G. A. Logan, R. Buick, R. E. Summons, (1999) Science 285, 1033-1036.

  6. Role of fluid mixing and fault-related sulfide in the origin of the Ray Point Uranium District, south Texas

    SciTech Connect

    Goldhaber, M.B.; Reynolds, R.L.; Rye, R.O.

    1983-09-01

    The Lamprecht and Felder deposits are two of many roll-type uranium deposits hosted by the Miocene Oakville Sandstone in the Ray Point (south Texas) uranium district. The deposits in this district are aligned parallel to or are intersected by the Oakville fault which suggests control by the faults on their origin and/or preservation. The Lamprecht and Felder deposits show fundamentally similar patterns of geochemical zonation and of distribution of authigenic iron disulfide (FeS/sub 2/) minerals. Distribution of U, Mo, and Se are typical of roll-type deposits that result from invasion of geochemically reduced rock by oxygenated uranium-bearing solutions. Sulfur content of these deposits is high (as much as 9%), with almost all sulfur occurring as FeS/sub 2/ minerals. Organic carbon is virtually absent. Four distinct stages of FeS/sub 2/ mineral formation are recognized: (1) a generation of isotopically light (delta/sup 34/S < -20%o) preor pyrite, (2) a generation of isotopically light (delta/sup 34/S < -20%o) marcasite that formed mostly before, but also during, ore deposition, (3) a postore generation of isotopically heavy pyrite (delta/sup 34/S > 0%o), and (4) a yet later generation of marcasite with isotopically light sulfur close to the values of stages 1 and 2. The altered tongue in these deposits is anomalous in that it contains FeS/sub 2/ minerals in contrast to other Texas and Wyoming roll-type deposits which typically have an oxidized (ferric iron-bearing) altered tongue. The dominant FeS/sub 2/ mineral in the altered tongue is isotopically heavy pyrite (stage 3) with subordinate amounts of late marcasite (stage 4).

  7. Receiver autonomous integrity monitoring using a 24-satellite GPS constellation

    NASA Astrophysics Data System (ADS)

    Brown, Alison K.

    A 24-satellite GPS configuration is studied in order to explore the conditions under which both failure detection and isolation are possible using receiver autonomous integrity monitoring (RAIM). Simulation results show that the satellite coverage provided by both the 3-plane and the 6-plane constellations considered are suitable to provide integrity for all phases of flight except for nonprecision approaches. Although the 6-plane constellation has marginally poorer geometry for satellite failure detection than the 3-plane constellation, the average satellite isolation geometry is significantly better, making the 6-plane constellation preferable for RAIM.

  8. Space Technology 5 - A Successful Micro-Satellite Constellation Mission

    NASA Technical Reports Server (NTRS)

    Carlisle, Candace; Webb, Evan H.

    2007-01-01

    The Space Technology 5 (ST5) constellation of three micro-satellites was launched March 22, 2006. During the three-month flight demonstration phase, the ST5 team validated key technologies that will make future low-cost micro-sat constellations possible, demonstrated operability concepts for future micro-sat science constellation missions, and demonstrated the utility of a micro-satellite constellation to perform research-quality science. The ST5 mission was successfully completed in June 2006, demonstrating high-quality science and technology validation results.

  9. Constellation X-Ray Mission and Support

    NASA Technical Reports Server (NTRS)

    Grady, Jean (Technical Monitor); Tananbaum, H.

    2004-01-01

    This Fifth Annual Report summarizes work performed by the Smithsonian Astrophysical Observatory (SAO) for NASA Goddard Space Flight Center (GSFC) under Cooperative Agreement NCC5-368. The Agreement is entitled 'Constellation X-ray Mission Study and Support.' This report covers the period from October 1, 2002 through September 30,2003. The report summarizes the main areas of SAO activity. Most of the work has been done jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). We describe SAO participation in these efforts. In spite of the work being mainly a level of effort, a significant amount of work was accomplished. Under the Agreement, SAO performed work in eight major areas of activity. These areas related to: 1) Constellation X-ray Mission Facility Definition Team and Study Management; 2) Science Support; 3) Spectroscopy X-ray Telescope (SXT); 4) Systems Engineering; 5) Travel in Support of the Work Effort; 6) In-house Management and Coordination; 7) Technical Readiness and Implementation Plan (TRIP) Report and Follow-up; 8) Industry Liaison and Study Preparation.

  10. Hyperspectral Cubesat Constellation for Natural Hazard Response

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Crum, Gary; Ly, Vuong; Handy, Matthew; Huemmrich, Karl F.; Ong, Lawrence; Holt, Ben; Maharaja, Rishabh

    2016-01-01

    The authors on this paper are team members of the Earth Observing 1 (E0-1) mission which has flown an imaging spectrometer (hyperspectral) instrument called Hyperion for the past 15+ years. The satellite is able to image any spot on Earth in the nadir looking direction every 16 days and with slewing, of the satellite for up to a 23 degree view angle, any spot on the Earth can be imaged approximately every 2 to 3 days. EO-1 has been used to track many natural hazards such as wildfires, volcanoes and floods. An enhanced capability that has been sought is the ability to image natural hazards in a daily time series for space-based imaging spectrometers. The Hyperion cannot provide this capability on EO-1 with the present polar orbit. However, a constellation of cubesats, each with the same imaging spectrometer, positioned strategically can be used to provide daily coverage or even diurnal coverage, cost-effectively. This paper sought to design a cubesat constellation mission that would accomplish this goal and then to articulate the key tradeoffs.

  11. Constellation Pathfinder: A University Nanosatellite Project

    NASA Astrophysics Data System (ADS)

    Spence, Harlan E.; Petschek, Harry E.

    2002-08-01

    Under the task of nanosatellite mission design, we developed a mission concept that enables hundreds of one-kilogram spacecraft to be placed into orbit with a single mothership. We performed trade studies to arrive at a positive feasibility assessment. The results of that study were described in two publications. Second, under the task of spacecraft design, we developed nanosatellite designs needed to enable constellation missions. Design studies were conducted and subsystems prototyped, including a spin-table and launcher concept for a small stack of nanosatellites. Engineering design studies of this work appeared in the refereed literature. Instruments to be flown on such a small craft have been specified and then developed as part of a related AF SBIR effort. Undergraduate students (>100 in the Aerospace Engineering, Mechanical Engineering, and Electrical and Computer Engineering departments) played an enormous role in the mission and spacecraft definitions of the Constellation Pathfinder project. In addition to five publications, numerous invited and contributed presentations of these studies have been presented at national and international meetings.

  12. Precise orbit determination of Multi-GNSS constellation including GPS GLONASS BDS and GALIEO

    NASA Astrophysics Data System (ADS)

    Dai, Xiaolei

    2014-05-01

    In addition to the existing American global positioning system (GPS) and the Russian global navigation satellite system (GLONASS), the new generation of GNSS is emerging and developing, such as the Chinese BeiDou satellite navigation system (BDS) and the European GALILEO system. Multi-constellation is expected to contribute to more accurate and reliable positioning and navigation service. However, the application of multi-constellation challenges the traditional precise orbit determination (POD) strategy that was designed usually for single constellation. In this contribution, we exploit a more rigorous multi-constellation POD strategy for the ongoing IGS multi-GNSS experiment (MGEX) where the common parameters are identical for each system, and the frequency- and system-specified parameters are employed to account for the inter-frequency and inter-system biases. Since the authorized BDS attitude model is not yet released, different BDS attitude model are implemented and their impact on orbit accuracy are studied. The proposed POD strategy was implemented in the PANDA (Position and Navigation Data Analyst) software and can process observations from GPS, GLONASS, BDS and GALILEO together. The strategy is evaluated with the multi-constellation observations from about 90 MGEX stations and BDS observations from the BeiDou experimental tracking network (BETN) of Wuhan University (WHU). Of all the MGEX stations, 28 stations record BDS observation, and about 80 stations record GALILEO observations. All these data were processed together in our software, resulting in the multi-constellation POD solutions. We assessed the orbit accuracy for GPS and GLONASS by comparing our solutions with the IGS final orbit, and for BDS and GALILEO by overlapping our daily orbit solution. The stability of inter-frequency bias of GLONASS and inter-system biases w.r.t. GPS for GLONASS, BDS and GALILEO were investigated. At last, we carried out precise point positioning (PPP) using the multi-constellation

  13. FAST TRACK COMMUNICATION: Affine constellations without mutually unbiased counterparts

    NASA Astrophysics Data System (ADS)

    Weigert, Stefan; Durt, Thomas

    2010-10-01

    It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations. The observed discrepancies make a deeper relation between the two existence problems unlikely.

  14. Distributed Avionics and Software Verification for the Constellation Program

    NASA Technical Reports Server (NTRS)

    Hood, Laura E.; Adams, James E.

    2008-01-01

    This viewgraph presentation reviews the planned verification of the avionics and software being developed for the Constellation program.The Constellation Distributed System Integration Laboratory (DSIL) will consist of multiple System Integration Labs (SILs), Simulators, Emulators, Testbeds, and Control Centers interacting with each other over a broadband network to provide virtual test systems for multiple test scenarios.

  15. Development of Constellation's Launch Control System

    NASA Technical Reports Server (NTRS)

    Lougheed, Kirk D.; Peaden, Cary J.

    2010-01-01

    The paper focuses on the National Aeronautics and Space Administration (NASA) Constellation Program's Launch Control System (LCS) development effort at Kennedy Space Center (KSC). It provides a brief history of some preceding efforts to provide launch control and ground processing systems for other NASA programs, and some lessons learned from those experiences. It then provides high level descriptions of the LCS mission, objectives, organization, architecture, and progress. It discusses some of our development tenets, including our use of standards based design and use of off-the-shelf products whenever possible, incremental development cycles, and highly reliable, available, and supportable enterprise class system servers. It concludes with some new lessons learned and our plans for the future.

  16. Launching the Future... Constellation Program at KSC

    NASA Technical Reports Server (NTRS)

    Denson, Erik C.

    2010-01-01

    With the Constellation Program, NASA is entering a new age of space exploration that will take us back to the Moon, to Mars, and beyond, and NASA is developing the new technology and vehicles to take us there. At the forefront are the Orion spacecraft and the Ares I launch vehicle. As NASA's gateway to space, Kennedy Space Center (KSC) will process and launch the new vehicles. This will require new systems and extensive changes to existing infrastructure. KSC is designing a new mobile launcher, a new launch control system, and new ground support equipment; modifying the Vehicle Assembly Building, one of the launch pads, and other facilities; and launching the Ares I-X flight test. It is an exciting and challenging time to be an engineer at KSC.

  17. Electric Propulsion for Low Earth Orbit Constellations

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; Sankovic, John M.

    1998-01-01

    Hall effect electric propulsion was evaluated for orbit insertion, satellite repositioning, orbit maintenance and de-orbit applications for a sample low earth orbit satellite constellation. Since the low masses of these satellites enable multiple spacecraft per launch, the ability to add spacecraft to a given launch was used as a figure of merit. When compared to chemical propulsion, the Hall thruster system can add additional spacecraft per launch using planned payload power levels. One satellite can be added to the assumed four satellite baseline chemical launch without additional mission times. Two or three satellites may be added by providing part of the orbit insertion with the Hall system. In these cases orbit insertion times were found to be 35 and 62 days. Depending, on the electric propulsion scenario, the resulting launch vehicle savings is nearly two, three or four Delta 7920 launch vehicles out of the chemical baseline scenario's eight Delta 7920 launch vehicles.

  18. Constellation-X mirror technology development

    NASA Astrophysics Data System (ADS)

    Zhang, W. W.; Bolognese, J.; Byron, G.; Chang, K. W.; Content, D. A.; Hadjimichael, T. J.; He, Charles; Hill, M. D.; Hong, M.; Lehan, J. P.; Lozipone, L.; Mazzarella, J. M.; McClelland, R.; Nguyen, D. T.; Olsen, L.; Petre, R.; Robinson, D.; Rohrbach, S. O.; Russell, R.; Saha, T. T.; Sharpe, M.; Gubarev, M. V.; Jones, W. D.; O'Dell, S. L.; Davis, W.; Caldwell, D. R.; Freeman, M.; Podgorski, W.; Reid, P. B.

    2008-07-01

    As NASA's next major space X-ray observatory, the Constellation-X mission (Bookbinder et al. 2008) requires mirror assemblies with unprecedented characteristics that cannot be provided by existing optical technologies. In the past several years, the project has supported a vigorous mirror technology development program. This program includes the fabrication of lightweight mirror segments by slumping commercially available thin glass sheets, the support and mounting of these thin mirror segments for accurate metrology, the mounting and attachment of these mirror segments for the purpose of X-ray tests, and development of methods for aligning and integrating these mirror segments into mirror assemblies. This paper describes our efforts and developments in these areas.

  19. Constellation X-Ray Mission and Support

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.; Grady, Jean (Technical Monitor)

    2005-01-01

    This Final Report summarizes work performed by the Smithsonian Astrophysical Observatory (SAO) for NASA Goddard Space Flight Center (GSFC) under Cooperative Agreement NCC5-368. The Agreement is entitled "Constellation X-ray Mission Study and Support." The report covers the full duration of the Agreement which ran from October 1,1998 to October 14,2004. Included in the report is a description of previously unreported work that was performed between October 2003 and the end of the Agreement. For convenience, the previously unreported work is covered first in Section 2.0. Then, an overall summary of all work performed under the Agreement is presented in Section 3. Section 4.0 contains a list of all formal reports that SAO has submitted to GSFC along with publications and presentations at various conferences.

  20. Amidst the Beauty of the Night Sky, Which of the Constellations am I?

    NASA Astrophysics Data System (ADS)

    Herrmann, Kimberly A.

    2011-01-01

    A well known constellation am I- I never set in the northern sky. Native Americans and Greeks, you see, Wrote legends when they recognized me. Two close stars still test for keen eyesight. Two point to the North Star - what a light! Look for my galaxies, you know where. I am ---- -----, the ----- ----! (If you've an answer you'd care to try, Or check out more riddles, please stop by! Note: All my astronomy riddles are copyrighted.)

  1. A mars communication constellation for human exploration and network science

    NASA Astrophysics Data System (ADS)

    Castellini, Francesco; Simonetto, Andrea; Martini, Roberto; Lavagna, Michèle

    2010-01-01

    Zenith Sea Launch rockets in March 2021 and carrying four satellites each. After the entrance in Mars sphere of influence, the single spacecrafts separate and spiral-down with Hall effect thrusters until they reach the final operational orbits in April 2025, at 17,030 km of altitude and 37 deg of inclination. The preliminary design includes 105 kg and 577 W of mass and power margin for each satellite, that can be allocated for scientific payloads. The main challenges of the proposed design are represented by the optical technology development and the connected strict pointing constraints satisfaction, as well as by the Martian constellation operations management. This mission study has therefore shown the possibility of deploying an effective communication infrastructure in Mars orbit employing a small amount of the resources needed for the human exploration programme, additionally providing the chance of performing important scientific research either from orbit or with a network of small rovers carried on-board and deployed on the surface.

  2. Cubesat Constellation Design for Air Traffic Monitoring

    NASA Technical Reports Server (NTRS)

    Nag, Sreeja; Rios, Joseph Lucio; Gerhardt, David; Pham, Camvu

    2015-01-01

    Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. The ADS-B signal, emitted from the aircraft's Mode-S transponder, is currently tracked by terrestrial based receivers but not over remote oceans or sparsely populated regions such as Alaska or the Pacific Ocean. Lack of real-time aircraft time/location information in remote areas significantly hinders optimal planning and control because bigger "safety bubbles" (lateral and vertical separation) are required around the aircraft until they reach radar-controlled airspace. Moreover, it presents a search-and-rescue bottleneck. Aircraft in distress, e.g. Air France AF449 that crashed in 2009, take days to be located or cannot be located at all, e.g. Malaysia Airlines MH370 in 2014. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring and provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data has been obtained from the Future ATM Concepts Evaluation Tool (FACET), developed at NASA Ames Research Center, simulated over the Alaskan airspace over a period of one day. The simulation is driven by MATLAB with satellites propagated and coverage calculated using AGI's Satellite ToolKit(STK10).

  3. RAD-seq data point to a northern origin of the arctic-alpine genus Cassiope (Ericaceae).

    PubMed

    Hou, Yan; Nowak, Michael D; Mirré, Virginia; Bjorå, Charlotte Sletten; Brochmann, Christian; Popp, Magnus

    2016-02-01

    Many arctic-alpine plants display a highly disjunct distribution between the Arctic/Boreal regions and the southern Asian mountains. Two main hypotheses have been proposed to explain the origin of this biogeographic pattern: (1) south-to-north migration in the late Pliocene/early Pleistocene, and (2) north-to-south migration during the Miocene. The genus Cassiope is disjunctly distributed between the Arctic/Boreal regions and the Himalayan-Hengduan Mountains (HHM) and was selected to test these hypotheses. We constructed a fossil-calibrated phylogeny of Ericaceae using two plastid regions to estimate the crown group age of Cassiope, and used sequence data from thousands of loci produced by restriction site associated DNA sequencing (RAD-seq) to reconstruct the phylogeny of Cassiope. We also performed Bayesian divergence time analysis and biogeographic analysis. The Cassiope crown group was estimated to have originated in the Miocene, which predates the onset of Northern hemisphere glaciation. All HHM species formed a clade together with one eastern Siberian species, and this clade was sister to all other Arctic/Boreal species. This topology implies a northern origin of Cassiope, which is confirmed by our biogeographic analysis. Our results thus suggest that the ancient north-to-south migration hypothesis is most consistent with the origin of Cassiope. PMID:26691641

  4. Science and the Constellation Systems Program Office

    NASA Technical Reports Server (NTRS)

    Mendell, Wendell

    2007-01-01

    An underlying tension has existed throughout the history of NASA between the human spaceflight programs and the external scientific constituencies of the robotic exploration programs. The large human space projects have been perceived as squandering resources that might otherwise be utilized for scientific discoveries. In particular, the history of the relationship of science to the International Space Station Program has not been a happy one. The leadership of the Constellation Program Office, created in NASA in October, 2005, asked me to serve on the Program Manager s staff as a liaison to the science community. Through the creation of my position, the Program Manager wanted to communicate and elucidate decisions inside the program to the scientific community and, conversely, ensure that the community had a voice at the highest levels within the program. Almost all of my technical contributions at NASA, dating back to the Apollo Program, has been within the auspices of what is now known as the Science Mission Directorate. However, working at the Johnson Space Center, where human spaceflight is the principal activity, has given me a good deal of incidental contact and some more direct exposure through management positions to the structures and culture of human spaceflight programs. I entered the Constellation family somewhat naive but not uninformed. In addition to my background in NASA science, I have also written extensively over the past 25 years on the topic of human exploration of the Moon and Mars. (See, for example, Mendell, 1985). I have found that my scientific colleagues generally have little understanding of the structure and processes of a NASA program office; and many of them do not recognize the name, Constellation. In many respects, the international ILEWG community is better informed. Nevertheless, some NASA decision processes on the role of science, particularly with respect to the formulation of a lunar surface architecture, are not well known

  5. Does the Constellation Program Offer Opportunities to Achieve Space Science Goals in Space?

    NASA Technical Reports Server (NTRS)

    Thronson, Harley A.; Lester, Daniel F.; Dissel, Adam F.; Folta, David C.; Stevens, John; Budinoff, Jason G.

    2008-01-01

    Future space science missions developed to achieve the most ambitious goals are likely to be complex, large, publicly and professionally very important, and at the limit of affordability. Consequently, it may be valuable if such missions can be upgraded, repaired, and/or deployed in space, either with robots or with astronauts. In response to a Request for Information from the US National Research Council panel on Science Opportunities Enabled by NASA's Constellation System, we developed a concept for astronaut-based in-space servicing at the Earth-Moon L1,2 locations that may be implemented by using elements of NASA's Constellation architecture. This libration point jobsite could be of great value for major heliospheric and astronomy missions operating at Earth-Sun Lagrange points. We explored five alternative servicing options that plausibly would be available within about a decade. We highlight one that we believe is both the least costly and most efficiently uses Constellation hardware that appears to be available by mid-next decade: the Ares I launch vehicle, Orion/Crew Exploration Vehicle, Centaur vehicle, and an airlock/servicing node developed for lunar surface operations. Our concept may be considered similar to the Apollo 8 mission: a valuable exercise before descent by astronauts to the lunar surface.

  6. Guidance and Control System for a Satellite Constellation

    NASA Technical Reports Server (NTRS)

    Bryson, Jonathan Lamar; Cox, James; Mays, Paul Richard; Neidhoefer, James Christian; Ephrain, Richard

    2010-01-01

    A distributed guidance and control algorithm was developed for a constellation of satellites. The system repositions satellites as required, regulates satellites to desired orbits, and prevents collisions. 1. Optimal methods are used to compute nominal transfers from orbit to orbit. 2. Satellites are regulated to maintain the desired orbits once the transfers are complete. 3. A simulator is used to predict potential collisions or near-misses. 4. Each satellite computes perturbations to its controls so as to increase any unacceptable distances of nearest approach to other objects. a. The avoidance problem is recast in a distributed and locally-linear form to arrive at a tractable solution. b. Plant matrix values are approximated via simulation at each time step. c. The Linear Quadratic Gaussian (LQG) method is used to compute perturbations to the controls that will result in increased miss distances. 5. Once all danger is passed, the satellites return to their original orbits, all the while avoiding each other as above. 6. The delta-Vs are reasonable. The controller begins maneuvers as soon as practical to minimize delta-V. 7. Despite the inclusion of trajectory simulations within the control loop, the algorithm is sufficiently fast for available satellite computer hardware. 8. The required measurement accuracies are within the capabilities of modern inertial measurement devices and modern positioning devices.

  7. Probing Dark Energy with Constellation-X

    SciTech Connect

    Rapetti, David; Allen, Steven W.; /KIPAC, Menlo Park

    2006-09-08

    Constellation-X (Con-X) will carry out two powerful and independent sets of tests of dark energy based on X-ray observations of galaxy clusters, providing comparable accuracy to other leading dark energy probes. The first group of tests will measure the absolute distances to clusters, primarily using measurements of the X-ray gas mass fraction in the largest, dynamically relaxed clusters, but with additional constraining power provided by follow-up observations of the Sunyaev-Zel'dovich (SZ) effect. As with supernovae studies, such data determine the transformation between redshift and true distance, d(z), allowing cosmic acceleration to be measured directly. The second, independent group of tests will use the exquisite spectroscopic capabilities of Con-X to determine scaling relations between X-ray observables and mass. Together with forthcoming X-ray and SZ cluster surveys, these data will help to constrain the growth of structure, which is also a strong function of cosmological parameters.

  8. Dark matter or point sources? Utilizing the 1-pt PDF to understand the origin of the GeV excess seen by the Fermi LAT detector

    NASA Astrophysics Data System (ADS)

    Harrison, Natalie; Gaskins, Jennifer; Fermi LAT Collaboration

    2015-04-01

    An excess of gamma rays from the Inner Galaxy in the Fermi LAT data has been identified. This emission has been interpreted as a possible signature of the annihilation of dark matter particles, or as originating from a collection of unresolved point sources, such as gamma-ray millisecond pulsars. We explore the clustering properties of the diffuse emission arising from a population of gamma-ray point sources and from the annihilation of dark matter particles in the halo of the Galaxy using the 1-pt probability distribution function of counts in pixels (1pt-PDF, the number of pixels with a specified number of counts as a function of counts); this approach is also known as fluctuation analysis or P(D) analysis. We analyze the 1-pt PDF of the GeV excess within a +/- 5 degree box around the Galactic Center. For both dark matter and point sources we adopt the spatial distribution and spectrum to fit the GeV excess. We determine the contributions to the 1-pt PDF from the Galactic diffuse and isotropic diffuse emissions, dark matter, and point sources, and discuss the implications of this analysis for the origin of the GeV excess.

  9. Dark matter or point sources? Utilizing the 1-pt PDF to understand the origin of the GeV excess seen by the Fermi LAT detector

    NASA Astrophysics Data System (ADS)

    Harrison, Natalie; Siegal-Gaskins, Jennifer M.

    2015-01-01

    An excess of gamma rays from the Inner Galaxy in the Fermi LAT data has been identified. This emission has been interpreted as a possible signature of the annihilation of dark matter particles, or as originating from a collection of unresolved point sources, such as gamma-ray millisecond pulsars. We explore the clustering properties of the diffuse emission arising from a population of gamma-ray point sources and from the annihilation of dark matter particles in the halo of the Galaxy using the 1-pt probability distribution function of counts in pixels (1pt-PDF, the number of pixels with a specified number of counts as a function of counts); this approach is also known as fluctuation analysis or P(D) analysis. We analyze the 1-pt PDF of the GeV excess within a +/- 5 degree box around the Galactic Center. For both dark matter and point sources we adopt the spatial distribution and spectrum to fit the GeV excess. We determine the contributions to the 1-pt PDF from the Galactic diffuse and isotropic diffuse emission, dark matter, and point sources, and discuss the implications of this analysis for the origin of the GeV excess.

  10. Origins Rock Art and Calendar in Armenia and Anania Shirakatsi

    NASA Astrophysics Data System (ADS)

    Tokhatyan, Karen

    2014-10-01

    A review on the origin of rock art and calendars in Armenia, as well as Anania Shirakatsi's views are given. Astronomy and calendar, formation of the constellations, types of calendars, the Armenian ancient calendar, Armenian Hayk/Orion constellation and corresponding mythological heroes, and further phases of the Armenian calendar are discussed.

  11. Analysis For Monitoring the Earth Science Afternoon Constellation

    NASA Technical Reports Server (NTRS)

    Demarest, Peter; Richon, Karen V.; Wright, Frank

    2005-01-01

    The Earth Science Afternoon Constellation consists of Aqua, Aura, PARASOL, CALIPSO, Cloudsat, and the Orbiting Carbon Observatory (OCO). The coordination of flight dynamics activities between these missions is critical to the safety and success of the Afternoon Constellation. This coordination is based on two main concepts, the control box and the zone-of-exclusion. This paper describes how these two concepts are implemented in the Constellation Coordination System (CCS). The CCS is a collection of tools that enables the collection and distribution of flight dynamics products among the missions, allows cross-mission analyses to be performed through a web-based interface, performs automated analyses to monitor the overall constellation, and notifies the missions of changes in the status of the other missions.

  12. The New Millenium Program ST-5 Mission: Nanosatellite Constellation Trailblazer

    NASA Technical Reports Server (NTRS)

    Slavin, James A.

    1999-01-01

    NASA's New Millenium Program has recently selected the Nanosatellite Constellation Trailblazer (NCT) as its fifth mission (ST-5). NCT will consist of 3 small, very capable and highly autonomous satellites which will be operated as a single "constellation" with minimal ground operations support. Each spacecraft will be approximately 40 cm in diameter by 20 cm in height and weigh only 20 kg. These small satellites will incorporate 8 new technologies essential to the further miniaturization of space science spacecraft which need space flight validation. In this talk we will describe in greater detail the NCT mission concept and goals, the exciting new technologies it will validate, and the role of miniaturized particles and fields sensors in this project. Finally, NCT's pathfinder function for such future NASA missions as Magnetotail Constellation and Inner Magnetosphere Constellation will be discussed.

  13. A Mars Communication Constellation For Human Exploration and Network Science

    NASA Astrophysics Data System (ADS)

    Castellini, Francesco; Lavagna, Michèle; Simonetto, Andrea

    : particular attention has been paid in optimizing the mission analysis and identifying the best power generation solution. Attention has been also focused on the optical communication architecture, strictly connected with the precise attitude control. The resulting solution foresees two propulsion modules to be placed on a C3 0 escape orbit with two launches in March 2021, equipped with gridded ion thrusters capable of the 4.5 Km/s deltaV needed for the Earth-Mars transfer; each module carries four satellites until the entrance in Mars sphere of influence with near-zero relative velocity, where they separate and singularly spiral-down with their own Hall effect thrusters until they reach the final operational orbits, at 17030 km of altitude and 37 deg of inclination. The main challenges of the proposed design are represented by the optical technology development, the constellation operations management and the strict pointing constraints satisfaction imposed by the lasers. The subsystems design of both the spacecrafts and the electric propulsion buses are presented in the paper, that lead to a total margined mass of 3590 kg per launch. The overall constellation has been thought to be fitted into two Zenith SL rockets, that allow more than 410 kg of excess mass per launch, that can be allocated for scientific payloads. Moreover the power requirements of the Hall thrusters in the spiral-in phase largely exceed the total operational requirements, therefore more than 1 kW is available for science payloads on-board each spacecraft even at EOL, after 4 years of transfer and 10 years of operations, and at the maximum Sun-Mars distance. This mission study has therefore shown the possibility of deploying an effective communication infrastructure in Mars orbit employing a small amount of the resources needed for the human exploration programme; moreover the designed constellation of satellites would have enough power and mass margin to perform important scientific research from orbit

  14. Development of a prototype nickel optic for the Constellation-X hard x-ray telescope

    NASA Astrophysics Data System (ADS)

    Romaine, S.; Basso, S.; Bruni, R. J.; Burkert, W.; Citterio, O.; Cotroneo, V.; Engelhaupt, D.; Freyberg, M. J.; Gorenstein, P.; Gubarev, M.; Hartner, G.; Mazzoleni, F.; O'Dell, S.; Pareschi, G.; Ramsey, B. D.; Speegle, C.; Spiga, D.

    2007-09-01

    The Constellation-X mission concept has been streamlined to a single Atlas V 551 configuration. This decision was reached by the project team after considering the increases in launch costs announced in 2006 coupled with the constrained budget environment apparent with the release of the NASA 2007 budget. Along with the Spectroscopy X-ray Telescopes, this new configuration continues to carry a Hard X-ray Telescope (HXT) component, with some modifications to the original requirements to adjust to the new configuration. The total effective area requirement in the 7 - 40 keV band has been reduced, but at the same time the angular resolution requirement has been increased from 1 arcmin to 30 arcsec. The Smithsonian Astrophysical Observatory, Marshall Space Flight Center and Brera Observatory, Italy) have been collaborating to develop and HXT which meets the requirements of Constellation-X. The development work we have been engaged in to produce multilayer coated Electroformed-Nickel-Replicate (ENR) shells is well suited for this new configuration. We report here on results of fabrication and testing of a prototyped optic for the HXT. Full beam illumination X-ray tests, taken at MPE-Panter Test Facility, show that these optics meet the new requirement of 30 arcsec for the streamlined Constellation-X configuration. This report also presents preliminary results from studies using titanium nitride as a release agent to simplify and improve the nickel electroforming replication process.

  15. Space Technology 5: Enabling Future Micro-Sat Constellation Science Missions

    NASA Technical Reports Server (NTRS)

    Carlisle, Candace C.; Webb, Evan H.; Slavin, James A.

    2004-01-01

    The Space Technology 5 (ST-5) Project is part of NASA s New Millennium Program. ST-5 will consist of a constellation of three micro-satellites, each approximately 25 kg in mass. The mission goals are to demonstrate the research-quality science capability of the ST-5 spacecraft, to operate the three spacecraft as a constellation; and to design, develop and flight-validate three capable micro-satellites with new technologies. ST-5 is designed to measurably raise the utility of small satellites by providing high functionality in a low mass, low power, and low volume package. The whole of ST-5 is greater than the sum of its parts: the collection of components into the ST-5 spacecraft allows it to perform the functionality of a larger scientific spacecraft on a micro-satellite platform. The ST-5 mission was originally designed to be launched as a secondary payload into a Geosynchronous Transfer Orbit (GTO). Recently, the mission has been replanned for a Pegasus XL dedicated launch into an elliptical polar orbit. A three-month flight demonstration phase, beginning in March 2006, will validate the ability to perform science measurements, as well as the technologies and constellation operations. ST- 5 s technologies and concepts will then be transferred to future micro-sat science missions.

  16. Space Technology 5: Enabling Future Micro-Sat Constellation Science Missions

    NASA Technical Reports Server (NTRS)

    Carlisle, Candace C.; Webb, Evan H.

    2004-01-01

    The Space Technology 5 (ST-5) Project is part of NASA s New Millennium Program. ST-5 will consist of a constellation of three micro-satellites, each approximately 25 kg in mass. The mission goals are to demonstrate the research-quality science capability of the ST-5 spacecraft; to operate the three spacecraft as a constellation; and to design, develop and flight-validate three capable micro-satellites with new technologies. ST-5 is designed to measurably raise the utility of small satellites by providing high functionality in a low mass, low power, and low volume package. The whole of ST-5 is greater than the sum of its parts: the collection of components into the ST-5 spacecraft allows it to perform the functionality of a larger scientific spacecraft on a micro-satellite platform. The ST-5 mission was originally designed to be launched as a secondary payload into a Geosynchronous Transfer Orbit (GTO). Recently, the mission has been replanned for a Pegasus XL dedicated launch into an elliptical polar orbit. A three-month flight demonstration phase, beginning in March 2006, will validate the ability to perform science measurements, as well as the technologies and constellation operations. ST- 5 s technologies and concepts will then be transferred to future micro-sat science missions.

  17. Test and Verification Approach for the NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Strong, Edward

    2008-01-01

    This viewgraph presentation is a test and verification approach for the NASA Constellation Program. The contents include: 1) The Vision for Space Exploration: Foundations for Exploration; 2) Constellation Program Fleet of Vehicles; 3) Exploration Roadmap; 4) Constellation Vehicle Approximate Size Comparison; 5) Ares I Elements; 6) Orion Elements; 7) Ares V Elements; 8) Lunar Lander; 9) Map of Constellation content across NASA; 10) CxP T&V Implementation; 11) Challenges in CxP T&V Program; 12) T&V Strategic Emphasis and Key Tenets; 13) CxP T&V Mission & Vision; 14) Constellation Program Organization; 15) Test and Evaluation Organization; 16) CxP Requirements Flowdown; 17) CxP Model Based Systems Engineering Approach; 18) CxP Verification Planning Documents; 19) Environmental Testing; 20) Scope of CxP Verification; 21) CxP Verification - General Process Flow; 22) Avionics and Software Integrated Testing Approach; 23) A-3 Test Stand; 24) Space Power Facility; 25) MEIT and FEIT; 26) Flight Element Integrated Test (FEIT); 27) Multi-Element Integrated Testing (MEIT); 28) Flight Test Driving Principles; and 29) Constellation s Integrated Flight Test Strategy Low Earth Orbit Servicing Capability.

  18. 75 FR 2163 - Constellation Energy; Notice of Docketing of Special Nuclear Material License SNM-2505 Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... COMMISSION Constellation Energy; Notice of Docketing of Special Nuclear Material License SNM-2505 Amendment... June 15, 2009, from Constellation Energy (Constellation) to amend its Special Nuclear Material License... will remain the same for this action. An NRC review, documented in a letter to Constellation dated...

  19. Role of fluid mixing and fault-related sulfide in the origin of the Ray Point uranium district, south Texas.

    USGS Publications Warehouse

    Goldhaber, M.B.; Reynolds, R.L.; Rye, R.O.

    1983-01-01

    The Lamprecht and Felder deposits are two of many roll-type uranium deposits hosted by the Miocene Oakville sandstone in the Ray Point district, Live Oak County, S Texas. Both deposits show similar patterns of geochemical zonation and distribution of authigenic iron disulphide minerals, and both appear to be genetically related to the nearby Oakville fault. Distribution of U, Mo and Se are typical of roll-type deposits. Sulphur isotope data indicate four stages of FeS2 mineral formation. Geochemical data suggest that the host sandstone near the Oakville fault is the site of a complex zone of mixing between fault-derived saline brines and oxygenated meteoric water. Conditions were thus provided in this zone for the proliferation of sulphate-reducing bacteria that in turn gave rise to the ore mineralization. A detailed discussion of the geological evolution of these deposits is presented.-J.E.S.

  20. Linking Satellites Via Earth "Hot Spots" and the Internet to Form Ad Hoc Constellations

    NASA Technical Reports Server (NTRS)

    Mandl, Dan; Frye, Stu; Grosvenor, Sandra; Ingram, Mary Ann; Langley, John; Miranda, Felix; Lee, Richard Q.; Romanofsky, Robert; Zaman, Afoz; Popovic, Zoya

    2004-01-01

    As more assets are placed in orbit, opportunities emerge to combine various sets of satellites in temporary constellations to perform collaborative image collections. Often, new operations concepts for a satellite or set of satellites emerge after launch. To the degree with which new space assets can be inexpensively and rapidly integrated into temporary or "ad hoc" constellations, will determine whether these new ideas will be implemented or not. On the Earth Observing 1 (EO-1) satellite, a New Millennium Program mission, a number of experiments were conducted and are being conducted to demonstrate various aspects of an architecture that, when taken as a whole, will enable progressive mission autonomy. In particular, the target architecture will use adaptive ground antenna arrays to form, as close as possible, the equivalent of wireless access points for low earth orbiting satellites. Coupled with various ground and flight software and the Internet. the architecture enables progressive mission autonomy. Thus, new collaborative sensing techniques can be implemented post-launch. This paper will outline the overall operations concept and highlight details of both the research effort being conducted in constellations, mission autonomy and

  1. The Availability of Space Service for Inter-Satellite Links in Navigation Constellations.

    PubMed

    Tang, Yinyin; Wang, Yueke; Chen, Jianyun

    2016-01-01

    Global navigation satellite systems (GNSS) are widely used in low Earth orbit (LEO) satellite navigation; however, their availability is poor for users in medium Earth orbits (MEO), and high Earth orbits (HEO). With the increasing demand for navigation from MEO and HEO users, the inadequate coverage of GNSS has emerged. Inter-satellite links (ISLs) are used for ranging and communication between navigation satellites and can also serve space users that are outside the navigation constellation. This paper aims to summarize their application method and analyze their service performance. The mathematical model of visibility is proposed and then the availability of time division ISLs is analyzed based on global grid points. The BeiDou navigation constellation is used as an example for numerical simulation. Simulation results show that the availability can be enhanced by scheduling more satellites and larger beams, while the presence of more users lowers the availability. The availability of navigation signals will be strengthened when combined with the signals from the ISLs. ISLs can improve the space service volume (SSV) of navigation constellations, and are therefore a promising method for navigation in MEO/HEO spacecraft. PMID:27548181

  2. Symbolics of the constellations of sagittarius and centaurus in russian traditional culture

    NASA Astrophysics Data System (ADS)

    Bagdasarov, R.

    2001-12-01

    Centaurus falls into the category of 'imaginary animals'. The Russian tradition used not only the symbol Sgr (a result of its acquaintance with the circle of Zodiac), but also the symbol Cen, which fact, as we shall demonstrate, is an evidence of certain mythological-astronomical conceptions. Both the constellations Sagittarius (Sgr) and Centaurus (Cen) are usually represented as versions of the picture of a fantastic being, a Centaur, shaped as man from head to waist, and as an animal, mostly, a horse, from waist down. 'Centaurus' (from the Greek word kev (or kevw)) for 'kill' and o, for 'bull') means 'bull killer', and is probably related to the opposition of the zodiacal constellations Taurus and Sagittarius. When the latter begins to rise on to the night sky, the former disappears completely from view. Sagittarius is represented at ancient monuments related to astronomy as a centaur holding a bow and pointing at certain stars. The constellation of Centaurus is also symbolised by a centaur, but holding not a bow, but a staff or a spear in one hand and an 'animal of sacrifice' in the other (Higinus, Astronomica, III, 37, 1; Chernetsov, 1975, Figure 1). The attributes stand for the Peliases Spear (The Mithological Dictionary, 1991), depicted in astrological maps as The Spear of Centaurus1, The Wolf (Lupus), the Panther or the Beast (Flammarion, 1994).

  3. RapidEye constellation relative radiometric accuracy measurement using lunar images

    NASA Astrophysics Data System (ADS)

    Steyn, Joe; Tyc, George; Beckett, Keith; Hashida, Yoshi

    2009-09-01

    The RapidEye constellation includes five identical satellites in Low Earth Orbit (LEO). Each satellite has a 5-band (blue, green, red, red-edge and near infrared (NIR)) multispectral imager at 6.5m GSD. A three-axes attitude control system allows pointing the imager of each satellite at the Moon during lunations. It is therefore possible to image the Moon from near identical viewing geometry within a span of 80 minutes with each one of the imagers. Comparing the radiometrically corrected images obtained from each band and each satellite allows a near instantaneous relative radiometric accuracy measurement and determination of relative gain changes between the five imagers. A more traditional terrestrial vicarious radiometric calibration program has also been completed by MDA on RapidEye. The two components of this program provide for spatial radiometric calibration ensuring that detector-to-detector response remains flat, while a temporal radiometric calibration approach has accumulated images of specific dry dessert calibration sites. These images are used to measure the constellation relative radiometric response and make on-ground gain and offset adjustments in order to maintain the relative accuracy of the constellation within +/-2.5%. A quantitative comparison between the gain changes measured by the lunar method and the terrestrial temporal radiometric calibration method is performed and will be presented.

  4. Amidst the Beauty of the Night Sky, which of the Constellations am I?

    NASA Astrophysics Data System (ADS)

    Herrmann, K. A.

    2012-08-01

    A well known constellation am I- I never set in the northern sky. Native Americans and Greeks, you see, Wrote legends when they recognized me. Two close stars still test for keen eyesight. Two point to the North Star - what a light! Look for my galaxies, you know where. I am ____ _____, the _____ ____! © Kimberly A. Herrmann, 2003) I have loved rhyming poetry ever since I can remember - from Dr. Seuss's Green Eggs and Ham and Maurice Sendak's Chicken Soup with Rice, to the works of Shel Silverstein and Jack Prelutsky. It was not until high school, though, that I realized that I could combine two of my loves - those for poetry and astronomy. Since then, I have written almost 100 astronomical riddles and always attempted to include as much astronomy content as possible - even in the riddles about constellations. Consequently, I have found them effective in teaching or reviewing aspects of astronomy in several venues, including college astronomy courses for non-science majors and events with elementary school students. More recently I have used 23 constellation riddles to create informative and entertaining seating slides that have been playing at Lowell Observatory and the Youngstown Planetarium. I hope to have these slides played at other venues as well and also hope to publish my riddles as a series of books someday.

  5. Mathematical minimum of Geometric Dilution of Precision (GDOP) for dual-GNSS constellations

    NASA Astrophysics Data System (ADS)

    Teng, Yunlong; Wang, Jinling; Huang, Qi

    2016-01-01

    Selecting optimal satellites for positioning calculation is a basic problem for the positioning, navigation and timing (PNT) applications with Global Navigation Satellite System (GNSS), and the Geometric Dilution of Precision (GDOP) is a key index to handle this problem. In general, the lower the GDOP values are, the more accurate the PNT solution is. Therefore, the minimum value of GDOP should be pursued. In this paper, we focused on the five-satellite as at least five satellites are required for dual-GNSS constellations. Utilizing the characteristics of matrix partial orders, the mathematical minimum of GDOP in the five-satellite case together with the optimal distribution of the five satellites has been theoretically derived. Furthermore, from a theoretical point of view, the detailed expressions of the impact of different constellational combinations of these satellites on the GDOP have been obtained. The results demonstrated that, for dual-GNSS, even if the geometric distribution of the five satellites is fixed, different constellational combinations of these satellites lead to different values of GDOP. This is different from the single-GNSS case.

  6. Enhancing comprehensive inversions using the Swarm constellation

    NASA Astrophysics Data System (ADS)

    Sabaka, T. J.; Olsen, N.

    2006-04-01

    This paper reports on the findings of a simulation study designed to test various satellite configurations sug-gested for the upcoming Swarm magnetic mapping mission. The test is to see whether the mission objectives of recovering small-scale core secular variation (SV) and lithospheric magnetic signals, as well as information about mantle conductivity structure, can be met. The recovery method used in this paper is known as com-prehensive inversion (CI) and involves the parameterization of all major fields followed by a co-estimation of these parameters in a least-squares sense in order to achieve proper signal separation. The advantage of co-estimation over serial estimation of parameters is demonstrated by example. Synthetic data were calculated for a pool of six Swarm satellites from a model based heavily on the CM4 comprehensive model, but which has more small-scale lithospheric structure, a more complicated magnetospheric field, and an induced field reflecting a 3-D conductivity model. These data also included realistic magnetic noise from spacecraft and payload. Though the parameterization for the CI is based upon that of CM4, modifications have been made to accommodate these new magnetospheric and induced fields, in particular with orthogonality constraints defined so as to avoid covariance between slowly varying induced fields and SV. The use of these constraints is made feasible through an efficient numerical implementation. Constellations of 4, 3, 2, and 1 satellites were considered; that with 3 was able to meet the mission objectives, consistently resolving the SV to about spherical harmonic (SH) degree n = 15 and the lithosphere to a limited n < 90 due to external field leakage, while those with 2 and 1 were not; 4 was an improvement over 3, but was much less than the improvement from 2 to 3. The resolution of the magnetospheric and induced SH time-series from the 3 satellite configuration was sufficient enough to allow the detection of 3-D mantle

  7. Characteristics of Signals Originating near the Lithium-Diffused N+ Contact of High Purity Germanium P-Type Point Contact Detectors

    SciTech Connect

    Aguayo, E.; Amman, M.; Avignone, F. T.; Barton, P. J.; Beene, James R; Bertrand Jr, Fred E; Boswell, M.; Brudanin, V.; Busch, M.; Chan, Y-D; Christofferson, C. D.; Collar, Juan I.; Combs, D. C.; Detwiler, J.A.; Doe, P. J.; Efremenko, Yuri; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J.E.; Fields, N.; Finnerty, P.; Gehman, V. M.; Giovanetti, G. K.; Green, M. P.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hoppe, E.W.; Horton, M.; Howard, S.; Howe, M. A.; Keeter, K.J.; Kidd, M. F.; Knecht, A.; Kochetov, O.; Konovalov, S.I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Looker, Q.; Luke, P.N.; MacMullin, S.; Martin, R.D.; Merriman, J. H.; Miller, M. L.; Mizouni, L.; Orrell, John L.; Overman, N. R.; Perumpilly, G.; Phillips II, D. G.; et al.

    2013-01-01

    A study of signals originating near the lithium-diffused n+ contact of p-type point contact (PPC) high purity germanium detectors (HPGe) is presented. The transition region between the active germanium and the fully dead layer of the n+ contact is examined. Energy depositions in this transition region are shown to result in partial charge collection. This provides a mechanism for events with a well defined energy to contribute to the continuum of the energy spectrum at lower energies. A novel technique to quantify the contribution from this source of background is introduced. Experiments that operate germanium detectors with a very low energy threshold may benefit from the methods presented herein.

  8. Dark Energy, Dark Matter and Science with Constellation-X

    NASA Technical Reports Server (NTRS)

    Cardiff, Ann Hornschemeier

    2005-01-01

    Constellation-X, with more than 100 times the collecting area of any previous spectroscopic mission operating in the 0.25-40 keV bandpass, will enable highthroughput, high spectral resolution studies of sources ranging from the most luminous accreting supermassive black holes in the Universe to the disks around young stars where planets form. This talk will review the updated Constellation-X science case, released in booklet form during summer 2005. The science areas where Constellation-X will have major impact include the exploration of the space-time geometry of black holes spanning nine orders of magnitude in mass and the nature of the dark energy and dark matter which govern the expansion and ultimate fate of the Universe. Constellation-X will also explore processes referred to as "cosmic feedback" whereby mechanical energy, radiation, and chemical elements from star formation and black holes are returned to interstellar and intergalactic medium, profoundly affecting the development of structure in the Universe, and will also probe all the important life cycles of matter, from stellar and planetary birth to stellar death via supernova to stellar endpoints in the form of accreting binaries and supernova remnants. This talk will touch upon all these areas, with particular emphasis on Constellation-X's role in the study of Dark Energy.

  9. Realistic Covariance Prediction for the Earth Science Constellation

    NASA Technical Reports Server (NTRS)

    Duncan, Matthew; Long, Anne

    2006-01-01

    Routine satellite operations for the Earth Science Constellation (ESC) include collision risk assessment between members of the constellation and other orbiting space objects. One component of the risk assessment process is computing the collision probability between two space objects. The collision probability is computed using Monte Carlo techniques as well as by numerically integrating relative state probability density functions. Each algorithm takes as inputs state vector and state vector uncertainty information for both objects. The state vector uncertainty information is expressed in terms of a covariance matrix. The collision probability computation is only as good as the inputs. Therefore, to obtain a collision calculation that is a useful decision-making metric, realistic covariance matrices must be used as inputs to the calculation. This paper describes the process used by the NASA/Goddard Space Flight Center's Earth Science Mission Operations Project to generate realistic covariance predictions for three of the Earth Science Constellation satellites: Aqua, Aura and Terra.

  10. Risk to space sustainability from large constellations of satellites

    NASA Astrophysics Data System (ADS)

    Bastida Virgili, B.; Dolado, J. C.; Lewis, H. G.; Radtke, J.; Krag, H.; Revelin, B.; Cazaux, C.; Colombo, C.; Crowther, R.; Metz, M.

    2016-09-01

    The number of artificial objects in orbit continues to increase and, with it, a key threat to space sustainability. In response, space agencies have identified a set of mitigation guidelines aimed at enabling space users to reduce the generation of space debris by, for example, limiting the orbital lifetime of their spacecraft and launcher stages after the end of their mission. Planned, large constellations of satellites in low Earth orbit (LEO), though addressing the lack of basic internet coverage in some world regions, may disrupt the sustainability of the space environment enabled by these mitigation practices. We analyse the response of the space object population to the introduction of a large constellation conforming to the post-mission disposal guideline with differing levels of success and with different disposal orbit options. The results show that a high success rate of post-mission disposal by constellation satellites is a key driver for space sustainability.

  11. Design and Implementation of Satellite Formations and Constellations

    NASA Technical Reports Server (NTRS)

    Folta, David; Newman, Lauri Kraft; Quinn, David

    1998-01-01

    The direction to develop small low cost spacecraft has led many scientists to recognize the advantage of flying spacecraft in constellations and formations to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, constellations and formation flying impose additional complications on orbit selection and orbit maintenance, especially when each spacecraft has its own orbit or science requirements. The purpose of this paper is to develop an operational control method for maintenance of these missions. Examples will be taken from the Earth Observing-1 (EO-1) spacecraft that is part of the New Millennium Program (NMP) and from proposed Earth System Science Program Office (ESSPO) constellations. Results can be used to determine the appropriateness of constellations and formation flying for a particular case as well as the operational impacts. Applications to the ESSPO and NMP are highly considered in analysis and applications. After constellation and formation analysis is completed, implementation of a maneuver maintenance strategy becomes the driver. Advances in technology and automation by GSFC's Guidance, Navigation, and Control Center allow more of the burden of the orbit selection and maneuver maintenance to be automated and ultimately placed onboard the spacecraft, mitigating most of the associated operational concerns. This paper presents the GSFC closed-loop control method to fly in either constellations or formations through the use of an autonomous closed loop three-axis navigation control and innovative orbit maintenance support. Simulation results using AutoCon(Trademark) and FreeFlyer(Trademark) with various fidelity levels of modeling and algorithms are presented.

  12. Design and implementation of satellite formations and constellations

    NASA Technical Reports Server (NTRS)

    Folta, David; Newman, Lauri Kraft; Quinn, David

    1998-01-01

    The direction to develop small low cost spacecraft has led many scientists to recognize the advantage of flying spacecraft in constellations and formations to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, constellations and formation flying impose additional complications on orbit selection and orbit maintenance, especially when each spacecraft has its own orbit or science requirements. The purpose of this paper is to develop an operational control method for maintenance of these missions. Examples will be taken from the Earth Observing-1 (EO-1) spacecraft that is part of the New Millennium Program (NMP) and from proposed Earth System Science Program Office (ESSPO) constellations. Results can be used to determine the appropriateness of constellations and formation flying for a particular case as well as the operational impacts. Applications to the ESSPO and NMP are highly considered in analysis and applications. After constellation and formation analysis is completed, implementation of a maneuver maintenance strategy becomes the driver. Advances in technology and automation by GSFC's Guidance, Navigation, and Control Center allow more of the burden of the orbit selection and maneuver maintenance to be automated and ultimately placed onboard the spacecraft, mitigating most of the associated operational concerns. This paper presents the GSFC closed-loop control method to fly in either constellations or formations through the use of an autonomous closed loop three-axis navigation control and innovative orbit maintenance support. Simulation results using AutoCon(TM) and FreeFlyer(TM) with various fidelity levels of modeling and algorithms are presented.

  13. Infusing Stretch Goal Requirements into the Constellation Program

    NASA Technical Reports Server (NTRS)

    Lee, Young H.; Galpin, Roger A.; Ingoldsby, Kevin

    2008-01-01

    In 2004, the Vision for Space Exploration (VSE) was announced by the United States President's Administration in an effort to explore space and to extend a human presence across our solar system. Subsequently, the National Aeronautics and Space Administration (NASA) established the Exploration Systems Mission Directorate (ESMD) to develop a constellation of new capabilities, supporting technologies, and foundational research that allows for the sustained and affordable exploration of space. Then, ESMD specified the primary mission for the Constellation Program to carry out a series of human expeditions, ranging from Low Earth Orbit (LEO) to the surface of Moon, Mars, and beyond for the purposes of conducting human exploration of space. Thus, the Constellation Program was established at the Lyndon B. Johnson Space Center (JSC) to manage the development of the flight and ground infrastructure and systems that can enable continued and extended human access to space. Constellation Program's "Design Objectives" call for an early attention to the program's life cycle costs management through the Program's Need, Goals, and Objectives (NGO) document, which provides the vision, scope, and key areas of focus for the Program. One general policy of the Constellation Program, found in the Constellation Architecture Requirements Document (CARD), states: "A sustainable program hinges on how effectively total life cycle costs are managed. Developmental costs are a key consideration, but total life cycle costs related to the production, processing, and operation of the entire architecture must be accounted for in design decisions sufficiently to ensure future resources are available for ever more ambitious missions into the solar system....It is the intent of the Constellation Program to aggressively manage this aspect of the program using the design policies and simplicity." To respond to the Program's strong desire to manage the program life cycle costs, special efforts were

  14. Small Satellite Constellations: The Future for Operational Earth Observation

    NASA Technical Reports Server (NTRS)

    Stephens, J. Paul

    2007-01-01

    Nanosat, microsat and minisat are low-cost, rapid-response small-satellites built from advanced terrestrial technology. SSTL delivers the benefits of affordable access to space through low-cost, rapid response, small satellites designed and built with state-of-the-art COTS technologies by: a) reducing the cost of entry into space; b) Achieving more missions within fixed budgets; c) making constellations and formation flying financially viable; d) responding rapidly from initial concept to orbital operation; and e) bringing the latest industrial COTS component advances to space. Growth has been stimulated in constellations for high temporal revisit&persistent monitoring and military responsive space assets.

  15. CP Stars - probing stellar surface structure with BRITE Constellation

    NASA Astrophysics Data System (ADS)

    Lüftinger, T.; Weiss, W. W.

    2008-01-01

    More than 170 chemically peculiar (CP) stars will be observable by BRITE Constellation. These stars host a complex interplay of phenomena like strong magnetic fields, chemical diffusion, pulsation and rotation in the same object. Thus they serve as unique stellar laboratories where we can observe the correlation and interaction of these fundamental physical processes. We present here a summary of the unique potentials BRITE Constellation offers to obtain new insights in the atmospheric structure formation and the complex interplay of abundance variations, pulsation and magnetic fields under conditions that could never be reproduced on Earth.

  16. Characteristics of signals originating near the lithium-diffused N+ contact of high purity germanium p-type point contact detectors

    DOE PAGESBeta

    Aguayo, E.; Amman, M.; Avignone, F. T.; Barabash, A. S.; Barton, P. J.; Beene, J. R.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; et al

    2012-11-09

    A study of signals originating near the lithium-diffused n+ contact of p-type point contact (PPC) high purity germanium detectors (HPGe) is presented. The transition region between the active germanium and the fully dead layer of the n+ contact is examined. Energy depositions in this transition region are shown to result in partial charge collection. This provides a mechanism for events with a well defined energy to contribute to the continuum of the energy spectrum at lower energies. A novel technique to quantify the contribution from this source of background is introduced. Furthermore, experiments that operate germanium detectors with a verymore » low energy threshold may benefit from the methods presented herein.« less

  17. Characteristics of signals originating near the lithium-diffused N+ contact of high purity germanium p-type point contact detectors

    SciTech Connect

    Aguayo, E.; Amman, M.; Avignone, F. T.; Barabash, A. S.; Barton, P. J.; Beene, J. R.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Chan, Y. -D.; Christofferson, C. D.; Collar, J. I.; Combs, D. C.; Cooper, R. J.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Fields, N.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Gehman, V. M.; Giovanetti, G. K.; Green, M. P.; Guiseppe, V. E.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hoppe, E. W.; Horton, M.; Howard, S.; Howe, M. A.; Johnson, R. A.; Keeter, K. J.; Kidd, M. F.; Knecht, A.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; Looker, Q.; Luke, P. N.; MacMullin, S.; Marino, M. G.; Martin, R. D.; Merriman, J. H.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; Overman, N. R.; Perumpilly, G.; Phillips, D. G.; Poon, A. W. P.; Radford, D. C.; Rielage, K.; Robertson, R. G. H.; Ronquest, M. C.; Schubert, A. G.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Steele, D.; Strain, J.; Timkin, V.; Tornow, W.; Varner, R. L.; Vetter, K.; Vorren, K.; Wilkerson, J. F.; Yakushev, E.; Yaver, H.; Young, A. R.; Yu, C. -H.; Yumatov, V.

    2012-11-09

    A study of signals originating near the lithium-diffused n+ contact of p-type point contact (PPC) high purity germanium detectors (HPGe) is presented. The transition region between the active germanium and the fully dead layer of the n+ contact is examined. Energy depositions in this transition region are shown to result in partial charge collection. This provides a mechanism for events with a well defined energy to contribute to the continuum of the energy spectrum at lower energies. A novel technique to quantify the contribution from this source of background is introduced. Furthermore, experiments that operate germanium detectors with a very low energy threshold may benefit from the methods presented herein.

  18. Optimal design of the satellite constellation arrangement reconfiguration process

    NASA Astrophysics Data System (ADS)

    Fakoor, Mahdi; Bakhtiari, Majid; Soleymani, Mahshid

    2016-08-01

    In this article, a novel approach is introduced for the satellite constellation reconfiguration based on Lambert's theorem. Some critical problems are raised in reconfiguration phase, such as overall fuel cost minimization, collision avoidance between the satellites on the final orbital pattern, and necessary maneuvers for the satellites in order to be deployed in the desired position on the target constellation. To implement the reconfiguration phase of the satellite constellation arrangement at minimal cost, the hybrid Invasive Weed Optimization/Particle Swarm Optimization (IWO/PSO) algorithm is used to design sub-optimal transfer orbits for the satellites existing in the constellation. Also, the dynamic model of the problem will be modeled in such a way that, optimal assignment of the satellites to the initial and target orbits and optimal orbital transfer are combined in one step. Finally, we claim that our presented idea i.e. coupled non-simultaneous flight of satellites from the initial orbital pattern will lead to minimal cost. The obtained results show that by employing the presented method, the cost of reconfiguration process is reduced obviously.

  19. Video Games, Identity, and the Constellation of Information

    ERIC Educational Resources Information Center

    Martin, Crystle

    2012-01-01

    This article explores the identity of youth in relation to the information sources they choose in the constellation of information of video games, using the massively multiplayer online game "World of Warcraft" as an example. From this study, several identities are recognized that are combinations of the participants skill and level in the game,…

  20. Key issues in constellation design optimization for NGSO satellite systems

    NASA Astrophysics Data System (ADS)

    Wang, Arthur W.

    1998-01-01

    This paper presents various constellation design criteria for satellite systems in non-geostationary orbits (NGSO). Key design parameters, constraints, and tradeoffs are discussed for two classes of orbits: circular and non-circular. Circular orbits, such as the low earth orbits (LEO), the medium earth orbits (MEO), and the highly inclined geosynchronous orbits (IGSO), have equal coverage period for both north and south hemispheres while non-circular orbits such as the various type of elliptical orbits provide more focused coverage period at certain specific geographic locations. Different services require various constraints including delay, power economics, coverage region, frequency sharing, total capacity, satellite and launch-vehicle numbers. Detailed discussion of the relationship between these constraints and constellations are provided. A comparison between a proposed benchmark MEO system with other proposed broadband NGSO satellite systems is presented to demonstrate the importance of constellation design to enhance frequency-sharing capability. A potential ``satellite highway'' accommodating families of elliptical geosynchronous satellites is also presented. This is a novel approach to regulatory NGSO constellations which will facilitate sharing valuable resources of spectrum and useful spatial areas.

  1. Ocean observing satellite study: instrument and satellite constellation architecture options

    NASA Technical Reports Server (NTRS)

    Gerber, A. J.; McGuire, J.; Cunningham, J. D.; Pichel, W. G.

    2002-01-01

    This paper provides: (1) an overview of the set of active and passive instruments identified by the IPO designed to make the ocean measurements including visible and infrared medium and high resolution imagers, radiometers, altimeters, and synthetic aperture radars and (2) the instrument and satellite constellation architecture options studied, and their ability to meet the set of measurement requirements.

  2. The Constellation-X Mission: Science Prospects and Technology Challenges

    NASA Technical Reports Server (NTRS)

    Petre, Robert

    2007-01-01

    This talk will describe the Constellation-X mission. It will present the key scientific goals, relating to strong gravity, dark energy, ultra-dense matter and cosmic structure. The mission configuration will be described. Emphasis will be placed on the design and anticipated implementation of the X-ray mirror system.

  3. Launching Science: Science Opportunities Provided by NASA's Constellation System

    NASA Technical Reports Server (NTRS)

    2008-01-01

    In 2004 NASA began implementation of the first phases of a new space exploration policy. This implementation effort included the development of a new human-carrying spacecraft, known as Orion; the Altair lunar lander; and two new launch vehicles, the Ares I and Ares V rockets.collectively called the Constellation System (described in Chapter 5 of this report). The Altair lunar lander, which is in the very preliminary concept stage, is not discussed in detail in the report. In 2007 NASA asked the National Research Council (NRC) to evaluate the science opportunities enabled by the Constellation System. To do so, the NRC established the Committee on Science Opportunities Enabled by NASA's Constellation System. In general, the committee interpreted "Constellation-enabled" broadly, to include not only mission concepts that required Constellation, but also those that could be significantly enhanced by Constellation. The committee intends this report to be a general overview of the topic of science missions that might be enabled by Constellation, a sort of textbook introduction to the subject. The mission concepts that are reviewed in this report should serve as general examples of kinds of missions, and the committee s evaluation should not be construed as an endorsement of the specific teams that developed the mission concepts or of their proposals. Additionally, NASA has a well-developed process for establishing scientific priorities by asking the NRC to conduct a "decadal survey" for a particular discipline. Any scientific mission that eventually uses the Constellation System will have to be properly evaluated by means of this decadal survey process. The committee was impressed with the scientific potential of many of the proposals that it evaluated. However, the committee notes that the Constellation System has been justified by NASA and selected in order to enable human exploration beyond low Earth orbit.not to enable science missions. Virtually all of the science

  4. 75 FR 53688 - Constellation Mystic Power, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Constellation Mystic Power, LLC; Supplemental Notice That Initial Market... supplemental notice in the above-referenced proceeding of Constellation Mystic Power, LLC's application...

  5. 76 FR 66054 - Exelon Corporation Constellation Energy Group, Inc.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Exelon Corporation Constellation Energy Group, Inc.; Notice of Filing Take notice that, on October 11, 2011, Exelon Corporation and Constellation Energy Group, Inc....

  6. 78 FR 30295 - Constellation Energy Commoditiesgroup, Inc., ENI USA Gas Marketing LLC, Sequent Energy Canada...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ..., and 13-32-LNG] Constellation Energy Commoditiesgroup, Inc., ENI USA Gas Marketing LLC, Sequent Energy........... Constellation Order vacating blanket Energy authority to import/export Commodities natural gas from/to...

  7. VISTA - A Constellation for Real Time Regional Imaging

    NASA Astrophysics Data System (ADS)

    Meerman, Max; Boland, Lee; da Silva Curiel, Alex; Sweeting, Martin, , Sir

    2002-01-01

    The role of satellites in medium and high-resolution reconnaissance of the Earth's surface has been well demonstrated in recent years through missions such as Landsat, SPOT, IKONOS, ImageSat and Quickbird. The market for such data products is well served and likely to become more competitive with further very-high-resolution missions. Whereas commercial markets have concentrated on enhancing resolution, the small satellite sector has concentrated on reducing the cost of data products, and the development of systems providing niche services. One such EO requirement that can be well met by smaller satellites is the need for higher temporal resolution, as this typically requires a large number of satellites to operate as a constellation - thus far financially impractical using conventional EO satellites. Surrey is currently engaged in building its first constellation that will provide daily global coverage at moderate resolution (32-metre GSD and 600km swath) in three spectral bands. Targeted at providing timely quick-look data products for disaster mitigation and monitoring, the constellation comprises 7 satellites in a single orbital plane. Each satellite has a wide swath so that successive satellites progressively cover the entire globe in a single day. The Vista constellation takes this concept a step further, and is proposed for applications requiring near-continuous surveillance of regional activity. By introducing a multiple plane constellation of small Earth observation satellites, it is possible to monitor continuously selected regions anywhere on the globe. The paper describes the system trades and outlines the scope of the performance that could be obtained from such a system. A cost model illustrates that the balance between launch and space segment costs must be reached by considering suitable replacement strategies, and that the system is highly sensitive to requirement creep. Finally, it is shown that the use of cost effective, small satellites leads to

  8. Constellation Program Life-cycle Cost Analysis Model (LCAM)

    NASA Technical Reports Server (NTRS)

    Prince, Andy; Rose, Heidi; Wood, James

    2008-01-01

    The Constellation Program (CxP) is NASA's effort to replace the Space Shuttle, return humans to the moon, and prepare for a human mission to Mars. The major elements of the Constellation Lunar sortie design reference mission architecture are shown. Unlike the Apollo Program of the 1960's, affordability is a major concern of United States policy makers and NASA management. To measure Constellation affordability, a total ownership cost life-cycle parametric cost estimating capability is required. This capability is being developed by the Constellation Systems Engineering and Integration (SE&I) Directorate, and is called the Lifecycle Cost Analysis Model (LCAM). The requirements for LCAM are based on the need to have a parametric estimating capability in order to do top-level program analysis, evaluate design alternatives, and explore options for future systems. By estimating the total cost of ownership within the context of the planned Constellation budget, LCAM can provide Program and NASA management with the cost data necessary to identify the most affordable alternatives. LCAM is also a key component of the Integrated Program Model (IPM), an SE&I developed capability that combines parametric sizing tools with cost, schedule, and risk models to perform program analysis. LCAM is used in the generation of cost estimates for system level trades and analyses. It draws upon the legacy of previous architecture level cost models, such as the Exploration Systems Mission Directorate (ESMD) Architecture Cost Model (ARCOM) developed for Simulation Based Acquisition (SBA), and ATLAS. LCAM is used to support requirements and design trade studies by calculating changes in cost relative to a baseline option cost. Estimated costs are generally low fidelity to accommodate available input data and available cost estimating relationships (CERs). LCAM is capable of interfacing with the Integrated Program Model to provide the cost estimating capability for that suite of tools.

  9. Human Systems Integration in Practice: Constellation Lessons Learned

    NASA Technical Reports Server (NTRS)

    Zumbado, Jennifer Rochlis

    2012-01-01

    NASA's Constellation program provided a unique testbed for Human Systems Integration (HSI) as a fundamental element of the Systems Engineering process. Constellation was the first major program to have HSI mandated by NASA's Human Rating document. Proper HSI is critical to the success of any project that relies on humans to function as operators, maintainers, or controllers of a system. HSI improves mission, system and human performance, significantly reduces lifecycle costs, lowers risk and minimizes re-design. Successful HSI begins with sufficient project schedule dedicated to the generation of human systems requirements, but is by no means solely a requirements management process. A top-down systems engineering process that recognizes throughout the organization, human factors as a technical discipline equal to traditional engineering disciplines with authority for the overall system. This partners with a bottoms-up mechanism for human-centered design and technical issue resolution. The Constellation Human Systems Integration Group (HSIG) was a part of the Systems Engineering and Integration (SE&I) organization within the program office, and existed alongside similar groups such as Flight Performance, Environments & Constraints, and Integrated Loads, Structures and Mechanisms. While the HSIG successfully managed, via influence leadership, a down-and-in Community of Practice to facilitate technical integration and issue resolution, it lacked parallel top-down authority to drive integrated design. This presentation will discuss how HSI was applied to Constellation, the lessons learned and best practices it revealed, and recommendations to future NASA program and project managers. This presentation will discuss how Human Systems Integration (HSI) was applied to NASA's Constellation program, the lessons learned and best practices it revealed, and recommendations to future NASA program and project managers on how to accomplish this critical function.

  10. Vernal Point and Anthropocene

    NASA Astrophysics Data System (ADS)

    Chavez-Campos, Teodosio; Chavez S, Nadia; Chavez-Sumarriva, Israel

    2014-05-01

    The time scale was based on the internationally recognized formal chronostratigraphical /geochronological subdivisions of time: The Phanerozoic Eonathem/Eon; the Cenozoic Erathem/Era; the Quaternary System/Period; the Pleistocene and Holocene Series/Epoch. The Quaternary was divided into: (1) The Pleistocene that was characterized by cycles of glaciations (intervals between 40,000 and 100,000 years). (2) The Holocene that was an interglacial period that began about 12,000 years ago. It was believed that the Milankovitch cycles (eccentricity, axial tilt and the precession of the equinoxes) were responsible for the glacial and interglacial Holocene periods. The magnetostratigraphic units have been widely used for global correlations valid for Quaternary. The gravitational influence of the sun and moon on the equatorial bulges of the mantle of the rotating earth causes the precession of the earth. The retrograde motion of the vernal point through the zodiacal band is 26,000 years. The Vernal point passes through each constellation in an average of 2000 years and this period of time was correlated to Bond events that were North Atlantic climate fluctuations occurring every ≡1,470 ± 500 years throughout the Holocene. The vernal point retrogrades one precessional degree approximately in 72 years (Gleissberg-cycle) and approximately enters into the Aquarius constellation on March 20, 1940. On earth this entry was verify through: a) stability of the magnetic equator in the south central zone of Peru and in the north zone of Bolivia, b) the greater intensity of equatorial electrojet (EEJ) in Peru and Bolivia since 1940. With the completion of the Holocene and the beginning of the Anthropocene (widely popularized by Paul Crutzen) it was proposed the date of March 20, 1940 as the beginning of the Anthropocene. The date proposed was correlated to the work presented in IUGG (Italy 2007) with the title "Cusco base meridian for the study of geophysical data"; Cusco was

  11. Exploring the Architectural Tradespace of Severe Weather Monitoring Nanosatellite Constellations

    NASA Astrophysics Data System (ADS)

    Hitomi, N.; Selva, D.; Blackwell, W. J.

    2014-12-01

    MicroMAS-1, a 3U nanosatellite developed by MIT/LL, MIT/SSL, and University of Massachusetts, was launched on July 13, 2014 and is scheduled for deployment from the International Space Station in September. The development of MicroMAS motivates an architectural analysis of a constellation of nanosatellites with the goal of drastically reducing the cost of observing severe storms compared with current monolithic missions such as the Precision and All-Weather Temperature and Humidity (PATH) mission from the NASA Decadal Survey. Our goal is to evolve the instrument capability on weather monitoring nanosatellites to achieve higher performance and better satisfy stakeholder needs. Clear definitions of performance requirements are critical in the conceptual design phase when much of the project's lifecycle cost and performance will be fixed. Ability to perform trade studies and optimization of performance needs with instrument capability will enable design teams to focus on key technologies that will introduce high value and high return on investment. In this work, we approach the significant trades and trends of constellations for monitoring severe storms by applying our rule-based decision support tool. We examine a subset of stakeholder groups listed in the OSCAR online database (e.g., weather, climate) that would benefit from severe storm weather data and their respective observation requirements (e.g. spatial resolution, accuracy). We use ten parameters in our analysis, including atmospheric temperature, humidity, and precipitation. We compare the performance and cost of thousands of different possible constellations. The constellations support hyperspectral sounders that cover different portions of the millimeter-wave spectrum (50-60 GHz, 118GHz, 183GHz) in different orbits, and the performance results are compared against those of the monolithic PATH mission. Our preliminary results indicate that constellations using the hyperspectral millimeter wave sounders can

  12. A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells.

    PubMed

    Hussein, Islam T M; Ma, Eric J; Hill, Nichola J; Meixell, Brandt W; Lindberg, Mark; Albrecht, Randy A; Bahl, Justin; Runstadler, Jonathan A

    2016-07-01

    H9N2 influenza A viruses are on the list of potentially pandemic subtypes. Therefore, it is important to understand how genomic reassortment and genetic polymorphisms affect phenotypes of H9N2 viruses circulating in the wild bird reservoir. A comparative genetic analysis of North American H9N2 isolates of wild bird origin identified a naturally occurring reassortant virus containing gene segments derived from both North American and Eurasian lineage ancestors. The PB2 segment of this virus encodes 10 amino acid changes that distinguish it from other H9 strains circulating in North America. G590S, one of the 10 amino acid substitutions observed, was present in ~12% of H9 viruses worldwide. This mutation combined with R591 has been reported as a marker of pathogenicity for human pandemic 2009 H1N1 viruses. Screening by polymerase reporter assay of all the natural polymorphisms at these two positions identified G590/K591 and S590/K591 as the most active, with the highest polymerase activity recorded for the SK polymorphism. Rescued viruses containing these two polymorphic combinations replicated more efficiently in MDCK cells and they were the only ones tested that were capable of establishing productive infection in NHBE cells. A global analysis of all PB2 sequences identified the K591 signature in six viral HA/NA subtypes isolated from several hosts in seven geographic locations. Interestingly, introducing the K591 mutation into the PB2 of a human-adapted H3N2 virus did not affect its polymerase activity. Our findings demonstrate that a single point mutation in the PB2 of a low pathogenic H9N2 isolate could have a significant effect on viral phenotype and increase its propensity to infect mammals. However, this effect is not universal, warranting caution in interpreting point mutations without considering protein sequence context. PMID:27101787

  13. Methodology and method and appartus for signaling with capacity optimized constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2012-01-01

    Communication systems are described that use geometrically shaped constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. In several embodiments, the geometrically shaped is optimized based upon a capacity measure such as parallel decoding capacity or joint capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel.

  14. Enhancements to TetrUSS for NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Pandya, Mohagna J.; Frink, Neal T.; Abdol-Hamid, Khaled S.; Samareh, Jamshid A,; Parlete, Edward B.; Taft, James R.

    2011-01-01

    The NASA Constellation program is utilizing Computational Fluid Dynamics (CFD) predictions for generating aerodynamic databases and design loads for the Ares I, Ares I-X, and Ares V launch vehicles and for aerodynamic databases for the Orion crew exploration vehicle and its launch abort system configuration. This effort presents several challenges to applied aerodynamicists due to complex geometries and flow physics, as well as from the juxtaposition of short schedule program requirements with high fidelity CFD simulations. NASA TetrUSS codes (GridTool/VGRID/USM3D) have been making extensive contributions in this effort. This paper will provide an overview of several enhancements made to the various elements of TetrUSS suite of codes. Representative TetrUSS solutions for selected Constellation program elements will be shown. Best practices guidelines and scripting developed for generating TetrUSS solutions in a production environment will also be described.

  15. Life Support Requirements and Challenges for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Carasquillo, Robyn

    2007-01-01

    NASA's Constellation Program, which includes the mission objectives of establishing a permanently-manned lunar Outpost, and the exploration of Mars, poses new and unique challenges for human life support systems that will require solutions beyond the Shuttle and International Space Station state of the art systems. In particular, the requirement to support crews for 210 days duration at the lunar outpost with limited resource resupply capability wilt require closed-loop regenerative life support systems with minimal expendables. Planetary environmental conditions such as lunar dust and extreme temperatures, as well as the capability to support frequent and extended-duration EVA's will be particularly challenging. This presentation will summarize the key program and mission life support requirements for the Constellation Program and the unique challenges they present for technology and architecture development.

  16. Science with Constellation-X, Choice of Instrumentation

    NASA Technical Reports Server (NTRS)

    Hornscheimeier, Ann; White, Nicholas; Tananbaum, Harvey; Garcia, Michael; Bookbinder, Jay; Petre, Robert; Cottam, Jean

    2007-01-01

    The Constellation X-ray Observatory is one of the two Beyond Einstein Great Observatories and will provide a 100-fold increase in collecting area in high spectral resolving power X-ray instruments over the Chandra and XMM-Newton gratings instruments. The mission has four main science objectives which drive the requirements for the mission. This contribution to the Garmire celebration conference describes these four science areas: Black Holes, Dark Energy, Missing Baryons, and the Neutron Star Equation of State as well as the requirements flow-down that give rise to the choice of instrumentation and implementation for Constellation-X. As we show, each of these science areas place complementary constraints on mission performance parameters such as collecting area, spectral resolving power, timing resolution, and field of view. The mission's capabilities will enable a great breadth of science, and its resources will be open to the community through its General Observer program.

  17. Realistic Covariance Prediction For the Earth Science Constellations

    NASA Technical Reports Server (NTRS)

    Duncan, Matthew; Long, Anne

    2006-01-01

    Routine satellite operations for the Earth Science Constellations (ESC) include collision risk assessment between members of the constellations and other orbiting space objects. One component of the risk assessment process is computing the collision probability between two space objects. The collision probability is computed via Monte Carlo techniques as well as numerically integrating relative probability density functions. Each algorithm takes as inputs state vector and state vector uncertainty information for both objects. The state vector uncertainty information is expressed in terms of a covariance matrix. The collision probability computation is only as good as the inputs. Therefore, to obtain a collision calculation that is a useful decision-making metric, realistic covariance matrices must be used as inputs to the calculation. This paper describes the process used by NASA Goddard's Earth Science Mission Operations Project to generate realistic covariance predictions for three of the ESC satellites: Aqua, Aura, and Terra

  18. Global communication using a constellation of low earth meridian orbits

    NASA Astrophysics Data System (ADS)

    Oli, P. V. S.; Nagarajan, N.; Rayan, H. R.

    1993-07-01

    The concept of 'meridian orbits' is briefly reviewed. It is shown that, if a satellite in the meridian orbit makes an odd number of revolutions per day, then the satellite passes over the same set of meridians twice a day. Satellites in such orbits pass over the same portion of the sky twice a day and every day. This enables a user to adopt a programmed mode of tracking, thereby avoiding a computational facility for orbit prediction, look angle generation, and auto tracking. A constellation of 38 or more satellites placed in a 1200 km altitude circular orbit is favorable for global communications due to various factors. It is shown that appropriate phasing in right ascension of the ascending node and mean anomaly results in a constellation, wherein each satellite appears over the user's horizon one satellite after another. Visibility and coverage plots are provided to verify the continuous coverage.

  19. Intercalibration of High Frequency Channels on GPM Constellation

    NASA Astrophysics Data System (ADS)

    Ebrahimi, H.; Datta, S.; Jones, L.

    2014-12-01

    The Global Precipitation Measuring (GPM) mission is an international effort to measure precipitation worldwide every three hours. The research objective is to reduce errors in global rainfall estimates associated with temporal/spatial sampling by using a constellation of satellites. Inter-calibration of microwave radiometer channels using the GPM Microwave Imager (GMI) is a challenging task. In GPM constellation we have a combination of cross track and conical scanner sensors, the goal is to make a consistent measurement between all the sensors in this constellation. GMI is a conical scanner and is going to be a reference for the calibration of all the other sensors in the constellation., almost all the sensors with channels lower than 89 GHz are conical scanners, the inter-calibration between conical scanners have been done successfully over years, But for frequencies equal and higher than 89GHz, there is SSMIS on the Defense Meteorological Satellite Program (DMSP) which is a conical scanner, other sensors such as ATMS on AMSU, MHS on NOAA 18, NOAA 19, METOP A and METOP B and SAPHIR on Megha -Tropique , are cross track sensors. For these sensors each Instantaneous Field of View (IFOV) has different Earth incidence angles (EIA) and different slant paths through the atmosphere while conical scanner has constant earth incidence angle for all IFOVs. Here the double difference (DD) technique, which has been successfully applied for imager channel calibration before, has been applied to sounder channels, also the effect of using different surface emissivity models such as Elsasser's and RSS model and atmosphere models such as Rosenkranz and MonoRTM models, in these frequencies has been investigated.

  20. Constellation Program: Lessons Learned. Volume 1; Executive Summary

    NASA Technical Reports Server (NTRS)

    Rhatigan, Jennifer L. (Editor)

    2011-01-01

    This document (Volume I) provides an executive summary of the lessons learned from the Constellation Program. A companion Volume II provides more detailed analyses for those seeking further insight and information. In this volume, Section 1.0 introduces the approach in preparing and organizing the content to enable rapid assimilation of the lessons. Section 2.0 describes the contextual framework in which the Constellation Program was formulated and functioned that is necessary to understand most of the lessons. Context of a former program may seem irrelevant in the heady days of new program formulation. However, readers should take some time to understand the context. Many of the lessons would be different in a different context, so the reader should reflect on the similarities and differences in his or her current circumstances. Section 3.0 summarizes key findings developed from the significant lessons learned at the program level that appear in Section 4.0. Readers can use the key findings in Section 3.0 to peruse for particular topics, and will find more supporting detail and analyses in Section 4.0 in a topical format. Appendix A contains a white paper describing the Constellation Program formulation that may be of use to readers wanting more context or background information. The reader will no doubt recognize some very similar themes from previous lessons learned, blue-ribbon committee reviews, National Academy reviews, and advisory panel reviews for this and other large-scale human spaceflight programs; including Apollo, Space Shuttle, Shuttle/Mir, and the ISS. This could represent an inability to learn lessons from previous generations; however, it is more likely that similar challenges persist in the Agency structure and approach to program formulation, budget advocacy, and management. Perhaps the greatest value of these Constellation lessons learned can be found in viewing them in context with these previous efforts to guide and advise the Agency and its

  1. SCARF - The Swarm Satellite Constellation Application and Research Facility

    NASA Astrophysics Data System (ADS)

    Olsen, Nils

    2014-05-01

    Swarm, a three-satellite constellation to study the dynamics of the Earth's magnetic field and its interactions with the Earth system, has been launched in November 2013. The objective of the Swarm mission is to provide the best ever survey of the geomagnetic field and its temporal evolution, which will bring new insights into the Earth system by improving our understanding of the Earth's interior and environment. In order to take advantage of the unique constellation aspect of Swarm, considerably advanced data analysis tools have been developed. Scientific users will also benefit significantly from derived products, the so-called Level-2 products, that take into account the features of the constellation. The Swarm SCARF (Satellite Constellation Application and Research Facility), a consortium of several research institutions, has been established with the goal of deriving Level-2 products by combination of data from the three satellites, and of the various instruments. A number of Level-2 data products will be offered by this consortium, including various models of the core and lithospheric field, as well as of the ionospheric and magnetospheric field. In addition, derived parameters like mantle conductivity, thermospheric mass density and winds, field-aligned currents, an ionospheric plasma bubble index, the ionospheric total electron content and the dayside equatorial zonal electrical field will be calculated. This service is expected to be operational for a period of at least 5 years. The present paper describes the Swarm input data products (Level-1b and auxiliary data) used by SCARF, the various processing chains of SCARF, and the Level-2 output data products determined by SCARF.

  2. Comet Hale-Bopp in the constellation Andromeda

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Comet Hale-Bopp was photographed in the constellation Andromeda by George Shelton, photographer for The Bionetics Corp., at 8:14 p.m. on March 31, 1997, from Merritt Island, Florida, close to the Kennedy Space Center. During this 24-hour period, Comet Hale- Bopp is making its closest approach to the Sun.

  3. Sea State and Weather Capability for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Barbre, R. E.; Keller, V. W.

    2008-01-01

    Marine weather and related parameters such as wind, ocean wave height and period, air temperature, sea surface temperature, visibility, and potential for icing are critical to the design, operation, and safety of crewed space vehicles. The National Aeronautics and Space Administration's (NASA's) Constellation Program requires detailed assessment of marine weather related parameters that may be encountered during launch, abort, landing, and crew rescue operations for the crewed Axes/Orion space vehicles. This information is required for both space vehicle design and operational purposes. The space vehicles must be designed such that they cam withstand the environment they are likely to encounter. The crewed Axes/Orion space vehicles will launch from NASA's Kennedy Space Center (KSC), Florida for both International Space Station (ISS) missions with 51.6deg inclination orbits and lunar missions with approximately 280 inclination orbits. Since both missions will fly ever the Atlantic Ocean on ascent to orbit and will fly over the Pacific Ocean on descent from orbit, an unlikely but possible emergency abort could require parachuting the Orion capsule and crew into the ocean. This situation could potentially put the crew in an isolated and hazardous environment for severn hours while they await rescue. Therefore, abort, landing, and crew rescue elements of the Constellation Program must address weather related parameters on a global scale. This paper describes buoy measurement data, sea surface temperature satellite data, and sea state computer model data that are being utilized by the Constellation Program to address these design and operational issues.

  4. SCARF - The Swarm Satellite Constellation Application and Research Facility

    NASA Astrophysics Data System (ADS)

    Olsen, N.; Alken, P.; Beggan, C.; Chulliat, A.; Doornbos, E.; Floberghagen, R.; Friis-Christensen, E. A.; Hamilton, B.; Hulot, G.; van den IJssel, J.; Kuvshinov, A. V.; Lesur, V.; Luhr, H.; Macmillan, S.; Maus, S.; Olsen, P. H.; Park, J.; Plank, G.; Ritter, P.; Rother, M.; Sabaka, T. J.; Stolle, C.; Thebault, E.; Thomson, A. W.; Tøffner-Clausen, L.; Velimsky, J.; Visser, P. N.

    2011-12-01

    In order to take advantage of the unique constellation aspect of the Swarm mission, considerably advanced data analysis tools will need to be developed. Scientific use of data from the Swarm mission will also benefit significantly from derived products, the so-called Level-2 products, that take into account the features of the constellation. For this reason ESA has established a "Satellite Constellation Application and Research Facility" (SCARF), in the form of a consortium of several research institutions. A number of Level-2 data products will be offered by this consortium, including various models of the core and lithospheric field, as well as of the ionospheric and magnetospheric field. In addition, derived parameters like mantle conductivity, thermospheric mass density and winds, field-aligned currents, an ionospheric plasma bubble index, the ionospheric total electron content and the dayside equatorial zonal electrical field will be calculated. Following the end of the currently running 30-month development phase, this service is expected to be operational for a period of 5 years after the launch of the Swarm Mission, which is scheduled for summer 2012. All of the derived products will be available through the Swarm Payload Data Ground Segment (PDGS), located at ESRIN, the ESA Centre for Earth Observation in Frascati, Italy.

  5. System design for OFDM systems with high-density constellations

    NASA Astrophysics Data System (ADS)

    Gu, Jian

    2001-10-01

    This paper addresses issues in designing OFDM systems with high-density constellations. To achieve high data throughput, many high-speed OFDM systems such as HiperLAN2 and IEEE 802.11a use high-density constellations such as 64QAM to reach up to 54Mbits/s over a 20 MHz frequency bandwidth. Compared with low-density constellation modulations, OFDM systems using M-QAM (M>=64) are very sensitive to analog circuits/components variations causing so-called I-Q imbalances. Moreover, for the purpose of high integration level and low cost, simple front-end radio/analog architectures such as direct conversion and low-IF are desirable but such architectures are even more sensitive to circuitry and component variation. We have developed a patent-pending technology called IQ-Balancing, which removes the adverse effect of I-Q imbalance and enables OFDM systems to have high tolerance to circuitry and component variations. With IQ-Balancing technology, direct conversion and low-IF architectures become very attractive for high-speed OFDM systems. Exploring further with IQ- balancing technology leads to a simple implementation of software Defined Radio (SDR).

  6. Optimal Orbit Design for the Magnetospheric Imaging Constellation

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The Magnetospheric Imaging Constellation (MagIC) is a NASA space science concept to study the Earth's Magnetosphere. The concept proposes to apply tomography techniques using an array of spacecraft to obtain three dimensional images of the Earth's magnetosphere. This paper presents an optimal orbit design to ensure that the constellation is in the desired region of the magnetosphere for maximum time. The solution is found using a steepest descent optimization algorithm that takes into account perturbations from the non-spherical Earth, drag, Sun, Moon and other significant bodies. The solution also satisfies constraints on maximum eclipse duration and geometry constraints to allow an adequate GPS navigation solution. We present three solutions depending upon the epoch of the primary science: vernal equinox, summer solstice, and a third midway between the vernal equinox and summer solstice. Orbit insertion is also considered. All spacecraft are assumed to be launched on a single vehicle into a nominal orbit and the (Delta)V's to achieve the nominal orbit are presented. After insertion into the nominal orbit, each spacecraft undergoes a phasing maneuver to place it in the appropriate position with respect to the rest of the constellation. We present a minimum fuel approach to maneuver each spacecraft from the nominal orbit into the desired final orbit.

  7. Imaging sensor constellation for tomographic chemical cloud mapping.

    PubMed

    Cosofret, Bogdan R; Konno, Daisei; Faghfouri, Aram; Kindle, Harry S; Gittins, Christopher M; Finson, Michael L; Janov, Tracy E; Levreault, Mark J; Miyashiro, Rex K; Marinelli, William J

    2009-04-01

    A sensor constellation capable of determining the location and detailed concentration distribution of chemical warfare agent simulant clouds has been developed and demonstrated on government test ranges. The constellation is based on the use of standoff passive multispectral infrared imaging sensors to make column density measurements through the chemical cloud from two or more locations around its periphery. A computed tomography inversion method is employed to produce a 3D concentration profile of the cloud from the 2D line density measurements. We discuss the theoretical basis of the approach and present results of recent field experiments where controlled releases of chemical warfare agent simulants were simultaneously viewed by three chemical imaging sensors. Systematic investigations of the algorithm using synthetic data indicate that for complex functions, 3D reconstruction errors are less than 20% even in the case of a limited three-sensor measurement network. Field data results demonstrate the capability of the constellation to determine 3D concentration profiles that account for ~?86%? of the total known mass of material released. PMID:19340137

  8. Launching Science: Science Opportunities Provided by NASA's Constellation System

    NASA Astrophysics Data System (ADS)

    Committee On Science Opportunities Enabled By NASA's Constellation System National Research Board

    In January 2004 NASA was given a new policy direction known as the Vision for Space Exploration. That plan, now renamed the United States Space Exploration Policy, called for sending human and robotic missions to the Moon, Mars, and beyond. In 2005 NASA outlined how to conduct the first steps in implementing this policy and began the development of a new human-carrying spacecraft known as Orion, the lunar lander known as Altair, and the launch vehicles Ares I and Ares V. Collectively, these are called the Constellation System. In November 2007 NASA asked the National Research Council (NRC) to evaluate the potential for new science opportunities enabled by the Constellation System of rockets and spacecraft. The NRC committee evaluated a total of 17 mission concepts for future space science missions. Of those, the committee determined that 12 would benefit from the Constellation System and five would not. This book presents the committee's findings and recommendations, including cost estimates, a review of the technical feasibility of each mission, and identification of the missions most deserving of future study.

  9. The Science Goals of the Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.; Tananbaum, Harvey; Weaver, Kimberly; Petre, Robert; Bookbinder, Jay

    2004-01-01

    The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution spectroscopy. The mission will also perform routine high- resolution X-ray spectroscopy of faint and extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity, and ionization state for a wide range of astrophysical problems. This has enormous potential for the discovery of new unexpected phenomena. The Constellation-X mission is a high priority in the National Academy of Sciences McKee-Taylor Astronomy and Astrophysics Survey of new Astrophysics Facilities for the first decade of the 21st century.

  10. Learning Curve for Teaching Constellations in a Planetarium

    NASA Astrophysics Data System (ADS)

    Hintz, Eric G.; Smith, N.; Moody, J. W.; Stephens, D. C.; Joner, M. D.; Hintz, M.; Lawler, J.; Jones, M.; Bench, N.

    2014-01-01

    As part of a larger project we have examined how students learn constellations in a planetarium environment. Students in our introductory descriptive astronomy class were given a 50 object quiz before any instruction. This quiz includes 30 constellations, 17 bright stars, two star clusters, and the Orion Nebula. In addition we gathered a small set of demographic information. After the initial quiz we tracked student scores through the semester to see how long it took for them to learn all 50 objects. We also plan to give a follow-up constellation quiz to students who have previously taken the quiz to test for retention. This will cover a time line for 6 months up to 4 years. We will present our early results from this study. This data will also be used as a baseline for a study of Head Mounted Displays to teach a deaf audience in a planetarium. This work is partially supported by funding from the National Science Foundation grant IIS-1124548 and the Sorenson Foundation.

  11. Results of the Constellation-X Mission Architecture Study

    NASA Astrophysics Data System (ADS)

    Skinner, M. A.; Stober, J. J.; Miller, C. D.

    1999-09-01

    The Constellation X-ray Mission is a proposed high throughput X-ray spectroscopy mission, scheduled to be planned, designed, constructed, launched, and operated in the coming decade. Constellation-X will provide a factor of nearly 100 increase in sensitivity over current high resolution X-ray spectroscopy missions and, in so doing, will obtain high quality spectra for all classes of X-ray sources over a wide range of luminosity and redshift. Cooperatively with the NASA Goddard Space Flight Center and the Smithsonian Astrophysical Observatory, we have carried out a mission architecture study, consisting of a series of preliminary configuration trades, that considered the mission and payload requirements, launch vehicle capabilities, candidate orbits, costs, and instrument accommodation abilities. We generated a small number of concepts that meet the Constellation-X requirements, and have ranked them based on risk and cost considerations. Our concept for the mission architecture design includes a suite of hard and soft X-ray telescopes, to be launched aboard two Evolved Expendable Launch Vehicles (EELV). A fixed optical bench, fixed solar array, and fixed sunshade accommodate the required telescope focal length, and provide for the cryogenic microcalorimeter detectors, as well as the other X-ray instruments. An L2 orbit provides for the thermal requirements of the detectors, and offers other advantages. Below, we illuminate these and other considerations, with an emphasis on the accommodation of the instruments in the observatory.

  12. Peak-to-average power ratio reduction in all-optical orthogonal frequency division multiplexing system using rotated constellation approach

    NASA Astrophysics Data System (ADS)

    Hmood, Jassim K.; Noordin, Kamarul A.; Arof, Hamzah; Harun, Sulaiman W.

    2015-10-01

    In this paper, a new approach for reducing peak-to-average power ratio (PAPR) based on modulated half subcarriers in all-optical OFDM systems with rotated QAM constellation is presented. To reduce the PAPR, the odd subcarriers are modulated with rotated QAM constellation, while the even subcarriers are modulated with standard QAM constellation. The impact of the rotation angle on the PAPR is mathematically modeled. The effect of PAPR reduction on the system performance is investigated by simulating the all-optical OFDM system, which uses optical coupler-based inverse fast Fourier transform (IFFT)/fast Fourier transform (FFT). The all-optical system is numerically demonstrated with 29 subcarriers. Each subcarrier is modulated by a QAM modulator at a symbol rate of 25 Gsymbol/s. The results reveal that PAPR is reduced with increasing the angle of rotation. The PAPR reduction can reach about 0.8 dB when the complementary cumulative distribution function (CCDF) is 1 × 10-3. Furthermore, both the nonlinear phase noise and the optical signal-to-noise ratio (OSNR) of the system are improved in comparison with the original all-optical OFDM without PAPR reduction.

  13. Acquisition through Horizontal Gene Transfer of Plasmid pSMA198 by Streptococcus macedonicus ACA-DC 198 Points towards the Dairy Origin of the Species

    PubMed Central

    Papadimitriou, Konstantinos; Anastasiou, Rania; Maistrou, Eleni; Plakas, Thomas; Papandreou, Nikos C.; Hamodrakas, Stavros J.; Ferreira, Stéphanie; Supply, Philip; Renault, Pierre; Pot, Bruno; Tsakalidou, Effie

    2015-01-01

    Background Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex. Methodology/Principal Findings We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be reported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of the pSMA198 ori in L. lactis revealed a 100% stability of replication over 100 generations. Both pSMA198 and the chromosome of S. macedonicus exhibit a high percentage of potential pseudogenes, indicating that they have co-evolved under the same gene decay processes. We identified chromosomal regions in S. macedonicus that may have originated from pSMA198, also supporting a long co-existence of the two replicons. pSMA198 was also found in divergent biotypes of S. macedonicus and in strains isolated from dispersed geographic locations (e.g. Greece and Switzerland) showing that pSMA198’s acquisition is not a recent event. Conclusions/Significance Here we propose that S. macedonicus acquired plasmid pSMA198 from L. lactis via an ancestral genetic exchange event that took place most probably in milk or dairy products. We provide important evidence that point towards the dairy origin of this species. PMID:25584532

  14. On the Resolving Power of a Single Exact-Repeat Altimetric Satellite or a Coordinated Constellation of Satellites

    NASA Astrophysics Data System (ADS)

    Tai, C.

    2001-12-01

    It is proved that the mid-point grid, which is composed of samples obtained at ground track locations midway between crossover points (thus a subset of the full sampling), has the same resolving power as the full set; i.e., they resolve the same three-dimensional spectral space. The resolving power of the mid-point grid as derived previously by Tai (1995, 1998) is characterized by the Nyquist frequency ω c=π /T (where T is the repeat period of the exact-repeat satellite), and by (in local Cartesian coordinates) the zonal and meridional Nyquist wavenumber kc=2π /X and lc=2π /Y respectively (where X and Y are the east-west and north-south separation between adjacent parallel ground tracks). Here we re-derive this result in simplified terms. First, it is shown through the sampling theorem as demonstrated previously by Tai (1999) that even though samples of the real mid-point grid are not taken simultaneously, they resolve the same frequency range as that of a hypothetical mid-point grid, wherein samples are taken simultaneously at time t=nT (where n is an integer), hence sharing the same Nyquist frequency as cited above. This also reduces the three-dimensional problem to a two-dimensional one. The spatial part of the mid-point grid is a textbook regular grid with zonal and meridional sampling interval of X/2 and Y/2 respectively. As such, the Nyquist wavenumbers are exactly as those stated above. Now with the resolving power of the mid-point grid clearly understood, we are ready to prove that the mid-point grid provides the maximum resolving power. Putting the origin of the xy coordinate system on one of the crossover points, the proof comes in the demonstration that cos(2π x/X) is indistinguishable from cos(2π y/Y) along track; i.e., along-track samples are unable to distinguish the cosine part of the spectral component k=+/-kc, l=0 from that of the spectral component k=0, l=+/-lc. Thus any spatial spectral range containing both of these spectral components

  15. Microscopic origin of the 1.3 G{sub 0} conductance observed in oxygen-doped silver quantum point contacts

    SciTech Connect

    Tu, Xingchen; Wang, Minglang; Hou, Shimin; Sanvito, Stefano

    2014-11-21

    Besides the peak at one conductance quantum, G{sub 0}, two additional features at ∼0.4 G{sub 0} and ∼1.3 G{sub 0} have been observed in the conductance histograms of silver quantum point contacts at room temperature in ambient conditions. In order to understand such feature, here we investigate the electronic transport and mechanical properties of clean and oxygen-doped silver atomic contacts by employing the non-equilibrium Green's function formalism combined with density functional theory. Our calculations show that, unlike clean Ag single-atom contacts showing a conductance of 1 G{sub 0}, the low-bias conductance of oxygen-doped Ag atomic contacts depends on the number of oxygen impurities and their binding configuration. When one oxygen atom binds to an Ag monatomic chain sandwiched between two Ag electrodes, the low-bias conductance of the junction always decreases. In contrast, when the number of oxygen impurities is two and the O-O axis is perpendicular to the Ag-Ag axis, the transmission coefficients at the Fermi level are, respectively, calculated to be 1.44 for the junction with Ag(111) electrodes and 1.24 for that with Ag(100) electrodes, both in good agreement with the measured value of ∼1.3 G{sub 0}. The calculated rupture force (1.60 nN for the junction with Ag(111) electrodes) is also consistent with the experimental value (1.66 ± 0.09 nN), confirming that the measured ∼1.3 G{sub 0} conductance should originate from Ag single-atom contacts doped with two oxygen atoms in a perpendicular configuration.

  16. SLR tracking of GNSS constellations for improved future ITRF realizations

    NASA Astrophysics Data System (ADS)

    Pavlis, Erricos C.; Koenig, Daniel; Kuzmicz-Cieslak, Magdalena

    The development of various future products for the Global Geodetic Observing System—GGOS, will rely heavily on the IAG Services that comprise GGOS, and the synergisms that can be built amongst them. The International Terrestrial Reference Frame (ITRF) is the first product that has been since long identified as the prime GGOS contribution by the organization itself, as well as the Services contributing to its development. The ITRF has been pledged to the international community as the GGOS contribution to the greater effort under the auspices of the Global Earth Observation System of Systems (GEOSS). To meet the stringent requirements imposed by the user community, GGOS set strict goals for the accuracy and stability attributes of its products. The goal for the ITRF accuracy in the definition of the origin is 1 mm or better with a temporal stability on the order of 0.1 mm/y, and similar numbers for the scale and orientation components. These goals are based on extensive deliberations within the Earth science community. None of the IAG positioning techniques can achieve this goal alone. In part this is due to the non-observability of certain TRF attributes from each technique. Another reason is the poor and deteriorating state of some of the tracking networks (ground segment) and in the case of SLR, a further limitation is the lack of suitable available targets (space segment). The poor distribution of the aging SLR tracking stations is now being addressed through an international effort to rebuilt the network (along with those of the other techniques) in a well-planned, optimized fashion that will address all of these concerns and ensure full support the GGOS requirements. As far as the rather small number of satellite targets in orbit that are useful for ITRF development, there are multiple in-progress approaches to address this also at the moment. A new cannonball target (LARES) was recently added to the existing two LAGEOS’ and efforts are being made to

  17. Massive pulsating stars observed by BRITE-Constellation. I. The triple system β Centauri (Agena)

    NASA Astrophysics Data System (ADS)

    Pigulski, A.; Cugier, H.; Popowicz, A.; Kuschnig, R.; Moffat, A. F. J.; Rucinski, S. M.; Schwarzenberg-Czerny, A.; Weiss, W. W.; Handler, G.; Wade, G. A.; Koudelka, O.; Matthews, J. M.; Mochnacki, St.; Orleański, P.; Pablo, H.; Ramiaramanantsoa, T.; Whittaker, G.; Zocłońska, E.; Zwintz, K.

    2016-04-01

    modes originate in which component did not succeed, but there is potential for using this method when more BRITE data become available. Conclusions: Agena seems to be one of very few rapidly rotating massive objects with rich p- and g-mode spectra, and precisely known masses. It can therefore be used to gain a better understanding of the excitation of pulsations in relatively rapidly rotating stars and their seismic modeling. Lacking proper mode identification, the pulsation frequencies found in β Cen cannot yet be used to constrain the internal structure of the components, but it may be possible to achieve this in the future with the use of spectroscopy and spectropolarimetry. In particular, these kinds of data can be used for mode identification since they provide new radial velocities. In consequence, they may help to improve the orbital solution, derive more precise masses, magnetic field strength and geometry, inclination angles, and reveal rotation periods. They may also help to assign pulsation frequencies to components. Finally, the case studied here illustrates the potential of BRITE-Constellation data for the detection of rich-frequency spectra of small-amplitude modes in massive pulsating stars. Based on data collected by the BRITE-Constellation satellite mission, built, launched and operated thanks to support from the Austrian Aeronautics and Space Agency and the University of Vienna, the Canadian Space Agency (CSA) and the Foundation for Polish Science & Technology (FNiTP MNiSW) and National Centre for Science (NCN).

  18. The X-ray Microcalorimeter Spectrometer (XMS): A Reference Cryogenic Instrument Design for Constellation-X

    NASA Technical Reports Server (NTRS)

    Whitehouse, Paul L.

    2003-01-01

    Constellation-X, a mission now belonging to the Beyond Einstein initiative, is being planned to inherit the x-ray sky from Chandra, XMM-Newton and Astro-E. The first two of four observatories in the constellation will be launched together in 2013 and followed a year later by the launch of the remaining two. The four will independently orbit the Sun-Earth Lagrange point L2. An instrument compliment resides in the Focal Plane Module (FPM) of each observatory 10 m from the Optics Module and consists of three Hard X-ray Telescope (HXT) detectors, a Reflection Grating Spectrometer (RGS) focal plane CCD camera and an X-ray Microcalorimeter Spectrometer (XMS). Instrument awards are scheduled for early 2006. The reference detector for XMS is a 32 x 32 array of microcalorimetric superconducting Transition Edge Sensors (TES). Each pixel casts a variable resistance in a SQUID based multiplexed readout circuit which is coupled to series SQUID arrays for amplification and finally read out by external electronics. A multi-stage continuous ADR will provide the stable 50 mK desired for the TES array and a stable 1 K for the series SQUID arrays while also lifting thermal parasitic and inefficiency loads to a 6 K cryocooler interface. The 6 K cryocooler is expected to emerge from the joint-project Advanced Cryocooler Technology Development Program (ACTDP) in which Constellation-X is an active participant. Project Pre-Formulation activities are marked by extensive technology development necessitating early, but realistic, thermal and cooling load requirements for ADR and ACTDP-cryocooler design points. Such requirements are driven by the encompassing XMS cryostat and ultimately by the thermal environment imposed by the FPM. It is further desired that the XMS instrument be able to operate on its side in the laboratory, with a warm vacuum shell, during an extensive calibration regime. It is that reference system design of the XMS instrument (microcalorimeter, ADR, cryocooler and

  19. System and antenna design considerations for highly elliptical orbits as applied to the proposed Archimedes Constellation

    NASA Technical Reports Server (NTRS)

    Paynter, C.; Cuchanski, M.

    1995-01-01

    The paper discusses various aspects of the system design for a satellite in a highly elliptical inclined orbit, and presents a number of antenna design options for the proposed Archimedes mission. A satellite constellation was studied for the provision of multi media communication services in the L and S Band for northern latitudes. The inclined elliptical orbit would allow coverage of Europe, America, and East Asia. Using Canada and North America as the baseline coverage area, this paper addresses system considerations such as the satellite configuration and pointing, beam configuration, and requirements for antennas. A trade-off is performed among several antenna candidates including a direct radiating array, a focal-fed reflector, and a single reflector imaging system. Antenna geometry, performance, and beam forming methods are described. The impact of the designs on the antenna deployment is discussed.

  20. Inter-calibrating Brightness Temperatures of a Constellation of Radiometers

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz; Berg, Wesley; Kummerow, Christian; Stout, John

    2006-01-01

    In 2010, the National Aeronautics and Space Agency (NASA) of the U.S.A. and the Japanese Exploration Agency (JAXA) of Japan in cooperation with other U.S. and international partners will launch the Global Precipitation Measurement (GPM) mission. The mission center-piece is a core U.S. provided satellite holding a scanning microwave imager provided by the U.S. A. and a dual-frequency precipitation radar provided by Japan. The core satellite is in a 65 deg inclination (the current Tropical Rainfall Measuring Mission -TRMM is in a 35 deg inclination). Joining the core satellite are a constellation of approximately 8 satellites containing scanning radiometers. The purpose of the constellation is to increase the global sampling capability of the mission. One constellation satellite will be provided by NASA. Some of the constellation radiometers will provided by other U.S. agencies with existing (e.g. SSMI/S) or planned (NPOESS) radiometer assets. International groups have also expressed interest in contributing to the GPM mission including providing radiometer data for the GPM constellation. The use of a heterogeneous group of scanning radiometers each with its own unique purpose, characteristics and calibration offers a significant challenge for combining brightness temperatures or rain retrievals to create meaningful combined global radiometer products. However, the availability of active dual precipitation radar on the GPM core in combination with a well-calibrated radiometer on the same platform offers the possibility of inter-calibrating the constellation radiometers using the core satellite as a calibrator. This paper describes a joint NASA/GSFC and Colorado State University prototype effort at inter-calibrating existing radiometers using such a core calibrator approach. In the prototype, existing radiometers (i.e. SSM/I and AMSR-E) are intercalibrated, as required, using the TRMM Precipitation Radar (PR) and TRMM Microwave Imager (TMI) as the calibration core

  1. The large Curie-point depth and thermal lithospheric thickness of the Yellowstone hotspot: a nonplume model for the origin of the Yellowstone hotspot?

    NASA Astrophysics Data System (ADS)

    Wang, J.; Li, C.

    2012-12-01

    The western United States has experienced extensive magmatism and large-scale extension during the Cenozoic. The most noticeable magmatism since the mid-Miocene has been associated with the Columbia River Flood Basalts (CRFB) and Eastern Snake River Plain hotspot track (ESRP). Most studies postulated that the CRFB and ESRP arise from a mantle plume. We present our recent inversion of Curie-point depth (Zb) of the western United States based on fractal spectral analyses of magnetic anomalies. Our result indicates a shallow Zb in the ESRP and an intermediate Zb in the most area of the CRFB, but a deep Zb (~ 35 km) around the Yellowstone hotspot. We also calculate the Moho temperature and thermal lithospheric thickness to constrain the crustal geothermal state using the 1D stable thermal conduction equation with a temperature-dependent thermal conductivity model, taking the Curie temperature of 550°C as one of the boundary conditions. The thermal lithospheric thickness around the Yellowstone is about 100 km. Both the deep Zb and large thermal lithospheric thickness in the Yellowstone are not in line with a mantle plume model for the origin of Yellowstone hotspot. In addition, the imaged Moho temperature is low, about 570°C, around the Yellowstone caldera. Thus, we favor an upper mantle source for the origin of the Yellowstone hotspot. The extension of the northern Basin and Range Province (B&R) can date back to at least 30 Ma, initiated in an intra-arc and back-arc setting during the steepening of the subducting Farallon slab between 40~20 Ma and then strongly influenced by the lateral traction of the San Andreas transform fault. We prefer that the succeeding extension of the northwestern part of the B&R induced mantle upwelling, which is responsible for the voluminous tholeiitic basalt of the CRFB erupted from ~16.6 Ma in Steens Mountain and almost the coeval eruption of the ESRP at the same position. We also find a lineament and two arc-shaped belts concaving

  2. Multi-Objective Scheduling for the Cluster II Constellation

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.; Giuliano, Mark

    2011-01-01

    This paper describes the application of the MUSE multiobjecctive scheduling framework to the Cluster II WBD scheduling domain. Cluster II is an ESA four-spacecraft constellation designed to study the plasma environment of the Earth and it's magnetosphere. One of the instruments on each of the four spacecraft is the Wide Band Data (WBD) plasma wave experiment. We have applied the MUSE evolutionary algorithm to the scheduling problem represented by this instrument, and the result has been adopted and utilized by the WBD schedulers for nearly a year. This paper describes the WBD scheduling problem, its representation in MUSE, and some of the visualization elements that provide insight into objective value tradeoffs.

  3. Spacecraft autonomy using onboard processing for a SAR constellation mission

    NASA Technical Reports Server (NTRS)

    Sherwood, R. L.; Chien, S.; Castano, R.

    2002-01-01

    The Autonomous Sciencecraft Experiment (ASE) will fly onboard the Air Force TechSat 21 constellation of three spacecraft scheduled for launch in 2006. ASE uses onboard continuous planning, robust task and goal-based execution, model-based mode identification and reconfiguration, and onboard machine learning and pattem recognition to radically increase science retum by enabling intelligent downlink selection and autonomous retargeting. Demonstration of these capabilities in a flight environment will open up tremendous new opportunities in planetary science, space physics, and earth science that would be unreachable without this technology.

  4. Discovery of 4 New Double Stars in Constellation Serpens

    NASA Astrophysics Data System (ADS)

    Schlimmer, Joerg

    2015-01-01

    During observations in the constellation Serpens, four new double stars could be found: USNO B1.0 1007-0241735, USNO B1.0 1004-0244945, USNO B1.0 0950-0252685 and USNO B1.0 0949-0248260. All these double stars are listed as single stars in USNO catalog but can be separated into two components. Separations are between 4 and 10 arc seconds. In 3 cases proper motions are known and comply with Halbwachs' criteria for possible common proper motion pairs.

  5. Reliability of partial ambiguity fixing with multiple GNSS constellations

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Feng, Yanming

    2013-01-01

    Reliable ambiguity resolution (AR) is essential to real-time kinematic (RTK) positioning and its applications, since incorrect ambiguity fixing can lead to largely biased positioning solutions. A partial ambiguity fixing technique is developed to improve the reliability of AR, involving partial ambiguity decorrelation (PAD) and partial ambiguity resolution (PAR). Decorrelation transformation could substantially amplify the biases in the phase measurements. The purpose of PAD is to find the optimum trade-off between decorrelation and worst-case bias amplification. The concept of PAR refers to the case where only a subset of the ambiguities can be fixed correctly to their integers in the integer least squares (ILS) estimation system at high success rates. As a result, RTK solutions can be derived from these integer-fixed phase measurements. This is meaningful provided that the number of reliably resolved phase measurements is sufficiently large for least-square estimation of RTK solutions as well. Considering the GPS constellation alone, partially fixed measurements are often insufficient for positioning. The AR reliability is usually characterised by the AR success rate. In this contribution, an AR validation decision matrix is firstly introduced to understand the impact of success rate. Moreover the AR risk probability is included into a more complete evaluation of the AR reliability. We use 16 ambiguity variance-covariance matrices with different levels of success rate to analyse the relation between success rate and AR risk probability. Next, the paper examines during the PAD process, how a bias in one measurement is propagated and amplified onto many others, leading to more than one wrong integer and to affect the success probability. Furthermore, the paper proposes a partial ambiguity fixing procedure with a predefined success rate criterion and ratio test in the ambiguity validation process. In this paper, the Galileo constellation data is tested with

  6. Development of Constellation-X Optics Technologies at MSFC

    NASA Technical Reports Server (NTRS)

    Odell, S. L.; Jones, W. D.; Smith, W. S.; Ramsey, B. D.

    1999-01-01

    One of the major technological challenges for the Constellation X-ray Mission is the development of light-weight, high-resolution, grazing-incidence optics. NASA's Marshall Space Flight Center is developing and evaluating candidate technologies, based upon full-shell replication off precision mandrels. Here we report on recent progress in meeting the weight and imaging-performance requirements, using very thin, high-strength electroformed nickel alloys. In addition, we briefly describe MSFC's optics fabrication, metrology, and x-ray test facilities.

  7. Development of Constellation-X Optics Technologies at MSFC

    NASA Technical Reports Server (NTRS)

    ODell, S. L.; Jones, W. D.; Smith, W. S.; Ramsey, B. D.; Engelhaupt, D.

    2000-01-01

    One of the major technological challenges for the Constellation X-ray Mission is the development of light-weight, high-resolution, grazing-incidence optics. NASA's Marshall Space Flight Center is developing and evaluating candidate technologies, based upon full-shell replication off precision mandrels. Here we report on recent progress in meeting the weight and imaging-performance requirements, using very thin, high-strength electroformed nickel alloys. In addition, we briefly describe MSFC's optics fabrication, metrology, and x-ray test facilities.

  8. Development of Constellation-X Optics Technologies at MSFC

    NASA Technical Reports Server (NTRS)

    Ramsey, B. D.; ODell, S. L.; Jones, W. D.; Smith, W. S.; Engelhaupt, D.

    2000-01-01

    One of the major technological challenges for the Constellation X-ray Mission is the development of light-weight, high-resolution, grazing-incidence optics. NASA's Marshall Space Flight Center is developing and evaluating candidate technologies, based upon full-shell replication off precision mandrels. Here we report on recent progress in meeting the weight and imaging-performance requirements, using very thin, high- strength electroformed nickel alloys, In addition, we briefly describe MSFC's optics fabrication, metrology, and x-ray test facilities.

  9. Classical and modern control strategies for the deployment, reconfiguration, and station-keeping of the National Aeronautics and Space Administration (NASA) Benchmark Tetrahedron Constellation

    NASA Astrophysics Data System (ADS)

    Capo-Lugo, Pedro A.

    Formation flying consists of multiple spacecraft orbiting in a required configuration about a planet or through Space. The National Aeronautics and Space Administration (NASA) Benchmark Tetrahedron Constellation is one of the proposed constellations to be launched in the year 2009 and provides the motivation for this investigation. The problem that will be researched here consists of three stages. The first stage contains the deployment of the satellites; the second stage is the reconfiguration process to transfer the satellites through different specific sizes of the NASA benchmark problem; and, the third stage is the station-keeping procedure for the tetrahedron constellation. Every stage contains different control schemes and transfer procedures to obtain/maintain the proposed tetrahedron constellation. In the first stage, the deployment procedure will depend on a combination of two techniques in which impulsive maneuvers and a digital controller are used to deploy the satellites and to maintain the tetrahedron constellation at the following apogee point. The second stage that corresponds to the reconfiguration procedure shows a different control scheme in which the intelligent control systems are implemented to perform this procedure. In this research work, intelligent systems will eliminate the use of complex mathematical models and will reduce the computational time to perform different maneuvers. Finally, the station-keeping process, which is the third stage of this research problem, will be implemented with a two-level hierarchical control scheme to maintain the separation distance constraints of the NASA Benchmark Tetrahedron Constellation. For this station-keeping procedure, the system of equations defining the dynamics of a pair of satellites is transformed to take in account the perturbation due to the oblateness of the Earth and the disturbances due to solar pressure. The control procedures used in this research will be transformed from a continuous

  10. X-Ray Testing Constellation-X Optics at MSFC's 100-m Facility

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen; Baker, Markus; Content, David; Freeman, Mark; Glenn, Paul; Gubarev, Mikhail; Hair, Jason; Jones, William; Joy, Marshall

    2003-01-01

    In addition to the 530-m-long X-Ray Calibration Facility (XRCF), NASA's Marshall Space Flight Center (MSFC) operates a 104-m-long (source-to-detector) X-ray-test facility. Originally developed and still occasionally used for stray-light testing of visible-fight optical systems, the so-called "Stray-Light Facility" now serves primarily as a convenient and inexpensive facility for performance evaluation and calibration of X-ray optics and detectors. The facility can accommodate X-ray optics up to about 1-m diameter and 12-m focal length. Currently available electron-impact sources at the facility span the approximate energy range 0.2 to 100 keV, thus supporting testing of soft- and hard-X-ray optics and detectors. Available MSFC detectors are a front-illuminated CCD (charge-coupled device) and a scanning CZT (cadmium--zinc--telluride) detector, with low-energy cut-offs of about 0.8 and 3 keV, respectively. In order to test developmental optics for the Constellation-X Project, led by NASA's Goddard Space Flight Center (GSFC), MSFC undertook several enhancements to the facility. Foremost among these was development and fabrication of a five-degree-of-freedom (5-DoF) optics mount and control system, which translates and tilts the user-provided mirror assembly suspended from its interface plate. Initial Constellation-X tests characterize the performance of the Optical Alignment Pathfinder Two (OAP2) for the large Spectroscopy X-ray Telescope (SXT) and of demonstration mirror assemblies for the Hard X-ray Telescope (HXT). With the Centroid Detector Assembly (CDA), used for precision alignment of the Chandra (nee AXAF) mirrors, the Constellation-X SXT Team optically aligned the individual mirrors of the OAPZ at GSFC. The team then developed set-up and alignment procedures, including transfer of the alignment from the optical alignment facility at GSFC to the X-ray test facility at MSFC, using a reference flat and fiducials. The OAPZ incorporates additional ancillary

  11. Ad hoc CubeSat constellations: Secondary launch coverage and distribution

    NASA Astrophysics Data System (ADS)

    Marinan, A.; Nicholas, A.; Cahoy, K.

    The primary purpose of a constellation is to obtain global measurements with improved spatial and temporal resolution. The small size, low cost, standardized form factor, and increasing availability of commercial parts for CubeSats make them ideal for use in constellations. However, without taking advantage of secondary payload opportunities, it would be costly to launch and distribute a CubeSat constellation into a specific configuration. A cost-effective way to launch a constellation of CubeSats is via consecutive secondary payload launch opportunities, but the resulting constellation would be an ad hoc mix of orbit parameters. We focus on the feasibility of cobbling together constellation-like functionality from multiple secondary payload opportunities. Each participating CubeSat (or set of CubeSats) per launch could have completely different orbital parameters, even without propulsion onboard the CubeSats or intermediate transfer carriers. We look at the ground coverages that could be obtained for a constellation of five to six orbital planes with one to six satellites in each plane. We analyze past and announced future launch opportunities for CubeSats, including launch platforms supported by the NASA Educational Launch of Nanosatellites (ELaNa). We consider combinations of possible launch locations and temporal spacings over the course of one year and simulate the resulting ground coverage patterns and revisit times for an ad hoc constellation using these launch opportunities. We perform this analysis for two separate case studies - one with only US launches and one with both US and non-US opportunities - and vary the number of satellites per orbital plane. Typical CubeSat mission lifetimes and deorbit times for low-altitude orbits are included in these analyses. The ad hoc constellation results are compared to coverage from uniformly-placed LEO constellations and are quantified in terms of revisit time, time to 100% global coverage, and response time. For mu

  12. Constellation Map: Downstream visualization and interpretation of gene set enrichment results

    PubMed Central

    Tamayo, Pablo; Haining, W. Nicholas; Mesirov, Jill P.

    2015-01-01

    Summary: Gene set enrichment analysis (GSEA) approaches are widely used to identify coordinately regulated genes associated with phenotypes of interest. Here, we present Constellation Map, a tool to visualize and interpret the results when enrichment analyses yield a long list of significantly enriched gene sets. Constellation Map identifies commonalities that explain the enrichment of multiple top-scoring gene sets and maps the relationships between them. Constellation Map can help investigators take full advantage of GSEA and facilitates the biological interpretation of enrichment results. Availability: Constellation Map is freely available as a GenePattern module at http://www.genepattern.org. PMID:26594333

  13. High-pressure xenon detector development at Constellation Technology Corporation

    NASA Astrophysics Data System (ADS)

    Austin, Robert A.

    2007-08-01

    Xenon-filled ionization detectors, due to their high atomic number fill gas ( Z=54), moderate densities (˜0.3-0.5 g/cm 3) and good energy resolution (2-4% at 662 keV), fill an important niche between more familiar technologies such as NaI(Tl) scintillators and germanium detectors. Until recently, difficulties with obtaining sufficient xenon purity, reducing microphonic sensitivity, and developing low-noise electronics compatible with small ionization signals have hampered the development of this nuclear detection field. Constellation Technology Corporation, whose experience with xenon detectors goes back to the mid 1990s, has made significant progress in these areas and has developed a commercial line of detectors with active volumes ranging from small (35 g Xe) to large (1400 g Xe). Current applications for Constellation's detectors are principally in the area of defense (Unmanned Aerial Vehicles and Advanced Spectroscopic Portals), but as awareness of this technology grows, it will surely find applications in a much expanded range of fields.

  14. ARGOS: a laser star constellation for the LBT

    NASA Astrophysics Data System (ADS)

    Kanneganti, Shrikrishna; Rabien, Sebastian; Deysenroth, Matthias; Ziegleder, Julian; Gemperlein, Hans; Haug, Marcus

    2010-07-01

    ARGOS is an innovative multi-star adaptive optics system being built for use with LUCIFER on the Large Binocular Telescope (LBT). LUCIFER is a wide field imager and multi-object spectrograph. Using a constellation of laser guide stars permits PSF correction over a wide field in exchange for a relatively small sacrifice in achievable correction. The laser constellation consists of three stars per each of the two eyes of the LBT. The stars are nominally positioned on a circle 2' in radius, but each star can be moved by upto 0.5' in any direction. Nd:YAG (SHG) lasers from InnoLas Laser GmbH are used to create the green (532nm) laser stars, and have an output above 18 W each at the planned pulsing frequency of 10kHz. The lasers are launched using a 40cm telescope and focused at a height of 12 km. The laser system is designed to be optically simple yet configurable. It also provisions for a central sodium laser to be installed later. We detail the characteristics of the laser system and the current state of its development.

  15. Mean thermospheric density estimation derived from satellite constellations

    NASA Astrophysics Data System (ADS)

    Li, Alan; Close, Sigrid

    2015-10-01

    This paper defines a method to estimate the mean neutral density of the thermosphere given many satellites of the same form factor travelling in similar regions of space. A priori information to the estimation scheme include ranging measurements and a general knowledge of the onboard ADACS, although precise measurements are not required for the latter. The estimation procedure seeks to utilize order statistics to estimate the probability of the minimum drag coefficient achievable, and amalgamating all measurements across multiple time periods allows estimation of the probability density of the ballistic factor itself. The model does not depend on prior models of the atmosphere; instead we require estimation of the minimum achievable drag coefficient which is based upon physics models of simple shapes in free molecular flow. From the statistics of the minimum, error statistics on the estimated atmospheric density can be calculated. Barring measurement errors from the ranging procedure itself, it is shown that with a constellation of 10 satellites, we can achieve a standard deviation of roughly 4% on the estimated mean neutral density. As more satellites are added to the constellation, the result converges towards the lower limit of the achievable drag coefficient, and accuracy becomes limited by the quality of the ranging measurements and the probability of the accommodation coefficient. Comparisons are made to existing atmospheric models such as NRLMSISE-00 and JB2006.

  16. Going Beyond Einstein with the Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    White, Nicholas

    2007-01-01

    The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution X-ray spectroscopy.'The mission will also perform routine high-resolution X-ray spectroscopy of faint 2nd extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity; and ionization state for a wide range of astrophysical problems, including new constraints on the Neutron Star equation of state.

  17. Surface Landing Site Weather Analysis for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Altino, Karen M.; Burns, K. L.

    2008-01-01

    Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing of the Ares vehicles to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is art important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface weather conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center (MSFC) Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. This paper wiI1 describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that cab be obtained.

  18. Dynamic replanning on demand of UAS constellations performing ISR missions

    NASA Astrophysics Data System (ADS)

    Stouch, Daniel W.; Zeidman, Ernest; Callahan, William; McGraw, Kirk

    2011-05-01

    Unmanned aerial systems (UAS) have proven themselves to be indispensable in providing intelligence, surveillance, and reconnaissance (ISR) over the battlefield. Constellations of heterogeneous, multi-purpose UAS are being tasked to provide ISR in an unpredictable environment. This necessitates the dynamic replanning of critical missions as weather conditions change, new observation targets are identified, aircraft are lost or equipment malfunctions, and new airspace restrictions are introduced. We present a method to generate coordinated mission plans for constellations of UAS with multiple flight goals and potentially competing objectives, and update them on demand as the operational situation changes. We use a fast evolutionary algorithm-based, multi-objective optimization technique. The updated flight routes maintain continuity by considering where the ISR assets have already flown and where they still need to go. Both the initial planning and replanning take into account factors such as area of analysis coverage, restricted operating zones, maximum control station range, adverse weather effects, military terrain value, and sensor performance. Our results demonstrate that by constraining the space of potential solutions using an intelligently-formed air maneuver network with a subset of potential airspace corridors and navigational waypoints, we can ensure global optimization for multiple objectives considering the situation both before and after the replanning is initiated. We employ sophisticated visualization techniques using a geographic information system to help the user 'look under the hood" of the algorithms to understand the effectiveness and viability of the generated ISR mission plans and identify potential gaps in coverage.

  19. Eight-state trellis-coded optical modulation with signal constellations of four-dimensional M-ary quadrature-amplitude modulation.

    PubMed

    Ishimura, Shota; Kikuchi, Kazuro

    2015-03-01

    We apply the eight-state trellis-coded modulation (TCM) using signal constellations of four-dimensional M-ary quadrature-amplitude modulation (4D-MQAM) to optical communication systems for the first time to our knowledge. In the TCM scheme, the free distance of the trellis diagram is equal to the minimum distance between constellation points in partitioned subsets, which enlarges the coding gain effectively. In fact, its asymptotic power efficiency is 3-dB larger than that of the set-partitioned 4D-MQAM (SP-4D-MQAM) format, while their spectral efficiencies are the same. Such theoretical predictions are confirmed through computer simulations on eight-state TCM with constellations of 4D-4QAM (i.e., 4D quadrature phase-shift keying: 4D-QPSK) and 4D-16QAM. In particular, eight-state TCM with 4D-QPSK constellations is practically important because of its simple encoder structure, relatively low computational cost, and high coding gain against dual-polarization QPSK (DP-QPSK) and SP-4D-QPSK. Through measurements of its bit-error rate (BER) performance, we confirm that the coding gain against DP-QPSK is about 3 dB at BER=10(-3). PMID:25836886

  20. An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation

    NASA Astrophysics Data System (ADS)

    McManus, Lauren

    Lunar science missions such as LADEE and GRAIL achieved unprecedented measurements of the Lunar exosphere and gravity field. These missions were performed with one (LADEE) or two (GRAIL) traditional satellites. The global coverage achieved by these missions could have been greatly enhanced with the use of a constellation of satellites. A constellation of communication satellites at the Moon would also be necessary if a Lunar human base were to be established. Constellations with many satellites are expensive with traditional technology, but have become feasible through the technological advancements and affordability of cubesats. Cubesat constellations allow for full surface coverage in science or communication missions at a reasonable mission cost. Repeat ground track orbits offer interesting options for science or communication constellations, since they provide repeat coverage of the surface at a fixed time between sequential visits. Flower constellations are a family of constellations being studied primarily by Daniele Mortari at Texas A&M; University that make use of repeat ground tracks. Orbital parameters are selected such that the nodal period of the orbit matches the nodal period of the primary body by a factor dependent on the number of days and the number of revolutions to repeat the ground track. All orbits in a flower constellation have identical orbital elements, with the exception of the right ascension of the ascending node (RAAN) and the initial mean anomaly, which are determined based on the desired phasing scheme desired. Flower constellations have thus far primarily been studied at Earth. A flower constellation at the Moon could be quite useful for science or communication purposes. In this scenario, the flower constellation satellites would be small satellites, which introduces many unique challenges. The cubesats would have limited propulsion capability and would need to be deployed from a mothercraft. Orbital maintenance would then be

  1. Solar Occultation Constellation for Retrieving Aerosols and Trace Element Species (SOCRATES): Proposed Mission Concept

    NASA Astrophysics Data System (ADS)

    Gordley, L. L.; Bailey, S. M.

    2015-12-01

    The goal of SOCRATES is to resolve the critical but underexplored role of the upper troposphere/lower stratosphere (UTLS) in climate change. The mission would provide the suite of measurements required to quantify UTLS transport pathways and their contribution to UTLS composition, and to evaluate the radiative forcing implications of changes in UTLS composition forced by expected changes in these pathways as the climate evolves. The discrimination and quantification of UTLS transport pathways requires simultaneous measurement of several key trace gases and aerosols with high precision, accuracy, and vertical resolution. Furthermore, aerosols and clouds, often present in the UTLS, complicate the measurement of trace gases. The SOCRATES sensor is a 23-channel Gas Filter Correlation Radiometer (GFCR), referred to as GLO (GFCR Limb solar Occultation), with heritage from HALOE on UARS, and SOFIE on AIM. GLO measures aerosol extinction from 0.45 to 3.88 μm, important radiatively active gases in the UTLS (H2O, O3, CH4, N2O), key tracers of UTLS transport (HCN, CO, HDO), gases important in stratospheric O3 chemistry (HCl and HF), and temperature from cloud top to 50 km at a vertical resolution of < 1 km. Improved pointing knowledge will provide dramatically better retrieval precision in the UTLS, even in the presence of aerosols, than possible with HALOE. In addition, the GLO form factor is only of order 10% of that of HALOE, and costs for a constellation of GLO sensors is within the cost cap of a NASA Earth Venture mission. The SOCRATES mission concept is a 6-element constellation of autonomous small satellites, each mated with a GLO sensor, and deployed from a single launch vehicle. The SOCRATES/GLO approach reaps the advantages of solar occultation: high precision and accuracy; robust calibration; and high vertical resolution, while mitigating the sparse coverage of a single solar occultation sensor. We present the SOCRATES science case, and key elements of the

  2. Solar Occultation Constellation for Retrieving Aerosols and Trace Element Species (SOCRATES) Mission Concept

    NASA Astrophysics Data System (ADS)

    Bailey, S. M.; Bevilacqua, R. M.; Fish, C. S.; Gordley, L. L.; Fromm, M. D.

    2014-12-01

    The goal of SOCRATES is to quantify the critical role of the upper troposphere/lower stratosphere (UTLS) in the climate system. The mission would provide, for the first time, the suite of measurements required to quantify stratosphere/troposphere exchange (STE) pathways and their contribution to UTLS composition, and to evaluate the radiative forcing implications of potential changes in STE pathways with climate change. The discrimination and quantification of STE pathways requires simultaneous measurement of several key trace gases and aerosols with high precision, accuracy, and vertical resolution. Furthermore, aerosol and clouds, often present in the UTLS, complicate the measurement of trace gases. The SOCRATES sensor is a 23-channel Gas Filter Correlation Radiometer (GFCR), referred to as GLO (GFCR Limb solar Occultation), with heritage from HALOE on UARS, and SOFIE on AIM. GLO measures aerosol extinction from 0.45 to 3.88 μm, important radiatively active gases in the UTLS (H2O, O3, CH4, N2O), key tracers of STE (HCN, CO, HDO), gases important in stratospheric O3 chemistry (HCl and HF), and temperature from cloud top to 50 km at a vertical resolution of 1 km. Improved pointing knowledge will provide dramatically better retrieval precision in the UTLS, even in the presence of aerosols, than possible with HALOE. In addition, the GLO form factor is only a few percent of that of HALOE, and costs for a constellation of GLO sensors is within the cost cap of a NASA Venture mission. The SOCRATES mission concept is an 8-element constellation of autonomous CubeSats, each mated with a GLO sensor, deployed from a single launch vehicle. The SOCRATES/GLO approach reaps the advantages of solar occultation: high precision and accuracy; robust calibration; and high vertical resolution, while mitigating the sparse coverage of a single solar occultation sensor. We present the SOCRATES science case, and key elements of the SOCRATES mission and GLO instrument concepts.

  3. Precipitation from the GPM Microwave Imager and Constellation Radiometers

    NASA Astrophysics Data System (ADS)

    Kummerow, C. D.

    2012-12-01

    Satellite precipitation retrievals are fundamentally underconstrained requiring either implicit or explicit a-prior information to constrain the solutions. The radiometer algorithm being designed for the GPM core and constellation satellites makes this a-priori information explicit in the form of an a-priori database of possible rain structures and a Bayesian retrieval scheme. The a-priori database has its heritage in the TRMM satellite which ushered in an era of active/passive microwave retrievals. Because the output from such retrievals is physically consistent with the rainfall seen by the radar and the brightness temperatures seen by the radiometer, they are ideally suited for the a-priori database. This approach will be repeated for the Global Precipitation Mission, now scheduled for launch in February 2014. Its core satellite will carry a dual frequency radar and state of the art microwave radiometer. This combination of sensors, and the accompanying multi-sensor algorithm will provide a basis for creating the a-priori database for the radiometer only retrievals that is applicable not only to the wider swath of the GPM Microwave Imager (GMI), but to all the constellation radiometers. This talk will present the pre-launch synthesis of various satellite systems to simulate the core satellite retrieval necessary to have a reasonably robust database in place for the launch of the GPM core satellite. The talk will then focus on the implementation of the algorithm itself. This algorithm has a number of advances over previous versions. Most importantly, is the absence of screening routines that previously identified pixels as being raining or non-raining. This was particularly important over land where the surface could easily be mistaken for ice scattering in raining clouds. By having much better controls over the land surface and land surface emissivities, along with robust a-priori databases, the new algorithm relies completely on the Tb signature to determine

  4. Precipitation from the GPM Microwave Imager and Constellation Radiometers

    NASA Astrophysics Data System (ADS)

    Kummerow, Christian; Randel, David; Kirstetter, Pierre-Emmanuel; Kulie, Mark; Wang, Nai-Yu

    2014-05-01

    Satellite precipitation retrievals from microwave sensors are fundamentally underconstrained requiring either implicit or explicit a-priori information to constrain solutions. The radiometer algorithm designed for the GPM core and constellation satellites makes this a-priori information explicit in the form of a database of possible rain structures from the GPM core satellite and a Bayesian retrieval scheme. The a-priori database will eventually come from the GPM core satellite's combined radar/radiometer retrieval algorithm. That product is physically constrained to ensure radiometric consistency between the radars and radiometers and is thus ideally suited to create the a-priori databases for all radiometers in the GPM constellation. Until a robust product exists, however, the a-priori databases are being generated from the combination of existing sources over land and oceans. Over oceans, the Day-1 GPM radiometer algorithm uses the TRMM PR/TMI physically derived hydrometer profiles that are available from the tropics through sea surface temperatures of approximately 285K. For colder sea surface temperatures, the existing profiles are used with lower hydrometeor layers removed to correspond to colder conditions. While not ideal, the results appear to be reasonable placeholders until the full GPM database can be constructed. It is more difficult to construct physically consistent profiles over land due to ambiguities in surface emissivities as well as details of the ice scattering that dominates brightness temperature signatures over land. Over land, the a-priori databases have therefore been constructed by matching satellite overpasses to surface radar data derived from the WSR-88 network over the continental United States through the National Mosaic and Multi-Sensor QPE (NMQ) initiative. Databases are generated as a function of land type (4 categories of increasing vegetation cover as well as 4 categories of increasing snow depth), land surface temperature and

  5. Altered (copy-up) forms of initiator protein pi suppress the point mutations inactivating the gamma origin of plasmid R6K.

    PubMed Central

    Urh, M; Flashner, Y; Shafferman, A; Filutowicz, M

    1995-01-01

    The R6K gamma origin core contains the P2 promoter, whose -10 and -35 hexamers overlap two of the seven binding sites for the R6K-encoded pi protein. Two mutations, P2-201 and P2-203, which lie within the -35 region of P2, are shown to confer a promoter-down phenotype. We demonstrate here that these mutations prevent replication of a gamma origin core plasmid. To determine whether or not the reduced promoter activity caused by these mutations is responsible for their effect on replication, we generated two new mutations (P2-245-6-7 and P2-246) in the -10 hexamer of the P2 promoter. Although these new mutations inhibit P2 activity as much as the P2-201 and P2-203 mutations, they do not prevent replication of the gamma origin core. Therefore, activity of the P2 promoter does not appear to be required for replication. We also show that the inability of the gamma origin to function in the presence of the P2-201 and P2-203 mutations is reversed by the hyperactive variants of pi protein called copy-up pi. This suppression occurs despite the fact that in vivo dimethyl sulfate methylation protection patterns of the gamma origin iterons are identical in cells producing wild-type pi and those producing copy-up pi variants. We discuss how the P2-201 and P2-203 mutations could inhibit replication of the gamma origin core and what mechanisms might allow the copy-up pi mutants to suppress this deficiency. PMID:7592461

  6. Story Constellations: A Narrative Approach to Contextualizing Teachers' Knowledge of School Reform

    ERIC Educational Resources Information Center

    Craig, Cheryl J.

    2007-01-01

    This article traces the roots of narrative research in the social sciences and education, then centers on "story constellations," a version of narrative inquiry that uncovers teachers' knowledge of school reform in context. A fluid form of investigation that unfolds in a three-dimensional inquiry space, story constellations consists of a flexible…

  7. Tabitha's One Teacher Rural School: Insights into the Arts through the Use of a Story Constellation

    ERIC Educational Resources Information Center

    Garvis, Susanne

    2011-01-01

    This paper presents a story constellation about a beginning teacher (who is also the principal) located in a one-teacher school in an isolated community in Queensland, Australia. The constellation documents the teacher's self-efficacy for teaching the arts (music, dance, drama, visual arts and media). Tabitha, the participant, shares insights…

  8. ECLSS and Thermal Systems Integration Challenges Across the Constellation Architecture

    NASA Technical Reports Server (NTRS)

    Carrasquillo, Robyn

    2010-01-01

    As the Constellation Program completes its initial capability Preliminary Design Review milestone for the Initial Capability phase, systems engineering of the Environmental Control and Life Support (ECLS) and Thermal Systems for the various architecture elements has progressed from the requirements to design phase. As designs have matured for the Ares, Orion, Ground Systems, and Extravehicular (EVA) System, a number of integration challenges have arisen requiring analyses and trades, resulting in changes to the design and/or requirements. This paper will address some of the key integration issues and results, including the Orion-to-Ares shared compartment venting and purging, Orion-to-EVA suit loop integration issues with the suit system, Orion-to-ISS and Orion-to-Altair intermodule ventilation, and Orion and Ground Systems impacts from post-landing environments.

  9. Hyperspectral Cubesat Constellation for Rapid Natural Hazard Response

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Huemmrich, Karl; Crum, Gary; Ly, Vuong; Handy, Matthew; Ong, Lawrence

    2015-01-01

    Earth Observing 1 (E0-1) satellite has an imaging spectrometer (hyperspectral) instrument called Hyperion. The satellite is able to image any spot on Earth in the nadir looking direction every 16 days. With slewing of the satellite and allowing for up to a 23 degree view angle, any spot on the Earth can be imaged approximately every 2 to 3 days. EO-1 has been used to track many natural hazards such as wildfires, volcanoes and floods. An enhanced capability that is sought is the ability to image natural hazards in a daily time series for space based imaging spectrometers. The Hyperion can not provide this capability on EO-1 with the present polar orbit. However, a constellation of cubesats, each with the same imaging spectrometer, positioned strategically in the same orbit, can be used to provide daily coverage, cost-effectively.

  10. Fault Management Technology Maturation for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Waterman, Robert D.

    2010-01-01

    This slide presentation reviews the maturation of fault management technology in preparation for the Constellation Program. There is a review of the Space Shuttle Main Engine (SSME) and a discussion of a couple of incidents with the shuttle main engine and tanking that indicated the necessity for predictive maintenance. Included is a review of the planned Ares I-X Ground Diagnostic Prototype (GDP) and further information about detection and isolation of faults using Testability Engineering and Maintenance System (TEAMS). Another system that being readied for use that detects anomalies, the Inductive Monitoring System (IMS). The IMS automatically learns how the system behaves and alerts operations it the current behavior is anomalous. The comparison of STS-83 and STS-107 (i.e., the Columbia accident) is shown as an example of the anomaly detection capabilities.

  11. SAC-C Mission and the Morning Constellation

    NASA Astrophysics Data System (ADS)

    Colomb, F. R.; Alonso, C.; Hofmann, C.; Frulla, L.; Nollmann, I.; Milovich, J.; Kuba, J.; Ares, F.; Kalemkarian, M.

    2002-01-01

    components (ICARE), provided by CNES will permit improvement of risk estimation models for radiation effect on last generation integrated circuit technology. . On June 14th, 2000 CONAE and NASA signed an amendment to the Memorandum of Understanding for the SAC-C mission in order that the SAC-C satellite, were included in a constellation - named "Morning Constellation". It is integrated by USA satellites Landsat 7, EO 1, Terra, and Argentine SAC-C that feature on-board instruments from the United States, Argentina, Denmark, Italy, France, and Japan. The four satellite tracks on the Earth's surface are the same, their orbital height being 705 km and their inclination, 98.21 degrees. They cross the Equator at 10:00, 10:01, 10:15, and 10:30 hours, respectively (local time). Satellites comply with the World Wide Reference System. The Constellation has been working since March 2001 as a single mission and several cooperative activities have been undertaken and will be presented in this paper. Several jointly sponsored technical workshops have been held, and also collaborative spacecraft navigation experiments have been made. One of the objectives of the AM Constellation is the collaboration in the case of emergencies, NASA and CONAE agreed to give preference in those situation in the planification of their satellite acquisitions. From all the possible hazardous events, the most important for the country are fire and floods. In relation to fires, CONAE is presently adapting and developing the algorithms for using MODIS data to generate a fire map product. Additionally research on fire detection is carried out using the data from the HSTC camera. In relation to flooding, CONAE works in cooperation to national institutions providing the data and, in some cases, producing flood extent maps. In particular MMRS data is demonstrating to be very effective due to its spectral and radiometric resolutions, and its large swath which is well suited for extended countries like Argentina.

  12. Spacecraft autonomy using onboard processing for a SAR constellation mission

    NASA Technical Reports Server (NTRS)

    Sherwood, R. L.; Chien, S.; Castano, R.; Rabideau, G.

    2002-01-01

    The Autonomous Sciencecraft Experiment (ASE) will fly onboard the Air Force TechSat 21 constellation of three spacecraft scheduled for launch in 2006. ASE uses onboard continuous planning, robust task and goal-based execution, model-based mode identification and reconfiguration, and onboard machine learning and pattern recognition to radically increase science return by enabling intelligent downlink selection and autonomous retargeting. In this paper we discuss how these AI technologies are synergistically integrated in a hybrid multi-layer control architecture to enable a virtual spacecruft science agent. Demonstration of these capabilities in a flight environment will open up tremendous new opportunities in planetary science, space physics, and earth science that would be unreachable without this technology.

  13. CATIA V5 Virtual Environment Support for Constellation Ground Operations

    NASA Technical Reports Server (NTRS)

    Kelley, Andrew

    2009-01-01

    This summer internship primarily involved using CATIA V5 modeling software to design and model parts to support ground operations for the Constellation program. I learned several new CATIA features, including the Imagine and Shape workbench and the Tubing Design workbench, and presented brief workbench lessons to my co-workers. Most modeling tasks involved visualizing design options for Launch Pad 39B operations, including Mobile Launcher Platform (MLP) access and internal access to the Ares I rocket. Other ground support equipment, including a hydrazine servicing cart, a mobile fuel vapor scrubber, a hypergolic propellant tank cart, and a SCAPE (Self Contained Atmospheric Protective Ensemble) suit, was created to aid in the visualization of pad operations.

  14. High-pressure xenon detector development at Constellation Technology Corporation

    NASA Astrophysics Data System (ADS)

    Austin, Robert A.; Bastian, Lloyd F.

    2006-08-01

    Xenon-filled ionization detectors, due to their high atomic number fill gas (Z=54), moderate densities (~0.3 g/cm 3-0.5 g/cm 3) and good energy resolution (2%-4% at 662 keV), fill an important niche between more familiar technologies such as NaI(Tl) scintillators and Germanium detectors. Until recently, difficulties with obtaining sufficient Xenon purity, reducing microphonic sensitivity, and developing low-noise electronics compatible with small ionization signals have hampered the development of this nuclear detection field. Constellation Technology Corporation, whose experience with xenon detectors goes back to the mid 1990's, has made significant progress in these areas and has developed a commercial line of detectors with active volumes ranging from small (35 g Xe) to large (1400 g Xe). Here we will discuss our development of a mobile, large area, spectroscopic array.

  15. Scale analysis of equatorial plasma irregularities derived from Swarm constellation

    NASA Astrophysics Data System (ADS)

    Xiong, Chao; Stolle, Claudia; Lühr, Hermann; Park, Jaeheung; Fejer, Bela G.; Kervalishvili, Guram N.

    2016-07-01

    In this study, we investigated the scale sizes of equatorial plasma irregularities (EPIs) using measurements from the Swarm satellites during its early mission and final constellation phases. We found that with longitudinal separation between Swarm satellites larger than 0.4°, no significant correlation was found any more. This result suggests that EPI structures include plasma density scale sizes less than 44 km in the zonal direction. During the Swarm earlier mission phase, clearly better EPI correlations are obtained in the northern hemisphere, implying more fragmented irregularities in the southern hemisphere where the ambient magnetic field is low. The previously reported inverted-C shell structure of EPIs is generally confirmed by the Swarm observations in the northern hemisphere, but with various tilt angles. From the Swarm spacecrafts with zonal separations of about 150 km, we conclude that larger zonal scale sizes of irregularities exist during the early evening hours (around 1900 LT).

  16. Constellation Program Mission Operations Project Office Status and Support Philosophy

    NASA Technical Reports Server (NTRS)

    Smith, Ernest; Webb, Dennis

    2007-01-01

    The Constellation Program Mission Operations Project Office (CxP MOP) at Johnson Space Center in Houston Texas is preparing to support the CxP mission operations objectives for the CEV/Orion flights, the Lunar Lander, and and Lunar surface operations. Initially the CEV will provide access to the International Space Station, then progress to the Lunar missions. Initial CEV mission operations support will be conceptually similar to the Apollo missions, and we have set a challenge to support the CEV mission with 50% of the mission operations support currently required for Shuttle missions. Therefore, we are assessing more efficient way to organize the support and new technologies which will enhance our operations support. This paper will address the status of our preparation for these CxP missions, our philosophical approach to CxP operations support, and some of the technologies we are assessing to streamline our mission operations infrastructure.

  17. The Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Content, David; Lehan, John; O'Dell, Stephen; Owens, Scott; Podgorsky, William; Stewart, Jeff; Zhang, William

    2004-01-01

    The status of technology development for the Constellation-X Spectroscopy X-ray Telescope (SXT) mirror is presented. The SXT mirror combines a large (1.6 m) aperture with modest (12 arc sec half power diameter) angular resolution and low mass (750 kg). The overall collecting area, larger than 9,600 square cm at 0.25 keV, requires high throughput, and thus nesting of a substantial number of thin reflectors. A phased development program is underway to develop reflectors, mounting and alignment approaches, and metrology techniques for components and the mirror has a whole. The latest results in all these areas are summarized, along with an overview of results of optical testing of reflector performance.

  18. Waste Collector System Technology Comparisons for Constellation Applications

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.

    2006-01-01

    The Waste Collection Systems (WCS) for space vehicles have utilized a variety of hardware for collecting human metabolic wastes. It has typically required multiple missions to resolve crew usability and hardware performance issues that are difficult to duplicate on the ground. New space vehicles should leverage off past WCS systems. Past WCS hardware designs are substantially different and unique for each vehicle. However, each WCS can be analyzed and compared as a subset of technologies which encompass fecal collection, urine collection, air systems, pretreatment systems. Technology components from the WCS of various vehicles can then be combined to reduce hardware mass and volume while maximizing use of previous technology and proven human-equipment interfaces. Analysis of past US and Russian WCS are compared and extrapolated to Constellation missions.

  19. LAMOST 1: A Disrupted Satellite in the Constellation Draco

    NASA Astrophysics Data System (ADS)

    Vickers, John J.; Smith, Martin C.; Hou, Yonghui; Wang, Yuefei; Zhang, Yong

    2016-01-01

    Using Large Sky Area Multi-object Fibre Spectroscopic Telescope spectroscopic data, we find a strong signal of a comoving group of stars in the constellation of Draco. The group, observed near the apocenter of its orbit, is 2.6 kpc from the Sun with a metallicity of -0.64 dex. The system is observed as a streaming population of unknown provenance with mass of about 2.1+/- 0.4\\cdot {10}4 {M}⊙ and brightness of about {M}V˜ -3.6. Its high metallicity, diffuse physical structure, and eccentric orbit may indicate that the progenitor satellite was a globular cluster rather than a dwarf galaxy or an open cluster.

  20. Constellation Program Electrical Ground Support Equipment Research and Development

    NASA Technical Reports Server (NTRS)

    McCoy, Keegan S.

    2010-01-01

    At the Kennedy Space Center, I engaged in the research and development of electrical ground support equipment for NASA's Constellation Program. Timing characteristics playa crucial role in ground support communications. Latency and jitter are two problems that must be understood so that communications are timely and consistent within the Kennedy Ground Control System (KGCS). I conducted latency and jitter tests using Alien-Bradley programmable logic controllers (PLCs) so that these two intrinsic network properties can be reduced. Time stamping and clock synchronization also play significant roles in launch processing and operations. Using RSLogix 5000 project files and Wireshark network protocol analyzing software, I verified master/slave PLC Ethernet module clock synchronization, master/slave IEEE 1588 communications, and time stamping capabilities. All of the timing and synchronization test results are useful in assessing the current KGCS operational level and determining improvements for the future.

  1. Constellation Stick Figures Convey Information about Gravity and Neutrinos

    NASA Astrophysics Data System (ADS)

    Mc Leod, David Matthew; Mc Leod, Roger David

    2008-10-01

    12/21/98, at America's Stonehenge, DMM detected, and drew, the full stick-figure equivalent of Canis Major, CM, as depicted by our Wolf Clan leaders, and many others. Profound, foundational physics is implied, since this occurred in the Watch House there, hours before the ``model rose.'' Similar configurations like Orion, Osiris of ancient Egypt, show that such figures are projected through solid parts of the Earth, as two-dimensional equivalents of the three-dimensional star constellations. Such ``sticks'' indicate that ``line equivalents'' connect the stars, and the physical mechanism projects outlines detectable by traditional cultures. We had discussed this ``flashlight'' effect, and recognized some of its implications. RDM states that the flashlight is a strong, distant neutrino source; the lines represent neutrinos longitudinally aligned in gravitational excitation, opaque, to earthbound, transient, transversely excited neutrinos. ``Sticks'' represent ``graviton'' detection. Neutrinos' longitudinal alignment accounts for the weakness of gravitational force.

  2. The Apollo Experience Lessons Learned for Constellation Lunar Dust Management

    NASA Technical Reports Server (NTRS)

    Wagner, Sandra

    2006-01-01

    Lunar dust will present significant challenges to NASA's Lunar Exploration Missions. The challenges can be overcome by using best practices in system engineering design. For successful lunar surface missions, all systems that come into contact with lunar dust must consider the effects throughout the entire design process. Interfaces between all these systems with other systems also must be considered. Incorporating dust management into Concept of Operations and Requirements development are the best place to begin to mitigate the risks presented by lunar dust. However, that is only the beginning. To be successful, every person who works on NASA's Constellation lunar missions must be mindful of this problem. Success will also require fiscal responsibility. NASA must learn from Apollo the root cause of problems caused by dust, and then find the most cost-effective solutions to address each challenge. This will require a combination of common sense existing technologies and promising, innovative technical solutions

  3. Space Technology 5: Pathfinder for Future Micro-Sat Constellations

    NASA Technical Reports Server (NTRS)

    Carlisle, Candace; Finnegan, Eric

    2004-01-01

    The Space Technology 5 (ST-5) Project, currently in the implementation phase, is part of the National Aeronautics and Space Administration (NASA) s New Millennium Program (NMP). ST-5 will consist of a constellation of three miniature satellites, each with mass less than 25 kg and size approximately 60 cm by 30 cm. ST-5 addresses technology challenges, as well as fabrication, assembly, test and operations strategies for future micro-satellite missions. ST-5 will be deployed into a highly eccentric, geo-transfer orbit (GTO). This will expose the spacecraft to a high radiation environment as well as provide a low level magnetic background. A three-month flight demonstration phase is planned to validate the technologies and demonstrate concepts for future missions. Each ST-5 spacecraft incorporates NMP competitively-selected breakthrough technologies. These include Cold Gas Micro-Thrusters for propulsion and attitude control, miniature X-band transponder for space-ground communications, Variable Emittance Coatings for dynamic thermal control, and CULPRiT ultra low power logic chip used for Reed-Solomon encoding. The ST-5 spacecraft itself is a technology that can be infused into future missions. It is a fully functional micro-spacecraft built within tight volume and mass constraints. It is built to withstand a high radiation environment, large thermal variations, and high launch loads. The spacecraft power system is low-power and low-voltage, and is designed to turn on after separation &om the launch vehicle. Some of the innovations that are included in the ST-5 design are a custom spacecraft deployment structure, magnetometer deployment boom, nutation damper, X-band antenna, miniature spinning sun sensor, solar array with triple junction solar cells, integral card cage assembly containing single card Command and Data Handling and Power System Electronics, miniature magnetometer, and lithium ion battery. ST-5 will demonstrate the ability of a micro satellite to perform

  4. Constellation's First Flight Test: Ares I-X

    NASA Technical Reports Server (NTRS)

    Davis, Stephan R.; Askins, Bruce R.

    2010-01-01

    On October 28, 2009, NASA launched Ares I-X, the first flight test of the Constellation Program that will send human beings to the Moon and beyond. This successful test is the culmination of a three-and-a-half-year, multi-center effort to design, build, and fly the first demonstration vehicle of the Ares I crew launch vehicle, the successor vehicle to the Space Shuttle. The suborbital mission was designed to evaluate the atmospheric flight characteristics of a vehicle dynamically similar to Ares I; perform a first stage separation and evaluate its effects; characterize and control roll torque; stack, fly, and recover a solid-motor first stage testing the Ares I parachutes; characterize ground, flight, and reentry environments; and develop and execute new ground hardware and procedures. Built from existing flight and new simulator hardware, Ares I-X integrated a Shuttle-heritage four-segment solid rocket booster for first stage propulsion, a spacer segment to simulate a five-segment booster, Peacekeeper axial engines for roll control, and Atlas V avionics, as well as simulators for the upper stage, crew module, and launch abort system. The mission leveraged existing logistical and ground support equipment while also developing new ones to accommodate the first in-line rocket for flying astronauts since the Saturn IB last flew from Kennedy Space Center (KSC) in 1975. This paper will describe the development and integration of the various vehicle and ground elements, from conception to stacking in KSC s Vehicle Assembly Building; hardware performance prior to, during, and after the launch; and preliminary lessons and data gathered from the flight. While the Constellation Program is currently under review, Ares I-X has and will continue to provide vital lessons for NASA personnel in taking a vehicle concept from design to flight.

  5. Advanced Lithium-Ion Cell Development for NASA's Constellation Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Miller, Thomas B.; Manzo, Michelle A.; Mercer, Carolyn R.

    2008-01-01

    The Energy Storage Project of NASA s Exploration Technology Development Program is developing advanced lithium-ion batteries to meet the requirements for specific Constellation missions. NASA GRC, in conjunction with JPL and JSC, is leading efforts to develop High Energy and Ultra High Energy cells for three primary Constellation customers: Altair, Extravehicular Activities (EVA), and Lunar Surface Systems. The objective of the High Energy cell development is to enable a battery system that can operationally deliver approximately 150 Wh/kg for 2000 cycles. The Ultra High Energy cell development will enable a battery system that can operationally deliver 220 Wh/kg for 200 cycles. To accomplish these goals, cathode, electrolyte, separator, and safety components are being developed for High Energy Cells. The Ultra High Energy cell development adds lithium alloy anodes to the component development portfolio to enable much higher cell-level specific energy. The Ultra High Energy cell development is targeted for the ascent stage of Altair, which is the Lunar Lander, and for power for the Portable Life support System of the EVA Lunar spacesuit. For these missions, mass is highly critical, but only a limited number of cycles are required. The High Energy cell development is primarily targeted for Mobility Systems (rovers) for Lunar Surface Systems, however, due to the high risk nature of the Ultra High Energy cell development, the High Energy cell will also serve as a backup technology for Altair and EVA. This paper will discuss mission requirements and the goals of the material, component, and cell development efforts in further detail.

  6. Summary of Propulsion System Needs in Support of Project Constellation

    NASA Technical Reports Server (NTRS)

    Sumrall, Phil; Lorier, Terry; Baine, Michael

    2008-01-01

    In January 2004, the President of the United States established the Vision for Space Exploration (VSE) to return man to the moon and ultimately to extend manned space travel to Mars. This paper will summarize the manned space flight liquid propulsion system needs in support of Project Constellation over the next 10 years. It will include all engine needs to return man to the moon. An overview of engines currently under contract, those baselined but not yet under contract, and those engine needs that hav.e yet to be initiated. Project Constellation includes the components as shown Figure 1. Liquid propulsion systems supporting the manned portion of these elements include the following: the Crew Exploration Vehicle named Orion (crew module reaction control system (CMRCS), service module Orion Main Engine (OME), service module auxiliary RCS, and service module reaction control system (SMRCS)), the Crew Launch Vehicle named Ares 1 (J2X upper stage, first stage roll control system, second stage reaction control system, and the Ares I-X roll control system), the Heavy Lift Launch Vehicle named Ares V (RS68B first stage booster, J-2X upper stage, roll control systems, and the Earth Departure Stage (EDS) (powered by the same Ares V Upper Stage J-2X), and the Lunar Lander named Altair with both descent and ascent stages (lunar orbit insertion and descent main engine, ascent main engine, and attitude control systems for both stages). In addition, there may be additional engine needs for early demonstrators, but those will not be speculated on as part of this paper. Also, other portions of the VSE architecture, including the planned Orion abort demonstrations and the Lunar Precursor Robotic Program, are not addressed here as they either use solid motors or are focused on unmanned precursor missions.

  7. Surface Landing Site Weather Analysis for Constellation Program

    NASA Technical Reports Server (NTRS)

    Altino, Karen M.; Burns, K. Lee

    2008-01-01

    Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is an important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface atmospheric conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. Climatological time series of operational surface weather observations are used to calculate probabilities of occurrence of various sets of hypothetical vehicle constraint thresholds, Data are available for numerous geographical locations such that statistical analysis can be performed for single sites as well as multiple-site network configurations. Results provide statistical descriptions of how often certain weather conditions are observed at the site(s) and the percentage that specified criteria thresholds are matched or exceeded. Outputs are tabulated by month and hour of day to show both seasonal and diurnal variation. This paper will describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that can be obtained,

  8. Learning the Constellations: From Junior High to Undergraduate Descriptive Astronomy Class

    NASA Astrophysics Data System (ADS)

    Stephens, Denise C.; Hintz, Eric G.; Hintz, Maureen; Lawler, Jeannette; Jones, Michael; Bench, Nathan

    2015-01-01

    As part of two separate studies we have examined the ability of students to learn and remember a group of constellations, bright stars, and deep sky objects. For a group of junior high students we tested their knowledge of only the constellations by giving them a 'constellation quiz' without any instruction. We then provided the students with a lab session, and retested. We also tested a large number of undergraduate students in our descriptive astronomy classes, but in this case there were the same 30 constellations, 17 bright stars, and 3 deep sky objects. The undergraduate students were tested in a number of ways: 1) pre-testing without instruction, 2) self-reporting of knowledge, 3) normal constellation quizzes as part of the class, and 4) retesting students from previous semesters. This provided us with a set of baseline measurements, allowed us to track the learning curve, and test retention of the material. We will present our early analysis of the data.

  9. A possible space VLBI constellation utilizing the stable orbits around the TLPs in the Earth-Moon system.

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Tang, Jingshi; Hou, Xiyun

    2016-07-01

    Current studies indicate that there are stable orbits around but far away from the triangular libration points .Two special quasi-periodic orbits around each triangular libration points L4 , L5 in the Earth-Moon sys-tem perturbed by Sun are gain , and the stable orbits discussed in this work are ideal places for space colonies because no orbit control is needed. These stable orbits can also be used as nominal orbits for space VLBI (Very Long Baseline Interferometry) stations. The two stations can also form baselines with stations on the Earth and the Moon, or with stations located around another TLP. Due to the long distance between the stations, the observation precision can be greatly enhanced compared with the VLBI stations on the Earth. Such a VLBI constellation not only can advance the radio astronomy, but also can be used as a navigation system for human activities in the Earth-Moon system and even in the solar system. This paper will focus on the navigation constellation coverage issues, and the orbit determination accuracy problems within the Earth-Moon sys-tem and interplanetary space.

  10. Array of Neutral Density Relative Observations MEasuring Divergence in the Atmosphere (ANDROMEDA), A Constellation Concept for Studying Thermospheric Dynamics

    NASA Astrophysics Data System (ADS)

    Palo, S. E.; Pilinski, M.; Forbes, J. M.

    2015-12-01

    In addition to being critical to the prediction of satellite orbits, total mass density is a fundamental property of the thermosphere. Density measurements from accelerometers on the CHAMP satellite have revealed quasi-steady state distributions of density structures around the globe, density responses to changing solar and geomagnetic activity, and spatial structures of wave-like phenomena along the orbit. However, a basic limitation on the time scale of any observable phenomenon is the ~90-minute orbital period. Thus, single-satellite missions like CHAMP are unable to measure the time derivative of density or the mass flux divergence (MFD) at a single point in the atmosphere. While the two accelerometer-carrying GRACE satellites could theoretically measure the density time derivative, in practice this measurement is hampered by the very low-signal levels in the tenuous atmosphere at the ~500-km GRACE orbits, as well as inter-satellite biases and drifts. The Array of Neutral Density Relative Observations Measuring Divergence in the Atmosphere (ANDROMEDA) is a constellation of CubeSats aimed at improving our understanding of atmospheric dynamics by measuring and interpreting the characteristics of traveling atmospheric disturbances as well as the distribution of MFD in the thermosphere. The ANDROMEDA constellation consists of two to three identical CubeSats spaced approximately 300 km apart and making multi-point measurements of total mass density with an accuracy of <2%. The mass density measurements will be made using a novel torque balance technique enabled by an extremely accurate attitude determination and control system (ADCS) that actively compensates for atmospheric disturbance torques. The benefit of the torque-balance technique is the high level of inter-satellite accuracy. The constellation will be deployed from the ISS and will make observations between 400 km and 250 km altitude as the satellite orbits decay. Distance between the spacecraft will be

  11. Country-of-origin labeling prior to and at the point of purchase: an exploration of the information environment in Baltimore City grocery stores.

    PubMed

    Lagasse, Lisa P; Love, David C; Smith, Katherine Clegg

    2014-01-01

    The country-of-origin labeling (COOL) law requires United States grocers to indicate the origin and procurement method (farm-raised or wild-caught) for seafood. This study explored the presentation of COOL on fresh, frozen, packaged, and unpackaged seafood in Baltimore City grocery stores. Eight stores were visited bi-monthly to photograph seafood labels, and circulars were collected weekly from fourteen stores over three months. Ninety-six percent of products were labeled correctly. Forty-eight percent of advertisements included COOL. While in-store labels did not highlight COOL, advertising featured references to domestic and wild-caught seafood, signaling to customers that these are high-value product qualities. PMID:24437544

  12. Sequence similarities of the capsid gene of Chilean and European isolates of infectious pancreatic necrosis virus point towards a common origin.

    PubMed

    Mutoloki, Stephen; Evensen, Øystein

    2011-07-01

    The Chilean salmonid industry was developed by importing breeding materials, a practice still in effect due to deficits in the national supply of roe. Importation of breeding materials is often associated with the transmission of pathogens. The objectives of this study were to compare the infectious pancreatic necrosis virus (IPNV) isolates from Chile to those of European origin and to determine the diversity of the Chilean IPNV. The VP2 genes of IPNV from Chilean fish (whose eggs originated from Scotland, Iceland and Norway) were compared to isolates from fish in Norway and Ireland. The results show that the isolates are identical (97-99%) and cluster into one genogroup. Our findings support previous reports of association between the trade-in breeding materials and transmission of pathogens. Furthermore, our results demonstrate the genotypic diversity of Chilean IPNV isolates. These findings have important implications for IPNV disease diagnosis and control in Chile. PMID:21402593

  13. Cubesat-Based Dtv Receiver Constellation for Ionospheric Tomography

    NASA Astrophysics Data System (ADS)

    Bahcivan, H.; Leveque, K.; Doe, R. A.

    2013-12-01

    The Radio Aurora Explorer mission, funded by NSF's Space Weather and Atmospheric Research program, has demonstrated the utility of CubeSat-based radio receiver payloads for ionospheric research. RAX has primarily been an investigation of microphysics of meter-scale ionospheric structures; however, the data products are also suitable for research on ionospheric effects on radio propagation. To date, the spacecraft has acquired (1) ground-based UHF radar signals that are backscattered from meter-scale ionospheric irregularities, which have been used to measure the dispersion properties of meter-scale plasma waves and (2) ground-based signals, directly on the transmitter-spacecraft path, which have been used to measure radio propagation disturbances (scintillations). Herein we describe the application of a CubeSat constellation of UHF receivers to expand the latter research topic for global-scale ionospheric tomography. The enabling factor for this expansion is the worldwide availability of ground-based digital television (DTV) broadcast signals whose characteristics are optimal for scintillation analysis. A significant part of the populated world have transitioned, or soon to be transitioned, to DTV. The DTV signal has a standard format that contains a highly phase-stable pilot carrier that can be readily adapted for propagation diagnostics. A multi-frequency software-defined radar receiver, similar to the RAX payload, can measure these signals at a large number of pilot carrier frequencies to make radio ray and diffraction tomographic measurements of the ionosphere and the irregularities contained in it. A constellation of CubeSats, launched simultaneously, or in sequence over years, similar to DMSPs, can listen to the DTV stations, providing a vast and dense probing of the ionosphere. Each spacecraft can establish links to a preprogrammed list of DTV stations and cycle through them using time-division frequency multiplexing (TDFM) method. An on board program can

  14. Thin-foil reflection gratings for Constellation-X

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Akilian, Mireille; Chang, Chih-Hao; Forest, Craig R.; Joo, Chulmin; Lapsa, Andrew; Montoya, Juan C.; Schattenburg, Mark L.

    2004-10-01

    The Reflection Grating Spectrometer (RGS) on Constellation-X is designed to supply astronomers with high spectral resolution in the soft x-ray band from 0.25 to 2 keV. High resolution, large collecting area and low mass at grazing incidence require very flat and thin grating substrates, or thin-foil optics. Thin foils typically have a diameter-to-thickness ratio of 200 or higher and as a result very low stiffness. This poses a number of technological challenges in the areas of shaping, handling, positioning, and mounting of such optics. The most minute forces (gravity sag, friction, thermal mismatch with optic mount, etc.) can lead to intolerable deformations and limit figure metrology repeatability. We present results of our efforts in the manipulation and metrology of suitable grating substrates, utilizing a novel low-stress foil holder with friction-reducing flexures. A large number of reflection gratings is needed to achieve the required collecting area. We have employed nanoimprint lithography (NIL) - which uses imprint films as thin as 100 nm or less - for the high-fidelity and low-stress replication from 100 mm diameter saw-tooth grating masters.

  15. Visibility and Geometry of Global Satellite Navigation Systems Constellations

    NASA Astrophysics Data System (ADS)

    Januszewski, Jacek

    2015-12-01

    Nowadays (November 2015) there are two global fully operational satellite navigation systems, American GPS and Russian GLONASS. Two next are under construction, Galileo in Europe and BeiDou in China. As the error of observer's position obtained from these systems depends on geometry factor DOP (Dilution Of Precision) among other things the knowledge of the number of satellites visible by this observer above given masking elevation angle Hmin and the distributions of DOP coefficient values, GDOP in particular, is very important. The lowest and the greatest number of satellites visible in open area by the observer at different latitudes for different Hmin, the percentage of satellites visible above angle H (9 intervals, each 10O wide), distributions (in per cent) of satellites azimuths (8 intervals, each 45O wide) and GDOP coefficient values (8 intervals) for Hmin = 5O for all these four systems at different observer's latitudes (9 intervals, each wide 10O wide) are presented in the paper. Additionally the lowest elevation for which the number of satellites visible at different latitudes by the observer in open area above this angle is equal 4 or 3 and the distributions (in per cent) of GDOP coefficient values for different Hmin at observer's latitudes 50-60O for the same four systems are showed. All calculations were made for constellation of GPS 27 satellites, GLONASS 24, Galileo 30 and BeiDou 27 MEO satellites.

  16. The Rorschach Suicide Constellation: assessing various degrees of lethality.

    PubMed

    Fowler, J C; Piers, C; Hilsenroth, M J; Holdwick, D J; Padawer, J R

    2001-04-01

    In this article we examine the relation between the Rorschach Comprehensive System's Suicide Constellation (S-CON; Exner, 1993; Exner & Wiley, 1977) and lethality of suicide attempts during the course of patients' hospitalization at the Austen Riggs Center (Stockbridge, MA). Patient records were rated as nonsuicidal (n = 37), parasuicidal (n = 37), or near-lethal (n = 30) based on the presence and lethality of self-destructive acts. Diagnostic efficiency statistics utilizing a cutoff score of 7 or more positive indicators successfully predicted which patients would engage in near-lethal suicidal activity relative to parasuicidal patients (overall correct classification rate [OCC] = .79), nonsuicidal inpatients (OCC = .79), and college students (OCC = .89). Although these predictions were influenced by relatively high base rates in the hospital population (14.5%), base rate estimates were calculated for other hypothetical populations revealing different prediction estimates that should be considered when judging the relative efficacy of the S-CON. Logistic regression analysis revealed that an S-CON score of 7 or more was the sole predictor of near-lethal suicide attempts among 9 psychiatric and demographic variables. PMID:11393464

  17. From value chain to value constellation: designing interactive strategy.

    PubMed

    Normann, R; Ramírez, R

    1993-01-01

    In today's fast-changing competitive environment, strategy is no longer a matter of positioning a fixed set of activities along that old industrial model, the value chain. Successful companies increasingly do not just add value, they reinvent it. The key strategic task is to reconfigure roles and relationships among a constellation of actors--suppliers, partners, customers--in order to mobilize the creation of value by new combinations of players. What is so different about this new logic of value? It breaks down the distinction between products and services and combines them into activity-based "offerings" from which customers can create value for themselves. But as potential offerings grow more complex, so do the relationships necessary to create them. As a result, a company's strategic task becomes the ongoing reconfiguration and integration of its competencies and customers. The authors provide three illustrations of these new rules of strategy. IKEA has blossomed into the world's largest retailer of home furnishings by redefining the relationships and organizational practices of the furniture business. Danish pharmacies and their national association have used the opportunity of health care reform to reconfigure their relationships with customers, doctors, hospitals, drug manufacturers, and with Danish and international health organizations to enlarge their role, competencies, and profits. French public-service concessionaires have mastered the art of conducting a creative dialogue between their customers--local governments in France and around the world--and a perpetually expanding set of infrastructure competencies. PMID:10127040

  18. Vega-Constellation Tools to Analize Hyperspectral Images

    NASA Astrophysics Data System (ADS)

    Savorskiy, V.; Loupian, E.; Balashov, I.; Kashnitskii, A.; Konstantinova, A.; Tolpin, V.; Uvarov, I.; Kuznetsov, O.; Maklakov, S.; Panova, O.; Savchenko, E.

    2016-06-01

    Creating high-performance means to manage massive hyperspectral data (HSD) arrays is an actual challenge when it is implemented to deal with disparate information resources. Aiming to solve this problem the present work develops tools to work with HSD in a distributed information infrastructure, i.e. primarily to use those tools in remote access mode. The main feature of presented approach is in the development of remotely accessed services, which allow users both to conduct search and retrieval procedures on HSD sets and to provide target users with tools to analyze and to process HSD in remote mode. These services were implemented within VEGA-Constellation family information systems that were extended by adding tools oriented to support the studies of certain classes of natural objects by exploring their HSD. Particular developed tools provide capabilities to conduct analysis of such objects as vegetation canopies (forest and agriculture), open soils, forest fires, and areas of thermal anomalies. Developed software tools were successfully tested on Hyperion data sets.

  19. Earth's Radiation Imbalance from a Constellation of 66 Iridium Satellites

    NASA Astrophysics Data System (ADS)

    Chiu, J. C.; Wiscombe, W. J.

    2012-04-01

    The Earth Radiation Imbalance (ERI) at the top of the atmosphere is the primary driving force for climate change. If ERI is not zero, then Earth's temperature, both oceanic and atmospheric, will change gradually over time, tending toward a new steady state. The best estimates of current ERI from climate models range from 0.4 to 0.9 W/m2 (the imbalance being caused mainly by increasing CO2), but current satellite systems do not have the accuracy to measure ERI to even one significant digit. In this paper, we will describe a proposed constellation of 66 Earth radiation budget instruments, to be hosted on Iridium satellites. This system represents a quantum leap over current systems in several ways, in particular in providing ERI to at least one significant digit, thus enabling a crucial test of climate models. Because of its 24/7 coverage, the system will also provide ERI at three-hourly time scales without requiring extrapolations from narrowband geostationary instruments. This would allow studies of ERI's response to fast-evolving phenomena like dust storms and hurricanes. This offers a new, synoptic view of Earth radiation budget that will transform it from a monthly average into a dynamical variable alongside standard meteorological variables like temperature and pressure.

  20. "The Reflection Grating Spectrometer on Constellation-X"

    NASA Technical Reports Server (NTRS)

    Cottam, J.

    2006-01-01

    The Constellation-X Reflection Grating Spectrometer (RGS) is designed to provide high-throughput, high-resolution spectra in the long wavelength band of 6 to 50 angstrom. In the nominal design an array of reflection gratings is mounted at the exit of the Spectroscopy X-ray Telescope (SXT) mirror module. The gratings intercept and disperse light to a designated array of CCD detectors. To achieve the throughput (A_eff > 1000 cm2 below 0.6 keV) and resolution (R > 300 below 0.6 keV) requirements for the instrument we are investigating two possible grating designs. The first design uses in-plane gratings in a classical configuration that is very similar to the XMM-Newton RGS. The second design uses off-plane gratings in a conical configuration. The off-plane design has the advantage of providing higher reflectivity and potentially, a higher spectral resolution than the in-plane configuration. In our presentation we will describe the performance requirements and the current status of the technology development.

  1. Lunar Natural Environment for use by the Constellation Program

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    2009-01-01

    The Lunar Environments used by the Constellation Program are embodied in two documents, the NEDD (Natural Environments Definition for Design) and the DSNE (Design Specification for Natural Environments). Recently, the lunar environments for the NEDD have been defined and incorporated in the document, as the result of contributions from experts in all areas of lunar environments. The purpose of the NEDD is to provide a uniform description of the natural environment to serve as a basic framework for both the crewed and robotic missions of the Exploration Systems Mission Directorate (ESMD). It is intended to support engineering and analysis, requirements development, and verification involved in the development of exploration concepts and architectures, flight hardware, and new technologies. (It does not support the operational phases of the Program since models and data with different properties are needed for those applications.) By presenting a single benchmark definition of natural environment parameters it provides an easily accessible and uniform baseline for competitive studies, independent analyses, and concept studies.

  2. Efficient mission control for the 48-satellite Globalstar Constellation

    NASA Technical Reports Server (NTRS)

    Smith, Dan

    1994-01-01

    The Globalstar system is being developed by Globalstar, Limited Partnership and will utilize 48 satellites in low earth orbit (See Figure 1) to create a world-wide mobile communications system consistent with Vice President Gore's vision of a Global Information Infrastructure. As a large long term commercial system developed by a newly formed organization, Globalstar provides an excellent opportunity to explore innovative solutions for highly efficient satellite command and control. Design and operational concepts being developed are unencumbered by existing physical and organizational infrastructures. This program really is 'starting with a clean sheet of paper'. Globalstar operations challenges can appear enormous. Clearly, assigning even a single person around the clock to monitor and control each satellite is excessive for Globalstar (it would require a staff of 200! . Even with only a single contact per orbit per satellite, data acquisitions will start or stop every 45 seconds! Although essentially identical, over time the satellites will develop their own 'personalities'and will re quire different data calibrations and levels of support. This paper discusses the Globalstar system and challenges and presents engineering concepts, system design decisions, and operations concepts which address the combined needs and concerns of satellite, ground system, and operations teams. Lessons from past missions have been applied, organizational barriers broken, partnerships formed across the mission segments, and new operations concepts developed for satellite constellation management. Control center requirements were then developed from the operations concepts.

  3. CEOS: A Small, Low Cost Spectrometer for Use on the Iridium NEXT Constellation

    NASA Astrophysics Data System (ADS)

    Murphy, S. D.; Slagowski, S.; Greenbaum, A.; Landis, D.; Mustard, J. F.; Chance, K.

    2012-12-01

    As part of the proposed GEOScan sensor payload to be placed onboard the Iridium NEXT constellation; a small, low cost spectrometer will be included. The Compact Earth Observing Spectrometer (CEOS) is an ultraviolet-visible and near infrared (UV/VIS/NIR) optical spectrometer ideally suited for detailed earth observations. CEOS is derived from a spectrometer originally designed for NASA's O/OREOS mission, a CubeSat launched in November 2010 that is still performing extended science operations. It is also slated to be the key science payload component of VIOLET, a CubeSat mission designed to characterize the spectral characteristics of the upper atmosphere. The CEOS has several unique design elements that allow for high performance over a broad range of environmental conditions. The CEOS design allows for a range of customizations to tune the instrument performance for a wide range of science applications. The baseline instrument provides 200-1000 nm spectral coverage with 1 nm FWHM optical resolution, which is ideal for wide variety of science objectives. However by simply exchanging gratings in the instrument, it can be customized for narrower spectral range with significantly higher resolution. The CEOS instrument will also add a significant feature to allow for more detailed earth science observations. The optical portion of the spectrometer will be augmented with a second optical path designed to measure spectra from 1000 - 2000 nm. This will make the finished instrument capable of detailed spectral measurements from 200 - 2000 nm, covering the ultraviolet through near-infrared. The instrument will be designed to allow the independent operation of both the UV/VIS and NIR portions of the instrument to provide flexibility in science data product volumes. We will describe the design of this spectrometer as well as discuss the details of its design heritage. In addition to Iridium NEXT, we will describe other platforms that this spectrometer may be suited for. We

  4. Point Source All Sky

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This panoramic view encompasses the entire sky as seen by Two Micron All-Sky Survey. The measured brightnesses of half a billion stars (points) have been combined into colors representing three distinct wavelengths of infrared light: blue at 1.2 microns, green at 1.6 microns, and red at 2.2 microns. This image is centered on the core of our own Milky Way galaxy, toward the constellation of Sagittarius. The reddish stars seemingly hovering in the middle of the Milky Way's disc -- many of them never observed before -- trace the densest dust clouds in our galaxy. The two faint smudges seen in the lower right quadrant are our neighboring galaxies, the Small and Large Magellanic Clouds.

  5. A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.

    PubMed

    Fraga, I; Charters, F J; O'Sullivan, A D; Cochrane, T A

    2016-02-01

    Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented. PMID:26613353

  6. Identification of promiscuous ene-reductase activity by mining structural databases using active site constellations

    PubMed Central

    Steinkellner, Georg; Gruber, Christian C.; Pavkov-Keller, Tea; Binter, Alexandra; Steiner, Kerstin; Winkler, Christoph; Łyskowski, Andrzej; Schwamberger, Orsolya; Oberer, Monika; Schwab, Helmut; Faber, Kurt; Macheroux, Peter; Gruber, Karl

    2014-01-01

    The exploitation of catalytic promiscuity and the application of de novo design have recently opened the access to novel, non-natural enzymatic activities. Here we describe a structural bioinformatic method for predicting catalytic activities of enzymes based on three-dimensional constellations of functional groups in active sites (‘catalophores’). As a proof-of-concept we identify two enzymes with predicted promiscuous ene-reductase activity (reduction of activated C–C double bonds) and compare them with known ene-reductases, that is, members of the Old Yellow Enzyme family. Despite completely different amino acid sequences, overall structures and protein folds, high-resolution crystal structures reveal equivalent binding modes of typical Old Yellow Enzyme substrates and ligands. Biochemical and biocatalytic data show that the two enzymes indeed possess ene-reductase activity and reveal an inverted stereopreference compared with Old Yellow Enzymes for some substrates. This method could thus be a tool for the identification of viable starting points for the development and engineering of novel biocatalysts. PMID:24954722

  7. Constellation Program Lessons Learned in the Quantification and Use of Aerodynamic Uncertainty

    NASA Technical Reports Server (NTRS)

    Walker, Eric L.; Hemsch, Michael J.; Pinier, Jeremy T.; Bibb, Karen L.; Chan, David T.; Hanke, Jeremy L.

    2011-01-01

    The NASA Constellation Program has worked for the past five years to develop a re- placement for the current Space Transportation System. Of the elements that form the Constellation Program, only two require databases that define aerodynamic environments and their respective uncertainty: the Ares launch vehicles and the Orion crew and launch abort vehicles. Teams were established within the Ares and Orion projects to provide repre- sentative aerodynamic models including both baseline values and quantified uncertainties. A technical team was also formed within the Constellation Program to facilitate integra- tion among the project elements. This paper is a summary of the collective experience of the three teams working with the quantification and use of uncertainty in aerodynamic environments: the Ares and Orion project teams as well as the Constellation integration team. Not all of the lessons learned discussed in this paper could be applied during the course of the program, but they are included in the hope of benefiting future projects.

  8. Methodology and method and apparatus for signaling with capacity optimized constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged F. (Inventor); Jones, Christopher R. (Inventor)

    2011-01-01

    Communication systems having transmitter, includes a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate, a mapper configured to map encoded bits to symbols in a symbol constellation, a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper. In addition, the receiver includes a demodulator configured to demodulate the received signal via the communication channel, a demapper configured to estimate likelihoods from the demodulated signal, a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper. Furthermore, the symbol constellation is a capacity optimized geometrically spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes d.sub.min.

  9. 77 FR 16828 - Constellation Energy Commodities Group, Inc.; Notice of Designation of Certain Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Constellation Energy Commodities Group, Inc.; Notice of Designation of Certain Commission Personnel as Non-Decisional Commission staff members Sandra Waldstein and...

  10. A walk through the heavens : a guide to stars and constellations and their legends

    NASA Astrophysics Data System (ADS)

    Heifetz, Milton D.; Tirion, Wil

    What star is that? Where's the Great Bear? Who was Andromeda? A Walk through the Heavens is your guide to the pathways of the night sky, answering the commonest questions about what you can see up there. There are simplified maps of the constellations, together with instructions on how to gauge their sizes and the distances between them. With this information you can find the constellations easily, and make a journey by eye from one constellation to the next. Ancient myths surrounding the constellations are retold, enriching our understanding of how historical peoples saw the awe-inspiring spectacle of a sky sprinkled with stars. This book, magically illustrated by Wil Tirion, does not require any instrument or telescope. It is an ideal introduction to launch a young astronomer on a journey across starlit skies.

  11. Constellation Program Human-System Integration Requirements. Revision E, Nov. 19, 2010

    NASA Technical Reports Server (NTRS)

    Dory, Jonathan

    2010-01-01

    The Human-Systems Integration Requirements (HSIR) in this document drive the design of space vehicles, their systems, and equipment with which humans interface in the Constellation Program (CxP). These requirements ensure that the design of Constellation (Cx) systems is centered on the needs, capabilities, and limitations of the human. The HSIR provides requirements to ensure proper integration of human-to-system interfaces. These requirements apply to all mission phases, including pre-launch, ascent, Earth orbit, trans-lunar flight, lunar orbit, lunar landing, lunar ascent, Earth return, Earth entry, Earth landing, post-landing, and recovery. The Constellation Program must meet NASA's Agency-level human rating requirements, which are intended to ensure crew survival without permanent disability. The HSIR provides a key mechanism for achieving human rating of Constellation systems.

  12. Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

    NASA Technical Reports Server (NTRS)

    Lorenzini, E.

    1985-01-01

    This Quarterly Report deals with the deployment maneuver of a single-axis, vertical constellation with three masses. A new, easy to handle, computer code that simulates the two-dimensional dynamics of the constellation has been implemented. This computer code is used for designing control laws for the deployment maneuver that minimizes the acceleration level of the low-g platform during the maneuver.

  13. Management of the Reflection Grating Spectrometer on the Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    2004-01-01

    As RGS Integrated Product Team Lead, normal coordination and management efforts in the past year have involved setting and overseeing budgets and schedules, regular status reporting to the Program Manager at Goddard Space Flight Center (GSFC), interacting with Constellation-X groups at GSFC, Smithsonian Astrophysical Observatory (SAO), and RGS team institutions, and supporting the program needs of Constellation-X. In addition to the management aspects described above, there are four significant areas of direct contribution that were accomplished.

  14. Flying the ST-5 Constellation with "Plug and Play" Autonomy Components and the GMSEC Bus

    NASA Technical Reports Server (NTRS)

    Shendock, Bob; Witt, Ken; Stanley, Jason; Mandl, Dan; Coyle, Steve

    2006-01-01

    The Space Technology 5 (ST5) Project, part of NASA's New Millennium Program, will consist of a constellation of three micro-satellites. This viewgraph document presents the components that will allow it to operate in an autonomous mode. The ST-5 constellation will use the GSFC Mission Services Evolution Center (GMSEC) architecture to enable cost effective model based operations. The ST-5 mission will demonstrate several principles of self managing software components.

  15. An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation

    NASA Astrophysics Data System (ADS)

    McManus, Lauren

    Lunar science missions such as LADEE and GRAIL achieved unprecedented measurements of the Lunar exosphere and gravity field. These missions were performed with one (LADEE) or two (GRAIL) traditional satellites. The global coverage achieved by these missions could have been greatly enhanced with the use of a constellation of satellites. A constellation of communication satellites at the Moon would also be necessary if a Lunar human base were to be established. Constellations with many satellites are expensive with traditional technology, but have become feasible through the technological advancements and affordability of cubesats. Cubesat constellations allow for full surface coverage in science or communication missions at a reasonable mission cost. Repeat ground track orbits offer interesting options for science or communication constellations, since they provide repeat coverage of the surface at a fixed time between sequential visits. Flower constellations are a family of constellations being studied primarily by Daniele Mortari at Texas A&M; University that make use of repeat ground tracks. Orbital parameters are selected such that the nodal period of the orbit matches the nodal period of the primary body by a factor dependent on the number of days and the number of revolutions to repeat the ground track. All orbits in a flower constellation have identical orbital elements, with the exception of the right ascension of the ascending node (RAAN) and the initial mean anomaly, which are determined based on the desired phasing scheme desired. Flower constellations have thus far primarily been studied at Earth. A flower constellation at the Moon could be quite useful for science or communication purposes. In this scenario, the flower constellation satellites would be small satellites, which introduces many unique challenges. The cubesats would have limited propulsion capability and would need to be deployed from a mothercraft. Orbital maintenance would then be

  16. Human Systems Integration (HSI) Case Studies from the NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Baggerman, Susan; Berdich, Debbie; Whitmore, Mihriban

    2009-01-01

    The National Aeronautics and Space Administration (NASA) Constellation Program is responsible for planning and implementing those programs necessary to send human explorers back to the moon, onward to Mars and other destinations in the solar system, and to support missions to the International Space Station. The Constellation Program has the technical management responsibility for all Constellation Projects, including both human rated and non-human rated vehicles such as the Crew Exploration Vehicle, EVA Systems, the Lunar Lander, Lunar Surface Systems, and the Ares I and Ares V rockets. With NASA s new Vision for Space Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, inclusion in trade offs and analyses, and an iterative "prototype/test/ redesign" process. Personnel at the NASA Johnson Space Center are involved in the Constellation Program at both the Program and Project levels as human system integrators. They ensure that the human is considered as a system, equal to hardware and software vehicle systems. Systems to deliver and support extended human habitation on the moon are extremely complex and unique, presenting new opportunities to employ Human Systems Integration, or HSI practices in the Constellation Program. The purpose of the paper is to show examples of where human systems integration work is successfully employed in the Constellation Program and related Projects, such as in the areas of habitation and early requirements and design concepts.

  17. Long-Term Collision Risk Prediction for Low Earth Orbit Satellite Constellations

    NASA Astrophysics Data System (ADS)

    Walker, R.; Stokes, P. H.; Wilkinson, J. E.; Swinerd, G. G.

    2000-07-01

    In the light of recent changes to planned Low Earth Orbit (LEO) satellite constellation designs and enhancements made to the DERA IDES model, we have conducted a new study on long-term debris environment evolution. This includes the collision interactions of constellation systems with the orbital debris environment over the next 50 years. In this new study, we use the IDES model to simulate long-term evolution in four 'business as usual' future traffic scenarios, which differ by the presence and absence of foreseen satellite constellation traffic and debris mitigation measures. The IDES model is capable of taking high spatial resolution snapshots of the debris flux environment at regular time intervals. By accessing these snapshots, the IDES model is able to predict the long-term variation of debris flux incident on a specific target orbit. This technique is harnessed to predict the average debris flux trends for a typical LEO constellation satellite. Furthermore, we estimate the average debris-induced satellite failure rates for a whole constellation system. Finally, we discuss our new findings on the long-term effects of constellations on the debris environment and vice versa.

  18. Mission Study and Optics Development Support for Constellation X

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.

    1999-01-01

    This document is the Final Report for NASA Cooperative Agreement NCC5-268 between NASA Goddard Space Flight Center (GSFC) and the Smithsonian Astrophysical Observatory (SAO). The Agreement is entitled "Constellation X-ray Mission Study and Optics Development." The report is required by the terms of the Agreement. There were four modifications to the Agreement. The period of performance was from February 1, 1998 through March 31, 1999. The report summarizes the main areas of SAO activity. Other than the design and analysis related to the SXT Mirror (see Section 4.0), most of the work was carried out jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). Consequently, we do not mean to imply that such activities were carried out exclusively by SAO. Rather, we have tried to describe the SAO participation in these efforts.The report summarizes the main areas of SAO activity. Other than the design and analysis related to the SXT Mirror (see Section 4.0), most of the work was carried out jointly with personnel from GSFC and Marshall Space Flight Center (MSFC). Consequently, we do not mean to imply that such activities were carried out exclusively by SAO. Rather, we have tried to describe the SAO participation in these efforts. As is appropriate to a Cooperative Agreement, SAO worked with GSFC in an integrated team mode. SAO was involved in the mission management, technology development, and mission definition. The organization is shown in Figure 1. While overall management responsibility resided with GSFC, scientific lead and subordinate responsibilities were shared between GSFC and SAO.

  19. Precise science orbits for the Swarm satellite constellation

    NASA Astrophysics Data System (ADS)

    van den IJssel, Jose; Encarnação, João; Doornbos, Eelco; Visser, Pieter

    2015-09-01

    The European Space Agency (ESA) Swarm mission was launched on 22 November 2013 to study the dynamics of the Earth's magnetic field and its interaction with the Earth system. The mission consists of three identical satellites, flying in carefully selected near polar orbits. Two satellites fly almost side-by-side at an initial altitude of about 480 km, and will descend due to drag to around 300 km during the mission lifetime. The third satellite was placed in a higher orbit of about 530 km altitude, and therefore descends much more slowly. To geolocate the Swarm observations, each satellite is equipped with an 8-channel, dual-frequency GPS receiver for Precise Orbit Determination (POD). Onboard laser retroreflectors provide the opportunity to validate the orbits computed from the GPS observations using Satellite Laser Ranging (SLR) data. Precise Science Orbits (PSOs) for the Swarm satellites are computed by the Faculty of Aerospace Engineering at Delft University of Technology in the framework of the Swarm Satellite Constellation Application and Research Facility (SCARF). The PSO product consists of both a reduced-dynamic and a kinematic orbit solution. After a short description of the Swarm GPS data characteristics, the adopted POD strategy for both orbit types is explained and first PSO results from more than one year of Swarm GPS data are presented. Independent SLR validation shows that the reduced-dynamic Swarm PSOs have an accuracy of better than 2 cm, while the kinematic orbits have a slightly reduced accuracy of about 4-5 cm. Orbit comparisons indicate that the consistency between the reduced-dynamic and kinematic Swarm PSO for most parts of the Earth is at the 4-5 cm level. Close to the geomagnetic poles and along the geomagnetic equator, however, the kinematic orbits show larger errors, which are probably due to ionospheric scintillations that affect the Swarm GPS receivers over these areas.

  20. Hyperspectral Cubesat Constellation for Rapid Natural Hazard Response

    NASA Astrophysics Data System (ADS)

    Mandl, D.; Huemmrich, K. F.; Ly, V. T.; Handy, M.; Ong, L.; Crum, G.

    2015-12-01

    With the advent of high performance space networks that provide total coverage for Cubesats, the paradigm for low cost, high temporal coverage with hyperspectral instruments becomes more feasible. The combination of ground cloud computing resources, high performance with low power consumption onboard processing, total coverage for the cubesats and social media provide an opprotunity for an architecture that provides cost-effective hyperspectral data products for natural hazard response and decision support. This paper provides a series of pathfinder efforts to create a scalable Intelligent Payload Module(IPM) that has flown on a variety of airborne vehicles including Cessna airplanes, Citation jets and a helicopter and will fly on an Unmanned Aerial System (UAS) hexacopter to monitor natural phenomena. The IPM's developed thus far were developed on platforms that emulate a satellite environment which use real satellite flight software, real ground software. In addition, science processing software has been developed that perform hyperspectral processing onboard using various parallel processing techniques to enable creation of onboard hyperspectral data products while consuming low power. A cubesat design was developed that is low cost and that is scalable to larger consteallations and thus can provide daily hyperspectral observations for any spot on earth. The design was based on the existing IPM prototypes and metrics that were developed over the past few years and a shrunken IPM that can perform up to 800 Mbps throughput. Thus this constellation of hyperspectral cubesats could be constantly monitoring spectra with spectral angle mappers after Level 0, Level 1 Radiometric Correction, Atmospheric Correction processing. This provides the opportunity daily monitoring of any spot on earth on a daily basis at 30 meter resolution which is not available today.

  1. Constellation Program Lessons Learned. Volume 2; Detailed Lessons Learned

    NASA Technical Reports Server (NTRS)

    Rhatigan, Jennifer; Neubek, Deborah J.; Thomas, L. Dale

    2011-01-01

    These lessons learned are part of a suite of hardware, software, test results, designs, knowledge base, and documentation that comprises the legacy of the Constellation Program. The context, summary information, and lessons learned are presented in a factual format, as known and described at the time. While our opinions might be discernable in the context, we have avoided all but factually sustainable statements. Statements should not be viewed as being either positive or negative; their value lies in what we did and what we learned that is worthy of passing on. The lessons include both "dos" and "don ts." In many cases, one person s "do" can be viewed as another person s "don t"; therefore, we have attempted to capture both perspectives when applicable and useful. While Volume I summarizes the views of those who managed the program, this Volume II encompasses the views at the working level, describing how the program challenges manifested in day-to-day activities. Here we see themes that were perhaps hinted at, but not completely addressed, in Volume I: unintended consequences of policies that worked well at higher levels but lacked proper implementation at the working level; long-term effects of the "generation gap" in human space flight development, the need to demonstrate early successes at the expense of thorough planning, and the consequences of problems and challenges not yet addressed because other problems and challenges were more immediate or manifest. Not all lessons learned have the benefit of being operationally vetted, since the program was cancelled shortly after Preliminary Design Review. We avoid making statements about operational consequences (with the exception of testing and test flights that did occur), but we do attempt to provide insight into how operational thinking influenced design and testing. The lessons have been formatted with a description, along with supporting information, a succinct statement of the lesson learned, and

  2. Nonuniform character of the population of spin projections K for a fissile nucleus at the scission point and anisotropies in the angular distributions of fragments originating from the induced fission of nuclei

    SciTech Connect

    Kadmensky, S. G.; Bunakov, V. E.; Kadmensky, S. S.

    2012-11-15

    It is shown that the emergence of anisotropies in the angular distributions of fragments originating from the spontaneous and induced fission of oriented actinide nuclei is possible only if nonuniformities in the population of the projectionsM (K) of the fissile-nucleus spin onto the z axis of the laboratory frame (fissile-nucleus symmetry axis) appear simultaneously in the vicinity of the scission point but not in the vicinity of the outer saddle point of the deformation potential. The possibilities for creating the orientation of fissile nuclei for spontaneous and induced fission and the effect of these orientations on the anisotropies under analysis are considered. The role of Coriolis interaction as a unique source of the mixing of different-K fissile-nucleus states at all stages of the fission process is studied with allowance for the dynamical enhancement of this interaction for excited thermalized states of the nucleus involved that is characterized by a high energy density. It is shown that the absence of thermalization of excited states of the fissile nucleus that appear because of the effect of nonadiabaticity of its collective deformation motion in the vicinity of the scission point is a condition of conservation of the influence that transition fission states formed at the inner and outer fission barriers exerts on the distribution of the spin projections K for lowenergy spontaneous nuclear fission. It is confirmed that anisotropies observed in the angular distributions of fragments originating from the fission of nuclei that is induced by fast light particles (multiply charged ions) are due to the appearance of strongly excited equilibrium(nonequilibrium) states of the fissile nucleus in the vicinity of its scission point that have a Gibbs (non-Gibbs) distribution of projections K.

  3. Opto-Mechanics of the Constellation-X SXT Mirrors: Challenges in Mounting and Assembling the Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Zhang, WIlliam W.; Saha, Timo; Lehan, John P.; Mazzarella, James; Lozipone, Lawrence; Hong, Melinda; Byron, Glenn

    2008-01-01

    The Constellation-X Spectroscopy X-Ray Telescopes consists of segmented glass mirrors with an axial length of 200 mm, a width of up to 400 mm, and a thickness of 0.4 mm. To meet the requirement of less than 15 arc-second half-power diameter with the small thickness and relatively large size is a tremendous challenge in opto-mechanics. How shall we limit distortion of the mirrors due to gravity in ground tests, that arises from thermal stress, and that occurs in the process of mounting, affixing and assembling of these mirrors? In this paper, we will describe our current opto-mechanical approach to these problems. We will discuss, in particular, the approach and experiment where the mirrors are mounted vertically by first suspending it at two points.

  4. DSMS investment in support of satellite constellations and formation flying

    NASA Technical Reports Server (NTRS)

    Statman, J. I.

    2003-01-01

    controllability of tightformations for precision constellation missions. In this paper we discuss the four classes of constellatiodformation support with emphasis of DSMS current status (technology and implementation) and plans in the first three areas.

  5. Constellation Architecture Team-Lunar: Lunar Habitat Concepts

    NASA Technical Reports Server (NTRS)

    Toups, Larry; Kennedy, Kriss J.

    2008-01-01

    This paper will describe lunar habitat concepts that were defined as part of the Constellation Architecture Team-Lunar (CxAT-Lunar) in support of the Vision for Space Exploration. There are many challenges to designing lunar habitats such as mission objectives, launch packaging, lander capability, and risks. Surface habitats are required in support of sustaining human life to meet the mission objectives of lunar exploration, operations, and sustainability. Lunar surface operations consist of crew operations, mission operations, EVA operations, science operations, and logistics operations. Habitats are crewed pressurized vessels that include surface mission operations, science laboratories, living support capabilities, EVA support, logistics, and maintenance facilities. The challenge is to deliver, unload, and deploy self-contained habitats and laboratories to the lunar surface. The CxAT-Lunar surface campaign analysis focused on three primary trade sets of analysis. Trade set one (TS1) investigated sustaining a crew of four for six months with full outpost capability and the ability to perform long surface mission excursions using large mobility systems. Two basic habitat concepts of a hard metallic horizontal cylinder and a larger inflatable torus concept were investigated as options in response to the surface exploration architecture campaign analysis. Figure 1 and 2 depicts the notional outpost configurations for this trade set. Trade set two (TS2) investigated a mobile architecture approach with the campaign focused on early exploration using two small pressurized rovers and a mobile logistics support capability. This exploration concept will not be described in this paper. Trade set three (TS3) investigated delivery of a "core' habitation capability in support of an early outpost that would mature into the TS1 full outpost capability. Three core habitat concepts were defined for this campaign analysis. One with a four port core habitat, another with a 2 port

  6. Does the NASA Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

    NASA Technical Reports Server (NTRS)

    Thronson, Harley; Lester, Daniel

    2008-01-01

    Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the U.S. have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a 10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover, as the recent Orbital Express and Automated Transfer Vehicle Missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth.

  7. On the optimum signal constellation design for high-speed optical transport networks.

    PubMed

    Liu, Tao; Djordjevic, Ivan B

    2012-08-27

    In this paper, we first describe an optimum signal constellation design algorithm, which is optimum in MMSE-sense, called MMSE-OSCD, for channel capacity achieving source distribution. Secondly, we introduce a feedback channel capacity inspired optimum signal constellation design (FCC-OSCD) to further improve the performance of MMSE-OSCD, inspired by the fact that feedback channel capacity is higher than that of systems without feedback. The constellations obtained by FCC-OSCD are, however, OSNR dependent. The optimization is jointly performed together with regular quasi-cyclic low-density parity-check (LDPC) code design. Such obtained coded-modulation scheme, in combination with polarization-multiplexing, is suitable as both 400 Gb/s and multi-Tb/s optical transport enabling technology. Using large girth LDPC code, we demonstrate by Monte Carlo simulations that a 32-ary signal constellation, obtained by FCC-OSCD, outperforms previously proposed optimized 32-ary CIPQ signal constellation by 0.8 dB at BER of 10(-7). On the other hand, the LDPC-coded 16-ary FCC-OSCD outperforms 16-QAM by 1.15 dB at the same BER. PMID:23037090

  8. A vector method for synthesis of orbits and the structure of satellite constellations for multiswath periodic coverage of the Earth

    NASA Astrophysics Data System (ADS)

    Saulskiy, V. K.

    2016-07-01

    Single satellites and multisatellite constellations for the periodic coverage of the Earth are considered. The main feature is the use of several cameras with different swath widths. A vector method is proposed which makes it possible to find orbits minimizing the periodicities of coverage of a given area of Earth uniformly for all swaths. Their number is not limited, but the relative dimensions should satisfy the Fibonacci series or some new numerical sequences. The results apply to constellations of any number of satellites. Formulas were derived for calculating their structure, i.e., relative position in the constellation. Examples of orbits and the structure of constellations for the Earth's multiswath coverage are presented.

  9. Positioning accuracy assessment for the 4GEO/5IGSO/2MEO constellation of COMPASS

    NASA Astrophysics Data System (ADS)

    Zhou, ShanShi; Cao, YueLing; Zhou, JianHua; Hu, XiaoGong; Tang, ChengPan; Liu, Li; Guo, Rui; He, Feng; Chen, JunPing; Wu, Bin

    2012-12-01

    Determined to become a new member of the well-established GNSS family, COMPASS (or BeiDou-2) is developing its capabilities to provide high accuracy positioning services. Two positioning modes are investigated in this study to assess the positioning accuracy of COMPASS' 4GEO/5IGSO/2MEO constellation. Precise Point Positioning (PPP) for geodetic users and real-time positioning for common navigation users are utilized. To evaluate PPP accuracy, coordinate time series repeatability and discrepancies with GPS' precise positioning are computed. Experiments show that COMPASS PPP repeatability for the east, north and up components of a receiver within mainland China is better than 2 cm, 2 cm and 5 cm, respectively. Apparent systematic offsets of several centimeters exist between COMPASS precise positioning and GPS precise positioning, indicating errors remaining in the treatments of COMPASS measurement and dynamic models and reference frame differences existing between two systems. For common positioning users, COMPASS provides both open and authorized services with rapid differential corrections and integrity information available to authorized users. Our assessment shows that in open service positioning accuracy of dual-frequency and single-frequency users is about 5 m and 6 m (RMS), respectively, which may be improved to about 3 m and 4 m (RMS) with the addition of differential corrections. Less accurate Signal In Space User Ranging Error (SIS URE) and Geometric Dilution of Precision (GDOP) contribute to the relatively inferior accuracy of COMPASS as compared to GPS. Since the deployment of the remaining 1 GEO and 2 MEO is not able to significantly improve GDOP, the performance gap could only be overcome either by the use of differential corrections or improvement of the SIS URE, or both.

  10. How to Enter, Fly In, and Exit the A-Train Constellation

    NASA Technical Reports Server (NTRS)

    Vincent, Mark A.

    2015-01-01

    The collaborative science obtained from the satellites in the A-Train is an unparalleled success. The constellation framework that has evolved is well-formulated and documented by its international members. Communication between teams is enhanced by a web-based Constellation Coordination System. Safety and correlated observations are ensured by defining independent control boxes with buffers in between. Each mission stays within its control box by regular drag makeup maneuvers. Annual inclination adjustments are coordinated by all missions to maintain their absolute and relative Mean Local Time of Ascending Node (MLTAN). Since the satellites are in different orbit planes their separation involves a three-dimensional triad made up of the along track separations, reference groundtracks and MLTAN's. For further safety, a Constellation Envelope has been defined to determine safe entry and exit orbits.

  11. Impact of Eccentricity Build-Up and Graveyard Disposal Strategies on Meo Navigation Constellations

    NASA Astrophysics Data System (ADS)

    Radtke, Jonas; Flegel, Sven Kevin; Sanchez-Ortiz, Noelia; Dominguez-Gonzalez, Raul; Merz, Klaus

    With currently two constellations being in or close to the build-up phase, in a few years the Medium Earth Orbit (MEO) region will be populated with four complete navigation systems in relatively close orbital altitudes: The American GPS, Russian GLONASS, European Galileo and Chinese Beidou. To guarantee an appropriate visibility of constellation satellites from Earth, these constellations rely on certain defined orbits. For these, both the repeat pattern, which is basically defined by the semi-major axis and inclination, as well as the orbital planes, which are defined by the right ascension of ascending node, are important. To avoid an overcrowding of the region of interest, the disposal of satellites after their end-of-life is recommended. Because of their distances to Earth, ordinary disposal manoeuvers leading to a direct or delayed re-entry due to atmospheric drag are not feasible: The needed fuel masses for such manoeuvers are by far above the reasonable limits and available fuel budgets. Thus, additional approaches have to be applied. For this, in general two options do exist: Disposal to graveyard orbits or the disposal to eccentricity build-up orbits. For the graveyard strategy, the key criterium for the disposed spacecraft is that they must keep a safe minimum distance to altitude of the active constellation on a long-term time scale of up to 200 years. This constraint imposes stringent requirements on the stability of the graveyard orbit. Similar disposals are also performed for high LEO satellites. The eccentricity build-up strategy on the other hand uses an effect that is characteristic for the orbital regime of MEO navigation constellations: Due to resonant effects between the Earth's geopotential, the Sun and the Moon, depending on the initial conditions, a large eccentricity build-up takes place, which can lead to a re-entry of the satellite. In this paper, the effects of applying either the first or the second disposal strategy on all payloads

  12. The Afternoon Constellation: A Formation of Earth Observing Systems for the Atmosphere and Hydrosphere

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2002-01-01

    Two of the large EOS observatories, Aqua (formerly EOS-PM) and Aura (formerly EOS-CHEM) will fly is nearly the same inclination with 1:30 PM -15 min ascending node equatorial crossing times. Between Aura and Aqua a series of smaller satellites will be stationed: Cloudsat, CALYPSO (formerly PICASSO-CENA), and PARASOL. This constellation of low earth orbit satellites will provide an unprecedented opportunity to make near simultaneous atmospheric cloud and aerosol observations. This paper will provide details of the science opportunity and describe the sensor types for the afternoon constellation. This constellation by accretion provides a prototype for the Earth Science Vision sensor web and represent the building books for a future web structure.

  13. Double-Difference Carrier-Phase Network Solution Using Nominal Gnss Constellations (Future Perception)

    NASA Astrophysics Data System (ADS)

    Farah, A. M. A.

    2008-01-01

    Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning accuracy using different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, Glonass and Galileo) using different combinations. This study presents results of double-difference carrier-phase solution for five stations-network using the three constellations and different combinations.

  14. Using Space Weather Variability in Evaluating the Radiation Environment Design Specifications for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Coffey, Victoria N.; Blackwell, William C.; Minow, Joseph I.; Bruce, Margaret B.; Howard, James W.

    2007-01-01

    NASA's Constellation program, initiated to fulfill the Vision for Space Exploration, will create a new generation of vehicles for servicing low Earth orbit, the Moon, and beyond. Space radiation specifications for space system hardware are necessarily conservative to assure system robustness for a wide range of space environments. Spectral models of solar particle events and trapped radiation belt environments are used to develop the design requirements for estimating total ionizing radiation dose, displacement damage, and single event effects for Constellation hardware. We first describe the rationale using the spectra chosen to establish the total dose and single event design environmental specifications for Constellation systems. We then compare variability of the space environment to the spectral design models to evaluate their applicability as conservative design environments and potential vulnerabilities to extreme space weather events

  15. Defining the Natural Atmospheric Environment Requirements for the NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Roberts, Barry C.; Leahy, Frank

    2008-01-01

    The National Aeronautics and Space Administration began developing a new vehicle under the Constellation Program to replace the Space Shuttle. The Ares-1 launch vehicle and the Orion capsule will be used to ferry crew and some payloads to the International Space Station and will also be used for new missions to the moon, As development of this new vehicle begins, the Natural Environments Branch at Marshall Space Flight Center has been tasked with defining the natural environments the vehicle will encounter and working with the program to develop natural environmental requirements for the vehicles' elements. An overview of the structure of the program is given, along with a description of the Constellation Design Specification for Natural Environments and the Constellation Natural Environments Definition for Design documents and how they apply to the Ares-I and Orion vehicles.

  16. The Constellation-X Mission: The next giant step in X-ray Astronomy

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.

    2006-01-01

    Constellation-X is the x-ray astronomy equivalent of large ground-based optical telescopes such as the Keck and the VLT, complementing the high spatial resolution capabilities of Chandra. By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 100 increased sensitivity. with its increased capabilities, Constellation-X will address many fundamental astrophysics questions such as observing the formation and evolution of clusters of galaxies, constraining the Baryon content of the Universe, observing the effects of strong gravity close to the event horizon of black holes in AGN and using these effects to determine the black hole rotation. The Constellation-X mission has been under study for eight years and in the Presidents FY04 budget has been given approval to proceed with a launches in 2013 and 2014. In this talk I will review the science goals of the mission, and the implementation approach.

  17. Tracing the Energetics of the Universe with Constellation-X: Example Scientific Investigations

    NASA Technical Reports Server (NTRS)

    Hornschemeier, Ann

    2008-01-01

    Constellation-X will enable us to trace the energetics of a broad range of astrophysical phenomena owing to its capabilities for high spectral resolution X-ray spectroscopy. The dominant baryonic component of galaxy clusters and groups resides in the X-ray bandpass, and the hot phase of the ISM in galaxies harbors the heavy metal production from previous generation of stars. This talk will focus on a few example science questions that are expected to be important during the Constellation-X era. These include the nature of the missing baryons expected to reside in the hot portion of the Warm Hot Intergalactic Medium, which Constellation-X will address via absorption spectroscopy studies of background AGN. We will also discuss spatially resolved spectroscopy of metal enrichment and the effects of turbulence in clusters & groups and of starburst galaxy winds which deposit energy & metals into the Intergalactic Medium.

  18. Evaluation of Propylene Glycol-Based Fluids for Constellation Habitats and Vehicles

    NASA Technical Reports Server (NTRS)

    Lee, Steve

    2009-01-01

    Two fluid life tests have been conducted to evaluate propylene glycol-based fluids for use in Constellation habitats and vehicles. The first test was conducted from November 2008 to January 2009 to help determine the compatibility of the propylene glycol-based fluid selected for Orion at the time. When the first test uncovered problems with the fluid selection, an investigation and selection of a new fluid were conducted. A second test was started in March 2010 to evaluate the new selection. For the first test, the fluid was subjected to a thermal fluid loop that had flight-like properties, as compared to Orion. The fluid loop had similar wetted materials, temperatures, flow rates, and aluminum wetted surface area to fluid volume ratio. The test was designed to last for 10 years, the life expectancy of the lunar habitat. However, the test lasted less than two months. System filters became clogged with precipitate, rendering the fluid system inoperable. Upon examination of the precipitate, it was determined that the precipitate composition contained aluminum, which could have only come from materials in the test stand, as aluminum is not part of the original fluid composition. Also, the fluid pH was determined to have increased from 10.1, at the first test sample, to 12.2, at the completion of the test. This high of a pH is corrosive to aluminum and was certainly a contributing factor to the development of precipitate. Due to the problems encountered during this test, the fluid was rejected as a coolant candidate for Orion. A new propylene glycol-based fluid was selected by the Orion project for use in the Orion vehicle. The Orion project has conducted a series of screening tests to help verify that there will be no problems with the new fluid selection. To compliment testing performed by the Orion project team, a new life test was developed to test the new fluid. The new test bed was similar to the original test bed, but with some improvements based on experience

  19. Requirements and Sizing Investigation for the Constellation Space Suit Portable Life Support System Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Jennings, Mallory A.; Paul, Heather L.; Waguespack, Glenn M.

    2010-01-01

    This presentation summarized the results of a trade study that evaluated whether trace contaminant control within the Constellation Spacesuit PLSS could be achieved without a Trace Contaminant Control System (TCCS) by relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Mallory Jennings and Dr. Glenn Waguespack studied trace contaminant generation rates to verify that values reflected the latest designs for Constellation spacesuit system pressure garment materials and PLSS hardware. They also calculated TCCS sizing and conducted a literature survey to review the latest developments in trace contaminant technologies.

  20. A Case Study: Using Delmia at Kennedy Space Center to Support NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Kickbusch, Tracey; Humeniuk, Bob

    2010-01-01

    The presentation examines the use of Delmia (Digital Enterprise Lean Manufacturing Interactive Application) for digital simulation in NASA's Constellation Program. Topics include an overview of the Kennedy Space Center (KSC) Design Visualization Group tasks, NASA's Constellation Program, Ares 1 ground processing preliminary design review, and challenges and how Delmia is used at KSC, Challenges include dealing with large data sets, creating and maintaining KSC's infrastructure, gathering customer requirements and meeting objectives, creating life-like simulations, and providing quick turn-around on varied products,

  1. [Umbilical blood flow relations in different segments of the umbilical cord. Part 1. Physiologic index constellation].

    PubMed

    Kudielka, I; Raimann, H; Eppel, W; Schatten, C; Schurz, B; Reinold, E

    1992-08-01

    Based on a collective of 500 women with normal singleton pregnancies we examined the indices of flow resistance along the umbilical cord. Measurements were taken at the foetal abdominal side of the Aa. umbilicales on the one hand and at the placental insertion of the vessels on the other. According to our results we were able to establish a physiological constellation of the indices for each week of gestation, and - subsequently - for the whole duration of pregnancy. These constellations could be considered physiological. They may serve as a basis for the definition of pathological conditions. PMID:1411468

  2. [Umbilical blood flow relations in pregnancy complications. Part 2. Pathologic index constellations].

    PubMed

    Kudielka, I; Raimann, H; Eppel, W; Schatten, C; Schurz, B; Huber, J; Reinold, E

    1993-02-01

    In a study comprising a total of 700 pregnant women, umbilical resistance was examined. Measurements were taken at both sides of the cord. A decline in resistance was registered from the fetal abdominal wall to the placental insertion of the vessels. According to a collective of 500 patients with a normal development and outcome of their pregnancies a physiological constellation of the resistance indices could be confirmed. It was taken as a basis for the definition of pathological cases. Different pathologies were related quite clearly to a special (unphysiological) constellation of the indices. PMID:8465180

  3. Attribute and topology based change detection in a constellation of previously detected objects

    DOEpatents

    Paglieroni, David W.; Beer, Reginald N.

    2016-01-19

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  4. Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

    NASA Technical Reports Server (NTRS)

    Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

    1999-01-01

    The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

  5. Revisiting Elliptical Satellite Orbits to Enhance the O3b Constellation

    NASA Astrophysics Data System (ADS)

    Wood, L.; Lou, Yuxuan; Olusola, Opeoluwa

    Highly elliptical orbits can be used to provide targeted satellite coverage of locations at high latitudes. We review the history of use of these orbits for communication. How elliptical orbits can be used for broadband communication is outlined. We propose an addition of known elliptical orbits to the new equatorial O3b satellite constellation, extending O3b to cover high latitudes and the Earth's poles. We simulate the O3b constellation and compare this to recent measurement of the first real Internet traffic across the newly deployed O3b network.

  6. CYGNSS Spaceborne Constellation for Ocean Surface Winds: Mission Design and Sampling Properties

    NASA Astrophysics Data System (ADS)

    Ruf, Chris; Ridley, Aaron; Clarizia, Maria Paola; Gleason, Scott; Rose, Randall; Scherrer, John

    2014-05-01

    analogous to the sampling that would result from 32 simultaneous hurricane hunter aircraft making measurements of the wind speed directly below each aircraft. The temporal sampling is best described by a probability distribution of the revisit time at each location within the +/- 35o latitude coverage area. The median value of the revisit time is ~2 hours and the mean revisit time is ~6 hours. The bistatic radar cross section of the ocean surface at the specular reflection point between a GPS transmitter and a CYGNSS receiver is measured in the form of Delay-Doppler Maps (DDMs). Wind speed is estimated from the DDMs using a minimum variance (MV) estimator. The MV estimator is a composite of wind estimates obtained from different observables that can be derived from the DDMs. Regression-based wind retrievals are developed for each observable using geophysical model functions that relate an observable to the surface wind speed. The MV estimator exploits the partial decorrelation that is present between residual errors in each individual wind retrieval. The EGU 2014 presentation will include a summary of the current mission design, including the DDMI science payload, the spacecraft, the constellation orbital architecture, the mission concept of operations. The spatial and temporal sampling properties, and retrieval uncertainty, of the CYGNSS ocean surface wind measurements will also be presented.

  7. Impact of eccentricity build-up and graveyard disposal Strategies on MEO navigation constellations

    NASA Astrophysics Data System (ADS)

    Radtke, Jonas; Domínguez-González, Raúl; Flegel, Sven K.; Sánchez-Ortiz, Noelia; Merz, Klaus

    2015-12-01

    With currently two constellations being in or close to the build-up phase, in a few years the Medium Earth Orbit (MEO) region will be populated with four complete navigation systems in relatively close orbital altitudes: The American GPS, Russian GLONASS, European Galileo, and Chinese BeiDou. To guarantee an appropriate visibility of constellation satellites from Earth, these constellations rely on certain defined orbits. For this, both the repeat pattern, which is basically defined by the semimajor axis and inclination, as well as the orbital planes, which are defined by the right ascension of ascending node, are determining values. To avoid an overcrowding of the region of interest, the disposal of satellites after their end-of-life is recommended. However, for the MEO region, no internationally agreed mitigation guidelines exist. Because of their distances to Earth, ordinary disposal manoeuvres leading to a direct or delayed re-entry due to atmospheric drag are not feasible: The needed fuel masses for such manoeuvres are by far above the reasonable limits and available fuel budgets. Thus, additional approaches have to be applied. For this, in general two options exist: disposal to graveyard orbits or the disposal to eccentricity build-up orbits. In the study performed, the key criterion for the graveyard strategy is that the disposed spacecraft must keep a safe minimum distance to the altitude of the active constellation on a long-term time scale of up to 200 years. This constraint imposes stringent requirements on the stability of the graveyard orbit. Similar disposals are also performed for high LEO satellites and disposed GEO payloads. The eccentricity build-up strategy on the other hand uses resonant effects between the Earth's geopotential, the Sun and the Moon. Depending on the initial conditions, these can cause a large eccentricity build-up, which finally can lead to a re-entry of the satellite. In this paper, the effects of applying either the first or

  8. 77 FR 11169 - In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; R.E. Ginna Nuclear Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... approval and opportunity for a hearing was published in the Federal Register on July 8, 2011 (76 FR 40403... License] In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; R.E. Ginna Nuclear Power... (Exelon), and Exelon Ventures Company, LLC (Exelon Ventures), and Constellation Energy Nuclear Group,...

  9. Optimal signal constellation design for ultra-high-speed optical transport in the presence of nonlinear phase noise.

    PubMed

    Liu, Tao; Djordjevic, Ivan B

    2014-12-29

    In this paper, we first describe an optimal signal constellation design algorithm suitable for the coherent optical channels dominated by the linear phase noise. Then, we modify this algorithm to be suitable for the nonlinear phase noise dominated channels. In optimization procedure, the proposed algorithm uses the cumulative log-likelihood function instead of the Euclidian distance. Further, an LDPC coded modulation scheme is proposed to be used in combination with signal constellations obtained by proposed algorithm. Monte Carlo simulations indicate that the LDPC-coded modulation schemes employing the new constellation sets, obtained by our new signal constellation design algorithm, outperform corresponding QAM constellations significantly in terms of transmission distance and have better nonlinearity tolerance. PMID:25607183

  10. Earth Radiation Imbalance from a Constellation of 66 Iridium Satellites: Technological Aspects

    NASA Technical Reports Server (NTRS)

    Wiscombe, W.; Chiu, C. J-Y.

    2012-01-01

    Iridium Communications Inc. is launching a new generation of polar orbiting communication satellites in 2015-2017. Iridium will provide a hosted payload bay on each of the 66 satellites (plus 6 in-space spares). This offers the potential for a paradigm shift in the way we measure Earth radiation imbalance from space, as well as massive cost savings. Because the constellation provides 24/7 global coverage, there is no need to account for diurnal cycle via extrapolations from uncalibrated narrowband geostationary imagers. And the spares can be rolled over to view the Sun and deep space, then transfer their calibration to the other members of the constellation during the frequent cross-overs. In part using simulations of the constellation viewing realistic Earth scenes, this presentation will address the technological aspects of such a constellation: (1) the calibration strategy; (2) the highly-accurate and stable radiometers for measuring outgoing flux; and (3) the GRACE-inspired algorithms for representing the outgoing flux field in spherical harmonics and thus achieving rv500-km spatial resolution and two-hour temporal resolution.

  11. Adaptation and Re-Use of Spacecraft Power System Models for the Constellation Program

    NASA Technical Reports Server (NTRS)

    Hojnicki, Jeffrey S.; Kerslake, Thomas W.; Ayres, Mark; Han, Augustina H.; Adamson, Adrian M.

    2008-01-01

    NASA's Constellation Program is embarking on a new era of space exploration, returning to the Moon and beyond. The Constellation architecture will consist of a number of new spacecraft elements, including the Orion crew exploration vehicle, the Altair lunar lander, and the Ares family of launch vehicles. Each of these new spacecraft elements will need an electric power system, and those power systems will need to be designed to fulfill unique mission objectives and to survive the unique environments encountered on a lunar exploration mission. As with any new spacecraft power system development, preliminary design work will rely heavily on analysis to select the proper power technologies, size the power system components, and predict the system performance throughout the required mission profile. Constellation projects have the advantage of leveraging power system modeling developments from other recent programs such as the International Space Station (ISS) and the Mars Exploration Program. These programs have developed mature power system modeling tools, which can be quickly modified to meet the unique needs of Constellation, and thus provide a rapid capability for detailed power system modeling that otherwise would not exist.

  12. Environmental Assessment for the Construction and Operation of the Constellation Program A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    Kennedy, Carolyn D.

    2007-01-01

    This document is an environmental assessment that examines the environmental impacts of a proposed plan to clear land and to construct a test stand for use in testing the J-2X rocket engine at simulated altitude conditions in support of NASA's Constellation Program.

  13. Implementation of a Collision Probability Prediction Technique for Constellation Maneuver Planning

    NASA Technical Reports Server (NTRS)

    Concha, Marco a.

    2007-01-01

    On March 22, 2006, the Space Technology 5 (ST5) constellation spacecraft were successfully delivered to orbit by a Pegasus XI, launch vehicle. An unexpected relative motion experienced by the constellation after orbit insertion brought about a problem. Soon after launch the observed relative position of the inert rocket body was between the leading and the middle spacecraft within the constellation. The successful planning and execution of an orbit maneuver that would create a fly-by of the rocket body was required to establish the.formation. This maneuver would create a close approach that needed to conform to predefined collision probability requirements. On April 21, 2006, the ST5 "155" spacecraft performed a large orbit maneuver and successfully passed the inert Pegasus 3rd Stage Rocket Body on April 30, 2006 15:20 UTC at a distance of 2.55 km with a Probability of Collision of less than 1.0E-06. This paper will outline the technique that was implemented to establish the safe planning and execution of the fly-by maneuver. The method makes use of Gaussian distribution models of state covariance to determine underlying probabilities of collision that arise under low velocity encounters. Specific numerical examples used for this analysis are discussed in detail. The mechanics of this technique are explained to foster deeper understanding of the concepts presented and to improve existing processes for use in future constellation maneuver planning.

  14. Using Problem-Based Learning: New Constellations for the 21st Century

    ERIC Educational Resources Information Center

    Savin-Baden, Maggi

    2014-01-01

    The author argues that there is still too much teaching to the test, and the consequence is growing "constellations" of problem-based learning (PBL), some of which are useful, and some of which are not. Today, what passes for PBL practice often seems more like guidelines than any kind of reasoned pedagogy. While at one level the range of…

  15. Stress Constellations and Coping Styles of Older Adults with Age-Related Visual Impairment

    ERIC Educational Resources Information Center

    Lee, Kyoung Othelia; Brennan, Mark

    2006-01-01

    Narrative data from two earlier studies of adaptation to age-related visual impairment were examined for constellations of stressors and coping styles. In the course of previous qualitative analyses, the researchers identified stress and coping codes according to behavioral, psychological, and social domains using a grounded theory approach. In…

  16. An efficient QoS-aware routing algorithm for LEO polar constellations

    NASA Astrophysics Data System (ADS)

    Tian, Xin; Pham, Khanh; Blasch, Erik; Tian, Zhi; Shen, Dan; Chen, Genshe

    2013-05-01

    In this work, a Quality of Service (QoS)-aware routing (QAR) algorithm is developed for Low-Earth Orbit (LEO) polar constellations. LEO polar orbits are the only type of satellite constellations where inter-plane inter-satellite links (ISLs) are implemented in real world. The QAR algorithm exploits features of the topology of the LEO satellite constellation, which makes it more efficient than general shortest path routing algorithms such as Dijkstra's or extended Bellman-Ford algorithms. Traffic density, priority, and error QoS requirements on communication delays can be easily incorporated into the QAR algorithm through satellite distances. The QAR algorithm also supports efficient load balancing in the satellite network by utilizing the multiple paths from the source satellite to the destination satellite, and effectively lowers the rate of network congestion. The QAR algorithm supports a novel robust routing scheme in LEO polar constellation, which is able to significantly reduce the impact of inter-satellite link (ISL) congestions on QoS in terms of communication delay and jitter.

  17. The Orion Constellation as an Installation: An Innovative Three-Dimensional Teaching and Learning Environment

    ERIC Educational Resources Information Center

    Brown, Daniel

    2013-01-01

    Visualizing the three-dimensional distribution of stars within a constellation is highly challenging for both students and educators, but when carried out in an interactive collaborative way, it can create an ideal environment to explore common misconceptions about size and scale within astronomy. We present how the common tabletop activities…

  18. The CYGNSS ground segment; innovative mission operations concepts to support a micro-satellite constellation

    NASA Astrophysics Data System (ADS)

    Rose, D.; Vincent, M.; Rose, R.; Ruf, C.

    Hurricane track forecasts have improved in accuracy by ~50% since 1990, while in that same period there has been essentially no improvement in the accuracy of intensity prediction. One of the main problems in addressing intensity occurs because the rapidly evolving stages of the tropical cyclone (TC) life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. NASA's most recently awarded Earth science mission, the NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) has been designed to address this deficiency by using a constellation of micro-satellite-class Observatories designed to provide improved sampling of the TC during its life cycle. Managing a constellation of Observatories has classically resulted in an increased load on the ground operations team as they work to create and maintain schedules and command loads for multiple Observatories. Using modern tools and technologies at the Mission Operations Center (MOC) in conjunction with key components implemented in the flight system and an innovative strategy for pass execution coordinated with the ground network operator, the CYGNSS mission reduces the burden of constellation operations to a level commensurate with the low-cost mission concept. This paper focuses on the concept of operations for the CYGNSS constellation as planned for implementation at the CYGNSS MOC in conjunction with the selected ground network operator.

  19. Reach for the Stars: A Constellational Approach to Ethnographies of Elite Schools

    ERIC Educational Resources Information Center

    Prosser, Howard

    2014-01-01

    This paper offers a method for examining elite schools in a global setting by appropriating Theodor Adorno's constellational approach. I contend that arranging ideas and themes in a non-deterministic fashion can illuminate the social reality of elite schools. Drawing on my own fieldwork at an elite school in Argentina, I suggest that local…

  20. Participants' Experiences in Hellinger's Family Constellation Work: A Grounded Theory Study

    ERIC Educational Resources Information Center

    Georgiadou, Sofia

    2012-01-01

    As a recently introduced to the U.S. model of intergenerational systemic therapy from Germany, Bert Hellinger's Family Constellation Work (FCW) has very limited research support. Hellinger himself has authored a number of publications referencing hundreds of cases, where he implemented his method to approach a broad array of physical,…

  1. Post-disposal orbital evolution of satellites and upper stages used by the GPS and GLONASS navigation constellations: The long-term impact on the Medium Earth Orbit environment

    NASA Astrophysics Data System (ADS)

    Pardini, Carmen; Anselmo, Luciano

    2012-08-01

    The long-term evolution and environmental impact in MEO of all the abandoned spacecraft and upper stages associated with the GPS and GLONASS navigation constellations were analyzed. The orbits of the disposed objects, as of 1 May 2011, were propagated for 200 years and snapshots of their evolving distribution were obtained, together with an estimation of the changing collision probability with the spacecraft of the operational navigation systems existing or planned in MEO, i.e., GLONASS, GPS, Beidou and Galileo. The probability that the abandoned objects considered will collide with the operational spacecraft of the navigation constellations is very low, even taking into account the intrinsic eccentricity instability of the disposal orbits. Assuming the present or envisaged configuration of the constellations in MEO, the probability of collision, integrated over 200 years, would be <1/300 with a GLONASS spacecraft, <1/15,000 with a GPS or Beidou spacecraft, and <1/250,000 with a Galileo spacecraft. The worst disposal strategy consists in abandoning satellites and upper stages close to the altitude of the operational constellation (GLONASS), while a re-orbiting a few hundred km away (GPS) is able to guarantee an effective long-term dilution of the collision risk, irrespective of the eccentricity instability due to geopotential and luni-solar perturbations. The disposal strategies applied so far to the GPS satellites should be able to guarantee for at least a few centuries a sustainable MEO environment free of collisions among intact objects. Consequently, there would be no need to adopt disposal schemes targeting also the optimal value of the eccentricity vector. However, it should be pointed out that the GPS disposal strategy was devised well in advance of the Beidou constellation announcement, so most of the abandoned satellites were re-orbited fairly close to the altitude of the new Chinese system. A new re-orbiting approach will be therefore needed in the future.

  2. An investigation into new advances in geodesy utilizing future satellite constellations

    NASA Astrophysics Data System (ADS)

    Gunter, B.; Teixeira da Encarnacao, J.; Ditmar, P.; Klees, R.

    2011-12-01

    The ability to measure temporal gravity field variations is of great interest to the Earth sciences community. These gravity measurements provide a unique source of information about Earth's mass transport processes, such as ocean currents, sea-level change, atmospheric variations, continental hydrology, movements of the solid earth, and the flux of ice in the cryosphere. Dedicated gravity field missions such as the Gravity Recovery and Climate Experiment (GRACE) have been collecting valuable global time-variable gravity measurements for nearly a decade now; however, as a single instrument pair, the spatial and temporal resolution of the GRACE mission is inherently limited by its ground track coverage. The information from these dedicated missions could be significantly enhanced if the information from a constellation of (non-dedicated) satellites were available. For example, the precise positions determined from a constellation of satellites equipped with GNSS receivers could be differentiated to reveal the gravitational accelerations acting on each satellite. The measurements from the constellation would not match the accuracy of those collected from GRACE, but would be sufficient to observe the large scale (> 1000 km) gravity variations. More importantly, these variations would be observed at time scales as short as six hours, covering a spectrum of the gravity field not possible from missions such as GRACE. In this context, the gravity data from the constellation would provide new information about Earth's global gravity field that would be fully complementary to data from dedicated gravity missions. In addition, the gravity data from the constellations could serve as an independent source of global time-variable gravity data in the event there is a gap between the end of the current GRACE mission (est. 2015-2016) and the proposed GRACE follow-on mission. Such constellations could soon become a reality, as satellite networks such as Iridium NEXT and others are

  3. Human G3P[9] rotavirus strains possessing an identical genotype constellation to AU-1 isolated at high prevalence in Brazil, 1997–1999

    PubMed Central

    Rainwater-Lovett, Kaitlin; Tsutsumi, Hiroyuki

    2015-01-01

    Rotavirus (RV) A is a very common cause of acute diarrhoea in infants and young children worldwide. Most human strains are classified into two major Wa-like and DS-1-like genotype constellations, whilst a minor third strain, AU-1, was described in 1989 among human RV isolates from Japan. AU-1 demonstrates a high degree of homology to a feline RV, FRV-1, which suggests interspecies transmission of feline RV. However, there has been no subsequent report of RVs possessing the AU-1 genotype throughout all 11 genes of the genome. Between March 1997 and December 1999, 157 RV-positive stool samples were collected from Brazilian children, and 16 of the RVs (10.2 %) were P[9] genotype. We analysed eight strains by almost full-genome sequencing. These eight strains were divided into two groups: five AU-1-like and three Wa-like strains. Four of the five AU-1-like strains had the AU-1-like genotype constellation throughout the 11 genes. The remaining AU-1-like strain was considered to be a reassortant strain comprosed of nine, two and one genes from the AU-1-like, Wa-like and G9 strains, respectively. The three Wa-like strains were considered to be reassortants comprising seven to eight genes and three to four genes from Wa-like and non-Wa-like strains, respectively. This report of human G3P[9] RV strains possessing the AU-1 genotype constellation throughout all genes demonstrates the stability and infectivity of the AU-1-like strain with its original genotype over distance and time. PMID:25467218

  4. A Model-based Approach to Controlling the ST-5 Constellation Lights-Out Using the GMSEC Message Bus and Simulink

    NASA Technical Reports Server (NTRS)

    Witt, Kenneth J.; Stanley, Jason; Shendock, Robert; Mandl, Daniel

    2005-01-01

    Space Technology 5 (ST-5) is a three-satellite constellation, technology validation mission under the New Millennium Program at NASA to be launched in March 2006. One of the key technologies to be validated is a lights-out, model-based operations approach to be used for one week to control the ST-5 constellation with no manual intervention. The ground architecture features the GSFC Mission Services Evolution Center (GMSEC) middleware, which allows easy plugging in of software components and a standardized messaging protocol over a software bus. A predictive modeling tool built on MatLab's Simulink software package makes use of the GMSEC standard messaging protocol to interface to the Advanced Mission Planning System (AMPS) Scenario Scheduler which controls all activities, resource allocation and real-time re-profiling of constellation resources when non-nominal events occur. The key features of this system, which we refer to as the ST-5 Simulink system, are as follows: Original daily plan is checked to make sure that predicted resources needed are available by comparing the plan against the model. As the plan is run in real-time, the system re-profiles future activities in real-time if planned activities do not occur in the predicted timeframe or fashion. Alert messages are sent out on the GMSEC bus by the system if future predicted problems are detected. This will allow the Scenario Scheduler to correct the situation before the problem happens. The predictive model is evolved automatically over time via telemetry updates thus reducing the cost of implementing and maintaining the models by an order of magnitude from previous efforts at GSFC such as the model-based system built for MAP in the mid-1990's. This paper will describe the key features, lessons learned and implications for future missions once this system is successfully validated on-orbit in 2006.

  5. Operational Simulation of the GPM Constellation and Evaluation of its Efficiency in Measuring Precipitation

    NASA Astrophysics Data System (ADS)

    Fotopoulos, F.; Bras, R. L.

    2002-05-01

    The purpose of this research is to simulate the operation of the GPM constellation and to evaluate its efficiency in measuring precipitation by comparing the actual precipitation recorded by ground instruments to the precipitation profile obtained by solely utilizing the snapshots taken by the satellites over an area. The GPM constellation consists of one mothership satellite and several drones. It is dynamic in its nature, so that one or more satellites can be added or subtracted from the constellation without significantly altering its functionality. For the time being, six satellites are considered to be part of the GPM constellation: DMSP-F13, DMSP-F14, DMSP-F15, ADEOS-II, AQUA (EOS-PM) and TRMM. The study area is the Rondonia basin in Amazon, Brazil. The ground data set used comes from the LBA experiment, conducted from November 1st 1998 to February 28th 1999. During most of this period, four rain gages networks and the SPOL radar were in operation. The rain gages record rainfall every hour while the SPOL radar takes several snapshots every hour. Due to the orbit characteristics of the satellites, the duration of each visit is small, practically less than a minute. Therefore, in order to obtain comparable measurements, the areal precipitation is estimated using GIS techniques, and then it is disaggregated into one-minute time intervals. The satellites collect one-minute snapshots of this areal precipitation, and after the end of the simulation the snapshots are aggregated in order to reproduce the measured areal precipitation. By comparing the measured areal precipitation with that recorded by the ground instruments, a measure of the constellation's efficiency is acquired.

  6. Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

    NASA Technical Reports Server (NTRS)

    Thronson, Harley A.; Lester, Daniel F.

    2008-01-01

    Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx.10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover, as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders, if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating

  7. Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

    NASA Technical Reports Server (NTRS)

    Thronson, Harley; Lester, Daniel F.

    2008-01-01

    Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx. 10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover. as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders. if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating

  8. First Point of Aries

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    An alternative term for vernal equinox. At one time (some 2000 years ago) the vernal equinox lay in the constellation of Aries but, due to precession, this is no longer the case and the vernal equinox has moved into Pisces....

  9. Evaluation of Carbon Dioxide Sensors for the Constellation Space Suit Life Support System for Surface Exploration

    NASA Technical Reports Server (NTRS)

    Dietrich, Daniel L.; Paul, Heather L.; Conger, Bruce C.

    2009-01-01

    This paper presents the findings of the trade study to evaluate carbon dioxide (CO2) sensing technologies for the Constellation (Cx) space suit life support system for surface exploration. The trade study found that nondispersive infrared absorption (NDIR) is the most appropriate high Technology Readiness Level (TRL) technology for the CO2 sensor for the Cx space suit. The maturity of the technology is high, as it is the basis for the CO2 sensor in the Extravehicular Mobility Unit (EMU). The study further determined that while there is a range of commercial sensors available, the Cx CO2 sensor should be a new design. Specifically, there are light sources (e.g., infrared light emitting diodes) and detectors (e.g., cooled detectors) that are not in typical commercial sensors due to cost. These advanced technology components offer significant advantages in performance (weight, volume, power, accuracy) to be implemented in the new sensor. The exact sensor design (light source, transmitting optics, path length, receiving optics and detector) will be specific for the Cx space suit and will be determined by the performance requirements of the Cx space suit. The paper further identifies specifications for some of the critical performance parameters as well as discussing the engineering aspects of implementing the sensor into the Portable Life Support System (PLSS). The paper then presents testing results from three CO2 sensors with respect to issues important to Extravehicular Activity (EVA) applications; stability, humidity dependence and low pressure compatibility. The three sensors include two NDIR sensors, one commercial and one custom-developed by NASA (for a different purpose), and one commercial electrochemical sensor. The results show that both NDIR sensors have excellent stability, no dependence on ambient humidity (when the ambient temperature is above the dew point) and operate in low pressure conditions and after being exposed to a full vacuum. The commercial

  10. Invited Talk: Photometry of Bright Variable Stars with the BRITE Constellation Nano-Satellites: Opportunities for Amateur Astronomers

    NASA Astrophysics Data System (ADS)

    Guinan, E. F.

    2014-06-01

    (Abstract only) The BRIght Target Explorer (BRITE) is a joint Austrian-Canadian-Polish Astronomy mission to carry out high precision photometry of bright (mv < 4 mag.) variable stars. BRITE consists of a "Constellation" of 20 × 20 × 20-cm nano-satellite cubes equipped with wide field (20 × 24 deg.) CCD cameras, control systems, solar panels, onboard computers, and so on. The first two (of up to six) satellites were successfully launched during February 2013. After post-launch commissioning, science operations commenced during October 2013. The primary goals are to carry out continuous multi-color (currently blue and red filters) high-precision millimag (mmag) photometry in particular locations in the sky. Typically these pointings will last for two to four months and secure simultaneous blue/red photometry of bright variable stars within the field. The first science pointing is centered on the Orion region. Since most bright stars are intrinsically luminous, hot O/B stars, giants, and supergiants will be the most common targets. However, some bright eclipsing binaries (such as Algol, b Lyr, e Aur) and a few chromospherically-active RS CVn stars (such as Capella) may be eventually be monitored. The BRITE-Constellation program of high precision, two color photometry of bright stars offers a great opportunity to study a wide range of stellar astrophysical problems. Bright stars offer convenient laboratories to study many current and important problems in stellar astrophysics. These include probing stellar interiors and pulsation in pulsating stars, tests of stellar evolution and structure for Cepheids and other luminous stars. To scientifically enhance the BRITE science returns, the BRITE investigators are very interested in securing contemporaneous ground-based spectroscopy and standardized photometry of target stars. The BRITE Ground Based Observations Team is coordinating ground-based observing efforts for BRITE targets. The team helps coordinate collaborations

  11. A Flexible Evolvable Architecture for Constellation Mission Systems User Applications

    NASA Technical Reports Server (NTRS)

    Trimble, Jay P.; Crocker, Alan R.

    2008-01-01

    While simulating a complex set of repair tasks to be performed by EVA crewmembers on an upcoming mission, flight controllers and astronauts determine that the repair will take much longer than originally anticipated. All equipment in the vicinity of the worksite must be powered off to maintain a safe environment for the astronauts. Because heater power will be unavailable, several critical components will now be at risk of freezing and permanent damage. If an impending thermal violation is detected, Mission Control will have very limited time to react. Therefore, flight controllers must not only modify their procedures to account for these risks, they must also incorporate into their displays outputs from thermal models, alternate temperature measurements, new alarm limits, and emergency power-on commands to enable the detection and response to freezing conditions. Current software for mission control systems makes scenarios like this difficult to address. Given the time frame for modifying software, operations teams are left with labor-intensive operational workarounds as their only options. NASA Ames Research Center (ARC) and NASA Johnson Space Center (JSC) are collaborating on the development of a flexible software system for mission operations that will enable greater user flexibility than has been available to date. Using composable software, end users in the scenario described above could recompose procedures and command and control displays to allow flight controllers to monitor temperature measurements, identify time-critical conditions, and execute the procedures required to respond to these conditions before flight hardware is permanently damaged.

  12. A collaborative optimization approach to improve the design and deployment of satellite constellations

    NASA Astrophysics Data System (ADS)

    Budianto, Irene Arianti

    This thesis introduces a systematic, multivariable, multidisciplinary method for the conceptual design of satellite constellations. The system consisted of three separate, but coupled, contributing analyses. The configuration and orbit design module performed coverage analysis for different orbit parameters and constellation patterns. The spacecraft design tool estimated mass, power, and costs for the payload and spacecraft bus that satisfy the resolution and sensitivity requirements. The launch manifest model found the minimum launch cost strategy, to deploy the given constellation system to the specified orbit. Collaborative Optimization (CO) has been previously implemented successfully as a design architecture for large-scale, highly-constrained multidisciplinary optimization problems related to aircraft and space vehicle studies. It is a distributed design architecture that allows its subsystems flexibility with regards to computing platforms and programming environment and, as its name suggests, many opportunities for collaboration. It is thus well suited to a team-oriented design environment, such as found in the constellation design process, and was implemented in this research. Two problems were solved using the CO method related to the design and deployment of a space-based infrared system to provide early missile warning. Successful convergence of these problems proved the feasibility of the CO architecture for solving the satellite constellation design problem. Verification of the results was accomplished by also implementing a large All-at-Once (AAO) optimization. This study further demonstrated several advantages of this approach over the standard practice used for designing satellite constellation systems. The CO method explored the design space more systematically and more extensively, improved subsystem flexibility, and its formulation was more scalable to growth in problem complexity. However, the intensive computational requirement of this method

  13. Extrapolating the Results of DICE to Constellation CubeSat Missions for Space Science

    NASA Astrophysics Data System (ADS)

    Swenson, C.; Fish, C. S.; Crowley, G.; Gunther, J.

    2012-12-01

    One of the most promising observation strategies still to be developed to advance space science is the capability to conduct simultaneous multipoint observations of the Earth system from space. These types of observations are required to understand the "big picture" of coupling between disparate regions: solar-wind, magnetosphere, ionosphere, thermosphere, mesosphere, atmosphere, land, ocean on a planetary scale. Affordable large constellations of scientific "space-buoys" can only be achieved through miniature spacecraft such as CubeSats due to the high cost of launching larger spacecraft. What has not yet been explored is how constellations of such satellites can be made effective for multipoint scientific studies. To be effective the architecture must: 1) Allow large amounts, Gigabits of data per day, of scientific data to be retrieved from the constellation and, 2) Address the orbital configuration and control of the constellation. The communications architecture, in which a constellation of "space-buoys" that are size, weight and power constrained addresses these needs, is lacking. The "Dynamic Ionosphere CubeSat Experiment" or "DICE" mission was selected and funded by the National Science Foundation in October 2009 in response to a cooperative proposal from ASTRA LLC, Utah State University's Space Dynamics Laboratory (USU/SDL), and Embry Riddle University. DICE consists of two identical "CubeSats" launched on October 27, 2011 as secondary payloads from a Delta II rocket and released into an 809 to 457 km at 102° inclination with one satellite chasing the other. The DICE mission is not using traditional CubeSat communications systems, but is instead using government radio bands and high speed downlink rates that are consistent with a NSF funded mission. A half-duplex UHF modem developed for DICE provides a 3 Mbit/s downlink and a 19.2 kbit/s uplink. The ground stations are located at Wallops Island on the east coast and/or at SRI on the west coast. In this

  14. [The paternal constellation: a pilot study in prenatal period.].

    PubMed

    Cupa, D; Riazuelo-Deschamps, H

    2001-01-01

    In a research where the authors had argued that some maternal prenatal representations concerning the infant had a decisive impact on precocious interactions (Cupa et al., 1992), they have asked in parallel, what was the weight on these very same interactions of paternal representations during pregnancy, knowing that in this specific period psychic reorganization of the father are profound (Bouchard-Godard, 1976; Cupa et al., 1997). If, in the intertwining of the two theoretical fields where the authors situate their work, being that of psychoanalysis and developmental psychology, there is a an important literature on the father, results and contribution allow to appreciate the impact of studies on the father during pregnancy and present theoretical points of reference of the authors' hypotheses. The presentation of the following study is that of a comparative longitudinal research carried out from the 7th month of pregnancy to 9 months after birth. It appeared indeed to the authors that in order to explore simultaneously the two representational universes and to observe the effects on the triadic interactions, this type of methodology was the most relevant. The results proposed in the last part, only concern the analysis of paternal representations. PMID:18253593

  15. High performance computing: Clusters, constellations, MPPs, and future directions

    SciTech Connect

    Dongarra, Jack; Sterling, Thomas; Simon, Horst; Strohmaier, Erich

    2003-06-10

    Last year's paper by Bell and Gray [1] examined past trends in high performance computing and asserted likely future directions based on market forces. While many of the insights drawn from this perspective have merit and suggest elements governing likely future directions for HPC, there are a number of points put forth that we feel require further discussion and, in certain cases, suggest alternative, more likely views. One area of concern relates to the nature and use of key terms to describe and distinguish among classes of high end computing systems, in particular the authors use of ''cluster'' to relate to essentially all parallel computers derived through the integration of replicated components. The taxonomy implicit in their previous paper, while arguable and supported by some elements of our community, fails to provide the essential semantic discrimination critical to the effectiveness of descriptive terms as tools in managing the conceptual space of consideration. In this paper, we present a perspective that retains the descriptive richness while providing a unifying framework. A second area of discourse that calls for additional commentary is the likely future path of system evolution that will lead to effective and affordable Petaflops-scale computing including the future role of computer centers as facilities for supporting high performance computing environments. This paper addresses the key issues of taxonomy, future directions towards Petaflops computing, and the important role of computer centers in the 21st century.

  16. First Crewed Flight: Rationale, Considerations and Challenges from the Constellation Experience

    NASA Technical Reports Server (NTRS)

    Noriega, Carlos; Arceneaux, William; Williams, Jeffrey A.; Rhatigan, Jennifer L.

    2011-01-01

    NASA's Constellation Program has made the most progress in a generation towards building an integrated human-rated spacecraft and launch vehicle. During that development, it became clear that NASA's human-rating requirements lacked the specificity necessary to defend a program plan, particularly human-rating test flight plans, from severe budget challenges. This paper addresses the progress Constellation achieved, problems encountered in clarifying and defending a human-rating certification plan, and discusses key considerations for those who find themselves in similar straits with future human-rated spacecraft and vehicles. We assert, and support with space flight data, that NASA's current human-rating requirements do not adequately address "unknown-unknowns", or the unexpected things the hardware can reveal to the designer during test.

  17. Strategy for Mitigating Collision Between Landsat-5 and the Afternoon Constellation

    NASA Technical Reports Server (NTRS)

    Levi, Joshua A.; Palmer, Eric J.

    2011-01-01

    The NASA Goddard Space Flight Center Earth Science Mission Operations project, the French space agency Centre National d tudes Spatiales, the Argentinian space agency Comisi n Nacional de Actividades Espaciales, and the United States Geological Survey all operate spacecraft in sun-synchronous frozen orbits. The orbits are planned to not place any of the spacecraft at risk of colliding with another. However, evolution of these orbits over time has com-promised the safe interaction between Landsat-5 and the Afternoon Constella-tion. This paper analyzes the interactions between the Landsat-5 spacecraft and the Afternoon Constellation members over a period of 6 years, describing the current risk and plan to mitigate collisions in the future.

  18. Coverage and control of constellations of elliptical inclined frozen lunar orbits

    NASA Technical Reports Server (NTRS)

    Ely, Todd A.

    2005-01-01

    A great deal of scientific interest exists regarding the permanently shadowed craters near the poles of the Moon where there may be frozen volatiles. These regions, particularly the Moon's South Pole, have been proposed for extensive robotic and human exploration. Unfortunately, they are typically not in view of Earth, and would require some form of communication relay to facilitate exploration via robotic and/or human missions. One solution for such a relay is a long-lived constellation of lunar telecommunication orbiters providing focused coverage at the pole of interest. Robust support requires this coverage to be continuous, redundant, and, in order to minimize costs, this constellation should consist of 3 satellites or fewer.

  19. Requirements and Sizing Investigation for Constellation Space Suit Portable Life Support System Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Jennings, Mallory A.; Waguespack, Glenn

    2010-01-01

    The Trace Contaminant Control System (TCCS), located within the ventilation loop of the Constellation Space Suit Portable Life Support System (PLSS), is responsible for removing hazardous trace contaminants from the space suit ventilation flow. This paper summarizes the results of a trade study that evaluated if trace contaminant control could be accomplished without a TCCS, relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Trace contaminant generation rates were revisited to verify that values reflect the latest designs for Constellation Space Suit System (CSSS) pressure garment materials and PLSS hardware. Additionally, TCCS sizing calculations were performed and a literature survey was conducted to review the latest developments in trace contaminant technologies.

  20. Determination of the Earth's lithospheric magnetic field using vector gradient data from the Swarm satellite constellation

    NASA Astrophysics Data System (ADS)

    Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

    2015-04-01

    One of the main goals of the Swarm three-satellite constellation mission is to determine the lithospheric field globally with the best possible resolution. To achieve that, explicit advantage of the constellation aspect of Swarm has to be taken by using gradient estimates. We derive lithospheric field models using more than one year of East-West and North-South magnetic gradient data, approximated by first differences of field vector data between the two lower Swarm satellites and along each satellite orbit, respectively. Despite the current relatively high altitude of 450 km of the Swarm satellites, the results are promising. We find that Swarm gradient data are less sensitive to large-scale external field fluctuations and enhance the resolution of the determined lithospheric field compared to only vector data. The derived models agree very well with previous models derived from CHAMP data, serving as an initial validation of the Swarm mission.

  1. The Orion Constellation as an Installation: An Innovative Three-Dimensional Teaching and Learning Environment

    NASA Astrophysics Data System (ADS)

    Brown, Daniel

    2013-03-01

    Visualizing the three-dimensional distribution of stars within a constellation is highly challenging for both students and educators, but when carried out in an interactive collaborative way, it can create an ideal environment to explore common misconceptions about size and scale within astronomy. We present how the common tabletop activities based upon the Orion constellation miss out on this opportunity. Transforming them into a walkthrough Orion installation that includes the position of our solar system allows the students to fully immerse themselves within the model and experience parallax. It enables participants to explore within the installation many other aspects of astronomy relating to sky culture, stellar evolution, and stellar sizes, establishing an innovative learning and teaching environment.

  2. The long-term implications of operating satellite constellations in the low earth orbit debris environment

    NASA Astrophysics Data System (ADS)

    Walker, R.; Crowther, R.; Swinerd, G. G.

    1997-05-01

    DRA's Integrated Debris Evolution Suite (IDES) model is used in this study to predict the future evolution of the orbital debris environment for two distinct scenarios. For the first case, a pre-generated background debris population for 1995 and `business as usual' future launch/explosion rates are used as input to the model. IDES then employs its collision event prediction algorithm to simulate evolution from 1996 to 2020 as a baseline. The second scenario uses the same initial conditions and future trends, but in addition, a large constellation is introduced into the simulation process from year 1998 onwards. The additional contribution of the constellation to the temporal variation of key environment/population parameters is presented; including enhancement from any long-term collision coupling effects.

  3. A novel 3D constellation-masked method for physical security in hierarchical OFDMA system.

    PubMed

    Zhang, Lijia; Liu, Bo; Xin, Xiangjun; Liu, Deming

    2013-07-01

    This paper proposes a novel 3D constellation-masked method to ensure the physical security in hierarchical optical orthogonal frequency division multiplexing access (OFDMA) system. The 3D constellation masking is executed on the two levels of hierarchical modulation and among different OFDM subcarriers, which is realized by the masking vectors. The Lorenz chaotic model is adopted for the generation of masking vectors in the proposed scheme. A 9.85 Gb/s encrypted hierarchical QAM OFDM signal is successfully demonstrated in the experiment. The performance of illegal optical network unit (ONU) with different masking vectors is also investigated. The proposed method is demonstrated to be secure and efficient against the commonly known attacks in the experiment. PMID:23842348

  4. The CEOS Atmospheric Composition Constellation: Enhancing the Value of Space-Based Observations

    NASA Technical Reports Server (NTRS)

    Eckman, Richard; Zehner, Claus; Al-Saadi, Jay

    2015-01-01

    The Committee on Earth Observation Satellites (CEOS) coordinates civil space-borne observations of the Earth. Participating agencies strive to enhance international coordination and data exchange and to optimize societal benefit. In recent years, CEOS has collaborated closely with the Group on Earth Observations (GEO) in implementing the Global Earth Observing System of Systems (GEOSS) space-based objectives. The goal of the CEOS Atmospheric Composition Constellation (ACC) is to collect and deliver data to improve monitoring, assessment and predictive capabilities for changes in the ozone layer, air quality and climate forcing associated with changes in the environment through coordination of existing and future international space assets. A project to coordinate and enhance the science value of a future constellation of geostationary sensors measuring parameters relevant to air quality supports the forthcoming European Sentinel-4, Korean GEMS, and US TEMPO missions. Recommendations have been developed for harmonization to mutually improve data quality and facilitate widespread use of the data products.

  5. The design and networking of dynamic satellite constellations for global mobile communication systems

    NASA Technical Reports Server (NTRS)

    Cullen, Cionaith J.; Benedicto, Xavier; Tafazolli, Rahim; Evans, Barry

    1993-01-01

    Various design factors for mobile satellite systems, whose aim is to provide worldwide voice and data communications to users with hand-held terminals, are examined. Two network segments are identified - the ground segment (GS) and the space segment (SS) - and are seen to be highly dependent on each other. The overall architecture must therefore be adapted to both of these segments, rather than each being optimized according to its own criteria. Terrestrial networks are grouped and called the terrestrial segment (TS). In the SS, of fundamental importance is the constellation altitude. The effect of the altitude on decisions such as constellation design choice and on network aspects like call handover statistics are fundamental. Orbit resonance is introduced and referred to throughout. It is specifically examined for its useful properties relating to GS/SS connectivities.

  6. The identification of inanna with the planet venus: A criterion for the time determination of the recognition of constellations in ancient mesopotamia

    NASA Astrophysics Data System (ADS)

    Kurtik, G. E.

    The author of the paper believes that the identification of Inanna with Venus as the morning or evening star chronologically preceded the time when the first constellations began to be recognized in Ancient Mesopotamia. If this is correct, the date of identification can be used as a reference point for the determination of the earliest probable limit for the epoch when in Mesopotamia the process of constellation recognition have been started. The earliest known images with the symbol of Inanna date from the period of archaic Uruk. They can be divided into two groups: (1) the images on seals and ceramics where there are no astral attributes; (2) the pictographic texts where the picture of a star and the signs of a sunrise or a sunset are placed alongside the symbol of Inanna. The pictographic texts, however, admit also a non-astral interpretation, if the picture of a star is a determinative of a deity. The astral nature of Inanna for the Uruk period therefore cannot be considered as finally proved. The identification of Inanna with Venus is reliably certified on seals of the Early Dynastic Period where there are at once three astral symbols - the crescent, the solar disk and the star of Inanna.

  7. The Costa Concordia last cruise: The first application of high frequency monitoring based on COSMO-SkyMed constellation for wreck removal

    NASA Astrophysics Data System (ADS)

    Ciampalini, Andrea; Raspini, Federico; Bianchini, Silvia; Tarchi, Dario; Vespe, Michele; Moretti, Sandro; Casagli, Nicola

    2016-02-01

    The Italian vessel Costa Concordia wrecked on January 13th 2012 offshore the Giglio Island (Tuscany, Italy), with the loss of 32 lives. Salvage operation of the vessel started immediately after the wreck. This operation was the largest and most expensive maritime salvage ever attempted on a wrecked ship and it ended in July 2014 when the Costa Concordia was removed from the Giglio Island, and dragged in the port of Genoa where it was dismantled. The refloating and removal phases of the Costa Concordia were monitored, in the period between 14th and 27th of July, exploiting SAR (Synthetic Aperture Radar) images acquired by the X-band COSMO-SkyMed satellite constellation in crisis mode. The main targets of the monitoring system were: (i) the detection of possible spill of pollutant material from the vessel and (ii) to exclude that oil slicks, illegally produced by other vessels, could be improperly linked to the naval convoy during its transit along the route between the Giglio Island and the port of Genoa. Results point out that the adopted monitoring system, through the use of the COSMO-SkyMed constellation, can be profitably employed to monitor emergency phases related to single ship or naval convoy over wide areas and with a suitable temporal coverage. Furthermore, the refloating and removal phases of the Costa Concordia were a success because no pollution was produced during the operations.

  8. The Role of Cloud and Precipitation Radars in Convoys and Constellations

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Durden, Stephen L.; Im, Eastwood; Sadowy, Gregory A.

    2013-01-01

    We provide an overview of which benefits a radar, and only a radar, can provide to any constellation of satellites monitoring Earth's atmosphere; which aspects instead are most useful to complement a radar instrument to provide accurate and complete description of the state of the troposphere; and finally which goals can be given a lower priority assuming that other types of sensors will be flying in formation with a radar.

  9. Constellations of elliptical inclined lunar orbits providing polar and global coverage

    NASA Technical Reports Server (NTRS)

    Ely, Todd A.; Lieb, Erica

    2005-01-01

    Prior results have developed a methodology for selecting a long-lived constellation of 3 satellites that provide persistent, stable coverage to either the North or South Pole with no requirement for stationkeeping under the influence of only gravitational perturbations. In the present study, the sensitivity of this coverage in the presence of non-gravitational forces is determined, and a design strategy is formulated that minimizes any potential sensitivity to these accelerations.

  10. Small Satellites Constellation for Monitoring of Natural and Man-made Catastrophes

    NASA Astrophysics Data System (ADS)

    Boyarchuk, K.; Oraevsky, V.; Salikhov, R.; Danilkin, V.

    The possibility of creation a new conception of using the small satellites constellation arises today in connection with the development of the circuit technology for manufacturing real small space vehicles (SSV). Their low price allows to form the multi purpose satellite constellation. Such constellation is formed in frame of the Russian Federal space program till 2006. It is intended for monitoring of the natural (typhoons, hurricanes, eruptions of volcano etc.) and man-made (radioactive contamination etc.) catastrophes. The space segment will be designed and manufactured by Research Institute for Electromechanics Federal State Unitary Enterprise. The scientific instrumentation and program will be designed by IZMIRAN. Three types of SSV will be in the constellation: The high-altitude group is composed by 4 SV (200 kg each) and the low-altitude group consists of up to 12 SV (200 kg or 60 kg each). Parameters measured by the on-board information system are as follows: plasma composition, ionosphere altitude profile, UHF/VHF/HF noise factor, atmosphere glow, weather parameters, the Earth surface temperature, high-energy particles, magnetic field, electric field. The multi-spectrum instrumentation of remote sensing will be also mounted on vehicle. The first SV are scheduled to be launched to the sun-sinchronous orbit by ROCOT, STRELA or SHTEL launch- vehicles within 2005 - 2006. After realization of the first projects the system configuration can be changed.For example the multisatellite system can provide: - Short-term, intermediate term and long-term prognosis of earthquakes, typhoons, hurricanes, tsunami; - Monitoring of radioactive and other contaminations - Evaluation of extreme situations and consequences of catastrophes in regions; - Analysis of a condition of the equipment and pipelines of gas and oil complex, scattering of gas emissions in turbulent atmosphere, prediction of the probable man- made catastrophes; - Analysis of influence of solar activity on

  11. Design of meo constellations for galileo: towards a ''design to cost'' approach

    NASA Astrophysics Data System (ADS)

    Abbondanza, S.; Zwolska, F.

    2001-12-01

    GALILEO aims at involving Europe in a new generation of satellite navigation services. In the context of the phase A of this programme, many system options are still widely open: detailed requirements, constraints and hypotheses are not yet fully stabilised. In order to design a satellite constellation satisfying civil aviation and other users needs in this early stage of the system definition, it is necessary not only to take into account classical performance aspects, such as accuracy and availability of accuracy, but also cost constraints. The paper describes the design and dimensioning method which has led ALCATEL to propose a set of MEO constellations in the frame of the GALILEO project for ESA. It especially places emphasis upon the sensitivity of the system design to numerous parameters as well as its sensitivity to performance requirements. Potential candidate constellations obviously need to meet given performance specifications which are determined by operational aspects such as: satellite reliability, maintenance strategy (spare in orbit, launch on schedule, launch on need), deployment strategy (launcher choice, etc.). The estimated cost of a potential solution is mainly derived from the number of satellites and the deployment/maintenance strategy, but it is representative of the whole life-cycle of the constellation. Furthermore, the exhibited solution shall be "as robust as" possible to requirement or assumption changes. So, it should be a baseline solution that could be easily updated in order to take into account small upgrades. This has led to the performance of some trend analyses to understand the actual influence of some constraints or requirements on the system design, and to see how initial requirements can be efficiently relaxed in order to obtain the maximum system cost diminution for a minimum constraint relaxation. This will be very useful, if cost reduction is necessary, to quickly propose alternative or sub-solutions to the baseline one.

  12. Inter-comparison of precipitation retrievals from the Global Precipitation Measurement mission constellation.

    NASA Astrophysics Data System (ADS)

    Kidd, Chris; Matsui, Toshihisa; Randel, Dave; Stocker, Erich; Kummerow, Chris

    2015-04-01

    The Global Precipitation Measurement mission (GPM) is an international satellite mission that brings together a number of different component satellites and sensors, each contributing observations capable of providing information on precipitation. The joint US-Japan core observatory, launched on 27 February 2014, carries the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR). The core observatory serves as a standard against which other sensors in the constellation are calibrated, providing a consistent observational dataset to ensure the highest quality precipitation retrievals to be made. Precipitation retrievals from the constellation of partner satellites are generated through the common framework of the Goddard-PROFiling (GPROF) scheme, and is applied to both the conically-scanning sensors and the cross-track sensors; the provision of precipitation estimates from all the constellation sensors contributing to the better-than 3-hour average temporal sampling. This study focuses upon the inter-comparison of the products from the different sensors during the first year of GPM operations; March 2014-February 2015. The two regions chosen for the inter-comparison, are the United States and Western Europe, and utilize the extensive radar networks of these regions. Statistical results were generated for instantaneous precipitation retrievals for each of the constellation sensors. Results show that overall the retrievals from the cross-track observations produce higher correlations with the surface radar data sets than the retrievals from the conically-scanning observations, although they tend to have higher root-mean squared errors. Some variation in performance between the individual types of sensors is also noted, which may be attributed to assumptions within the retrieval scheme (e.g. resolution, background fields, etc); other differences require further investigation.

  13. Kennedy Space Center: Constellation Program Electrical Ground Support Equipment Research and Development

    NASA Technical Reports Server (NTRS)

    McCoy, Keegan

    2010-01-01

    The Kennedy Space Center (KSC) is NASA's spaceport, launching rockets into space and leading important human spaceflight research. This spring semester, I worked at KSC on Constellation Program electrical ground support equipment through NASA's Undergraduate Student Research Program (USRP). This report includes a discussion of NASA, KSC, and my individual research project. An analysis of Penn State's preparation of me for an internship and my overall impressions of the Penn State and NASA internship experience conclude the report.

  14. A Hard X-Ray Telescope Science Enhancement Package for the Constellation X-Ray Mission

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian; Gorenstein, Paul

    2007-01-01

    Details of a hard-x-ray science enhancement package for the Constellation-X mission are presented. A scientific case is made for the inclusion of such an instrument on the planned mission and a detailed design is presented that will satisfy science requirements yet fall within the ground rules for enhancement packages: a cost of less than $100M and a mass of no more than 100 kg.

  15. The Constellation-EdF nuclear joint venture: regulatory issues and subsequent resolutions

    SciTech Connect

    Pfaff, Ryan; Lubow, Howard; Malko, J. Robert

    2010-03-15

    Corporate restructurings of electric utilities in the U.S. have become a significant and controversial issue due to the differing perspectives of electric utility executives and regulatory commissioners relating to corporate restructuring associated with mergers, diversification, and functional separation of generation, transmission, and distribution. The Maryland Public Service Commission assessed a joint venture between Constellation Energy Group and Electricite de France that reflects these tradeoffs. (author)

  16. Pegasus dedicated and multiple launch capabilities for low earth orbit communications satellite constellations

    NASA Astrophysics Data System (ADS)

    Mosier, Marty

    1992-03-01

    The design and standard payload interfaces of the Pegasus air-launched space booster are described and an overview of integration and launch operations is presented. Specific attention is given to services which are available to support multiple satellite launches. A recent multiple launch of seven small communication satellites is described which demonstrates Pegasus' capabilities to populate LEO communications satellite constellations quickly and cost effectively.

  17. An analytic method of space debris cloud evolution and its collision evaluation for constellation satellites

    NASA Astrophysics Data System (ADS)

    Zhang, Binbin; Wang, Zhaokui; Zhang, Yulin

    2016-09-01

    When a debris cloud is formed in the neighborhood of a constellation, the constellation satellites will face a serious threat of collision. In order to evaluate the collision probability in a long time scale, first we build an analytic model to describe the evolution process of the debris cloud. Under the perturbations of atmospheric drag, nonspherical gravity field, etc., results of numerical simulation indicate that after the breakup of an object, the distribution of debris cloud will evolve into a relatively stable band. Based on the stable distribution characteristic of the debris cloud, fragments are divided into several groups according their orbital heights and area-mass ratios. For each debris group, the dynamics of the distribution process under the perturbation of atmosphere drag is described by a partial differential equation (PDE). Solutions of those PDEs are obtained. And the distribution of the debris cloud can be easily propagated over long time scales. Applying this analytic model, the collision probability between a debris cloud and the Globalstar satellites is analyzed and computed. Results show that the collision probability is nearly 10,000 times of the average collision probability in the near Earth environment. Moreover, as the band distribution of the space debris cloud is stable, the collisional risk on constellation satellites will last for quite a long time.

  18. An operational near-space ballooncraft constellation for scientific and commercial use

    NASA Astrophysics Data System (ADS)

    Frische, E.

    The long lead times and high costs of placing satellites in orbit has led both the commercial industry and researchers to look for alternative platforms for their payloads For missions where the primary requirement is a wide geographical view or where placement above most of the earth s atmosphere is critical an alternative exists Lighter than air LTA systems operating in the near space or stratospheric environment can fill these requirements at a fraction of the cost of traditional space-borne systems Stratospheric LTA systems provide the additional benefits of payload recovery improved link budget adjustable altitudes and significantly reduced launch schedules In order to exploit these advantages Space Data Corporation has developed and placed in operation a stratospheric LTA constellation of free drifting ballooncraft This operational commercial system utilizes weather balloons to carry small telecommunications packages at controlled altitudes of 20 to 38 km The ballooncraft called SkySite mbox textregistered Platforms operate as a controlled constellation to provide wireless telecommunications coverage in remote regions currently not covered by terrestrial wireless systems Over 8000 SkySite mbox textregistered Platforms have been launched in support of this mission to date The SkySite mbox textregistered Constellation is designed to be extremely mission flexible and has been used for missions including earth imagery weather data collection and military communications The

  19. Mission design and operations of a constellation of small satellites for remote sensing

    NASA Astrophysics Data System (ADS)

    Sorensen, Trevor C.; Pilger, Eric J.; Wood, Mark S.; Nunes, Miguel A.; Yoneshige, Lance K.

    2013-05-01

    The Hawaii Space Flight Laboratory (HSFL) at the University of Hawaii at Manoa is developing the capabilities to design, build, and operate constellations of small satellites than can be tailored to efficiently execute a variety of remote sensing missions. With the Operationally Responsive Space (ORS) Office, HSFL is developing the Super Strypi launch vehicle that on its initial mission in 2013 will launch the HSFL 55-kg HawaiiSat-1 into a near polar orbit, providing the first deployment of these technologies. This satellite will be carrying a miniature hyperspectral thermal imager developed by the Hawaii Institute of Geophysics and Planetology (HIGP). HSFL has also developed a method to efficiently deploy a constellation of small satellites using a minimal number of launch vehicles. Under a three-year NASA grant, HSFL is developing a Comprehensive Open-architecture Space Mission Operations System (COSMOS) to support these types of missions. COSMOS is being designed as a System of Systems (SoS) software integrator, tying together existing elements from different technological domains. This system should be easily adaptable to new architectures and easily scalable. It will be provided as Open Source to qualified users, so will be adoptable by even universities with very restricted budgets. In this paper we present the use of COSMOS as a System of Systems integrator for satellite constellations of up to 100 satellites and numerous ground stations and/or contact nodes, including a fully automated "lights out" satellite contact capability.

  20. Deploying a single-launch nanosatellite constellation to several orbital planes using drag maneuvers

    NASA Astrophysics Data System (ADS)

    Leppinen, Hannu

    2016-04-01

    This paper proposes a method for deploying a nanosatellite constellation to several orbital planes from a single launch vehicle. The method is based on commercially available deorbit devices that are used to lower the initial orbit, and that are discarded after the correct altitude has been reached. Nodal precession of the right ascension of the ascending node at different altitudes results in spreading the orbital planes of the satellites. Maneuvering all satellites to a similar final altitude freezes the relative separation of the orbital planes. Calculations and simulations of the method are presented, and the results indicate that with a launch of 6 satellites to an initial 800 km sun-synchronous orbit, orbital plane separation of approximately 30° between each satellite can be achieved within 5 years, with each satellite in its own final 600 km orbital plane. Such a constellation could provide continuous global coverage, while requiring only one launch vehicle. Due to the timescales required by the method, it is best suited for nanosatellite missions designed for long lifetimes. Possible applications of such constellations are also discussed.

  1. A model of Earth's magnetic field derived from 2 years of Swarm satellite constellation data

    NASA Astrophysics Data System (ADS)

    Olsen, Nils; Finlay, Christopher C.; Kotsiaros, Stavros; Tøffner-Clausen, Lars

    2016-07-01

    More than 2 years of magnetic field data taken by the three-satellite constellation mission Swarm are used to derive a model of Earth's magnetic field and its time variation. This model is called SIFMplus. In addition to the magnetic field observations provided by each of the three Swarm satellites, explicit advantage is taken of the constellation aspect of Swarm by including East-West magnetic intensity and vector field gradient information from the lower satellite pair. Along-track differences of the magnetic intensity as well as of the vector components provide further information concerning the North-South gradient. The SIFMplus model provides a description of the static lithospheric field that is very similar to models determined from CHAMP data, up to at least spherical harmonic degree n=75. Also the core field part of SIFMplus, with a quadratic time dependence for n ≤ 6 and a linear time dependence for n=7-15, demonstrates the possibility to determine high-quality field models from only 2 years of Swarm data, thanks to the unique constellation aspect of Swarm. To account for the magnetic signature caused by ionospheric electric currents at polar latitudes we co-estimate, together with the model of the core, lithospheric and large-scale magnetospheric fields, a magnetic potential that depends on quasi-dipole latitude and magnetic local time.

  2. Ground Plane and Near-Surface Thermal Analysis for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Gasbarre, Joseph F.; Amundsen, Ruth M.; Scola, Salvatore; Leahy, Frank F.; Sharp, John R.

    2008-01-01

    Most spacecraft thermal analysis tools assume that the spacecraft is in orbit around a planet and are designed to calculate solar and planetary fluxes, as well as radiation to space. On NASA Constellation projects, thermal analysts are also building models of vehicles in their pre-launch condition on the surface of a planet. This process entails making some modifications in the building and execution of a thermal model such that the radiation from the planet, both reflected albedo and infrared, is calculated correctly. Also important in the calculation of pre-launch vehicle temperatures are the natural environments at the vehicle site, including air and ground temperatures, sky radiative background temperature, solar flux, and optical properties of the ground around the vehicle. A group of Constellation projects have collaborated on developing a cohesive, integrated set of natural environments that accurately capture worst-case thermal scenarios for the pre-launch and launch phases of these vehicles. The paper will discuss the standardization of methods for local planet modeling across Constellation projects, as well as the collection and consolidation of natural environments for launch sites. Methods for Earth as well as lunar sites will be discussed.

  3. Establishment criteria, routing algorithms and probability of use of inter-satellite links in mixed navigation constellations

    NASA Astrophysics Data System (ADS)

    Han, Songhui; Gui, Qingming; Li, Jianwen

    2013-06-01

    In this paper, the establishment criteria, routing algorithm and the probability of use of ISLs (inter-satellite links) in the mixed navigation constellation of GEO satellites, IGSO satellites and MEO satellites are analyzed. Firstly, the general criteria of ISL establishment in mixed navigation constellation are proposed from the perspective of geometry, and the influences of these criteria on routing algorithms and the probability of use of ISLs are discussed. Then, from the perspective of autonomous orbit determination, the routing algorithm in mixed navigation constellation is designed. Thirdly, a stochastic study of ISLs load in mixed navigation constellation is proposed, and the formulae of probability of use of ISLs are given. Finally, in the simulation, the establishment criteria, routing algorithm and the probability of use of ISLs in a specific mixed navigation constellation of 3GEO + 3IGSO + 24MEO are discussed in detail. The findings of this paper provide a basis for the ISL establishment and routing algorithm, and offer the quantitative indicators for the use of ISL in the mixed navigation constellation.

  4. The Origin(s) of Whales

    NASA Astrophysics Data System (ADS)

    Uhen, Mark D.

    2010-05-01

    Whales are first found in the fossil record approximately 52.5 million years ago (Mya) during the early Eocene in Indo-Pakistan. Our knowledge of early and middle Eocene whales has increased dramatically during the past three decades to the point where hypotheses of whale origins can be supported with a great deal of evidence from paleontology, anatomy, stratigraphy, and molecular biology. Fossils also provide preserved evidence of behavior and habitats, allowing the reconstruction of the modes of life of these semiaquatic animals during their transition from land to sea. Modern whales originated from ancient whales at or near the Eocene/Oligocene boundary, approximately 33.7 Mya. During the Oligocene, ancient whales coexisted with early baleen whales and early toothed whales. By the end of the Miocene, most modern families had originated, and most archaic forms had gone extinct. Whale diversity peaked in the late middle Miocene and fell thereafter toward the Recent, yielding our depauperate modern whale fauna.

  5. Original Misunderstanding

    ERIC Educational Resources Information Center

    Holtzman, Alexander

    2009-01-01

    Humorist Josh Billings quipped, "About the most originality that any writer can hope to achieve honestly is to steal with good judgment." Billings was harsh in his view of originality, but his critique reveals a tension faced by students every time they write a history paper. Research is the essence of any history paper. Especially in high school,…

  6. Review of the Constellation Level II Safety, Reliability, and Quality Assurance (SR&QA) Requirements Documents during Participation in the Constellation Level II SR&QA Forum

    NASA Technical Reports Server (NTRS)

    Cameron, Kenneth D.; Gentz, Steven J.; Beil, Robert J.; Minute, Stephen A.; Currie, Nancy J.; Scott, Steven S.; Thomas, Walter B., III; Smiles, Michael D.; Schafer, Charles F.; Null, Cynthia H.; Bay, P. Michael

    2009-01-01

    At the request of the Exploration Systems Mission Directorate (ESMD) and the Constellation Program (CxP) Safety, Reliability; and Quality Assurance (SR&QA) Requirements Director, the NASA Engineering and Safety Center (NESC) participated in the Cx SR&QA Requirements forum. The Requirements Forum was held June 24-26; 2008, at GRC's Plum Brook Facility. The forums purpose was to gather all stakeholders into a focused meeting to help complete the process of refining the CxP to refine its Level II SR&QA requirements or defining project-specific requirements tailoring. Element prime contractors had raised specific questions about the wording and intent of many requirements in areas they felt were driving costs without adding commensurate value. NESC was asked to provide an independent and thorough review of requirements that contractors believed were driving Program costs, by active participation in the forum. This document contains information from the forum.

  7. Noncommutative Point Sources

    SciTech Connect

    Stern, A.

    2008-02-15

    We construct a perturbative solution to classical noncommutative gauge theory on R{sup 3} minus the origin using the Groenewald-Moyal star product. The result describes a noncommutative point charge. Applying it to the quantum mechanics of the noncommutative hydrogen atom gives shifts in the 1S hyperfine splitting which are first order in the noncommutativity parameter.

  8. Origins of Coordinate Searching.

    ERIC Educational Resources Information Center

    Kilgour, Frederick G.

    1997-01-01

    Reviews the origins of post-coordinate searching and emphasizes that the focal point should be on the searcher, not on the item being indexed. Highlights include the history of the term information retrieval; edge notched punch cards; the "peek-a-boo" system; the Uniterm system; and using computers to search for information. (LRW)

  9. Understanding Geospace on a Grand Scale: The Global Ionoshphere/Thermosphere Constellation

    NASA Technical Reports Server (NTRS)

    Pfaff, Robert; Pesnell, Dean

    2011-01-01

    We present the concept of a constellation of polar orbiting satellites equally spaced in longitude (local time) to systematically sample both the neutral and ionzed gas components of the Earth in circular orbits near 350 km, including their density, temperature, and velocities. The instrumentation would include techniques to measure the height of the ionospheric "F-peak" and its variations along the orbit. The number of satellites (l2? 24? 48?) and their configuration would be determined from modeling analysis and expected geophysical phenomena, including their drivers and characteristic time scales. Together with imaging data from separate satellites, the array of satellites with in situ probes would be expected to provide a new picture of (1) high latitude electrodynamics and atmospheric processes and associated coupling with magnetospheric mass and momentum input, (2) the response of the global ionosphere and thermosphere to magnetic storms, and (3) global neutral wind circulation patterns, neutral density structure, tides, planetary waves, and gravity waves. The comprehensive measurements gathered by the IT-Constellation envisioned here would provide a major leap forward in each of these areas, addressing global physical processes and providing fundamental, new knowledge of Geospace. In particular, by its very nature, the constellation addresses "system science", revealing how the ionosphere-thermosphere connects globally to the magnetosphere above and the troposphere below. We present this concept as the next logical step in observing the "whole" space environment using in situ probes in conjunction with imagers. We invite modelers to not only comment on this concept but also to become actively engaged in helping to define it.

  10. Measuring Earth Radiation Imbalance from a Massive Constellation of Flux Radiometers

    NASA Astrophysics Data System (ADS)

    Wiscombe, W. J.; Chiu, J.; Ardanuy, P. E.; Barker, H.; Han, S.; Lorentz, S. R.; Schwartz, S. E.; Trenberth, K. E.

    2012-12-01

    The most important climate variable that is not now measured from space with sufficient accuracy (not even one significant digit on any time scale) is Earth Radiation Imbalance (ERI), a subject of much discussion lately in relation to the "global warming hiatus". The greatest temporal challenges for ERI measurements are very long (decadal) and very short (diurnal) time scales. The decadal challenge is mainly one of calibration and continuity, whereas the diurnal challenge is mainly one of temporal coverage. ERI measurements must meet both challenges. We discuss here a massive constellation of flux radiometers in Low Earth Orbit that is capable of meeting both challenges. At least 30-40 satellites are required for diurnal coverage, an order of magnitude more than in any previous Earth science mission. This same diurnal coverage would make possible, for the first time, the use of ERI measurements in data assimilation, as well as providing a much more temporally resolved dataset for tuning and evaluating climate models. Although a large number of instruments on many satellites might seem to pose a gargantuan calibration challenge, actually, the more satellites, the better the intercalibration: satellites can not only follow each other closely in the same orbit plane, viewing exactly the same scene a few minutes apart, but they can engage in a spider web of crossovers in the polar regions, allowing many further such intercalibrations. Furthermore, keystone satellites can roll over to obtain an absolute calibration from the Sun and deep space, which can then be transferred to the other satellites. Simulations of ERI from such a constellation will be shown, along with the tradeoffs necessary to create an optimal configuration and to mitigate the problems experienced by previous generations of Earth radiation budget radiometers. A tentative instrument design will also be described.Constellation of flux radiometers for measuring Earth Radiation Imbalance

  11. Development of arrays of position-sensitive microcalorimeters for Constellation-X

    NASA Technical Reports Server (NTRS)

    Smith, S. J.; Bandler, S. R.; Brekosky, R. P.; Brown, A.-D.; Chervenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Kolbourne, C. A.; Porter, F. S.; Figueroa-Feliciano, E.

    2008-01-01

    We are developing arrays of position-sensitive transition-edge sensor (POST) X-ray detectors for future astronomy missions such as NASA's Constellation-X. The POST consists of multiple absorbers thermally coupled to one or more transition-edge sensor (TES). Each absorber element has a different thermal coupling to the TES. This results in a distribution of different pulse shapes and enables position discrimination between the absorber elements. POST'S are motivated by the desire to achieve the largest possible focal plane area with the fewest number of readout channels and are ideally suited to increasing the Constellation-X focal plane area, without comprising on spatial sampling. Optimizing the performance of POST'S requires careful design of key parameters such as the thermal conductances between the absorbers, TES and the heat sink. as well as the absorber heat capacities. Using recently developed signal processing algorithms we have investigated the trade-off between position-sensitivity, energy resolution and pulse decay time. based on different device design parameters for PoST's. Our new generation of PoST's utilize technology successfully developed on high resolution (approximately 2.5eV) single pixels arrays of Mo/Au TESs. also under development for Constellation-X. This includes noise mitigation features on the TES and low resistivity electroplated absorbers. We report on the first experimental results from these new one and two-channel PoST"s, consisting of all Au and composite Au/Bi absorbers, which are designed to achieve an energy resolution of < 10 eV. coupled with count-rates of 100's per pixel per second and position sensitivity over the energy range 0.3-10 keV.

  12. Usage of Fault Detection Isolation & Recovery (FDIR) in Constellation (CxP) Launch Operations

    NASA Technical Reports Server (NTRS)

    Ferrell, Rob; Lewis, Mark; Perotti, Jose; Oostdyk, Rebecca; Spirkovska, Lilly; Hall, David; Brown, Barbara

    2010-01-01

    This paper will explore the usage of Fault Detection Isolation & Recovery (FDIR) in the Constellation Exploration Program (CxP), in particular Launch Operations at Kennedy Space Center (KSC). NASA's Exploration Technology Development Program (ETDP) is currently funding a project that is developing a prototype FDIR to demonstrate the feasibility of incorporating FDIR into the CxP Ground Operations Launch Control System (LCS). An architecture that supports multiple FDIR tools has been formulated that will support integration into the CxP Ground Operation's Launch Control System (LCS). In addition, tools have been selected that provide fault detection, fault isolation, and anomaly detection along with integration between Flight and Ground elements.

  13. Alignment and Integration Techniques for Mirror Segment Pairs on the Constellation X Telescope

    NASA Technical Reports Server (NTRS)

    Hadjimichael, Theo; Lehan, John; Olsen, Larry; Owens, Scott; Saha, Timo; Wallace, Tom; Zhang, Will

    2007-01-01

    We present the concepts behind current alignment and integration techniques for testing a Constellation-X primary-secondary mirror segment pair in an x-ray beam line test. We examine the effects of a passive mount on thin glass x-ray mirror segments, and the issues of mount shape and environment on alignment. We also investigate how bonding and transfer to a permanent housing affects the quality of the final image, comparing predicted results to a full x-ray test on a primary secondary pair.

  14. The DUBAISAT-2/DEIMOS-2 constellation: public-private cooperation between Emirates and Spain

    NASA Astrophysics Data System (ADS)

    Pirondini, Fabrizio; Al Marri, Salem

    2014-10-01

    The Emirates Institution for Advanced Science and Technology (EIAST) was established by the Dubai Government in 2006 with the goal of promoting a culture of advanced scientific research and technology innovation in Dubai and the UAE, and enhancing technology innovation and scientific skills among UAE nationals. EIAST launched in November 2013 the DubaiSat-2, its second Earth Observation satellite, and the first to provide VHR multispectral imagery. The satellite has successfully completed its in-orbit commissioning and it is now fully operational. ELECNOR DEIMOS is a private Spanish company, part of the Elecnor industrial group, which owns and operates DEIMOS-1, the first Spanish Earth Observation satellite, launched in 2009. ELECNOR DEIMOS launched in June 2014 its second satellite, DEIMOS-2, a VHR, agile satellite capable of providing 4-bands multispectral imagery. The whole end-to-end DEIMOS- 2 system has been designed to provide a cost-effective and highly responsive service to cope with the increasing need of fast access to VHR imagery. The two satellites, with a mass of 300 kg each, were developed in cooperation with Satrec-I (South Korea), and are based on the SpaceEye-1 platform. The two satellites have an identical payload, and produce 75- cm resolution pan-sharpened imagery across a 12-km swath. Together, they have a combined collection capacity of more than 300,000 sqkm per day. EIAST and ELECNOR DEIMOS have set up a unique, trans-national public-private partnership to operate the two satellites as a constellation, jointly commercialize the imagery of both satellites, and interchange technical and operational information to increase the efficiency of both systems. The operations of the constellation are based on four ground stations: Al Khawaneej (Dubai), Puertollano (Spain), Kiruna (Sweden) and Inuvik (Canada), which assure at least a contact per orbit with each satellite. The constellation functionalities of the ground segment were developed by EIAST

  15. [Multidisciplinary care during peripartum: mother-baby dyad in the center of the relational constellations].

    PubMed

    Girard, E; Ortiz, N; Alberque, C; Almeida Heymans, A; Epiney, M; Canuto, A; Weber, K

    2013-02-13

    Pregnancy and new motherhood may be crisis and vulnerability periods and therefore increase the risk of psychiatric disorders. Liaison psychiatry plays a major role in the first psychiatric evaluation of mothers in order to specify a diagnosis and to initiate a treatment when necessary. This article describes the care of mothers suffering from peripartum psychiatric disorders by the liaison psychiatry in the maternity ward, an outpatient practice, as well as an in-patient care unit where mother and baby can stay together. The multidisciplinary approach and its constellation around the mother-baby dyad are detailed and two clinical cases are reported. PMID:23477067

  16. Performance of Duplex Communication between a Leo Satellite and Terrestrial Location Using a Geo Constellation

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.; Konangi, Vijay K.; Wallett, Thomas M.

    1998-01-01

    A network comprised of a terrestrial site, a constellation of three GEO satellites and a LEO satellite is modeled and simulated. Continuous communication between the terrestrial site and the LEO satellite is facilitated by the GEO satellites. The LEO satellite has the orbital characteristics of the International Space Station. Communication in the network is based on TCP/IP over ATM, with the ABR service category providing the QoS, at OC-3 data rate. The OSPF protocol is used for routing. We simulate FTP file transfers, with the terrestrial site serving as the client and the LEO satellite being the server. The performance characteristics are presented.

  17. Compilation of Trade Studies for the Constellation Program Extravehicular Activity Spacesuit Power System

    NASA Technical Reports Server (NTRS)

    Fincannon, James

    2009-01-01

    This compilation of trade studies performed from 2005 to 2006 addressed a number of power system design issues for the Constellation Program Extravehicular Activity Spacesuit. Spacesuits were required for spacewalks and in-space activities as well as lunar and Mars surface operations. The trades documented here considered whether solar power was feasible for spacesuits, whether spacesuit power generation should be a distributed or a centralized function, whether self-powered in-space spacesuits were better than umbilically powered ones, and whether the suit power system should be recharged in place or replaced.

  18. Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

    NASA Technical Reports Server (NTRS)

    Lorenzini, E. C.; Arnold, D. A.; Grossi, M. D.; Gullahorn, G. E.

    1986-01-01

    The g-tuning maneuvers of a 3-mass, vertical tethered system are considered. In particular, the case of reaching a zero-g acceleration level on board the middle mass from a non-zero initial condition is analyzed. A control law that provides a satisfactory transient response is derived. The constellation dynamics in the case of the middle mass travelling from one tether tip to the other is also investigated. Instabilities that take place at the end of the maneuver are analyzed and accommodated by devising suitable damping algorithms.

  19. Stellar Imager (SI): Enhancements to the Mission Enabled by the Constellation Architecture (Ares I/Ares V)

    NASA Technical Reports Server (NTRS)

    Carpenter, Kenneth G.; Lyon, Richard G.; Karovska, Margarita; Mozurkwich, D.; Schrijver, Carolus

    2009-01-01

    Stellar Imager (SI) is a space-based, UV/Optical Interferometer (UVOI) with over 200x the resolution of HST. It will enable 0.1 milli-aresec spectral imaging of stellar surfaces and the Universe in general and open an enormous new "discovery space" for astrophysics with its combination of high angular resolution, dynamic imaging , and spectral energy resolution. SI's goal is to study the role of magnetism in the Universe and revolutionize our understanding of 1) Solar/Stellar Magnetic Activity and their impact on Space Weather, Planetary Climates, and Life, 2) Magnetic and Accretion Processes and their roles in the Origin & Evolution of Structure and in the Transport of Matter throughout the Universe, 3) the close-in structure of Active Galactic Nuclei and their winds, and 4) Exo-Solar Planet Transits and Disks. SI is a "Landmark-Discovery Mission" in 2005 Heliophysics Roadmap and a candidate UVOI in the 2006 Astrophysics Strategic Plan and is targeted for launch in the mid-2020's. It is a NASA Vision Mission and has been recommended for further study in a 2008 NRC report on missions potentially enabled/enhanced by an Ares V launch. In this paper, we discuss the science goals and required capabilities of SI, the baseline architecture of the mission assuming launch on one or more Delta rockets, and then the potential significant enhancements to the SI science and mission architecture that would be made possible by a launch in the larger volume Ares V payload fairing, and by servicing options under consideration in the Constellation program.

  20. Tipping Point

    MedlinePlus Videos and Cool Tools

    ... Tipping Point by CPSC Blogger September 22 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  1. Eukaryotic origins

    PubMed Central

    Lake, James A.

    2015-01-01

    The origin of the eukaryotes is a fundamental scientific question that for over 30 years has generated a spirited debate between the competing Archaea (or three domains) tree and the eocyte tree. As eukaryotes ourselves, humans have a personal interest in our origins. Eukaryotes contain their defining organelle, the nucleus, after which they are named. They have a complex evolutionary history, over time acquiring multiple organelles, including mitochondria, chloroplasts, smooth and rough endoplasmic reticula, and other organelles all of which may hint at their origins. It is the evolutionary history of the nucleus and their other organelles that have intrigued molecular evolutionists, myself included, for the past 30 years and which continues to hold our interest as increasingly compelling evidence favours the eocyte tree. As with any orthodoxy, it takes time to embrace new concepts and techniques. PMID:26323753

  2. Collagen fibril surface displays a constellation of sites capable of promoting fibril assembly, stability, and hemostasis

    SciTech Connect

    Orgel, J.P.; Antipova, O.; Sagi, I.; Bitler, A.; Qiu, D.; Wang, R.; Xu, Y.; San Antonio, J.D.

    2011-12-14

    Fibrillar collagens form the structural basis of organs and tissues including the vasculature, bone, and tendon. They are also dynamic, organizational scaffolds that present binding and recognition sites for ligands, cells, and platelets. We interpret recently published X-ray diffraction findings and use atomic force microscopy data to illustrate the significance of new insights into the functional organization of the collagen fibril. These data indicate that collagen's most crucial functional domains localize primarily to the overlap region, comprising a constellation of sites we call the 'master control region.' Moreover, the collagen's most exposed aspect contains its most stable part - the C-terminal region that controls collagen assembly, cross-linking, and blood clotting. Hidden beneath the fibril surface exists a constellation of 'cryptic' sequences poised to promote hemostasis and cell - collagen interactions in tissue injury and regeneration. These findings begin to address several important, and previously unresolved, questions: How functional domains are organized in the fibril, which domains are accessible, and which require proteolysis or structural trauma to become exposed? Here we speculate as to how collagen fibrillar organization impacts molecular processes relating to tissue growth, development, and repair.

  3. Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

    NASA Technical Reports Server (NTRS)

    Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

    2010-01-01

    Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, in a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation; testing results, and other information. Where appropriate, actual performance history was used for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to verify compliance with requirements and to highlight design or performance shortcomings for further decision-making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability and maintainability analysis, and present findings and observation based on analysis leading to the Ground Systems Preliminary Design Review milestone.

  4. Optical Metrology for the Segmented Optics on the Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Content, David; Colella, David; Fleetwood, Charles; Hadjimichael, Theo; Lehan, John; McMann, Joseph; Reid, Paul; Saha, Timo; Wright, Geraldine; Zhang, William

    2004-01-01

    We present the metrology requirements and metrology implementation necessary to prove out the reflector technology for the Constellation X(C-X) spectroscopy X-ray telescope (SXT). This segmented, 1.6m diameter highly nested Wolter-1 telescope presents many metrology and alignment challenges. In particular, these mirrors have a stringent imaging error budget as compared to their intrinsic stiffness; This is required for Constellation-X to have sufficient effective area with the weight requirement. This has implications for the metrology that can be used. A variety of contract and noncontact optical profiling and interferometric methods are combined to test the formed glass substrates before replication and the replicated reflector segments.The reflectors are tested both stand-alone and in-situ in an alignment tower.Some of these methods have not been used on prior X-ray telescopes and some are feasible only because of the segmented approach used on the SXT. Methods discussed include high precision coordinate measurement machines using very low force or optical probe axial interferometric profiling azimuthal circularity profiling and use of advanced null optics such as conical computer generated hologram (CGHs).

  5. Precise orbit determination of BeiDou constellation based on BETS and MGEX network.

    PubMed

    Lou, Yidong; Liu, Yang; Shi, Chuang; Yao, Xiuguang; Zheng, Fu

    2014-01-01

    Chinese BeiDou Navigation Satellite System is officially operational as a regional constellation with five Geostationary Earth Orbit (GEO) satellites, five Inclined Geosynchronous Satellite Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Observations from the BeiDou Experimental Tracking Stations (BETS) and the IGS Multi-GNSS Experiment (MGEX) network from 1 January to 31 March 2013 are processed for orbit determination of the BeiDou constellation. Various arc lengths and solar radiation pressure parameters are investigated. The reduced set of ECOM five-parameter model produces better performance than the full set of ECOM nine-parameter model for BeiDou IGSO and MEO. The orbit overlap for the middle days of 3-day arc solutions is better than 20 cm and 14 cm for IGSO and MEO in RMS, respectively. Satellite laser ranging residuals are better than 10 cm for both IGSO and MEO. For BeiDou GEO, the orbit overlap of several meters and satellite laser ranging residuals of several decimetres can be achieved. PMID:24733025

  6. Precise orbit determination of BeiDou constellation based on BETS and MGEX network

    NASA Astrophysics Data System (ADS)

    Lou, Yidong; Liu, Yang; Shi, Chuang; Yao, Xiuguang; Zheng, Fu

    2014-04-01

    Chinese BeiDou Navigation Satellite System is officially operational as a regional constellation with five Geostationary Earth Orbit (GEO) satellites, five Inclined Geosynchronous Satellite Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Observations from the BeiDou Experimental Tracking Stations (BETS) and the IGS Multi-GNSS Experiment (MGEX) network from 1 January to 31 March 2013 are processed for orbit determination of the BeiDou constellation. Various arc lengths and solar radiation pressure parameters are investigated. The reduced set of ECOM five-parameter model produces better performance than the full set of ECOM nine-parameter model for BeiDou IGSO and MEO. The orbit overlap for the middle days of 3-day arc solutions is better than 20 cm and 14 cm for IGSO and MEO in RMS, respectively. Satellite laser ranging residuals are better than 10 cm for both IGSO and MEO. For BeiDou GEO, the orbit overlap of several meters and satellite laser ranging residuals of several decimetres can be achieved.

  7. RaInCube: a proposed constellation of atmospheric profiling radars in cubesat

    NASA Astrophysics Data System (ADS)

    Haddad, Ziad S.; Peral, Eva; Tanelli, Simone; Sy, Ousmane; Stephens, Graeme

    2016-05-01

    Numerical climate and weather models depend on measurements from space-borne satellites to complete model validation and improvements. Precipitation profiling capabilities are currently limited to a few instruments deployed in Low Earth Orbit (LEO), which cannot provide the temporal resolution necessary to observe the evo- lution of short time-scale weather phenomena and improve numerical weather prediction models. A constellation of cloud- and precipitation-profiling instruments in LEO would provide this essential capability, but the cost and timeframe of typical satellite platforms and instruments constitute a possibly prohibitive challenge. A new radar instrument architecture that is compatible with low-cost satellite platforms, such as CubeSats and SmallSats, has been designed at JPL. Its small size, moderate mass and low power requirement enable constellation missions, which will vastly expand our ability to observe weather systems and their dynamics and thermodynamics at sub-diurnal time scales down to the temporal resolutions required to observe developing convection. In turn, this expanded observational ability can revolutionize weather now-casting and medium-range forecasting, and enable crucial model improvements to improve climate predictions.

  8. Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

    NASA Technical Reports Server (NTRS)

    Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

    2010-01-01

    Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, within a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability, and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation, testing results, and other information. Where appropriate, actual performance history was used to calculate failure rates for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to assess compliance with requirements and to highlight design or performance shortcomings for further decision making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability, and maintainability analysis, and present findings and observation based on analysis leading to the Ground Operations Project Preliminary Design Review milestone.

  9. The Boreas concept for imaging polar winds from the Iridium-NEXT constellation

    NASA Astrophysics Data System (ADS)

    Chesters, Dennis; Riishojgaard, Lars Peter

    2008-08-01

    The Iridium communications satellite constellation is a swarm of 66 LEO satellites in 6 pole-crossing orbits. Iridium LLC plans a NEXT generation to be launched 2013-16, and has invited secondary "bolt and go" payloads from Earthobserving agencies. A swarm of infrared imagers on Iridium-NEXT could track water vapor and clouds to estimate the unobserved winds above the 55-60 degree latitude limit of geosynchronous satellite imagery. This kind of polar overpass data has been demonstrated to significantly improve medium-range weather forecasts by tracking water vapor features at 6.7 microns in successive images near the pole from NASA's MODIS instruments. A "Boreas" instrument design is proposed for a push-broom imager combining two miniature sensors: uncooled microbolometric cameras gathering 4- band infrared radiometry, and small star trackers providing attitude information. An autonomous instrument package has been designed with low mass, power, and data rate. The "Boreas" instrument would use the Iridium constellation itself to relay the raw imagery from 3 successive images to ground stations that would navigate the data and extract wind vectors. Wind vectors could be generated automatically for the polar caps every few hours, and delivered for assimilation into numerical weather models during Iridium-NEXT operations, during 2016-2030.

  10. Summary of Liquid Propulsion System Needs in Support of the Constellation Program

    NASA Technical Reports Server (NTRS)

    Lorier, Terry; Sumrall, Phil; Baine, Michael

    2008-01-01

    In January 2004, the President of the United States established the Vision for Space Exploration (VSE) to complete the International Space Station, retire the Space Shuttle and develop its replacement, and expand the human presence on the Moon as a stepping stone to human exploration of Mars and worlds beyond. In response, NASA developed the Constellation Program, consisting of the components shown in Figure 1. This paper will summarize the manned spaceflight liquid propulsion system needs in support of the Constellation Program over the next 10 years. It will address all liquid engine needs to support human exploration from low Earth orbit (LEO) to the lunar surface, including an overview of engines currently under contract, those baselined but not yet under contract, and those propulsion needs that have yet to be initiated. There may be additional engine needs for early demonstrators, but those will not be addressed as part of this paper. Also, other portions of the VSE architecture, including the planned Orion abort test boosters and the Lunar Precursor Robotic Program, are not addressed here as they either use solid motors or are focused on unmanned elements of returning humans to the Moon.

  11. Precise orbit determination of BeiDou constellation based on BETS and MGEX network

    PubMed Central

    Lou, Yidong; Liu, Yang; Shi, Chuang; Yao, Xiuguang; Zheng, Fu

    2014-01-01

    Chinese BeiDou Navigation Satellite System is officially operational as a regional constellation with five Geostationary Earth Orbit (GEO) satellites, five Inclined Geosynchronous Satellite Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Observations from the BeiDou Experimental Tracking Stations (BETS) and the IGS Multi-GNSS Experiment (MGEX) network from 1 January to 31 March 2013 are processed for orbit determination of the BeiDou constellation. Various arc lengths and solar radiation pressure parameters are investigated. The reduced set of ECOM five-parameter model produces better performance than the full set of ECOM nine-parameter model for BeiDou IGSO and MEO. The orbit overlap for the middle days of 3-day arc solutions is better than 20 cm and 14 cm for IGSO and MEO in RMS, respectively. Satellite laser ranging residuals are better than 10 cm for both IGSO and MEO. For BeiDou GEO, the orbit overlap of several meters and satellite laser ranging residuals of several decimetres can be achieved. PMID:24733025

  12. F region postsunset plasma structures at low latitudes deduced from the Swarm satellite constellation

    NASA Astrophysics Data System (ADS)

    Stolle, Claudia; Xiong, Chao; Kervalishvili, Guram; Lühr, Hermann; Rauberg, Jan; Michaelis, Ingo

    2016-04-01

    ESA's constellation mission Swarm was successfully launched on 22 November 2013. The three satellites are orbiting the Earth at 470 km and 520 km altitude. The spacecraft carry instruments to monitor the plasma density and magnetic eld magnitude and their variations with high quality. We will present results on low latitude F region post sunset plasma irregularities (EPIs). EPIs are characterised by severe plasma density gradients and distinct magnetic field variations and cause GPS signal detection degradations. Our results show rather small scale sizes of EPIs (>44 km) in the zonal direction as well as more fragmented irregularities in the southern hemisphere where the ambient magnetic field is lower than on the northern hemisphere. From the Swarm spacecraft constellation with a zonal separation of about 150 km, we conclude that larger zonal scale sizes of irregularities exist in the early evening hours (around 1900 LT) and that the irregularities break into smaller structures later in the evening. However, we also observe examples where only one satellite detects EPIs, while the others show undisturbed ionization. We will present also such an example, and compare these observations with detections of depletions on satellites from other missions. There exist a strong link to low-latitude space weather: the plasma irregularities give rise to severe disturbances of GPS navigational signals and these can also be monitored on board the Swarm satellites simultaneously with the plasma irregularities.

  13. One of 50: Challenger, the University of Colorado Boulder QB50 Constellation Satellite

    NASA Astrophysics Data System (ADS)

    Palo, S. E.; Rainville, N.; Dahir, A.; Rouleau, C.; Stark, J.; Nell, N.; Fukushima, J.; Antunes de Sa, A.

    2015-12-01

    QB50 is a bold project lead by the Von Karman Institute of Fluid Dynamics as part of the European Union FP7 program to launch fifty cubesats from a single launch vehicle. With a planned deployment altitude of 380km, the QB50 constellation will stay below the space station and deorbit within 9-12 months, depending upon solar conditions. Forty of the QB50 satellites are flying specified scientific sensors which include an ion-neutral mass spectrometer, a Langmuir probe or a FIPEX oxygen sensor. This constellation of cubesats will yield an unprecedented set of distributed measurements of the lower-thermosphere. The University of Colorado Boulder was selected as part of a four team consortium of US cubesat providers to participate in the QB50 mission and is supported by the National Science Foundation. The Challenger cubesat, designed and built by a multidisciplinary team of students at the University of Colorado Boulder will carry the ion-neutral mass spectrometer as a science instrument and has heritage from the Colorado Student Space Weather Experiment (CSSWE) and Miniature X-Ray Spectrometer (MinXSS) cubesats. Many of the cubesat subsystems were designed, built and tested by students in the Space Technology Integration (STIg) lab. This paper will provide an overview and a status update of the QB50 program in addition to details of the Challenger cubesat.

  14. Close Approach Prediction Analysis of the Earth Science Constellation with the Fengyun-1C Debris

    NASA Technical Reports Server (NTRS)

    Duncan, Matthew; Rand, David K.

    2008-01-01

    Routine satellite operations for the Earth Science Constellation (ESC) include collision risk assessment between members of the constellation and other orbiting space objects. Each day, close approach predictions are generated by a U.S. Department of Defense Joint Space Operations Center Orbital Safety Analyst using the high accuracy Space Object Catalog maintained by the Air Force's 1" Space Control Squadron. Prediction results and other ancillary data such as state vector information are sent to NASAJGoddard Space Flight Center's (GSFC's) Collision Risk Assessment analysis team for review. Collision analysis is performed and the GSFC team works with the ESC member missions to develop risk reduction strategies as necessary. This paper presents various close approach statistics for the ESC. The ESC missions have been affected by debris from the recent anti-satellite test which destroyed the Chinese Fengyun- 1 C satellite. The paper also presents the percentage of close approach events induced by the Fengyun-1C debris, and presents analysis results which predict the future effects on the ESC caused by this event. Specifically, the Fengyun-1C debris is propagated for twenty years using high-performance computing technology and close approach predictions are generated for the ESC. The percent increase in the total number of conjunction events is considered to be an estimate of the collision risk due to the Fengyun-1C break- UP.

  15. The NASA Constellation University Institutes Project: Thrust Chamber Assembly Virtual Institute

    NASA Technical Reports Server (NTRS)

    Tucker, P. Kevin; Rybak, Jeffry A.; Hulka, James R.; Jones, Gregg W.; Nesman, Tomas; West, Jeffrey S.

    2006-01-01

    This paper documents key aspects of the Constellation University Institutes Project (CUIP) Thrust Chamber Assembly (TCA) Virtual Institute (VI). Specifically, the paper details the TCA VI organizational and functional aspects relative to providing support for Constellation Systems. The TCA VI vision is put forth and discussed in detail. The vision provides the objective and approach for improving thrust chamber assembly design methodologies by replacing the current empirical tools with verified and validated CFD codes. The vision also sets out ignition, performance, thermal environments and combustion stability as focus areas where application of these improved tools is required. Flow physics and a study of the Space Shuttle Main Engine development program are used to conclude that the injector is the key to robust TCA design. Requirements are set out in terms of fidelity, robustness and demonstrated accuracy of the design tool. Lack of demonstrated accuracy is noted as the most significant obstacle to realizing the potential of CFD to be widely used as an injector design tool. A hierarchical decomposition process is outlined to facilitate the validation process. A simulation readiness level tool used to gauge progress toward the goal is described. Finally, there is a description of the current efforts in each focus area. The background of each focus area is discussed. The state of the art in each focus area is noted along with the TCA VI research focus in the area. Brief highlights of work in the area are also included.

  16. Classified and clustered data constellation: An efficient approach of 3D urban data management

    NASA Astrophysics Data System (ADS)

    Azri, Suhaibah; Ujang, Uznir; Castro, Francesc Antón; Rahman, Alias Abdul; Mioc, Darka

    2016-03-01

    The growth of urban areas has resulted in massive urban datasets and difficulties handling and managing issues related to urban areas. Huge and massive datasets can degrade data retrieval and information analysis performance. In addition, the urban environment is very difficult to manage because it involves various types of data, such as multiple types of zoning themes in the case of urban mixed-use development. Thus, a special technique for efficient handling and management of urban data is necessary. This paper proposes a structure called Classified and Clustered Data Constellation (CCDC) for urban data management. CCDC operates on the basis of two filters: classification and clustering. To boost up the performance of information retrieval, CCDC offers a minimal percentage of overlap among nodes and coverage area to avoid repetitive data entry and multipath query. The results of tests conducted on several urban mixed-use development datasets using CCDC verify that it efficiently retrieves their semantic and spatial information. Further, comparisons conducted between CCDC and existing clustering and data constellation techniques, from the aspect of preservation of minimal overlap and coverage, confirm that the proposed structure is capable of preserving the minimum overlap and coverage area among nodes. Our overall results indicate that CCDC is efficient in handling and managing urban data, especially urban mixed-use development applications.

  17. Original Version

    Cancer.gov

    The EPEC-O (Education in Palliative and End-of-Life Care for Oncology) Self-Study Original Version is a free comprehensive multimedia curricula for health professionals caring for persons with cancer and their families. The curricula is available as an online Self-Study Section and as a CD-ROM you can order.

  18. Mechanical and Thermal Analysis of the Spectroscopy X-ray Telescopes for the Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Bolognese, Jeffrey; Saha, Timo; Sturm, James; Zhang, William

    2007-01-01

    Area and mass requirements for the Constellation-X Spectroscopy X-Ray Telescopes restrict the thickness of the mirror segment to below a mm. Requirement of angular resolution of 15" over the soft x-ray band implies that allowable optic deformation is sub-micrometer for these thin segments. These requirements place stringent constraint on the mounting, alignment and affixing of these mirror segments in both the metrology and integration processes. We present analyses and optimization of the Constellation-X mirrors under relevant mechanical and thermal environments.

  19. The Magnetospheric Constellation Mission. Dynamic Response and Coupling Observatory (DRACO): Understanding the Global Dynamics of the Structured Magnetotail

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Magnetospheric Constellation Dynamic Response and Coupling Observatory (DRACO) is the Solar Terrestrial Probe (STP) designed to understand the nonlinear dynamics, responses, and connections within the Earth's structured magnetotail, using a constellation of approximately 50 to 100 distributed vector measurement spacecraft. DRACO will reveal magnetotail processes operating within a domain extending 20 Earth radii (R(sub E)) across the tail and 40 R(sub E)down the tail, on spatial and time scales accessible to global circulation models, i.e., approximately 2 R(sub E) and 10 seconds.

  20. Origins--2.

    ERIC Educational Resources Information Center

    Fergusson, J. E.

    1979-01-01

    The abundance and distribution of the elements on the earth can, in part, be explained in terms of chemical properties such as reduction potentials, solubilities, ionic size, densities, melting points, and pH. The relative abundance of the elements, their distribution, and their concentration, particularly on the earth, are discussed. (Author/BB)

  1. Constellation of CubeSats for Realtime Ionospheric E-field Measurements for Global Space Weather

    NASA Astrophysics Data System (ADS)

    Crowley, G.; Swenson, C.; Pilinski, M.; Fish, C. S.; Neilsen, T. L.; Stromberg, E. M.; Azeem, I.; Barjatya, A.

    2014-12-01

    Inexpensive and robust space-weather monitoring instruments are needed to fill upcoming gaps in the Nation's ability to meet requirements for space weather specification and forecasting. Foremost among the needed data are electric fields, since they drive global ionospheric and thermospheric behavior, and because there are relatively few ground-based measurements. We envisage a constellation of CubeSats to provide global coverage of the electric field and its variability. The DICE (Dynamic Ionosphere CubeSat Experiment) mission was a step towards this goal, with two identical 1.5U CubeSats, each carrying three space weather instruments: (1) double probe instruments to measure AC and DC electric fields; (2) Langmuir probes to measure ionospheric electron density, and; (3) a magnetometer to measure field-aligned currents. DICE launched in October 2011. DICE was the first CubeSat mission to observe a Storm Enhanced Density event, fulfilling a major goal of the mission. Due to attitude control anomalies encountered in orbit, the DICE electric field booms have not yet been deployed. Important lessons have been learned for the implementation of a spin-stabilized CubeSat, and the design and performance of the Attitude Determination & Control System (ADCS). These lessons are now being applied to the DIME SensorSat, a risk-reduction mission that is capable of deploying flexible electric field booms up to a distance of 10-m tip-to-tip from a 1.5U CubeSat. DIME will measure AC and DC electric fields, and will exceed several IORD-2 threshold requirements. Ion densities, and magnetic fields will also be measured to characterize the performance of the sensor in different plasma environments. We show the utility of a constellation of electric field measurements, describe the DIME SensorSat, and demonstrate how the measurement will meet or exceed IORD requirements. The reduced cost of these sensors will enable constellations that can, for the first time, adequately resolve the

  2. The Study and Applications of Satellite and Satellite Constellation Autonomous Orbit Determination Using Star Sensor

    NASA Astrophysics Data System (ADS)

    Gan, Q. B.

    2012-07-01

    Autonomous satellite orbit determination is a key technique in autonomous satellite navigation. Many kinds of technologies have been proposed to realize the autonomous satellite navigation, such as the star sensor, the Earth magnetometer, the occultation time survey, and the phase measurement of X-ray pulsar signals. This dissertation studies a method of autonomous satellite orbit determination using star sensor. Moreover, the method is extended to the autonomous navigation of satellite constellation and the space-based surveillance. In chapters 1 and 2, some usual time and reference systems are introduced. Then the principles of several typical autonomous navigation methods, and their merits and shortcomings are analyzed. In chapter 3, the autonomous satellite orbit determination using star sensor and infrared Earth sensor (IRES) is specifically studied, which is based on the status movement simulation, the stellar background observation from star sensor, and the Earth center direction survey from IRES. By simulating the low Earth orbit satellites and pseudo Geostationary Earth orbit (PGEO) satellites, the precision of position and speed with autonomous orbit determination using star sensor is obtained. Besides, the autonomous orbit determination using star sensor with double detectors is studied. According to the observation equation's characters, an optimized type of star sensor and IRES initial assembly model is proposed. In the study of the PGEO autonomous orbit determination, an efficient sampling frequency of measurements is promoted. The simulation results confirm that the autonomous satellite orbit determination using star sensor is feasible for satellites with all kinds of altitudes. In chapter 4, the method of autonomous satellite orbit determination using star sensor is extended to the autonomous navigation of mini-satellite constellation. Combining with the high-accuracy inter satellite links data, the precision of the determined orbit and

  3. Temporal Experiment for Storms and Tropical Systems (TEMPEST) CubeSat Constellation

    NASA Astrophysics Data System (ADS)

    Reising, S. C.; Todd, G.; Padmanabhan, S.; Brown, S. T.; Lim, B.; Kummerow, C. D.; Chandra, C. V.; van den Heever, S. C.; L'Ecuyer, T. S.; Luo, Z. J.; Haddad, Z. S.; Munchak, S. J.; Ruf, C. S.; Berg, G.; Koch, T.; Boukabara, S. A.

    2014-12-01

    TEMPEST addresses key science needs related to cloud and precipitation processes using a constellation of five CubeSats with identical five-frequency millimeter-wave radiometers spaced 5-10 minutes apart in orbit. The deployment of CubeSat constellations on satellite launches of opportunity allows Earth system observations to be accomplished with greater robustness, shorter repeat times and at a small fraction of the cost of typical Earth Science missions. The current suite of Earth-observing satellites is capable of measuring precipitation parameters using radar or radiometric observations. However, these low Earth-orbiting satellites provide only a snapshot of each storm, due to their repeat-pass times of many hours to days. With typical convective events lasting 1-2 hours, it is highly unlikely that the time evolution of clouds through the onset of precipitation will be observed with current assets. The TEMPEST CubeSat constellation directly observes the time evolution of clouds and identifies changes in time to detect the moment of the onset of precipitation. The TEMPEST millimeter-wave radiometers penetrate into the cloud to directly observe changes as the cloud begins to precipitate or ice accumulates inside the storm. The evolution of ice formation in clouds is important for climate prediction because it largely drives Earth's radiation budget. TEMPEST improves understanding of cloud processes and helps to constrain one of the largest sources of uncertainty in climate models. TEMPEST provides observations at five millimeter-wave frequencies from 90 to 183 GHz using a single compact instrument that is well suited for a 6U CubeSat architecture and fits well within the NASA CubeSat Launch Initiative (CSLI) capabilities. Five identical CubeSats deployed in the same orbital plane with 5-10 minute spacing at 390-450 km altitude and 50-65 degree inclination capture 3 million observations of precipitation, including 100,000 deep convective events in a one

  4. Constellation Program Thermal and Environmental Control and Life Support System Status: 2009 - 2010

    NASA Technical Reports Server (NTRS)

    Williams, David E.; Carrasquillo, Robyn L.; Bagdigian, Robert M.

    2009-01-01

    The Constellation Program (CxP) consists of spacecrafts, launch vehicles, and support systems to execute the Exploration Architecture. The Program is currently divided into three distinct phases. The first phase is to develop a vehicle to provide limited cargo resupply capability and allow crew member rotation to the International Space Station (ISS). The second phase is to support the return of humans to the moon. The final phase is currently envisioned to allow the delivery of humans and cargo to Mars for an extended time. To implement this phased approach the CxP is currently working on the first vehicle and support systems to replace the Space Shuttle and allow continued access to space. This paper provides a summary of the CxP Thermal and Environmental Control and Life Support (ECLS) work that that has occurred across the different parts of the Program in support of these three phases over the past year.

  5. Wallops Low Elevation Link Analysis for the Constellation Launch/Ascent Links

    NASA Technical Reports Server (NTRS)

    Cheung, Keith; Ho, C.; Kantak, A.; Lee, C.; Tye, R.; Richards, E.; Sham, C.; Schlesinger, A.; Barritt, B.

    2011-01-01

    To execute the President's Vision for Space Exploration, the Constellation Program (CxP) was formed to build the next generation spacecraft Orion and launch vehicles Ares, to transport human and cargo to International Space Station (ISS), moon, and Mars. This paper focuses on the detailed link analysis for Orion/Ares s launch and ascent links with Wallops 11.3m antenna (1) Orion's Dissimilar Voice link: 10.24 Kbps, 2-way (2) Ares Developmental Flight Instrument link, 20 Mbps, downlink. Three launch trajectories are considered: TD7-E, F (Feb), and G (Aug). In certain launch scenarios, the critical events of main engine cutoff (MECO) and Separation occur during the low elevation regime of WFF s downrange -- less than 5 degree elevation angle. The goal of the study is to access if there is enough link margins for WFF to track the DV and DFI links.

  6. DICER1-pleuropulmonary blastoma familial tumor predisposition syndrome: a unique constellation of neoplastic conditions

    PubMed Central

    Yang, Jiandong; Doros, Leslie; Williams, Gretchen M.; Harris, Anne; Stewart, Douglas R.; Messinger, Yoav; Field, Amanda; Dehner, Louis P.; Hill, D Ashley

    2014-01-01

    Germline mutations in DICER1 are associated with increased risk for a wide variety of neoplastic conditions, including pleuropulmonary blastoma (PPB), cystic nephroma, nasal chondromesenchymal hamartoma, ovarian Sertoli-Leydig cell tumors, botryoid embryonal rhabdomyosarcoma of the uterine cervix, ciliary body medulloepithelioma, pineoblastoma, pituitary blastoma and nodular thyroid hyperplasia or thyroid carcinoma. These tumors may be seen in isolation or in constellation with other characteristic tumor types in individuals or family members. Here we describe the medical history of a child with a heterozygous, loss of function germline DICER1 mutation and multiple tumors associated with the syndrome.. Although germline mutations in DICER1 are rare, tumors of these types will be seen by practicing pathologists and should prompt consideration of an underlying DICER1 mutation. PMID:25356068

  7. Technology Development for the Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Lehan, John; O'Dell, Stephen; Owens, Scott; Reid, Paul B.; Saha, Timo; Stewart, Jeff; Jones, William D.; Zhang, William

    2005-01-01

    The Constellation-X Spectroscopy X-ray Telescope (SXT) is a large diameter, high throughput, grazing incidence imaging mirror system, designed to perform high sensitivity spectroscopy of cosmic X-ray sources in the 0.2-10.0 keV band. The baseline effective area requirement is -3 m# at 1 keV. The system-level angular-resolution requirement is a 15-arcseconds half-power diameter, with a 5-arcsecond goal. The effective area is attained through a modular design, involving the nesting of many confocal, thin-walled Wolter I mirror segments. Considerable progress has been made in developing thin, thermally formed, glass mirror substrates that meet or better the angular-resolution requirement. Several approaches to mounting and aligning reflector segments into a mirror system are under investigation. We report here on the progress of the SXT technology development program toward reaching the performance goals.

  8. Earth observation with MEO transmitters and UAS receivers: A potential utilization of Galileo constellation

    NASA Astrophysics Data System (ADS)

    D'Errico, Marco; Renga, Alfredo; Graziano, Maria Daniela

    2014-01-01

    Remote sensing application of Galileo upcoming constellation in the field of civil security is preliminarily analyzed, defining low resolution (25 m) and high resolution (7.5 m) working modes for a bistatic Synthetic Aperture Radar system utilizing Galileo satellites as transmitters and Unmanned Aerial Systems as receivers. Simulations offshore Somali coast and in a South Mediterranean Sea region showed that both low and high resolution acquisitions are feasible. For the low resolution mode a probability of successful image formation no matter the azimuth position of the receiving UAS has been estimated at nearly 100%. Whereas, for the high resolution mode it decreases to about 90%, which, if deemed unsatisfactory for the application, leads to the need for UAS to adapt its route to the actual Galileo satellite coverage.

  9. Superpolishing and Precision Metrology on a Metal Mandrel and Replicated Segments for Constellation-X

    NASA Technical Reports Server (NTRS)

    Content, D.; Lyons, J.; Saha, T.; Wright, G.; Zaniewski, J.; Petre, R.; Chan, K. W.

    1999-01-01

    We have superpolished a diamond-turned aluminum mandrel (coated with electroless Ni) to an axial roughness of 0.34 nm rms. The mandrel is made to the Astro-E secondary mirror design for the 81st shell. Precision metrology at 100 mm to submicron scales has established the power spectral density of the mandrel and ultralightweight gold coated replicated segments. Predicted image quality of a set of optimally aligned replicated segments of this and a matching primary is substantially improved as compared to the flight mirrors for Astro-E. This approach using metal mandrels, superpolishing, and replicated ultralightweight foil mirrors, may represent a cost-effective approach to meeting the 15 arcsec half-energy width and weight requirements for the Constellation-X mission. Descriptions of the polishing apparatus, the precision metrology instruments, and the surface data analysis are presented. The general methods described are applicable to precision optics for both normal incidence and grazing incidence optics.

  10. Superpolishing and Precision Metrology on a Metal Mandrel and Replicated Segments for Constellation-X

    NASA Technical Reports Server (NTRS)

    Content, D.; Saha, T.; Petre, R.; Lyons, J. J., III; Wright, G.; Zaniewski, J.; Chan, K. W.

    1999-01-01

    We have superpolished a diamond-turned aluminum mandrel (coated with electroless Ni) to an axial roughness of 6.34 nm rms. The mandrel is made to the Astro-E secondary mirror design for the 81st shell. Precision metrology at 100 mm to submicron scales has established the power spectral density of the mandrel and ultralightweight gold coated replicated segments. Predicted image quality of a set of optimally aligned replicated segments of this and a matching primary is substantially improved as compared to the flight mirrors for Astro-E. This approach using metal mandrels, superpolishing, and replicated ultralightweight foil mirrors, may represent a cost-effective approach to meeting the 15 arcsec half-energy width and weight requirements for the Constellation-X mission. Descriptions of the polishing apparatus, the precision metrology instruments, and the surface data analysis are presented. The general methods described are applicable to precision optics for both normal incidence and grazing incidence optics.

  11. Under the axis II radar: clinically relevant personality constellations that escape DSM-IV diagnosis.

    PubMed

    Blagov, Pavel S; Bradley, Rebekah; Westen, Drew

    2007-06-01

    Research suggests that personality pathology lies on a continuum from relatively severe to less severe and that subthreshold variants may not be adequately captured by axis II of DSM-IV. In this study, we used a measure of personality and psychopathology designed for experienced clinical observers (the SWAP-200) to derive subthreshold personality constellations in a sample of 159 psychotherapy patients who were high functioning but nevertheless suffered from maladaptive personality patterns. Using Q-factor analysis (an empirical clustering procedure), we identified 4 diagnostic groupings or SPC, which resembled the clinical concept of "neurotic styles": depressive, hostile-competitive, obsessive, and hysterical. The results of this study should stimulate further research on subthreshold personality configurations. PMID:17568295

  12. Oxygen Concentration Flammability Thresholds of Selected Aerospace Materials Considered for the Constellation Program

    NASA Technical Reports Server (NTRS)

    Hirsch, David B.; Williams, James H.; Harper, Susan A.; Beeson, Harold; Pedley, Michael D.

    2007-01-01

    Materials selection for spacecraft is based on an upward flammability test conducted in a quiescent environment in the highest expected oxygen concentration environment. The test conditions and its pass/fail test logic do not provide sufficient quantitative materials flammability information for an advanced space exploration program. A modified approach has been suggested determination of materials self-extinguishment limits. The flammability threshold information will allow NASA to identify materials with increased flammability risk from oxygen concentration and total pressure changes, minimize potential impacts, and allow for development of sound requirements for new spacecraft and extraterrestrial landers and habitats. This paper provides data on oxygen concentration self-extinguishment limits under quiescent conditions for selected materials considered for the Constellation Program.

  13. Development of Prototype Nickel Optic for the Constellation-X Hard X-Ray Telescope

    NASA Astrophysics Data System (ADS)

    Romaine, S.; Gorenstein, P.; Bruni, R.; Pareschi, G.; Citterio, O.; Ghigo, M.; Mazzoleni, F.; Spiga, D.; Basso, S.; Conti, G.; Ramsey, B.; Gubarev, M.; O'Dell, S.; Speegle, C.; Engelhaupt, D.; Freyberg, M.; Burkert, W.; Hartner, G.

    2005-12-01

    The Constellation-X mission planned for launch in 2015, will feature an array of Hard X-ray telescopes (HXT) whose bandwidth extends to \\ 70 keV. Several technologies are being investigated for fabrication of these optics, including multilayer Coated Electroformed-Nickel-Replicated (ENR) shells. We are building a prototype HXT mirror module using an ENR process to fabricate the in dividual shells.This prototype consists of 5 shells with diameters ranging from 150 mm to 280 mm with a length of 426 mm. This paper presents a progress update and focuses on accomplishments during this past year. In particular, we will present results from high energy full illumination tests, taken at the MPE Panter Test Facility. This work was supported in part by NASA Grant NNG05WC27G and CONX/NASA grant 44A-1046805.

  14. Constellation Program Design Challenges as Opportunities for Educational Outreach and Workforce Development for Senior Design Classes

    NASA Technical Reports Server (NTRS)

    Trevino, Robert C.

    2009-01-01

    The Texas Space Grant Consortium (TSGC) and the Exploration Systems Mission Directorate (ESMD) both have programs that present design challenges for university senior design classes that offer great opportunities for educational outreach and workforce development. These design challenges have been identified by NASA engineers and researchers as real design problems faced by the Constellation Program in its exploration missions and architecture. Student teams formed in their senior design class select and then work on a design challenge for one or two semesters. The senior design class follows the requirements set by their university, but it must also comply with the Accreditation Board for Engineering and Technology (ABET) in order to meet the class academic requirements. Based on a one year fellowship at a TSGC university under the NASA Administrator's Fellowship Program (NAFP) and several years of experience, results and metrics are presented on the NASA Design Challenge Program.

  15. Constellation Program Design Challenges as Opportunities for Educational Outreach- Lessons Learned

    NASA Technical Reports Server (NTRS)

    Trevino, Robert C.

    2010-01-01

    The Texas Space Grant Consortium (TSGC) and the NASA Exploration Systems Mission Directorate (ESMD) Education Office both have programs that present design challenges for university senior design classes that offer great opportunities for educational outreach and workforce development. These design challenges have been identified by NASA engineers and scientists as actual design problems faced by the Constellation Program in its exploration missions and architecture. Student teams formed in their senior design class select and then work on a design challenge for one or two semesters. The senior design class follows the requirements set by their university, but it must also comply with the Accreditation Board for Engineering and Technology (ABET) in order to meet the class academic requirements. Based on a one year fellowship at a TSGC university under the NASA Administrator's Fellowship Program (NAFP) and several years of experience, lessons learned are presented on the NASA Design Challenge Program.

  16. Lessons Learned for Cx PRACA. Constellation Program Problem Reporting, Analysis and Corrective Action Process and System

    NASA Technical Reports Server (NTRS)

    Kelle, Pido I.; Ratterman, Christian; Gibbs, Cecil

    2009-01-01

    This slide presentation reviews the Constellation Program Problem Reporting, Analysis and Corrective Action Process and System (Cx PRACA). The goal of the Cx PRACA is to incorporate Lessons learned from the Shuttle, ISS, and Orbiter programs by creating a single tool for managing the PRACA process, that clearly defines the scope of PRACA applicability and what must be reported, and defines the ownership and responsibility for managing the PRACA process including disposition approval authority. CxP PRACA is a process, supported by a single information gathering data module which will be integrated with a single CxP Information System, providing interoperability, import and export capability making the CxP PRACA a more effective and user friendly technical and management tool.

  17. Aries - Global communication through a constellation of low earth orbit satellites

    NASA Astrophysics Data System (ADS)

    Summers, Robert A.; Lepkowski, Ronald J.

    1992-03-01

    Constellations of low earth orbit satellites can provide global communications with low-cost, low-power transceivers. The Aries system provides a full range of voice, data and position location services to users worldwide. It uses 48 LEO Lightsats to provide continuous connectivity between a user terminal and a gateway earth station, which in turn connects with other switched networks. The system uses the RDSS frequencies at L, S and C-bands to offer voice and data communication in addition to radio location. The in-bound L-band link to the LEO satellite transmits a single channel per carrier signal from the inexpensive low-power user terminal to the satellite, which is then retransmitted to the gateway at C-band. The outbound TDM signal is transmitted to the satellite at C-band, spread to 16 MHz with a CDMA waveform, and broadcast by the satellite at S-band.

  18. Seal Materials Compatible with the Electroplating Solvent Used in Constellation-X Mirrors

    NASA Technical Reports Server (NTRS)

    Pei, Xiong-Skiba

    1999-01-01

    The existing gasket seals used in electroplating of the Constellation-X mirrors are difficult to assemble, and the current seal material is hydrophobic and too thick. The combination of the above problems result in: 1) non-uniform plating; 2) defect sites such as pits on the mirror edges; 3) "bear claws" on the edges of the mandrels and mirrors causing difficulties in shell-mirror separations; and 4) leakage of the plating solution past the seals into the mandrel causing chemical etching of the mandrel interior. This paper reports the results of this summer study in searching for alternate seal materials chemically compatible with the electroplating solvent. Fifteen common elastomeric rubber seal materials made-by Parker Seals were investigated including butyl, ethylene propylene, fluorosilicone, nitrile, Viton fluorocarbon, and silicone. Test results showed that Viton fluorocarbon compounds as a group were superior to the other tested compounds for chemical compatibility with the plating bath.

  19. Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

    NASA Technical Reports Server (NTRS)

    McFarland, Shane

    2009-01-01

    Field of view has always been a design feature paramount to helmets, and in particular space suits, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view will be required. Through taxonimization of various parameters that affect suited field of view, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was employed to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables while sacrificing minimal fidelity.

  20. Constellation Architecture Team-Lunar Scenario 12.0 Habitation Overview

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Toups, Larry; Rudisill, Marianne

    2009-01-01

    This paper will describe an overview of the Constellation Architecture Team Lunar Scenario 12.0 surface habitation approach, concept, and assessments performed during the study definition. The Lunar Scenario 12 architecture study focused on two primary habitation approaches: a horizontally-oriented habitation module (LS-12.0) and a vertically-oriented habitation module (LS-12.1). This paper will provide an overview of 12.0 lunar surface campaign, the associated outpost architecture, habitation functionality, concept description, system integration strategy, mass and power resource estimates. The Scenario 12 architecture resulted from combining three previous scenarios after the Lunar Surface Systems (LSS) Project Office meeting in April 28-30, 2009. The best attributes from Scenario 4 "Optimized Exploration", Scenario 5 "Fission Surface Power System" and Scenario 8 "Initial Extensive Mobility" were combined into Scenario 12 along with an added emphasis on defining the excursion ConOps while the crew is away from the outpost location.

  1. A Constellation of Microsatellites Promises to Help in a Range of Geoscience Research

    NASA Technical Reports Server (NTRS)

    Kuo, Y. H.; Chao, B. F.; Lee, L. C.

    1999-01-01

    An octet of microsatellites to be launched in 2003 promises to deliver a large amount of useful data for meteorological, climatic, ionospheric, and geodetic research as well as for operational weather forecasting and space weather monitoring. Known as the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), the joint Taiwan-U.S. scientific satellite project makes use of Global Positioning System (GPS) occultation and tracking signals. COSMIC's final operational configuration is depicted in Figure 1. Each of the eight microsatellites in low-Earth-orbit (LEO, shown relative to the high-altitude GPS satellite orbits) will carry in particular an advanced limb-sounding GPS receiver, a Tiny Ionospheric Photometer, and a triband beacon transmitter.

  2. Evaluation of Dowfrost(TM) HD as a Thermal Control Fluid for Constellation Vehicles

    NASA Technical Reports Server (NTRS)

    Lee, Steve

    2009-01-01

    A test was conducted from November 2008 to January 2009 to help determine the compatibility of an inhibited propylene glycol/water solution with planned Constellation vehicles. Dowfrost(TradeMark) HD was selected as the baseline for Orion, as well as other Constellation systems. Therefore, the same Dowfrost(TradeMark) HD/Water solution planned for Orion was chosen for this test. The fluid was subjected to a thermal fluid loop that had flightlike properties, as compared to Orion. The fluid loop had similar wetted materials, temperatures, flow rates, and aluminum wetted surface area to fluid volume ratio. The test was designed to last for 10 years, the life expectancy of the lunar habitat. However, the test lasted less than two months. System filters became clogged with precipitate, rendering the fluid system inoperable. Upon examination of the precipitate, it was determined that the precipitate composition contained aluminum, which could have only come from materials in the test stand, as aluminum is not part of the Dowfrost(TradeMark HD composition. Also, the fluid pH was determined to have increased from 10.1, at the first test sample, to 12.2, at the completion of the test. This high of a pH is corrosive to aluminum and was certainly a contributing factor to the development of precipitate. Chemical analyses and bench-top tests are currently ongoing to determine the underlying cause for this rapid degradation of the fluid. Hamilton Sundstrand, the contractor developing the Orion thermal fluid loop, is performing a parallel effort to not only understand the cause of fluid degradation in the test, but also to investigate solutions to avoid this problem in the Orion s thermal control system. JSC also consulted with the Hamilton Sundstrand team in the development of this test and the subsequent analysis.

  3. A 6U CubeSat Constellation for Atmospheric Temperature and Humidity Sounding

    NASA Technical Reports Server (NTRS)

    Padmanabhan, Sharmila; Brown, Shannon; Kangaslahti, Pekka; Cofield, Richard; Russell, Damon; Stachnik, Robert; Steinkraus, Joel; Lim, Boon

    2013-01-01

    We are currently developing a 118/183 GHz sensor that will enable observations of temperature and precipitation profiles over land and ocean. The 118/183 GHz system is well suited for a CubeSat deployment as 10cm antenna aperture provides sufficiently small footprint sizes (is approx. 25km). This project will enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U CubeSat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters that are needed to improve prediction of extreme weather events. We will take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass and low-power high frequency airborne radiometers. The 35 nm InP enabling technology provides significant reduction in power consumption (Low Noise Amplifier + Mixer Block consumes 24 mW). In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder instrument on the 6U CubeSat. In addition, a summary of radiometer calibration and retrieval techniques of the temperature and humidity will be discussed. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a constellation consisting of suite of these instruments. The proposed constellation of these 6U CubeSat radiometers would allow sampling of tropospheric temperature and humidity with fine temporal (on the order of minutes) and spatial resolution (is approx. 25 km).

  4. Monitoring lowermost tropospheric carbon monoxide from a geostationary constellation: observation simulations

    NASA Astrophysics Data System (ADS)

    Barre, J.; Worden, H. M.; Edwards, D. P.; Arellano, A. F.; Lahoz, W. A.

    2013-12-01

    In this study we present simulations of carbon monoxide (CO) observations to compare the capabilities of three geostationary thermal and near infrared (TIR/NIR) instruments over different regions of the globe - a geostationary constellation. We simulate MOPITT-like observations with a geostationary footprint over three regions: North America, Europe and Eastern Asia. We use GEOS-5 model output as the Nature run. To simulate the geostationary observations we use the singular vector decomposition (SVD) technique of Worden et al. 2013 to derive scene dependent averaging kernels (AKs) and thus avoid a full retrieval calculation. This technique uses a multiple regression approach for deriving scene-dependent AKs with predictors based on state parameters such as thermal contrast, CO mixing ratios, water vapor, and solar zenith angle. With this technique, we can produce with relatively little computational cost realistic monthly data sets (scene dependent AKs) with high spatial and temporal resolution (10-20 km and 1 hour, respectively). The three different regions of interest show different meteorological and chemical characteristics. We assess the impact of clouds on the observations, and find the instrument over Eastern Asia is the most affected. On average, only 30% of the data are available, and in some regions (South East Asia) this figure is reduced to less than 10%. Clouds, with an average of 70% coverage, less affect the instruments over North America and Europe. The Mediterranean and California regions have temporal coverage close to 100%. We also focus on the temporal variability of CO over megacities and less urbanized regions, and assess the performance of the three instruments for these cases. The next step of this study will be to perform an observation simulation system experiment (OSSE), i.e., assimilate these data at the global scale and study the synergies between the three instruments. We will focus on processes affecting long-range transport of

  5. "Constellation-X and JWST: Concurrent X-ray and Infrared Great Observatories"

    NASA Technical Reports Server (NTRS)

    Hornschemeier, Ann

    2007-01-01

    Great synergy has been enjoyed between NASA's current Great Observatories and we expect that this will continue in the next decade with the concurrent operation of both Constellation-X and JWST. The great increase in sensitivity offered by these two observatories, working in unison, will be required for a number of key science investigations, several of which we describe in this poster. For instance, although >SO% of the cosmic X-ray background is resolved at 2-8 keV in the deepest Chandra surveys, the peak of the cosmic X-ray background remains largely unexplained (at energies of 8-40 keV). There may be a significant population of obscured (perhaps Compton-thick) AGN that produce this part of the extragalactic background radiation, and Constellation-X's large collecting area and spectroscopic capabilities over the 1-40 keV bandpass will allow determination of the nature of the obscuring material. This obscured nuclear emission is expected to be re-emitted at longer wavelengths and hence mid-infrared (MIR) observations can be crucial to reveal obscured AGN emission. However, current photometric observations in the infrared are limited by contamination from star formation, and sensitive, moderate-to-high resolution IR spectroscopy (provided by JWST) will be required. In addition, the two observatories will make great advances in unraveling the nature of the highest redshift AGN (4 < z < 8; and possibly 8dow)n to Seyfert luminosities and will probe the formation and evolution of galaxy groups and clusters (including important cosmological measurements). This poster describes these science areas and briefly touches upon the role of the various Con-X and JWST instruments in these science investigations.

  6. Preliminary Performance Analyses of the Constellation Program ARES 1 Crew Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Phillips, Mark; Hanson, John; Shmitt, Terri; Dukemand, Greg; Hays, Jim; Hill, Ashley; Garcia, Jessica

    2007-01-01

    By the time NASA's Exploration Systems Architecture Study (ESAS) report had been released to the public in December 2005, engineers at NASA's Marshall Space Flight Center had already initiated the first of a series of detailed design analysis cycles (DACs) for the Constellation Program Crew Launch Vehicle (CLV), which has been given the name Ares I. As a major component of the Constellation Architecture, the CLV's initial role will be to deliver crew and cargo aboard the newly conceived Crew Exploration Vehicle (CEV) to a staging orbit for eventual rendezvous with the International Space Station (ISS). However, the long-term goal and design focus of the CLV will be to provide launch services for a crewed CEV in support of lunar exploration missions. Key to the success of the CLV design effort and an integral part of each DAC is a detailed performance analysis tailored to assess nominal and dispersed performance of the vehicle, to determine performance sensitivities, and to generate design-driving dispersed trajectories. Results of these analyses provide valuable design information to the program for the current design as well as provide feedback to engineers on how to adjust the current design in order to maintain program goals. This paper presents a condensed subset of the CLV performance analyses performed during the CLV DAC-1 cycle. Deterministic studies include development of the CLV DAC-1 reference trajectories, identification of vehicle stage impact footprints, an assessment of launch window impacts to payload performance, and the computation of select CLV payload partials. Dispersion studies include definition of input uncertainties, Monte Carlo analysis of trajectory performance parameters based on input dispersions, assessment of CLV flight performance reserve (FPR), assessment of orbital insertion accuracy, and an assessment of bending load indicators due to dispersions in vehicle angle of attack and side slip angle. A short discussion of the various

  7. Maritime surveillance with synthetic aperture radar (SAR) and automatic identification system (AIS) onboard a microsatellite constellation

    NASA Astrophysics Data System (ADS)

    Peterson, E. H.; Zee, R. E.; Fotopoulos, G.

    2012-11-01

    New developments in small spacecraft capabilities will soon enable formation-flying constellations of small satellites, performing cooperative distributed remote sensing at a fraction of the cost of traditional large spacecraft missions. As part of ongoing research into applications of formation-flight technology, recent work has developed a mission concept based on combining synthetic aperture radar (SAR) with automatic identification system (AIS) data. Two or more microsatellites would trail a large SAR transmitter in orbit, each carrying a SAR receiver antenna and one carrying an AIS antenna. Spaceborne AIS can receive and decode AIS data from a large area, but accurate decoding is limited in high traffic areas, and the technology relies on voluntary vessel compliance. Furthermore, vessel detection amidst speckle in SAR imagery can be challenging. In this constellation, AIS broadcasts of position and velocity are received and decoded, and used in combination with SAR observations to form a more complete picture of maritime traffic and identify potentially non-cooperative vessels. Due to the limited transmit power and ground station downlink time of the microsatellite platform, data will be processed onboard the spacecraft. Herein we present the onboard data processing portion of the mission concept, including methods for automated SAR image registration, vessel detection, and fusion with AIS data. Georeferencing in combination with a spatial frequency domain method is used for image registration. Wavelet-based speckle reduction facilitates vessel detection using a standard CFAR algorithm, while leaving sufficient detail for registration of the filtered and compressed imagery. Moving targets appear displaced from their actual position in SAR imagery, depending on their velocity and the image acquisition geometry; multiple SAR images acquired from different locations are used to determine the actual positions of these targets. Finally, a probabilistic inference

  8. Social Determinants and the Classification of Disease: Descriptive Epidemiology of Selected Socially Mediated Disease Constellations

    PubMed Central

    Levine, Robert S.; Kilbourne, Barbara A.; Rust, George S.; Langston, Michael A.; Husaini, Baqar A.; Gittner, Lisaann S.; Sanderson, Maureen; Hennekens, Charles H.

    2014-01-01

    Background Most major diseases have important social determinants. In this context, classification of disease based on etiologic or anatomic criteria may be neither mutually exclusive nor optimal. Methods and Findings Units of analysis comprised large metropolitan central and fringe metropolitan counties with reliable mortality rates – (n = 416). Participants included infants and adults ages 25 to 64 years with selected causes of death (1999 to 2006). Exposures included that residential segregation and race-specific social deprivation variables. Main outcome measures were obtained via principal components analyses with an orthogonal rotation to identify a common factor. To discern whether the common factor was socially mediated, negative binomial multiple regression models were developed for which the dependent variable was the common factor. Results showed that infant deaths, mortality from assault, and malignant neoplasm of the trachea, bronchus and lung formed a common factor for race-gender groups (black/white and men/women). Regression analyses showed statistically significant, positive associations between low socio-economic status for all race-gender groups and this common factor. Conclusions Between 1999 and 2006, deaths classified as “assault” and “lung cancer”, as well as “infant mortality” formed a socially mediated factor detectable in population but not individual data. Despite limitations related to death certificate data, the results contribute important information to the formulation of several hypotheses: (a) disease classifications based on anatomic or etiologic criteria fail to account for social determinants; (b) social forces produce demographically and possibly geographically distinct population-based disease constellations; and (c) the individual components of population-based disease constellations (e.g., lung cancer) are phenotypically comparable from one population to another but genotypically different, in part, because

  9. Analysis of dual polarization images of precipitating clouds collected by the COSMO SkyMed constellation

    NASA Astrophysics Data System (ADS)

    Baldini, Luca; Roberto, Nicoletta; Gorgucci, Eugenio; Fritz, Jason; Chandrasekar, V.

    2014-07-01

    Currently, several satellite missions are employing X-band synthetic aperture radars (SAR) with polarimetric capabilities. In images collected over land by X-band SAR, precipitation results mainly in evident attenuation of the surface returns. Effects of precipitation in polarimetric SAR images and how to exploit them for precipitation studies are emerging topics of interest. This paper investigates polarimetric signatures of precipitation in images collected by the X-band SARs of the Italian Space Agency COSMO SkyMed constellation using the HH-VV alternate polarimetric mode. Analyzed images were collected in 2010 when the constellation was composed of three satellites and operated in the “tandem like” interferometric configuration, which allowed acquisition of the same scene with the same viewing geometry and a minimum decorrelation time of one day. Observations collected in Piedmont (Italy) and Tampa Bay (Florida, US) have been analyzed along with coincident observations collected by operational weather radars, used to reconstruct the component of SAR returns due to precipitation at horizontal and vertical polarization states. Different techniques are used depending on the different characteristics of terrestrial radars. SAR observations reconstructed from terrestrial measurements are in fairly good agreement with actual SAR observations. Results confirm that the attenuation signature in SAR images collected over land is particularly pronounced in the presence of precipitation cells and can be related to the radar reflectivity integrated along the same path. The difference between copolar HH and VV power measurements reveals a differential attenuation due to anisotropy of precipitation, whose range is limited when the SAR incidence angle is low. A specific feature observed in the CosmoSkyMed alternate polarization implementation is the presence of the scalloping effect, a periodic effect along the azimuth direction that cannot always be removed by standard de

  10. The Role and Quality of Software Safety in the NASA Constellation Program

    NASA Technical Reports Server (NTRS)

    Layman, Lucas; Basili, Victor R.; Zelkowitz, Marvin V.

    2010-01-01

    In this study, we examine software safety risk in the early design phase of the NASA Constellation spaceflight program. Obtaining an accurate, program-wide picture of software safety risk is difficult across multiple, independently-developing systems. We leverage one source of safety information, hazard analysis, to provide NASA quality assurance managers with information regarding the ongoing state of software safety across the program. The goal of this research is two-fold: 1) to quantify the relative importance of software with respect to system safety; and 2) to quantify the level of risk presented by software in the hazard analysis. We examined 154 hazard reports created during the preliminary design phase of three major flight hardware systems within the Constellation program. To quantify the importance of software, we collected metrics based on the number of software-related causes and controls of hazardous conditions. To quantify the level of risk presented by software, we created a metric scheme to measure the specificity of these software causes. We found that from 49-70% of hazardous conditions in the three systems could be caused by software or software was involved in the prevention of the hazardous condition. We also found that 12-17% of the 2013 hazard causes involved software, and that 23-29% of all causes had a software control. Furthermore, 10-12% of all controls were software-based. There is potential for inaccuracy in these counts, however, as software causes are not consistently scoped, and the presence of software in a cause or control is not always clear. The application of our software specificity metrics also identified risks in the hazard reporting process. In particular, we found a number of traceability risks in the hazard reports may impede verification of software and system safety.

  11. Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

    NASA Technical Reports Server (NTRS)

    McFarland, Shane M.

    2008-01-01

    Field of view has always been a design feature paramount to helmet design, and in particular space suit design, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a slightly different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view is required. Through taxonimization of various parameters that affect suited FOV, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was able to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables without sacrificing fidelity. The specific field of view angles were defined by considering mission segment activities, historical performance of other suits, comparison between similar requirements (pressure visor up versus down, etc.), estimated requirements from other teams for field of view (Orion, Altair, EVA), previous field of view tests, medical data for shirtsleeve field of view performance, and mapping of visual field data to generate 45degree off-axis field of view requirements. Full resolution of several specific field of view angle requirements warranted further work, which consisted of low and medium fidelity field of view testing in the rear entry ISuit and DO27 helmet prototype. This paper serves to document this reduction progress and followup testing employed to write the Constellation requirements for helmet field of view.

  12. Asynchronous Processing of a Constellation of Geostationary and Polar-Orbiting Satellites for Fire Detection and Smoke Estimation

    NASA Astrophysics Data System (ADS)

    Hyer, E. J.; Peterson, D. A.; Curtis, C. A.; Schmidt, C. C.; Hoffman, J.; Prins, E. M.

    2014-12-01

    The Fire Locating and Monitoring of Burning Emissions (FLAMBE) system converts satellite observations of thermally anomalous pixels into spatially and temporally continuous estimates of smoke release from open biomass burning. This system currently processes data from a constellation of 5 geostationary and 2 polar-orbiting sensors. Additional sensors, including NPP VIIRS and the imager on the Korea COMS-1 geostationary satellite, will soon be added. This constellation experiences schedule changes and outages of various durations, making the set of available scenes for fire detection highly variable on an hourly and daily basis. Adding to the complexity, the latency of the satellite data is variable between and within sensors. FLAMBE shares with many fire detection systems the goal of detecting as many fires as possible as early as possible, but the FLAMBE system must also produce a consistent estimate of smoke production with minimal artifacts from the changing constellation. To achieve this, NRL has developed a system of asynchronous processing and cross-calibration that permits satellite data to be used as it arrives, while preserving the consistency of the smoke emission estimates. This talk describes the asynchronous data ingest methodology, including latency statistics for the constellation. We also provide an overview and show results from the system we have developed to normalize multi-sensor fire detection for consistency.

  13. Constellation Program (CxP) Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) Independent Design Reliability Assessment. Volume 1

    NASA Technical Reports Server (NTRS)

    Kelly, Michael J.

    2010-01-01

    This report documents the activities, findings, and NASA Engineering and Safety Center (NESC) recommendations of a multidiscipline team to independently assess the Constellation Program (CxP) Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS). This assessment occurred during a period of 15 noncontiguous months between December 2008 and April 2010, prior to the CPAS Project's Preliminary Design Review (PDR) in August 2010.

  14. Toward a Complete Metrological Solution for the Mirrors for the Constellation-X Spectroscopy X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Lehan, John; Owens, S.; Hadjimichael, T.; Hong, M.; Chan, K.-W.; Saha, T. T.; Reid, P.; Zhang, W. W.

    2007-01-01

    We present an overview update of the metrological approach to be employed for the segmented mirror fabrication for Constellation-X spectroscopy x-ray telescope. We compare results achieved to date with mission requirements. This is discussed in terms of inherent capability versus in-practice capability.

  15. The Association between Persistent Disruptive Childhood Behaviour and the Psychopathic Personality Constellation in Adolescence: A Twin Study

    ERIC Educational Resources Information Center

    Forsman, Mats; Larsson, Henrik; Andershed, Henrik; Lichtenstein, Paul

    2007-01-01

    This study tested if persistent externalizing behaviour and symptoms of Attention Deficit Hyperactivity Disorder (ADHD) in childhood are associated with personality and behavioural aspects of the psychopathic personality constellation in adolescence. The target sample consisted of all 1,480 twin pairs born in Sweden between 1985 and 1986.…

  16. Constellations of New Demands Concerning Careers and Jobs: Results from a Two-Country Study on Social and Economic Change

    ERIC Educational Resources Information Center

    Obschonka, Martin; Silbereisen, Rainer K.; Wasilewski, Jacek

    2012-01-01

    Focusing on new demands posed by social and economic change, and applying a pattern-based approach, this study examined constellations of increasing labor market uncertainties (understood as threat) and increasing job-related learning tasks (understood as positive challenge). We investigated whether and how the groups of working individuals behind…

  17. Changes in the distribution of lineage constellations of G2P[4] Rotavirus A strains detected in Japan over 32 years (1980-2011).

    PubMed

    Doan, Yen Hai; Nakagomi, Toyoko; Agbemabiese, Chantal Ama; Nakagomi, Osamu

    2015-08-01

    Rotavirus A (RVA) is a leading cause of acute gastroenteritis in young children worldwide. Most human RVA strains are classified into three major genotype constellations: Wa-like, DS-1-like and AU-1-like. The evolution of G2P[4] strains possessing the DS-1-like genetic background was described in a few recent studies. However, the strains analyzed in these studies were almost exclusively the ones detected after 2000. In recognition of the scarcity of G2P[4] strains detected before 2000 for which whole genome information was available, this study was undertaken to characterize 19 Japanese G2P[4] strains detected between 1983 and 1990 (14 strains) and between 2001 and 2011 (5 strains), and to compare them with 131 G2P[4] strains from across the world. The Japanese strains along with the strains elsewhere in the world underwent stepwise changes from lineage I to IVa in 5 genes (the VP7, VP4, VP2, NSP1 and NSP5 genes) and from lineage I to V in 6 genes (the VP6, VP1, VP3, NSP2, NSP3 and NSP4 genes). Furthermore, G2P[4] strains detected after 2004 appeared to have undergone further intragenotype reassortment, resulting in the emergence of lineage V in the VP7 gene, and VI and VII in the VP3 and NSP4 genes. The time of the most recent common ancestor (tMRCA) for the emergent lineages VI and VII was estimated to be around the early 2000s. However, the year when the ancestor of the emergent lineages diverged from that of the rest of the lineages in the respective genes preceded the tMRCA 80-90 years. The origin of the emergent lineages is likely to be human RVA strains possessing genotypes other than G2P[4], and not RVA strains of an animal origin. In conclusion, stepwise changes in lineages imparted new genomic constellations to G2P[4] strains, which appears to have contributed to their successful spread across the globe, most notably since 2004. PMID:26026594

  18. "Origin," "creation," and "origin of life" some conceptual considerations.

    PubMed

    Charpa, Ulrich

    2012-01-01

    This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation. PMID:23316571

  19. NASA Constellation Program (CxP) Key Driving Requirements and Element Descriptions for International Architecture Working Group (IAWG) Functional Teams Human Transportation Cargo Transportation

    NASA Technical Reports Server (NTRS)

    Martinez, Roland M.

    2009-01-01

    The NASA Constellation uncrewed cargo mission delivers cargo to any designated location on the lunar surface (or other staging point) in a single mission. This capability is used to deliver surface infrastructure needed for lunar outpost construction, to provide periodic logistics resupply to support a continuous human lunar presence, and potentially deliver other assets to various locations.In the nominal mission mode, the Altair lunar lander is launched on Ares V into Low Earth Orbit (LEO), following a short Low Earth Orbit (LEO) loiter period, the Earth Departure Stage (EDS) performs the Trans Lunar Injection (TLI) burn and is then jettisoned. The Altair performs translunar trajectory correction maneuvers as necessary and performs the Lunar Orbit Insertion (LOI) burn. Altair then descends to the surface to land near a designated target, presumably in proximity to an Outpost location or another site of interest for exploration.Alternatively, the EDS and Altair Descent Stage could deliver assets to various staging points within their propulsive capabilities.

  20. SOFIA pointing history

    NASA Astrophysics Data System (ADS)

    Kärcher, Hans J.; Kunz, Nans; Temi, Pasquale; Krabbe, Alfred; Wagner, Jörg; Süß, Martin

    2014-07-01

    The original pointing accuracy requirement of the Stratospheric Observatory for Infrared Astronomy SOFIA was defined at the beginning of the program in the late 1980s as very challenging 0.2 arcsec rms. The early science flights of the observatory started in December 2010 and the observatory has reached in the mean time nearly 0.7 arcsec rms, which is sufficient for most of the SOFIA science instruments. NASA and DLR, the owners of SOFIA, are planning now a future 4 year program to bring the pointing down to the ultimate 0.2 arcsec rms. This may be the right time to recall the history of the pointing requirement and its verification and the possibility of its achievement via early computer models and wind tunnel tests, later computer aided end-to-end simulations up to the first commissioning flights some years ago. The paper recollects the tools used in the different project phases for the verification of the pointing performance, explains the achievements and may give hints for the planning of the upcoming final pointing improvement phase.