End of Life Disposal for Three Libration Point Missions through Manipulation of the Jacobi Constant and Zero Velocity Curves

NASA Technical Reports Server (NTRS)

Petersen, Jeremy; Brown, Jonathan

2015-01-01

Flight Dynamics Facility (FDF) located at NASA Goddard Space Flight Center (GSFC) provides the flight dynamics expertise for three Sun-Earth Moon L1 missions. Advanced Composition Explorer (ACE) launched August 1997 Solar and Heliospheric Observatory (SOHO) launched December 1995 Global Geospace Science WIND satellite launched November 1994 entered Lagrange point orbit in 2004.

Notch signaling deficiency underlies age-dependent depletion of satellite cells in muscular dystrophy

PubMed Central

Jiang, Chunhui; Wen, Yefei; Kuroda, Kazuki; Hannon, Kevin; Rudnicki, Michael A.; Kuang, Shihuan

2014-01-01

Duchenne muscular dystrophy (DMD) is a devastating disease characterized by muscle wasting, loss of mobility and death in early adulthood. Satellite cells are muscle-resident stem cells responsible for the repair and regeneration of damaged muscles. One pathological feature of DMD is the progressive depletion of satellite cells, leading to the failure of muscle repair. Here, we attempted to explore the molecular mechanisms underlying satellite cell ablation in the dystrophin mutant mdx mouse, a well-established model for DMD. Initial muscle degeneration activates satellite cells, resulting in increased satellite cell number in young mdx mice. This is followed by rapid loss of satellite cells with age due to the reduced self-renewal ability of mdx satellite cells. In addition, satellite cell composition is altered even in young mdx mice, with significant reductions in the abundance of non-committed (Pax7+ and Myf5−) satellite cells. Using a Notch-reporter mouse, we found that the mdx satellite cells have reduced activation of Notch signaling, which has been shown to be necessary to maintain satellite cell quiescence and self-renewal. Concomitantly, the expression of Notch1, Notch3, Jag1, Hey1 and HeyL are reduced in the mdx primary myoblast. Finally, we established a mouse model to constitutively activate Notch signaling in satellite cells, and show that Notch activation is sufficient to rescue the self-renewal deficiencies of mdx satellite cells. These results demonstrate that Notch signaling is essential for maintaining the satellite cell pool and that its deficiency leads to depletion of satellite cells in DMD. PMID:24906372

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

The Pluto system: Initial results from its exploration by New Horizons.

PubMed

Stern, S A; Bagenal, F; Ennico, K; Gladstone, G R; Grundy, W M; McKinnon, W B; Moore, J M; Olkin, C B; Spencer, J R; Weaver, H A; Young, L A; Andert, T; Andrews, J; Banks, M; Bauer, B; Bauman, J; Barnouin, O S; Bedini, P; Beisser, K; Beyer, R A; Bhaskaran, S; Binzel, R P; Birath, E; Bird, M; Bogan, D J; Bowman, A; Bray, V J; Brozovic, M; Bryan, C; Buckley, M R; Buie, M W; Buratti, B J; Bushman, S S; Calloway, A; Carcich, B; Cheng, A F; Conard, S; Conrad, C A; Cook, J C; Cruikshank, D P; Custodio, O S; Dalle Ore, C M; Deboy, C; Dischner, Z J B; Dumont, P; Earle, A M; Elliott, H A; Ercol, J; Ernst, C M; Finley, T; Flanigan, S H; Fountain, G; Freeze, M J; Greathouse, T; Green, J L; Guo, Y; Hahn, M; Hamilton, D P; Hamilton, S A; Hanley, J; Harch, A; Hart, H M; Hersman, C B; Hill, A; Hill, M E; Hinson, D P; Holdridge, M E; Horanyi, M; Howard, A D; Howett, C J A; Jackman, C; Jacobson, R A; Jennings, D E; Kammer, J A; Kang, H K; Kaufmann, D E; Kollmann, P; Krimigis, S M; Kusnierkiewicz, D; Lauer, T R; Lee, J E; Lindstrom, K L; Linscott, I R; Lisse, C M; Lunsford, A W; Mallder, V A; Martin, N; McComas, D J; McNutt, R L; Mehoke, D; Mehoke, T; Melin, E D; Mutchler, M; Nelson, D; Nimmo, F; Nunez, J I; Ocampo, A; Owen, W M; Paetzold, M; Page, B; Parker, A H; Parker, J W; Pelletier, F; Peterson, J; Pinkine, N; Piquette, M; Porter, S B; Protopapa, S; Redfern, J; Reitsema, H J; Reuter, D C; Roberts, J H; Robbins, S J; Rogers, G; Rose, D; Runyon, K; Retherford, K D; Ryschkewitsch, M G; Schenk, P; Schindhelm, E; Sepan, B; Showalter, M R; Singer, K N; Soluri, M; Stanbridge, D; Steffl, A J; Strobel, D F; Stryk, T; Summers, M E; Szalay, J R; Tapley, M; Taylor, A; Taylor, H; Throop, H B; Tsang, C C C; Tyler, G L; Umurhan, O M; Verbiscer, A J; Versteeg, M H; Vincent, M; Webbert, R; Weidner, S; Weigle, G E; White, O L; Whittenburg, K; Williams, B G; Williams, K; Williams, S; Woods, W W; Zangari, A M; Zirnstein, E

2015-10-16

The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected. Copyright © 2015, American Association for the Advancement of Science.

Global satellite composites - 20 years of evolution

NASA Astrophysics Data System (ADS)

Kohrs, Richard A.; Lazzara, Matthew A.; Robaidek, Jerrold O.; Santek, David A.; Knuth, Shelley L.

2014-01-01

For two decades, the University of Wisconsin Space Science and Engineering Center (SSEC) and the Antarctic Meteorological Research Center (AMRC) have been creating global, regional and hemispheric satellite composites. These composites have proven useful in research, operational forecasting, commercial applications and educational outreach. Using the Man computer Interactive Data System (McIDAS) software developed at SSEC, infrared window composites were created by combining Geostationary Operational Environmental Satellite (GOES), and polar orbiting data from the SSEC Data Center and polar data acquired at McMurdo and Palmer stations, Antarctica. Increased computer processing speed has allowed for more advanced algorithms to address the decision making process for co-located pixels. The algorithms have evolved from a simplistic maximum brightness temperature to those that account for distance from the sub-satellite point, parallax displacement, pixel time and resolution. The composites are the state-of-the-art means for merging/mosaicking satellite imagery.

Space exploration and the history of solar-system volatiles

NASA Technical Reports Server (NTRS)

Fanale, F. P.

1976-01-01

The thermochemical history of volatile substances in all solar-system planets, satellites, and planetoids is discussed extensively. The volatiles are viewed as an interface between the abiotic and biotic worlds and as a key to the history of bodies of the solar system. A flowsheet of processes and states is exhibited. Differences in bulk volatiles distribution between the planetary bodies and between the interior, surface, and atmosphere of each body are considered, as well as sinks for volatiles in degassing. The volatiles-rich Jovian and Saturnian satellites, the effect of large-planet magnetosphere sweeps on nearby satellites, volatiles of asteroids and comets, and the crucial importance of seismic, gravity, and libration data are treated. A research program encompassing analysis of the elemental and isotopic composition of rare gas in atmospheres, assay of volatiles-containing phases in regoliths, and examination of present or past atmospheric escape/accretion processes is recommended.

The Exploration of Titan and the Saturnian System

NASA Astrophysics Data System (ADS)

Coustenis, Athena

The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. Titan is also rich in organic molecules—more so in its surface and atmosphere than anyplace in the solar system, including Earth [4]. These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. I will discuss our current understanding of Titan's complex environment in view of recent exploration, in particular on the atmospheric structure (temperature and composition), and the surface nature. I will show how these and other elements can give us clues as to the origin and evolution of the satellite, and how they connect to the observations of the planet and the other satellites and rings. Future space missions to Titan can help us understand the kronian and also our Solar System as a whole. In particular, I will describe the future exploration of Titan and the Saturnian System with TSSM, a mission studied jointly by ESA and NASA in 2008 [1] and prioritized second for a launch around 2023-2025. TSSM comprises a Titan Orbiter provided by NASA that would carry two Titan in situ elements provided by ESA: a montgolfiere and a lake-landing lander. The mission would arrive 9 years later for a 4-year duration in the Saturn system. Following delivery of the ESA in situ elements to Titan, the Titan Orbiter would explore the Saturn system via a 2-year tour that includes Enceladus and Titan flybys. The montgolfiere would last at least 6 months at Titan and the lake lander 8-10 hours. Following the Saturn system tour, the Titan Orbiter would culminate in a —2-year orbit around Titan. References 1. TSSM and EJSM NASA/ESA Joint Summary Report, 16 January 2009 2. Coustenis et al. (2008). TandEM: Titan and Enceladus mission. Experimenta( Astron-omy, 23, 893-946. 3. Coustenis, A., Hirtzig, M., 2009. Cassini-Huygens results on Titan's surface. Research in Astronomy and Astrophysics 9, 249-268. 4. Coustenis et al., 2010, Titan trace gaseous composition from CIRS at the end of the Cassini-Huygens prime mission Icarus, in press. 5. Flasar, F. M., et al., 2005. Titan's atmospheric temperatures, winds, and composition. Science, 308, 975-978. 6. Fulchignoni, M., et al, 2005. In situ measurements of the physical characteristics of Titan's environment. Nature, 438, 785-791, doi:10.1038/nature04126. 7. Lebreton, J-P., Coustenis, A., et al., 2009. Results from the Huygens probe on Titan. Astron. Astrophys. Rev. 17, 149-179. 8. Tomasko, M. G., et al., 2005. Rain, winds and haze during the Huygens probe's descent to Titan's surface. Nature, 438, 765-778, doi: 10. 1038/nature04126.

The Effects of Radiation on the Adsorption of CO2 by Nonice Materials Relevant to Icy Satellites

NASA Astrophysics Data System (ADS)

Hibbitts, C.; Stockstill-Cahill, K.; Paranicas, C.; Wing, B. R.

2017-12-01

Water-ice and water-rich non-ice materials dominate the surfaces of the icy satellites of Jupiter and Saturn, with CO2 detected at trace amounts largely in the nonice materials [1,2]. Although, the mechanism by which CO2 is entrained within the nonice material has not yet been understood, one hypothesis is adsorption by van der Waals forces or induced dipole interactions, with laboratory measurements demonstrating some analog materials can stably retain adsorbed CO2 while under vacuum at the temperatures of the icy satellites [3,4]. The strength and spectral signature of the adsorbed CO2 is dependent upon the composition and temperature of the host material. So far, the most adsorptive analogs are complex expansive clays, probably because of the large microporosity and presence of charge compensating cations to act as adsorption sites. However, the surfaces of the airless Galilean and Saturnian satellites are bombarded by high-energy particles from the planetary magnetospheres, which could alter the nonice material affecting adsorptivity towards CO2 (and other volatiles). Thus, we have conducted experiments to explore the possibility that irradiation could increase the adsorptivity of other analogs more consistent with the expected composition of the satellites surfaces. This hypothesis is explored for CO2 adsorption onto pressed powder pellets that are cooled to the surface temperatures of the satellites' surfaces under solar illumination ( 125-150 K) and dosed with CO2 from directly above the surface of the pellet, while collecting spectra of the asymmetric stretch fundamental of the CO2 absorption band near 4.25 microns. After this initial spectrum, the pellet is warmed to degas any adsorbed CO2 and then recooled. The pellet is then irradiated with 40 keV electrons for 48-72 hours at a fluence of 80 microamps and the adsorption experiment is repeated. The infrared spectrum is a bidirectional reflectance measurement using a Bruker Vertex 70 FTIR with and external MCT detector and the chamber pressure 1e-8 torr or lower. References: [1] McCord et al. 1998. J. Geophys. Res., 103, E4, 8603-8626; [2] Clark et al. 2005. Nature, 435, 66-69; [3] Hibbitts, C.A. and J. Szanyi. 2007. Icarus, 191, 371-380; [4] Berlanga, G. et al., 2016. Icarus, 280, 366-377.

Dawn of a New Space Age: Developing a Global Exploration Strategy.

NASA Technical Reports Server (NTRS)

Volosin, Jeff

2006-01-01

Jeff Volosin is an aerospace engineer with over 20 years of experience in the design, development, and operations of both robotic and crewed spacecraft. Mr. Volosin is currently leading the NASA effort to develop and integrate a global exploration strategy which reflects the lunar exploration interests of international space agencies, academia and commercial stakeholders. Prior to joining NASA as a member of the Exploration Systems Mission Directorate in 2004, Jeff was an aerospace contractor, serving in a number of leadership positions including: Operations Manager for the NASA Communications Network and Flight Operations Manager for the Advanced Composition Explorer, Tropical Rainfall Measuring Mission, and the NOAA Polar and Geostationary satellite constellations. Earlier in his career, Jeff spent 4 years as a system engineer supporting the Space Exploration Initiative studies on human voyages to the Moon and Mars and also supported the Space Station program as an advanced life support engineer.

The ODINUS Mission Concept: a Mission for the exploration the Ice Giant Planets

NASA Astrophysics Data System (ADS)

Peron, Roberto

We present the scientific case and the mission concept of a proposal for the the comparative exploration of the ice giant planets Uranus and Neptune and their satellites with a pair of twin spacecraft: ODINUS (Origins, Dynamics and Interiors of Neptunian and Uranian Systems). The ODINUS proposal was submitted in response to the call for white papers for the definition of the themes of the L2 and L3 mission in the framework of ESA Cosmic Vision 2015-2025 program. The goal of ODINUS is the advancement of our understanding of the ancient past of the Solar System and, more generally, of how planetary systems form and evolve. The mission concept is focused on providing elements to answer to the scientific themes of the Cosmic Vision 2015-2025 program: What are the conditions for planetary formation and the emergency of life? How does the Solar System work? What are the fundamental physical laws of the Universe? In order to achieve its goals, ODINUS foresees the use of two twin spacecraft to be placed in orbit around Uranus and Neptune respectively, with selected flybys of their satellites. The proposed measurements aim to study the atmospheres and magnetospheres of the planets, the surfaces of the satellites, and the interior structure and composition of both satellites and planets. An important possibility for performing fundamental physics studies (among them tests of general relativity theory) is offered by the cruise phase. After the extremely positive evaluation of ESA Senior Survey Committee, who stated that ``the exploration of the icy giants appears to be a timely milestone, fully appropriate for an L class mission'', we discuss strategies to comparatively study Uranus and Neptune with future international missions.

NASA Ground-Truthing Capabilities Demonstrated

NASA Technical Reports Server (NTRS)

Lopez, Isaac; Seibert, Marc A.

2004-01-01

NASA Research and Education Network (NREN) ground truthing is a method of verifying the scientific validity of satellite images and clarifying irregularities in the imagery. Ground-truthed imagery can be used to locate geological compositions of interest for a given area. On Mars, astronaut scientists could ground truth satellite imagery from the planet surface and then pinpoint optimum areas to explore. These astronauts would be able to ground truth imagery, get results back, and use the results during extravehicular activity without returning to Earth to process the data from the mission. NASA's first ground-truthing experiment, performed on June 25 in the Utah desert, demonstrated the ability to extend powerful computing resources to remote locations. Designed by Dr. Richard Beck of the Department of Geography at the University of Cincinnati, who is serving as the lead field scientist, and assisted by Dr. Robert Vincent of Bowling Green State University, the demonstration also involved researchers from the NASA Glenn Research Center and the NASA Ames Research Center, who worked with the university field scientists to design, perform, and analyze results of the experiment. As shown real-time Hyperion satellite imagery (data) is sent to a mass storage facility, while scientists at a remote (Utah) site upload ground spectra (data) to a second mass storage facility. The grid pulls data from both mass storage facilities and performs up to 64 simultaneous band ratio conversions on the data. Moments later, the results from the grid are accessed by local scientists and sent directly to the remote science team. The results are used by the remote science team to locate and explore new critical compositions of interest. The process can be repeated as required to continue to validate the data set or to converge on alternate geophysical areas of interest.

Blue Marble, Eastern Hemisphere March 2014

NASA Image and Video Library

2014-08-21

Of all the planets NASA has explored, none have matched the dynamic complexity of our own. Earth is constantly changing, and NASA are working constantly to explore and understand the planet on scales from local to global. Though Earth science has been a key part of NASA’s mission since the agency was founded in 1958, this year has been one of the peaks. Two new Earth-observing satellites have already been launched and put to work: the Global Precipitation Measurement (GPM) and the Orbiting Carbon Observatory 2 (OCO-2). Three more missions are set to take off in the next six months: the wind-measuring ISS-RapidScat, the ISS Cloud-Aerosol Transport System (CATS), and the Soil Moisture Active Passive (SMAP). And research planes have been flying over polar ice, hurricanes, boreal forests, and pollution plumes. All of these new efforts complement an existing fleet of Earth-observing satellites. In visible light and many invisible wavelengths, NASA and its science partners are observing the entire planet every day. The image above was captured on March 30, 2014, by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. The composite image of the eastern hemisphere was compiled from eight orbits of the satellite and ten imaging channels, then stitched together to blend the edges of each satellite pass. Read more: earthobservatory.nasa.gov/IOTD/view.php?id=84214&eocn... NASA Earth Observatory image by Robert Simmon, using Suomi NPP VIIRS imagery from NOAA's Environmental Visualization Laboratory. Suomi NPP is the result of a partnership between NASA, NOAA and the Department of Defense. Caption by Mike Carlowicz. Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Surface penetrators for planetary exploration: Science rationale and development program

NASA Technical Reports Server (NTRS)

Murphy, J. P.; Reynolds, R. T.; Blanchard, M. B.; Clanton, U. S.

1981-01-01

Work on penetrators for planetary exploration is summarized. In particular, potential missions, including those to Mars, Mercury, the Galilean satellites, comets, and asteroids are described. A baseline penetrator design for the Mars mission is included, as well as potential instruments and their status in development. Penetration tests in soft soil and basalt to study material eroded from the penetrator; changes in the structure, composition, and physical properties of the impacted soil; seismic coupling; and penetrator deflection caused by impacting rocks, are described. Results of subsystem studies and tests are given for design of entry decelerators, high-g components, thermal control, data acquisition, and umbilical cable deployment.

Exploration of Extended-Area Treatment Effects in FACE-2 Using Satellite Imagery.

NASA Astrophysics Data System (ADS)

Meití, José G.; Woodley, William L.; Flueck, John A.

1984-01-01

The second phase of the Florida Area Cumulus Experiment (FACE-2) has been completed and an exploratory analysis has been conducted to investigate the possibility that cloud seeding may have affected the rainfall outside the intended target. Rainfall was estimated over a 3.5×105 km2 area centered on the target using geosynchronous, infrared satellite imagery and the Griffith-Woodley rain estimation technique. This technique was derived in South Florida by calibrating infrared images using raingage and radar observations to produce an empirical, diagnostic (a posteriori), satellite rain estimation technique. The satellite rain estimates for the extended area were adjusted based on comparisons of raingage and satellite rainfall estimates for the entire FACE target (1.3×104 km2). All daily rainfall estimates were composited in two ways: 1) in the original coordinate system and 2) in a relative coordinate system that rotates the research area as a function of wind direction. After compositing, seeding effects were sought as a function of space and time.The results show more rainfall (in the mean) on seed than no seed days both in and downwind of the target but lesser rainfall upwind. All differences (averaging 20% downwind and 10% upwind) are confined in space to within 200 km of the center of the FACE target and in time to the 8 h period after initial treatment. In addition, the positive correlation between untreated upwind rainfall and target rainfall is degraded on seed days, suggesting possible intermittent negative effects of seeding upwind. Although the development of these differences in space and time suggests that seeding may have been partially responsible for their generation, the results do not have strong inferential (P-value) support.

Composition measurements of the topside ionosphere.

PubMed

Hoffman, J H

1967-01-20

Data from a magnetic mass spectrometer flown on the Explorer 31 satellite show that the ionosphere above 1000 kilometers usually consists of hydrogen ions as the predominant species. Between this altitude and perigee (500 kilometers) the dominant ion species shifts to atomic oxygen, with a significant amount of atomic nitrogen ions also present. Helium ions are present in small quantities at all altitudes. Other minor ions observed are those of 2, 7, 8, 15, 18, and 20 atomic mass units.

A Study of Cirrus Clouds and Aerosols in the Upper Troposphere using Models and Satellite Data

NASA Technical Reports Server (NTRS)

Bergstrom, Robert W.

2004-01-01

This report is the final report for the Cooperative Agreement NCC2-1213. It is a compilation of publications produced under this Cooperative Agreement and conference presentations. The tasks for the Aerosol Physical Chemistry Model for the Upper Troposphere include: Task 1: To compare APCM predictions against the SUCCESS data and other aircraft campaigns and to investigate the role of aerosol composition on cirrus cloud nucleation; Task 2: To study the seasonal evolution and spatial distribution of upper-tropospheric tropical and polar cirrus; Task 3: To investigate CLAES cirrus data with other complementary (TOGA-COARE and CEPEX) data. Tasks for Upper Tropospheric Cirrus Clouds include: Task 1: Assemble 3-hourly (or more frequent) meteorological satellite data fiom geostationary satellites to obtain a global, or nearly global, dataset of infiared brightness temperatures as a function of time for airborne experimental periods; Task 2: Explore methods to improve the cloud top altitude distributions calculated fiom meteorological satellite data. This will focus on linlung the 6.5 micron channel geostationary brightness temperatures and the 10.5 micron brightness temperatures; Task 3: Explore methods to differentiate convective fiom stratiform cloudiness; Task 4: Perform trajectory analyses using an existing trajectory modeling package that links the cloud data with air mass histories; Task 5: Apply techniques from tasks 1 through 4 to provide meteorological support to the CRYSTAL-FACE mission, both in its preparation and deployment phases. The report include four published articles and two slide presentations.

The exploration of Titan with an orbiter and a lake probe

NASA Astrophysics Data System (ADS)

Mitri, Giuseppe; Coustenis, Athena; Fanchini, Gilbert; Hayes, Alex G.; Iess, Luciano; Khurana, Krishan; Lebreton, Jean-Pierre; Lopes, Rosaly M.; Lorenz, Ralph D.; Meriggiola, Rachele; Moriconi, Maria Luisa; Orosei, Roberto; Sotin, Christophe; Stofan, Ellen; Tobie, Gabriel; Tokano, Tetsuya; Tosi, Federico

2014-12-01

Fundamental questions involving the origin, evolution, and history of both Titan and the broader Saturnian system can be answered by exploring this satellite from an orbiter and also in situ. We present the science case for an exploration of Titan and one of its lakes from a dedicated orbiter and a lake probe. Observations from an orbit-platform can improve our understanding of Titan's geological processes, surface composition and atmospheric properties. Further, combined measurements of the gravity field, rotational dynamics and electromagnetic field can expand our understanding of the interior and evolution of Titan. An in situ exploration of Titan's lakes provides an unprecedented opportunity to understand the hydrocarbon cycle, investigate a natural laboratory for prebiotic chemistry and habitability potential, and study meteorological and marine processes in an exotic environment. We briefly discuss possible mission scenarios for a future exploration of Titan with an orbiter and a lake probe.

Exoplanets -New Results from Space and Ground-based Surveys

NASA Astrophysics Data System (ADS)

Udry, Stephane

The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. Titan is also rich in organic molecules—more so in its surface and atmosphere than anyplace in the solar system, including Earth [4]. These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. I will discuss our current understanding of Titan's complex environment in view of recent exploration, in particular on the atmospheric structure (temperature and composition), and the surface nature. I will show how these and other elements can give us clues as to the origin and evolution of the satellite, and how they connect to the observations of the planet and the other satellites and rings. Future space missions to Titan can help us understand the kronian and also our Solar System as a whole. In particular, I will describe the future exploration of Titan and the Saturnian System with TSSM, a mission studied jointly by ESA and NASA in 2008 [1] and prioritized second for a launch around 2023-2025. TSSM comprises a Titan Orbiter provided by NASA that would carry two Titan in situ elements provided by ESA: a montgolfiere and a lake-landing lander. The mission would arrive 9 years later for a 4-year duration in the Saturn system. Following delivery of the ESA in situ elements to Titan, the Titan Orbiter would explore the Saturn system via a 2-year tour that includes Enceladus and Titan flybys. The montgolfiere would last at least 6 months at Titan and the lake lander 8-10 hours. Following the Saturn system tour, the Titan Orbiter would culminate in a —2-year orbit around Titan. References 1. TSSM and EJSM NASA/ESA Joint Summary Report, 16 January 2009 2. Coustenis et al. (2008). TandEM: Titan and Enceladus mission. Experimenta( Astron-omy, 23, 893-946. 3. Coustenis, A., Hirtzig, M., 2009. Cassini-Huygens results on Titan's surface. Research in Astronomy and Astrophysics 9, 249-268. 4. Coustenis et al., 2010, Titan trace gaseous composition from CIRS at the end of the Cassini-Huygens prime mission Icarus, in press. 5. Flasar, F. M., et al., 2005. Titan's atmospheric temperatures, winds, and composition. Science, 308, 975-978. 6. Fulchignoni, M., et al, 2005. In situ measurements of the physical characteristics of Titan's environment. Nature, 438, 785-791, doi:10.1038/nature04126. 7. Lebreton, J-P., Coustenis, A., et al., 2009. Results from the Huygens probe on Titan. Astron. Astrophys. Rev. 17, 149-179. 8. Tomasko, M. G., et al., 2005. Rain, winds and haze during the Huygens probe's descent to Titan's surface. Nature, 438, 765-778, doi: 10. 1038/nature04126.

Satellite to measure equatorial ozone layer

NASA Technical Reports Server (NTRS)

1975-01-01

The Atmosphere Explorer E (Explorer 55) Satellite is described. The satellite will gather information on the earth's upper atmosphere, particularly regarding the condition of the protective ozone layer. The satellite will also provide information concerning the earth's heat balance, and heat flow characteristics, and energy conversion mechanisms.

Planetary rings and astrophysical discs

NASA Astrophysics Data System (ADS)

Latter, Henrik

2016-05-01

Disks are ubiquitous in astrophysics and participate in some of its most important processes. Of special interest is their role in star, planet and moon formation, the growth of supermassive black holes, and the launching of jets. Although astrophysical disks can be up to ten orders of magnitude larger than planetary rings and differ hugely in composition, all disks share to some extent the same basic dynamics and many physical phenomena. This review explores these areas of overlap. Topics covered include disk formation, accretion, collisions, instabilities, and satellite-disk interactions.

Early Rockets

NASA Image and Video Library

1959-10-21

This image is a cutaway illustration of the Explorer I satellite with callouts. The Explorer I satellite was America's first scientific satellite launched aboard the Jupiter C launch vehicle on January 31, 1958. The Explorer I carried the radiation detection experiment designed by Dr. James Van Allen and discovered the Van Allen Radiation Belt.

Development of a numerical system to improve particulate matter forecasts in South Korea using geostationary satellite-retrieved aerosol optical data over Northeast Asia

NASA Astrophysics Data System (ADS)

Lee, Sojin; Song, Chul-han; Park, Rae Seol; Park, Mi Eun; Han, Kyung man; Kim, Jhoon; Choi, Myungje; Ghim, Young Sung; Woo, Jung-Hun

2016-04-01

To improve short-term particulate matter (PM) forecasts in South Korea, the initial distribution of PM composition, particularly over the upwind regions, is primarily important. To prepare the initial PM composition, the aerosol optical depth (AOD) data retrieved from a geostationary equatorial orbit (GEO) satellite sensor, GOCI (Geostationary Ocean Color Imager) which covers a part of Northeast Asia (113-146° E; 25-47° N), were used. Although GOCI can provide a higher number of AOD data in a semicontinuous manner than low Earth orbit (LEO) satellite sensors, it still has a serious limitation in that the AOD data are not available at cloud pixels and over high-reflectance areas, such as desert and snow-covered regions. To overcome this limitation, a spatiotemporal-kriging (STK) method was used to better prepare the initial AOD distributions that were converted into the PM composition over Northeast Asia. One of the largest advantages in using the STK method in this study is that more observed AOD data can be used to prepare the best initial AOD fields compared with other methods that use single frame of observation data around the time of initialization. It is demonstrated in this study that the short-term PM forecast system developed with the application of the STK method can greatly improve PM10 predictions in the Seoul metropolitan area (SMA) when evaluated with ground-based observations. For example, errors and biases of PM10 predictions decreased by ˜ 60 and ˜ 70{%}, respectively, during the first 6 h of short-term PM forecasting, compared with those without the initial PM composition. In addition, the influences of several factors on the performances of the short-term PM forecast were explored in this study. The influences of the choices of the control variables on the PM chemical composition were also investigated with the composition data measured via PILS-IC (particle-into-liquid sampler coupled with ion chromatography) and low air-volume sample instruments at a site near Seoul. To improve the overall performances of the short-term PM forecast system, several future research directions were also discussed and suggested.

The number of satellite cells in slow and fast fibres from human vastus lateralis muscle.

PubMed

Kadi, Fawzi; Charifi, Nadia; Henriksson, Jan

2006-07-01

The aim of this investigation was to study the distribution of satellite cells in slow (type I fibres) and fast (type II fibres) fibres from human vastus lateralis muscle. This muscle is characterised by a mixed fibre type composition and is considered as the site of choice for biopsies in research work and for clinical diagnosis. Biopsy samples were obtained from five healthy young volunteers and a total of 1,747 type I fibres and 1,760 type II fibres were assessed. Satellite cells and fibre type composition were studied on serial muscle cross-sections stained with specific monoclonal antibodies. From a total of 218 satellite cells, 116 satellite cells were found in contact with type I fibres (53.6+/-8% of the satellite cells associated to type I fibres) and 102 satellite cells in contact with type II fibres (46.4+/-8% of the satellite cells associated to type II fibres). There was no significant difference (P=0.4) between the percentages of satellite cells in contact with type I and with type II fibres. Additionally, there was no relationship between the mean number of satellite cells per fibre and the mean cross-sectional area of muscle fibres. In conclusion, our results show that there is no fibre type-specific distribution of satellite cells in a human skeletal muscle with mixed fibre type composition.

A Comparison of the SOCIT and DebriSat Experiments

NASA Technical Reports Server (NTRS)

Ausay, Erick; Blake, Brandon; Boyle, Colleen; Cornejo, Alex; Horn, Alexa; Palma, Kirsten; Pistella, Frank; Sato, Taishi; Todd, Naromi; Zimmerman, Jeffrey;

"Data Day" and "Data Night" Definitions - Towards Producing Seamless Global Satellite Imagery

NASA Astrophysics Data System (ADS)

Schmaltz, J. E.

2017-12-01

For centuries, the art and science of cartography has struggled with the challenge of mapping the round earth on to a flat page, or a flat computer monitor. Earth observing satellites with continuous monitoring of our planet have added the additional complexity of the time dimension to this procedure. The most common current practice is to segment this data by 24-hour Coordinated Universal Time (UTC) day and then split the day into sun side "Data Day" and shadow side "Data Night" global imagery that spans from dateline to dateline. Due to the nature of satellite orbits, simply binning the data by UTC date produces significant discontinuities at the dateline for day images and at Greenwich for night images. Instead, imagery could be generated in a fashion that follows the spatial and temporal progression of the satellite which would produce seamless imagery everywhere on the globe for all times. This presentation will explore approaches to produce such imagery but will also address some of the practical and logistical difficulties in implementing such changes. Topics will include composites versus granule/orbit based imagery, day/night versus ascending/descending definitions, and polar versus global projections.

LADEE Satellite Modeling and Simulation Development

NASA Technical Reports Server (NTRS)

Adams, Michael; Cannon, Howard; Frost, Chad

2011-01-01

As human activity on and around the Moon increases, so does the likelihood that our actions will have an impact on its atmosphere. The Lunar Atmosphere and Dust Environment Explorer (LADEE), a NASA satellite scheduled to launch in 2013, will orbit the Moon collecting composition, density, and time variability data to characterize the current state of the lunar atmosphere. LADEE will also test the concept of the "Modular Common Bus" spacecraft architecture, an effort to reduce both development time and cost by designing reusable, modular components for use in multiple missions with similar requirements. An important aspect of this design strategy is to both simulate the spacecraft and develop the flight code in Simulink, a block diagram-style programming language that allows easy algorithm visualization and performance testing. Before flight code can be tested, however, a realistic simulation of the satellite and its dynamics must be generated and validated. This includes all of the satellite control system components such as actuators used for force and torque generation and sensors used for inertial orientation reference. My primary responsibilities have included designing, integrating, and testing models for the LADEE thrusters, reaction wheels, star trackers, and rate gyroscopes.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Dr. John Meisenheimer, launch weather officer for Explorer 1, speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Radiation analysis for manned missions to the Jupiter system

NASA Technical Reports Server (NTRS)

De Angelis, G.; Clowdsley, M. S.; Nealy, J. E.; Tripathi, R. K.; Wilson, J. W.

2004-01-01

An analysis for manned missions targeted to the Jovian system has been performed in the framework of the NASA RASC (Revolutionary Aerospace Systems Concepts) program on Human Exploration beyond Mars. The missions were targeted to the Jupiter satellite Callisto. The mission analysis has been divided into three main phases, namely the interplanetary cruise, the Jupiter orbital insertion, and the surface landing and exploration phases. The interplanetary phase is based on departure from the Earth-Moon L1 point. Interplanetary trajectories based on the use of different propulsion systems have been considered, with resulting overall cruise phase duration varying between two and five years. The Jupiter-approach and the orbital insertion trajectories are considered in detail, with the spacecraft crossing the Jupiter radiation belts and staying around the landing target. In the surface exploration phase the stay on the Callisto surface is considered. The satellite surface composition has been modeled based on the most recent results from the GALILEO spacecraft. In the transport computations the surface backscattering has been duly taken into account. Particle transport has been performed with the HZETRN heavy ion code for hadrons and with an in-house developed transport code for electrons and bremsstrahlung photons. The obtained doses have been compared to dose exposure limits. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

Radiation analysis for manned missions to the Jupiter system.

PubMed

De Angelis, G; Clowdsley, M S; Nealy, J E; Tripathi, R K; Wilson, J W

2004-01-01

An analysis for manned missions targeted to the Jovian system has been performed in the framework of the NASA RASC (Revolutionary Aerospace Systems Concepts) program on Human Exploration beyond Mars. The missions were targeted to the Jupiter satellite Callisto. The mission analysis has been divided into three main phases, namely the interplanetary cruise, the Jupiter orbital insertion, and the surface landing and exploration phases. The interplanetary phase is based on departure from the Earth-Moon L1 point. Interplanetary trajectories based on the use of different propulsion systems have been considered, with resulting overall cruise phase duration varying between two and five years. The Jupiter-approach and the orbital insertion trajectories are considered in detail, with the spacecraft crossing the Jupiter radiation belts and staying around the landing target. In the surface exploration phase the stay on the Callisto surface is considered. The satellite surface composition has been modeled based on the most recent results from the GALILEO spacecraft. In the transport computations the surface backscattering has been duly taken into account. Particle transport has been performed with the HZETRN heavy ion code for hadrons and with an in-house developed transport code for electrons and bremsstrahlung photons. The obtained doses have been compared to dose exposure limits. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

Improved atmospheric density estimation for ANDE-2 satellites using drag coefficients obtained from gas-surface interaction equations

NASA Astrophysics Data System (ADS)

Flanagan, Harold Patrick

A major issue in the process of predicting the future position of satellites in low earth orbit (LEO) is that the drag coefficient of a satellite is generally not precisely known throughout the satellite's lifespan. One reason for this problem is that as a satellite travels through the Earth's thermosphere, variations in the composition of the thermosphere directly affect the drag coefficient of the satellite. The greatest amount of uncertainty in the drag coefficient from these variations in the thermosphere comes from the amount of atomic oxygen that covers the satellites surface as the satellite descends to lower altitudes. This percent surface coverage of atomic oxygen directly affects the interaction between the surface of the satellite and the gas through which it is passing. The work performed in this thesis determines the drag coefficients of the ANDE-2 satellites over their life spans by using satellite laser ranging (SLR) data of the ANDE-2 satellites in unison with gas-surface interaction equations. The fractional coverage of atomic oxygen is determined by using empirically determined data and semi-empirical models that attempt to predict the fractional coverage of oxygen relative to the composition of the atmosphere. These drag coefficients are then used to determine the atmospheric densities experienced by these satellites over various days, so that inaccuracies in the atmospheric models can be observed. The drag coefficients of the ANDE-2 satellites decrease throughout the satellites' life, and vary most due to changes in the temperature and density of the atmosphere. The greatest uncertainty in the atmosphere's composition occurs at lower altitudes at the end of ANDE-2's life.

Constraints on Galactic Cosmic-Ray Origins from Elemental and Isotopic Composition Measurements

NASA Technical Reports Server (NTRS)

Binns, W. R.; Christian, E. R.; Cummings, A. C.; deNolfo, G. A.; Israel, M. H.; Leske, R. A.; Mewaldt, R. A,; Stone, E. C.; vonRosevinge, T. T.; Wiedenbeck, M. E.

2013-01-01

The most recent measurements by the Cosmic Ray Isotope Spectrometer (CRIS) aboard the Advanced Composition Explorer (ACE) satellite of ultra-heavy cosmic ray isotopic and elemental abundances will be presented. A range of isotope and element ratios, most importantly Ne-22/Ne-20, Fe-58/Fe-56, and Ga-31/Ge -32 show that the composition is consistent with source material that is a mix of approx 80% ISM (with Solar System abundances) and 20% outflow/ejecta from massive stars. In addition, our data show that the ordering of refractory and volatile elements with atomic mass is greatly improved when compared to an approx 80%/20% mix rather than pure ISM, that the refractory and volatile elements have similar slopes, and that refractory elements are preferentially accelerated by a factor of approx 4. We conclude that these data are consistent with an OB association origin of GCRs.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

A replica of the Explorer 1 satellite is seen on display during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Spacecraft technology. [development of satellites and remote sensors

NASA Technical Reports Server (NTRS)

1975-01-01

Developments in spacecraft technology are discussed with emphasis on the Explorer satellite program. The subjects considered include the following: (1) nutational behavior of the Explorer-45 satellite, (2) panoramic sensor development, (3) onboard camera signal processor for Explorer satellites, and (4) microcircuit development. Information on the zero gravity testing of heat pipes is included. Procedures for cleaning heat treated aluminum heat pipes are explained. The development of a five-year magnetic tape, an accurate incremental angular encoder, and a blood freezing apparatus for leukemia research are also discussed.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

During a ceremony at Cape Canaveral Air Force Station's Space launch Complex 26 a historical marker has been unveiled noting the launch of America's first satellite, Explorer 1. The satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Planets of the solar system. [Jupiter and Venus

NASA Technical Reports Server (NTRS)

Kondratyev, K. Y.; Moskalenko, N. I.

1978-01-01

Venera and Mariner spacecraft and ground based radio astronomy and spectroscopic observations of the atmosphere and surface of venus are examined. The composition and structural parameters of the atmosphere are discussed as the basis for development of models and theories of the vertical structure of the atmosphere, the greenhouse effect, atmospheric circulation and cloud cover. Recommendations for further meteorological studies are given. Ground based and Pioneer satellite observation data on Jupiter are explored as well as calculations and models of the cloud structure, atmospheric circulation and thermal emission field of Jupiter.

Hyperdust : An advanced in-situ detection and chemical analysis of microparticles in space

NASA Astrophysics Data System (ADS)

Sternovsky, Z.; Gruen, E.; Horanyi, M.; Kempf, S.; Maute, K.; Srama, R.

2014-12-01

Interplanetary dust that originates from comets and asteroids may be in different stages of Solar System evolution. Atmosphereless planetary bodies, e.g., planetary satellites, asteroids, or Kuiper belt objects are enshrouded in clouds of dust released by meteoroid impacts or by volcanism. The ejecta grains are samples from the surface of these objects and their analysis can be performed from orbit or flyby to determine the surface composition, interior structure and ongoing geochemical processes. Early dust mass spectrometers on the Halley missions had sufficient mass resolution in order to provide important cosmochemical information in the near-comet high dust flux environment. The Ulysses dust detector discovered interstellar grains within the planetary system (Gruen et al. A&A, 1994) and its twin detector on Galileo discovered the tenuous dust clouds around the Galilean satellites (Krueger et al., Icarus, 2003). The similar-sized Cosmic Dust Analyzer onboard the Cassini mission combined a highly sensitive dust detector with a low-mass resolution mass spectrometer. Compositional dust measurements from this instrument probed the deep interior of Saturn's Enceladus satellite (Postberg et al., Nature, 2009). Based on this experience new instrumentation was developed that combined the best attributes of all these predecessors and exceeded their capabilities in accurate trajectory determination. The Hyperdust instrument is a combination of a Dust Trajectory Sensor (DTS) together with an analyzer for the chemical composition of dust particles in space. Dust particles' trajectories are determined by the measurement of induced electric signals. Large area chemical analyzers of 0.1 m2 sensitive area have been tested at a dust accelerator and it was demonstrated that they have sufficient mass resolution to resolve ions with atomic mass number >100. The Hyperdust instrument is capable of distinguishing interstellar and interplanetary grains based on their trajectory composition information. In orbit or flyby near airless planetary bodies the instrument can map the surface compositional down to a spatial resolution of ~10 km. The Hyperdust instrument is currently being developed to TRL 6 funded by NASA's MatISSE program to be a low-mass, high performance instrument for future in-situ exploration.

Titan exploration with advanced systems. A study of future mission concepts

NASA Technical Reports Server (NTRS)

1983-01-01

The requirements, capabilities, and programmatic issues associated with science-intensive mission concepts for the advanced exploration of Saturn's largest satellite are assessed. The key questions to be answered by a Titan exploratory mission are: (1) the atmospheric composition; (2) the atmospheric structure; (3) the nature of the surface; and (4) the nature of the interior of Titan. Five selected mission concepts are described in terms of their design requirements. Mission hardware concepts include balloons and/or blimps which will allow both atmospheric and surface observations for a long period of time. Key aspects of performance analysis are presented. Mission profiles and cost summaries are given. Candidate payloads are identified for imaging and nonimaging orbiters, a buoyant station, a haze probe, and a penetrator.

CTIPe model capabilities during the 2015 St. Patrick's Day storm

NASA Astrophysics Data System (ADS)

Fernandez-Gomez, I.; Fedrizzi, M.; Codrescu, M.; Borries, C.

2017-12-01

The Coupled Thermosphere Ionosphere Plasmaphere electrodynamics (CTIPe) model is a global physics based model that will be used to explore the ionosphere - thermosphere system response to the onset of 2015 St. Patrick's day storm. This storm, which was one of the strongest geomagnetic storms of the solar cycle 24, was generated by a magnetic cloud followed by a coronal mass ejection (CME) impact. The ionospheric disturbances are identified to be caused by superposition of many effects, like prompt penetration electric fields, neutral winds, thermal expansion and composition changes. Over Europe, measurements like ionosonde observations and Total Electron Content (TEC) maps derived from Global Navigation Satellite System (GNSS) indicate four storm phases (compression, start of main phase, partial recovery and second substorm) during 17th March 2015. CTIPe reproduces well the positive ionospheric storm phases, the compression of the ionosphere to a thin shell and the surges excited in the Auroral region. Furthermore, it reproduces well the changes in the neutral mass density measured by the SWARM satellites. Finally, CTIPe exhibits a coherent storm response for the thermospheric winds, temperature, composition and electron densities during the storm. These model results will be used to support the interpretation of the storms driving mechanisms.

An Assessment of Smallsat Technology to Future Exploration Missions

NASA Technical Reports Server (NTRS)

Chan, Steve

1997-01-01

This reports the results of a general study for NASA Lewis in relation to the use of small satellites for a Mars Relay Satellite (MRS) that supports communications between Mars and Earth: commands to, and telemetry from, Mars Landers and Rover. The scope of the study encompasses a survey of small satellites, those that are lower than 800 kg in mass, by NASA, DoD, and commercial companies. Additionally, surveys in advanced technologies in the area of composite materials, propulsion subsystems, battery subsystems, communications components and subsystems, and ground operations are also provided, A summary of NASA Mars Programs and their status as relevant to MRS is also included. Attempts to draw detailed cost conclusion is generally not possible due to its proprietary nature. In any event, cost is driven by market demands rather than new technologies. A preliminary comparison with the cost estimate of the S-Tel/OSC report did suggest the possibility of cost savings for the MRS by the use of production busses. On the other hand, cost savings in normalized terms from the use of automated ground systems were obtained with some degree of details.

Development of a multifunctional particle spectrometer for space radiation imaging

NASA Astrophysics Data System (ADS)

Maddox, Erik; Palacios, Alex; Lampridis, Dimitris; Kraft, Stefan; Owens, Alan; Tomuta, Dana; Ostendorf, Reint

2008-06-01

For future exploration of the solar system, the European Space Agency (ESA) is planning missions to Mercury (BepiColombo), the Sun (SolarOrbiter) and to the moons of Jupiter and Saturn. The expected intensity of radiation during such missions is hazardous for the scientific instruments and the satellite. To extend the lifetime of the satellite and its payload a multifunctional particle spectrometer (MPS) is being developed. The basic function of the MPS is to send an alarm signal to the satellite control system during periods of high radiation. In addition the MPS is a scientific instrument that will unfold the composition of the different contributing particles on-line by the dE/dx versus E method. The energy spectrum and angular distribution of the particles will be recorded as well. This article describes the main requirements and the base line design for the MPS. A readout scheme consisting of a 32 channel ASIC from IDEAS is proposed and the signal filtering algorithm will run on a digital signal processor based on FPGA technology. Results are shown from prototype calibration studies with a proton beam.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Michael Watkins, Director of NASA's Jet Propulsion Laboratory, left, Susan Finley, who began working at NASA's Jet Propulsion Laboratory in January 1958 as a "human computer", center, and Thomas Zurbuchen, Associate Administrator for NASA's Science Mission Directorate, right, reenact the famous picture of Dr. William H. Pickering, Dr. James A. van Allen, and Dr. Wernher von Braun, hoisting a model of Explorer 1 above their heads at a press conference announcing the satellite's success with a replica of the Explorer 1 satellite during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Applications of Satellite Observations of Tropospheric Composition

NASA Astrophysics Data System (ADS)

Monks, Paul S.; Beirle, Steffen

A striking feature of the field of tropospheric composition is the sheer number of chemical species that have been detected and measured with satellite instruments. The measurements have found application both in atmospheric chemistry itself, providing evidence, for example, of unexpected cryochemistry in the Arctic regions, and also in environmental monitoring with, for example, the observed growth in NO2 emissions over eastern Asia. Chapter 8 gives an overview of the utility of satellite observations for measuring tropospheric composition, dealing with each of the many compounds seen in detail. A comprehensive compound by compound table of the many studies performed is a most useful feature.

Remote sensing strategies for global resource exploration and environmental management

NASA Astrophysics Data System (ADS)

Henderson, Frederick B.

Since 1972, satellite remote sensing, when integrated with other exploration techniques, has demonstrated operational exploration and engineering cost savings and reduced exploration risks through improved geological mapping. Land and ocean remote sensing satellite systems under development for the 1990's by the United States, France, Japan, Canada, ESA, Russia, China, and others, will significantly increase our ability to explore for, develop, and manage energy and mineral resources worldwide. A major difference between these systems is the "Open Skies" and "Non-Discriminatory Access to Data" policies as have been practiced by the U.S. and France and the restrictive nationalistic data policies as have been practiced by Russia and India. Global exploration will use satellite remote sensing to better map regional structural and basin-like features that control the distribution of energy and mineral resources. Improved sensors will better map lithologic and stratigraphic units and identify alteration effects in rocks, soils, and vegetation cover indicative of undiscovered subsurface resources. These same sensors will also map and monitor resource development. The use of satellite remote sensing data will grow substantially through increasing integration with other geophysical, geochemical, and geologic data using improved geographic information systems (GIS). International exploration will focus on underdeveloped countries rather than on mature exploration areas such as the United States, Europe, and Japan. Energy and mineral companies and government agencies in these countries and others will utilize available remote sensing data to acquire economic intelligence on global resources. If the "Non-Discriminatory Access to Data" principle is observed by satellite producing countries, exploration will remain competitive "on the ground". In this manner, remote sensing technology will continue to be developed to better explore for and manage the world's needed resources. If, however, satellite producing countries follow the Russian and Indian lead and restrict civil satellite data as tools of their national security and economic policies, remote sensing technology may become internationally competitive in space, redundant, prohibitively expensive, and generally unavailable to the world community.

Applications of Satellite Remote Sensing for Response to and Recovery from Meteorological Disasters

NASA Technical Reports Server (NTRS)

Molthan, Andrew I.; Burks, Jason E.; McGrath, Kevin M.; Bell, Jordan R.

2014-01-01

Numerous on-orbit satellites provide a wide range of spatial, spectral, and temporal resolutions supporting the use of their resulting imagery in assessments of disasters that are meteorological in nature. This presentation will provide an overview of recent use of Earth remote sensing by NASA's Short-term Prediction Research and Transition (SPoRT) Center in response to disaster activities in 2012 and 2013, along with case studies supporting ongoing research and development. The SPoRT Center, with support from NASA's Applied Sciences Program, has explored a variety of new applications of Earth-observing sensors to support disaster response. In May 2013, the SPoRT Center developed unique power outage composites representing the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Subsequent ASTER, MODIS, Landsat-7 and Landsat-8 imagery help to identify the damaged areas. Higher resolution imagery of Moore, Oklahoma were provided by commercial satellites and the recently available International Space Station (ISS) SERVIR Environmental Research and Visualization System (ISERV) instrument. New techniques are being explored by the SPoRT team in order to better identify damage visible in high resolution imagery, and to monitor ongoing recovery for Moore, Oklahoma. This presentation will provide an overview of near real-time data products developed for dissemination to SPoRT's partners in NOAA's National Weather Service, through collaboration with the USGS and other federal agencies. Specifically, it will focus on integration of various data sets within the NOAA National Weather Service Damage Assessment Toolkit, which allows meteorologists in the field to consult available satellite imagery while performing their damage assessment.

The ODINUS Mission Concept: a Mission to the Ice Giant Planets

NASA Astrophysics Data System (ADS)

Turrini, Diego; Politi, Romolo; Peron, Roberto; Grassi, Davide; Plainaki, Christina; Barbieri, Mauro; Massimo Lucchesi, David; Magni, Gianfranco; Altieri, Francesca; Cottini, Valeria; Gorius, Nicolas; Gaulme, Patrick; Schmider, François-Xavier; Adriani, Alberto; Piccioni, Giuseppe

2014-05-01

We present the scientific case and the mission concept for the comparative exploration of the ice giant planets Uranus and Neptune and their satellites with a pair of twin spacecraft: ODINUS (Origins, Dynamics and Interiors of Neptunian and Uranian Systems). The ODINUS proposal was submitted in response to the call for white papers for the definition of the themes of the L2 and L3 mission in the framework of the ESA Cosmic Vision 2015-2025 program. The goal of ODINUS is the advancement of our understanding of the ancient past of the Solar System and, more generally, of how planetary systems form and evolve. The mission concept is focused on providing elements to answer to the scientific themes of the Cosmic Vision 2015-2025 program: What are the conditions for planetary formation and the emergency of life? How does the Solar System work? What are the fundamental physical laws of the Universe? In order to achieve its goals, the ODINUS mission concept proposed the use of two twin spacecraft to be put in orbit around Uranus and Neptune respectively, with selected flybys of their satellites. The proposed measurements aim to study the atmospheres and magnetospheres of the planets, the surfaces of the satellites, and the interior structure and composition of both satellites and planets. An important possibility for performing fundamental physics studies (among them tests of general relativity theory) is offered by the cruise phase. After the extremely positive evaluation of ESA Senior Survey Committee, who stated that 'the exploration of the icy giants appears to be a timely milestone, fully appropriate for an L class mission', we discuss strategies to comparatively study Uranus and Neptune with future international missions.

Carbon composites in space vehicle structures

NASA Technical Reports Server (NTRS)

Mayer, N. J.

1974-01-01

Recent developments in the technology of carbon or graphite filaments now provide the designer with greatly improved materials offering high specific strength and modulus. Besides these advantages are properties which are distinctly useful for space applications and which provide feasibility for missions not obtainable by other means. Current applications include major and secondary structures of communications satellites. A number of R & D projects are exploring carbon-fiber application to rocket engine motor cases, advanced antenna systems, and space shuttle components. Future system studies are being made, based on the successful application of carbon fibers for orbiting space telescope assemblies, orbital transfer vehicles, and very large deployable energy generation systems. Continued technology development is needed in analysis, material standards, and advanced structural concepts to exploit the full potential of carbon filaments in composite materials.

Substorm variations in the magnitude of the magnetic field - AMPTE/CCE observations

NASA Technical Reports Server (NTRS)

Lopez, R. E.; Sibeck, D. G.; Lui, A. T. Y.; Takahashi, K.; Mcentire, R. W.

1988-01-01

Using energetic-particle data taken in the near-earth tail by the AMPTE/Charge Composition Explorer (CCE) satellite, 167 ion injection events, that were essentially dispersionless over a 25-285 keV energy range, were identified, and the variations in the total magnetic field strength over the course of these events were examined in order to determine the dependence of the magnetic field strength on dipole latitude. Results indicate that, during periods of substorm activity, the latitudinal position of the current sheet varied significantly within the 32-deg wedge centered on the dipole equator traversed by CCE. Results also suggest that, even in the near-earth magnetotail out to 8.8 R(E) (CCE apogee), the local field measurements are a better guide to the determination of satellite's position relative to the current shield during a substorm, than is the magnetic latitude.

JPL-20180131-EXPLORs-0001- 60th Anniversary Explorer 1 The Beginning of the US Space Program

NASA Image and Video Library

2018-01-31

Flashback to Jan. 31, 1958, the day a rocket carrying a javelin-shaped satellite took flight into space. Explorer 1 was America's first satellite. Here's a look back at the beginning of the Space Age.

Fractionation of Saprolegnia diclina (Oomycetes) satelite DNAs by AgNO3/Cs2SO4 density gradient centrifugation.

PubMed

Neish, G A; Green, B R

1977-12-14

Saprolegnia diclina DNA has been fractionated using preparative AgNO3/Cs2SO4 and CsCl density gradients. In addition to the previously identified major satellite DNA, there are two minor DNA components banding at 1.682 and 1.701 g - cm(-3) in CsCl. Purified major satellite DNA bands at 1.707 g - cm(-3) giving a base composition of 48% G + C in good agreement with 47% G + C calculated from its Tm value. The nuclear DNA base composition is 58% G + C by both methods. The base composition of the major satellite DNA suggests that it may represent ribosomal DNA cistrons.

Theories of the origin and evolution of the giant planets

NASA Technical Reports Server (NTRS)

Pollack, J. B.; Bodenheimer, P.

1989-01-01

Following the accretion of solids and gases in the solar nebula, the giant planets contracted to their present sizes over the age of the solar system. It is presently hypothesized that this contraction was rapid, but not hydrodynamic; at a later stage, a nebular disk out of which the regular satellites formed may have been spun out of the outer envelope of the contracting giant planets due to a combination of total angular momentum conservation and the outward transfer of specific angular momentum in the envelope. If these hypotheses are true, the composition of the irregular satellites directly reflects the composition of planetesimals from which the giant planets formed, while the composition of the regular satellites is indicative of the composition of the less volatile components of the outer envelopes of the giant planets.

Application of advanced computing techniques to the analysis and display of space science measurements

NASA Technical Reports Server (NTRS)

Klumpar, D. M.; Lapolla, M. V.; Horblit, B.

1995-01-01

A prototype system has been developed to aid the experimental space scientist in the display and analysis of spaceborne data acquired from direct measurement sensors in orbit. We explored the implementation of a rule-based environment for semi-automatic generation of visualizations that assist the domain scientist in exploring one's data. The goal has been to enable rapid generation of visualizations which enhance the scientist's ability to thoroughly mine his data. Transferring the task of visualization generation from the human programmer to the computer produced a rapid prototyping environment for visualizations. The visualization and analysis environment has been tested against a set of data obtained from the Hot Plasma Composition Experiment on the AMPTE/CCE satellite creating new visualizations which provided new insight into the data.

Monitoring vegetation greenness with satellite data

Treesearch

Robert E. Burgan; Roberta A. Hartford

1993-01-01

Vegetation greenness can be monitored at 1-km resolution for the conterminous United States through data obtained from the Advanced Very High Resolution Radiometer on the NOAA-11 weather satellites. The data are used to calculate biweekly composites of the Normalized Difference Vegetation Index. The resulting composite images are updated weekly and made available to...

Ices on the Satellites of Jupiter, Saturn, and Uranus

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.; Brown, Robert H.; Calvin, Wendy M.; Roush, Ted L.

1995-01-01

Three satellites of Jupiter, seven satellites of Saturn, and five satellites of Uranus show spectroscopic evidence of H2O ice on their surfaces, although other details of their surfaces are highly diverse. The icy surfaces contain contaminants of unknown composition in varying degrees of concentration, resulting in coloration and large differences in albedo. In addition to H2O, Europa has frozen SO2, and Ganymede has O2 in the surface; in both of these cases external causes are implicated in the deposition or formation of these trace components. Variations in ice exposure across the surfaces of the satellites are measured from the spectroscopic signatures. While H2O ice occurs on the surfaces of many satellites, the range of bulk densities of these bodies shows that its contribution to their overall compositions is highly variable from one object to another.

TOPEX satellite concept. TOPEX option study report

NASA Technical Reports Server (NTRS)

Meyer, D. P.; Case, C. M.

1982-01-01

Candidate bus equipment from the Viking, Applications Explorer Mission, and Small Scientific Satellite programs for application to the TOPEX mission options is assessed. Propulsion module equipment and subsystem candidates from the Applications Explorer Mission satellites and the Small Scientific Satellite spacecraft are evaluated for those TOPEX options. Several subsystem concepts appropriate to the TOPEX options are described. These descriptions consider performance characteristics of the subsystems. Cost and availability information on the candidate equipment and subsystems are also provided.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Tori McLendon of NASA Communications, speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Kennedy Space Center Director Bob Cabana speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Construction of Au@Pt core—satellite nanoparticles based on in-situ reduction of polymeric ionic liquid protected gold nanoparticles

NASA Astrophysics Data System (ADS)

Wu, Wenlan; Li, Junbo; Zou, Sheng; Guo, Jinwu; Zhou, Huiyun

2017-03-01

A method of in-situ reduction to prepare Au@Pt core-satellite nanoparticles (NPs) is described by using Au NPs coating poly[1-methyl 3-(2-methacryloyloxy propylimidazolium bromine)] (PMMPImB-@-Au NPs) as the template. After electrostatic complex chloroplatinic acid with PMMPImB shell, the composite NP was directly reduced with N2H4 to produce Au@Pt core-satellite NPs. The characterization of composite and core-satellite NPs under different amounts of chloroplatinic acid were studied by DLS, UV-vis absorption spectrum and TEM. The satellite Pt NPs with a small size ( 2 nm) dotted around Au core, and the resulting Au@Pt core-satellite NPs showed a red-shift surface plasmon resonance (SPR) and a good dispersion due to effectively electrostatic repulsion providing by the polymeric ionic liquid (PIL) shell. Finally, Au@Pt core-satellite NPs exhibit an enhanced catalytic activity and cycled catalytic capability for the reduction of p-nitrophenol with NaBH4.

Observations of interstellar hydrogen and deuterium toward Alpha Centauri A

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1984-01-01

A composite profile is presented of the Ly-alpha emission line of Alpha Cen A, obtained from 10 individual spectra with the high-resolution spectrograph aboard the International Ultraviolet Explorer (IUE) satellite. There is excellent overall agreement with two previous Copernicus observations. Interstellar deuterium is detected, and a lower limit is set on the deuterium to hydrogen ratio of nDI/nHI greater than 8 x 10 to the -6th. In addition, the deuterium bulk velocity appears blueshifted by 8 + or - 2 km/s with respect to interstellar hydrogen, suggesting a nonuniform medium along the line of sight.

Intriguing differences and similarities in the surface compositions of the icy Saturnian and Galilean satellites

NASA Astrophysics Data System (ADS)

Hibbitts, C.

2006-12-01

Many materials in addition to water ice have been discovered in the surfaces of the icy Galilean and Saturnian satellites. Spacecraft infrared spectroscopy show intriguing differences and similarities suggestive of variations in primordial compositions and subsequent alteration. However, within the diverse compositions in their surfaces are similarities that cross between the systems. For instance, when nonice material is detected on these satellites, it is always hydrated. CO2 is detected in both systems where it is trapped in a host material except possibly for Enceladus where it may be deposited as ice from plumes [1-7]. Satellites in both systems contain aromatic hydrocarbons [8] and possibly CN-bearing materials [9]. The surfaces of Callisto, Ganymede, Europa, Iapetus, Phoebe, Hyperion, and Dione each contain some low albedo non-ice materials. The spectra have a broad 3-micron absorption feature due to structural OH or adsorbed water. However, the band is not sharp like a well-ordered clay mineral but broad, similar in some regards to less well-structured palagonite, goethite, or Murchison meteorite. The hydration of Jovian satellite nonice materials is greater for surfaces that have experienced more tectonism and alteration (i.e. increases from Callisto inward to Europa). The nonice material on Callisto appears to be a single composition (though itself possibly a mixture) that is slightly hydrated [10]. The nonice material on Europa is also of uniform composition everywhere observed, a very heavily hydrated material, perhaps a salt, hydrated SO4 (i.e. sulfuric acid), or both, that either originates from the subsurface ocean, radiolytically altered surface material, or both [11-13]. Ganymede appears to contain two types nonice materials; one an unidentified heavily hydrated material spectrally distinct from the Europa hydrate [11] and a second much less-abundant, less hydrated material spectrally similar to the Callisto nonice material that is largely associated with dark ray craters, possibly impactor contamination or desiccated Ganymede hydrate. The nonice materials on Phoebe and Iapetus is redder (from 1-2.5 microns) than the reddest material on the Galilean satellites (on Callisto) and compositionally different from each other. Iapetus appears to contain some (more) tholin material than Phoebe [14]. The CO2 on both satellites is similar to the CO2 detected in the nonice materials on Callisto and Ganymede with a reflectance minimum ~ 4.258 microns. The spectrum of the CO2 detected on Hyperion and Dione is distinct from that on Iapetus and Phoebe, having a reflectance minimum 10nm shorter at ~ 4.246 microns. This suggests a different bonding energy and possibly a different host material. In summary, the compositions of the icy Galilean satellites reflect the evolutionary state of their surfaces. The compositions of the icy Saturnian satellites are also complex, but with the exception of Enceladus, do not yet show any obvious dependencies on surface structure. There may some commonality in primordial compositions between the satellites of the two systems. References: [1]1Carlson et al., (1996) Science; [2] McCord et al., (1998) J. Geophys. Res.;[3] Hibbitts et al., (2000), J. Geophys. Res; [4] Hibbitts et al., (2003) J. Geophys. Res; [5] Clark et al., (2005) Nature; [6] Buratti et al., (2005) Astrophys. J.; [7] Brown et al., (2006) , Icarus; [8] Clark et al., (2005), Fall AGU; [9] Cruikshank et al., (2005), DPS [10] Calvin et al., (1991), Icarus; [11] McCord et al., 2000; [12]Carlson et al., 1999; [13]Orlando et al., (2005) Icarus; [14] Owens et al., (2001) Icarus;.

Cryomagmatism in the outer solar system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kargel, J.S.

1990-01-01

Assemblages of cryovolcanic, tectonic, and impact structures form varied landscapes quite alien in their collective expression. Many variables can affect the cryovolcanic style of a satellite but none more so than cryolava composition. The compositional variable is examined in considerable detail. Existing knowledge of phase equilibria and physical properties of cosmochemically relevant unary, binary, and multi-component chemical systems are summarized. Where published knowledge was found lacking, measurements of the physical chemistry of volatile mixtures are presented. Cryovolcanic landscapes are briefly toured, and knowledge of the physical chemistry of volatile mixtures is applied to problems of cryovolcanological interest. Aqueous cryolavas maymore » range in composition from salt-water brines to cryogenic ammonia-water-rich multi-components solutions possibly involving methanol, ammonium sulfide, alkali chlorides, and many other potential components. Cryomagmatic distillation can greatly accentuate the importance of trace and minor constituents of icy satellites. The viscosities, densities, and other physical properties of these liquids vary considerably and depend sensitively on their exact compositions. These properties affect everything from cryovolcanic eruptive styles and landforms, to the way cryovolcanic crusts respond to tectonic stress. It is believed that the compositional variable is directly or indirectly implicated in a wide varity of geomorphic aspects of contrast among the icy satellites. Thus, even though as yet any specific morphology can be attributed to a specific composition, there appears to be a powerful link between composition of the ices originally accreted by a satellite and its subsequent interior evolution and exterior geomorphic appearance.« less

The United States' Next Generation of Atmospheric Composition and Coastal Ecosystem Measurements: NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

NASA Technical Reports Server (NTRS)

Fishman, J.; Iraci, Laura T.; Al-Saddi, J.; Chance, K.; Chavez, F.; Chin, M.; Coble, P.; Davis, C.; DiGiacomo, P. M.; Edwards, D.;

Observed formation of easterly waves over northeast Africa

NASA Astrophysics Data System (ADS)

Jury, Mark R.

2018-06-01

This study explores the thermodynamic and kinematic features of easterly waves over northeast Africa in July-September season 2005-2015. A daily African easterly wave (AEW) index is formulated from transient satellite rainfall and reanalysis vorticity, and the ten most intense cases are studied by composite analysis. Surface moisture is advected from central Africa towards the Red Sea during AEW formation. The anomalous 600 hPa wind circulation is comprized of a cyclonic-south anticyclonic-north rotor pair and accentuated easterly jet along 17N. Composite convection is initiated over Ethiopia and subsequently intensifies following interaction with a zonal circulation located downstream. Composite AEW temperature anomalies reveal a cool lower-warm upper layer heating profile. 2-8 day variance of satellite OLR reaches a maximum over the southern Arabian Peninsula, suggesting an upstream role for surface heating and the Somali Jet. The large scale environment is analyzed by regression of the AEW index onto daily fields of rainfall, surface air pressure and temperature in July-September season ( N = 1004). The rainfall regression reflects a westward propagating AEW wave-train of higher values on 13N and lower values on 7N with a longitude spacing of 25°. The air pressure and temperature regression features a N-S dipole indicating an anomalous northward ITCZ. A low pressure signal west of the Maritime Continent coupled with a warm zone across the South Indian Ocean coincides with AEW formation over the eastern Sahel.

Influence of structure on radiation shielding effectiveness of graphite fiber reinforced polyethylene composite

NASA Astrophysics Data System (ADS)

Emmanuel, A.; Raghavan, J.

2015-10-01

While LEO and GEO are used for most satellite missions, Highly Elliptical Orbits (HEOs) are also used for satellite missions covering Polar Regions of Earth. Satellites in HEO are exposed to a relatively harsher radiation environment than LEO and GEO. The mass of traditionally used aluminum radiation shield, required to attenuate the radiation to a level below a certain threshold that is safe for the satellite bus and payload, scales with the level of radiation. It has been shown (Emmanuel et al., 2014) that materials with low atomic number (Z) such as polyethylene (PE) can result in a lighter shield than aluminum (Al) in HEO. However, PE has to be reinforced with relatively high Z fibers such as graphite (G) to improve its mechanical properties. The effect of introduction of G and the resulting composite structure (that meets the requirements on mechanical properties, manufacturing and service) on the radiation shielding effectiveness of PE was studied through simulation using a layered PE-G composite. The Total Ionization Dose (TID), deposited in a silicon detector behind the composite shield, has been found to be function of layer volume fraction, layer thickness and stacking sequence of the PE and G layers. One composite configuration has resulted in a TID lower than that for PE, demonstrating the possibility of tailoring the mechanical properties of PE-based composite radiation shield with minimal negative impact on its radiation shielding effectiveness.

Dynamics Explorer twin spacecraft under evaluation tests

NASA Technical Reports Server (NTRS)

Redmond, C.

1981-01-01

The Dynamics Explorer A and B satellites designed to explore the interactive processes occuring between the magnetosphere and Earth's ionosphere, upper atmosphere, and plasmasphere are described. Effects of these interactions, satellite orbits, data collecting antennas, solar power systems, axes, configurations, and Earth based command, control and data display systems are mentioned.

ATLAS-SOHO: Satellite Arrival and Uncrating, Uncrating of the Propulsion Unit and Electric Module

NASA Technical Reports Server (NTRS)

1995-01-01

The SOHO satellite, part of the International Solar-Terrestrial Physics Program (ISTP), is a solar observatory designed to study the structure, chemical composition, and dynamics of the solar interior. It will also observe the structure (density, temperature and velocity fields), dynamics and composition of the outer solar atmosphere, and the solar wind and its relation to the solar atmosphere. The spacecraft was launched on December 2, 1995. This video shows the unloading of the satellite from the transport plane at the Kennedy Space Station and the lowering to an awaiting flatbed truck. The video also shows the uncrating of the satellite, the propulsion unit and the electric module in a clean room.

Global Lunar Gravity Field Recovery from SELENE

NASA Technical Reports Server (NTRS)

Matsumoto, Koji; Heki, Kosuke; Hanada, Hideo

2002-01-01

Results of numerical simulation are presented to examine the global gravity field recovery capability of the Japanese lunar exploration project SELENE (Selenological and Engineering Explorer) which will be launched in 2005. New characteristics of the SELENE lunar gravimetry include four-way satellite-to-satellite Doppler tracking of main orbiter and differential VLBI tracking of two small free-flier satellites. It is shown that planned satellites configuration will improve lunar gravity field in wide range of wavelength as well as far-side selenoid.

Hybrid Tank Technology

NASA Technical Reports Server (NTRS)

2004-01-01

Researchers have accomplished great advances in pressure vessel technology by applying high-performance composite materials as an over-wrap to metal-lined pressure vessels. These composite over-wrapped pressure vessels (COPVs) are used in many areas, from air tanks for firefighters and compressed natural gas tanks for automobiles, to pressurant tanks for aerospace launch vehicles and propellant tanks for satellites and deep-space exploration vehicles. NASA and commercial industry are continually striving to find new ways to make high-performance pressure vessels safer and more reliable. While COPVs are much lighter than all-metal pressure vessels, the composite material, typically graphite fibers with an epoxy matrix resin, is vulnerable to impact damage. Carbon fiber is most frequently used for the high-performance COPV applications because of its high strength-to-weight characteristics. Other fibers have been used, but with limitations. For example, fiberglass is inexpensive but much heavier than carbon. Aramid fibers are impact resistant but have less strength than carbon and their performance tends to deteriorate.

Magnetic storm of September 4, 1984 - A synthesis of ring current spectra and energy densities measured with AMPTE/CCE

NASA Technical Reports Server (NTRS)

Krimigis, S. M.; Mcentire, R. W.; Potemra, T. A.; Gloeckler, G.; Scarf, F. L.; Shelley, E. G.

1985-01-01

Compositional studies of the equatorial distributions of ring current ions during the September 4, 1984 magnetic storm have been made possible by comprehensive energy, charge state, and mass coverage data from the Charge Composition Explorer satellite. An examination of ion spectra at an L value of about 4 on September 5, in the local evening sector, shows that energy density was dominated by protons, with O ions contributing about 27 percent at the peak of about 150 keV, while He ions contributed less than about 2 percent. September 6 ion spectra, taken during the recovery phase of the storm, indicate that ion densities at more than 20 keV had decreased markedly, and that the ring current energy density was primarily provided by protons.

Uhuru (SAS-1/Explorer 42)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

NASA satellite, launched from the San Marco platform off the Kenyan coast in 1970. The first satellite dedicated to x-ray astronomy. Completed an all-sky x-ray survey and studied individual sources. Discovered x-ray binaries, including Hercules X-1 and Centaurus X-1, and confirmed the variability of Cygnus X-1. Uhuru means `freedom' in Swahili. (See also SMALL ASTRONOMY SATELLITE, EXPLORER.)...

Technology Development on ISS for Satellite Servicing and Exploration

NASA Technical Reports Server (NTRS)

Reed, Benjamin B.

2015-01-01

NASA's Satellite Servicing Capabilities Office is utilizing the International Space Station to demonstrate technologies essential to satellite servicing endeavors in support of human exploration and science. Within this presentation, we will discuss the status and implications of three of these technology payloads: Restore-L, Asteroid Redirect Robotic Mission (ARRM), Raven, Robotic Refueling Mission (RRM) Phase 2, and RRM Phase 3.

Spaced-based Cosmic Ray Astrophysics

NASA Astrophysics Data System (ADS)

Seo, Eun-Suk

2016-03-01

The bulk of cosmic ray data has been obtained with great success by balloon-borne instruments, particularly with NASA's long duration flights over Antarctica. More recently, PAMELA on a Russian Satellite and AMS-02 on the International Space Station (ISS) started providing exciting measurements of particles and anti-particles with unprecedented precision upto TeV energies. In order to address open questions in cosmic ray astrophysics, future missions require spaceflight exposures for rare species, such as isotopes, ultra-heavy elements, and high (the ``knee'' and above) energies. Isotopic composition measurements up to about 10 GeV/nucleon that are critical for understanding interstellar propagation and origin of the elements are still to be accomplished. The cosmic ray composition in the knee (PeV) region holds a key to understanding the origin of cosmic rays. Just last year, the JAXA-led CALET ISS mission, and the DAMPE Chinese Satellite were launched. NASA's ISS-CREAM completed its final verification at GSFC, and was delivered to KSC to await launch on SpaceX. In addition, a EUSO-like mission for ultrahigh energy cosmic rays and an HNX-like mission for ultraheavy nuclei could accomplish a vision for a cosmic ray observatory in space. Strong support of NASA's Explorer Program category of payloads would be needed for completion of these missions over the next decade.

The data of establishing a three-dimensional culture system for in vitro recapitulation and mechanism exploration of tumor satellite formation during cancer cell transition.

PubMed

Chen, Chun-Nan; Chen, You-Tzung; Yang, Tsung-Lin

2017-12-01

Tumor satellite formation is an indicator of cancer invasiveness and correlates with recurrence, metastasis, and poorer prognosis. By analyzing pathological specimens, tumor satellites formed at the tumor-host interface reflect the phenomena of epithelial-mesenchymal transition. It is impossible to reveal the dynamic processes and the decisive factors of tumor satellite formation using clinicopathological approaches alone. Therefore, establishment of an in vitro system to monitor the phenomena is important to explicitly elucidate underlying mechanisms. In this study, we explored the feasibility of creating an in vitro three-dimensional collagen culture system to recapitulate the process of tumor satellite formation. This data presented here are referred to the research article (Chen et al., 2017) [1]. Using this model, the dynamic process of tumor satellite formation could be recapitulated in different types of human cancer cells. Induced by calcium deprivation, the treated cells increased the incidence and migratory distance of tumor satellites. E-cadherin internalization and invadopodia formation were enhanced by calcium deprivation and were associated with cellular dynamic change during tumor satellite formation. The data confirmed the utility of this culture system to recapitulate dynamic cellular alteration and to explore the potential mechanisms of tumor satellite formation.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Michael Watkins, Director of NASA's Jet Propulsion Laboratory, left, Susan Finley, who began working at NASA's Jet Propulsion Laboratory in January 1958 as a "human computer", center, and Thomas Zurbuchen, Associate Administrator for NASA's Science Mission Directorate, right, pose for a picture with a replica of the Explorer 1 satellite during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Most Amazing High Definition Image of Earth - Blue Marble 2012

NASA Image and Video Library

2017-12-08

January 25, 2012 *Updated February 2, 2012: According to Flickr, "The western hemisphere Blue Marble 2012 image has rocketed up to over 3.1 million views making it one of the all time most viewed images on the site after only one week." A 'Blue Marble' image of the Earth taken from the VIIRS instrument aboard NASA's most recently launched Earth-observing satellite - Suomi NPP. This composite image uses a number of swaths of the Earth's surface taken on January 4, 2012. The NPP satellite was renamed 'Suomi NPP' on January 24, 2012 to honor the late Verner E. Suomi of the University of Wisconsin. Suomi NPP is NASA's next Earth-observing research satellite. It is the first of a new generation of satellites that will observe many facets of our changing Earth. Suomi NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS. To read more about NASA's Suomi NPP go to: www.nasa.gov/npp Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Characterizing the Asian Tropopause Aerosol Layer (ATAL) Using Satellite Observations, Balloon Measurements and a Chemical Transport Model

NASA Technical Reports Server (NTRS)

Fairlie, T. D.; Vernier, J.-P.; Liu, H.; Deshler, T.; Natarajan, M.; Bedka, K.; Wegner, T.; Baker, N.; Gadhavi, H.; Ratnam, M. V.;

The Asian Tropopause Aerosol Layer: Balloon-Borne Measurements, Satellite Observations and Modeling Approaches

NASA Technical Reports Server (NTRS)

Fairlie, T. D.; Vernier, J.-P.; Natarajan, M.; Deshler, Terry; Liu, H.; Wegner, T.; Baker, N.; Gadhavi, H.; Jayaraman, A.; Pandit, A.;

Exploring Multiple Constraints of Anthropogenic Pollution

NASA Astrophysics Data System (ADS)

Arellano, A. F., Jr.; Tang, W.; Silva, S. J.; Raman, A.

2017-12-01

It is imperative that we provide more accurate and consistent analysis of anthropogenic pollution emissions at scales that is relevant to air quality, energy, and environmental policy. Here, we present three proof-of-concept studies that explore observational constraints from ground, aircraft, and satellite-derived measurements of atmospheric composition on bulk characteristics of anthropogenic combustion in megacities and fire regions. We focus on jointly analyzing co-emitted combustion products such as CO2, NO2, CO, SO2, and aerosols from GOSAT, OCO-2, OMI, MOPITT, and MODIS retrievals, in conjunction with USEPA AQS and NASA field campaigns. Each of these constituents exhibit distinct atmospheric signatures that depend on fuel type, combustion technology, process, practices and regulatory policies. Our results show that distinguishable patterns and relationships between the increases in concentrations across the megacity (or enhancements) due to emissions of these constituents enable us to: a) identify trends in combustion activity and efficiency, and b) reconcile discrepancies between state- to country-based emission inventories and modeled concentrations of these constituents. For example, the trends in enhancement ratios of these species reveal combustion emission pathways for China and United States that are not captured by current emission inventories and chemical reanalysis. Analysis of their joint distributions has considerable potential utility in current and future integrated constituent data assimilation and inverse modeling activities for monitoring, verifying, and reporting emissions, particularly for regions with few observations and limited information on local combustion processes. This work also motivates the need for continuous and preferably collocated satellite measurements of atmospheric composition, including CH4 and CO2, and studies related to improving the applicability and integration of these observations with ground- and aircraft- based measurements.

Analysis of Imp-C data from the magnetospheric tail

NASA Technical Reports Server (NTRS)

Speiser, T. W.

1973-01-01

Satellite magnetic field measurements in the geomagnetic tail current sheet are analyzed to determine the normal field component, and other CS parameters such as thickness, motion, vector current density, etc., and to make correlations with auroral activity as measured by the A sub e index. The satellite data used in the initial part of this study were from Explorer 28 and Explorer 34 satellites.

Satellite Imagery Products - Office of Satellite and Product Operations

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Design of smart composite platforms for adaptive trust vector control and adaptive laser telescope for satellite applications

NASA Astrophysics Data System (ADS)

Ghasemi-Nejhad, Mehrdad N.

2013-04-01

This paper presents design of smart composite platforms for adaptive trust vector control (TVC) and adaptive laser telescope for satellite applications. To eliminate disturbances, the proposed adaptive TVC and telescope systems will be mounted on two analogous smart composite platform with simultaneous precision positioning (pointing) and vibration suppression (stabilizing), SPPVS, with micro-radian pointing resolution, and then mounted on a satellite in two different locations. The adaptive TVC system provides SPPVS with large tip-tilt to potentially eliminate the gimbals systems. The smart composite telescope will be mounted on a smart composite platform with SPPVS and then mounted on a satellite. The laser communication is intended for the Geosynchronous orbit. The high degree of directionality increases the security of the laser communication signal (as opposed to a diffused RF signal), but also requires sophisticated subsystems for transmission and acquisition. The shorter wavelength of the optical spectrum increases the data transmission rates, but laser systems require large amounts of power, which increases the mass and complexity of the supporting systems. In addition, the laser communication on the Geosynchronous orbit requires an accurate platform with SPPVS capabilities. Therefore, this work also addresses the design of an active composite platform to be used to simultaneously point and stabilize an intersatellite laser communication telescope with micro-radian pointing resolution. The telescope is a Cassegrain receiver that employs two mirrors, one convex (primary) and the other concave (secondary). The distance, as well as the horizontal and axial alignment of the mirrors, must be precisely maintained or else the optical properties of the system will be severely degraded. The alignment will also have to be maintained during thruster firings, which will require vibration suppression capabilities of the system as well. The innovative platform has been designed to have tip-tilt pointing and simultaneous multi-degree-of-freedom vibration isolation capability for pointing stabilization. Analytical approaches have been employed for determining the loads in the components as well as optimizing the design of the system. The different critical components such as telescope tube struts, flexure joints, and the secondary mirror mount have been designed and analyzed using finite element technique. The Simultaneous Precision Positioning and Vibration Suppression (SPPVS) smart composites platforms for the adaptive TVC and adaptive composite telescope are analogous (e.g., see work by Ghasemi-Nejhad and co-workers [1, 2]), where innovative concepts and control strategies are introduced, and experimental verifications of simultaneous thrust vector control and vibration isolation of satellites were performed. The smart composite platforms function as an active structural interface between the main thruster of a satellite and the satellite structure for the adaptive TVC application and as an active structural interface between the main smart composite telescope and the satellite structure for the adaptive laser communication application. The cascaded multiple feedback loops compensate the hysteresis (for piezoelectric stacks inside the three linear actuators that individually have simultaneous precision positioning and vibration suppression), dead-zone, back-lash, and friction nonlinearities very well, and provide precision and quick smart platform control and satisfactory thrust vector control capability. In addition, for example for the adaptive TVC, the experimental results show that the smart composite platform satisfactorily provided precision and fast smart platform control as well as the satisfactory thrust vector control capability. The vibration controller isolated 97% of the vibration energy due to the thruster firing.

Leveraging Machine Learning to Estimate Soil Salinity through Satellite-Based Remote Sensing

NASA Astrophysics Data System (ADS)

Welle, P.; Ravanbakhsh, S.; Póczos, B.; Mauter, M.

2016-12-01

Human-induced salinization of agricultural soils is a growing problem which now affects an estimated 76 million hectares and causes billions of dollars of lost agricultural revenues annually. While there are indications that soil salinization is increasing in extent, current assessments of global salinity levels are outdated and rely heavily on expert opinion due to the prohibitive cost of a worldwide sampling campaign. A more practical alternative to field sampling may be earth observation through remote sensing, which takes advantage of the distinct spectral signature of salts in order to estimate soil conductivity. Recent efforts to map salinity using remote sensing have been met with limited success due to tractability issues of managing the computational load associated with large amounts of satellite data. In this study, we use Google Earth Engine to create composite satellite soil datasets, which combine data from multiple sources and sensors. These composite datasets contain pixel-level surface reflectance values for dates in which the algorithm is most confident that the surface contains bare soil. We leverage the detailed soil maps created and updated by the United States Geological Survey as label data and apply machine learning regression techniques such as Gaussian processes to learn a smooth mapping from surface reflection to noisy estimates of salinity. We also explore a semi-supervised approach using deep generative convolutional networks to leverage the abundance of unlabeled satellite images in producing better estimates for salinity values where we have relatively fewer measurements across the globe. The general method results in two significant contributions: (1) an algorithm that can be used to predict levels of soil salinity in regions without detailed soil maps and (2) a general framework that serves as an example for how remote sensing can be paired with extensive label data to generate methods for prediction of physical phenomenon.

The Global ASTER Geoscience and Mineralogical Maps

NASA Astrophysics Data System (ADS)

Abrams, M.

2017-12-01

In 2012, Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) released 17 Geoscience mineral maps for the continent of Australia We are producing the CSIRO Geoscience data products for the entire land surface of the Earth. These maps are created from Advanced Spacecraft Thermal Emission and Reflection Radiometer (ASTER) data, acquired between 2000 and 2008. ASTER, onboard the United States' Terra satellite, is part of NASA's Earth Observing System. This multispectral satellite system has 14 spectral bands spanning: the visible and near-infrared (VNIR) @ 15 m pixel resolution; shortwave-infrared (SWIR) @ 30 m pixel resolution; and thermal infrared (TIR) @ 90 m pixel resolution. In a polar-orbit, ASTER acquires a 60 km swath of data.The CSIRO maps are the first continental-scale mineral maps generated from an imaging satellite designed to measure clays, quartz and other minerals. Besides their obvious use in resource exploration, the data have applicability to climatological studies. Over Australia, these satellite mineral maps improved our understanding of weathering, erosional and depositional processes in the context of changing weather, climate and tectonics. The clay composition map showed how kaolinite has developed over tectonically stable continental crust in response to deep weathering. The same clay composition map, in combination with one sensitive to water content, enabled the discrimination of illite from montmorillonite clays that typically develop in large depositional environments over thin (sinking) continental crust. This product was also used to measure temporal gains/losses of surface clay caused by periodic wind erosion (dust) and rainfall inundation (flood) events. The two-year project is undertaken by JPL with collaboration from CSIRO. JPL has in-house the entire ASTER global archive of Level 1B image data—more than 1,500,000 scenes. This cloud-screened and vegetation-masked data set will be the basis for creation of the suite of global Geoscience products using all of ASTER's 14 VNIR-SWIR-TIR spectral bands resampled to 100 m pixel resolution. We plan a staged release of the geoscience products through NASA's LPDAAC.

A comparison of satellite systems for gravity field measurements

NASA Technical Reports Server (NTRS)

Argentiero, P. D.; Lowrey, B. E.

1977-01-01

A detailed and accurate earth gravity field model is important to the understanding of the structure and composition of the earth's crust and upper mantle. Various satellite-based techniques for providing more accurate models of the gravity field are analyzed and compared. A high-low configuration satellite-to-satellite tracking mission is recommended for the determination of both the long wavelength and short wavelength portions of the field. Satellite altimetry and satellite gradiometry missions are recommended for determination of the short wavelength portion of the field.

The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries: Plasma Sheet Ion Composition

DOE PAGES

Denton, M. H.; Thomsen, M. F.; Reeves, G. D.; ...

2017-10-03

The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H + ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H +, O +, and He + ion fluxes in the plasma sheet. H+ shown to be the dominant ion in the plasma sheet in the calm-to-storm transition. However, the energy-flux ofmore » each ion changes in a quasi-linear manner during extended calm intervals. Heavy ions (O + and He +) become increasingly important during such periods as charge-exchange reactions result in faster loss for H + than for O + or He +. Results confirm previous investigations showing that the ion composition of the plasma sheet can be largely understood (and predicted) during calm intervals from knowledge of: (a) the composition of previously injected plasma at the onset of calm conditions, and (b) use of simple drift-physics models combined with calculations of charge-exchange losses.« less

The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries: Plasma Sheet Ion Composition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denton, M. H.; Thomsen, M. F.; Reeves, G. D.

The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H + ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H +, O +, and He + ion fluxes in the plasma sheet. H+ shown to be the dominant ion in the plasma sheet in the calm-to-storm transition. However, the energy-flux ofmore » each ion changes in a quasi-linear manner during extended calm intervals. Heavy ions (O + and He +) become increasingly important during such periods as charge-exchange reactions result in faster loss for H + than for O + or He +. Results confirm previous investigations showing that the ion composition of the plasma sheet can be largely understood (and predicted) during calm intervals from knowledge of: (a) the composition of previously injected plasma at the onset of calm conditions, and (b) use of simple drift-physics models combined with calculations of charge-exchange losses.« less

Applying satellite technology to energy and mineral exploration

USGS Publications Warehouse

Carter, William D.; Rowan, Lawrence C.

1978-01-01

IGCP Project 143 ("Remote Sensing and Mineral Exploration"), is a worldwide research project designed to make satellite data an operational geological tool along with the geologic pick, hand lens, topographic map, aerial photo and geophysical instruments and data that comprise the exploration package. While remote sensing data will not replace field exploration and mapping, careful study of such data prior to field work should make the effort more efficient.

Mechanical and thermal properties of planetologically important ices

NASA Technical Reports Server (NTRS)

Croft, Steven K.

1987-01-01

Two squences of ice composition were proposed for the icy satellites: a dense nebula model and a solar nebula model. Careful modeling of the structure, composition, and thermal history of satellites composed of these various ices requires quantitative information on the density, compressibility, thermal expansion, heat capacity, and thermal conductivity. Equations of state were fitted to the density data of the molecular ices. The unusual thermal and mechanical properties of the molecular and binary ices suggest a larger range of phenomena than previously anticipated, sufficiently complex perhaps to account for many of the unusual geologic phenomena found on the icy satellites.

Low-Earth orbit effects on organic composite materials flown on LDEF

NASA Technical Reports Server (NTRS)

George, Pete E.; Dursch, Harry W.

1993-01-01

Over 35 different types of organic matrix composites were flown as part of 11 different experiments onboard the NASA Long Duration Exposure Facility (LDEF) satellite. This materials and systems experiment satellite flew in low-earth orbit (LEO) for 69 months. For that period, the experiments were subjected to the LEO environment including atomic oxygen (AO), ultraviolet (UV) radiation, thermal cycling, microvacuum, meteoroid and space debris (M&D), and particle radiation. Since retrieval of the satellite in January of 1990, the principal experiment investigators have been deintegrating, examining, and testing the materials specimens flown. The most detrimental environmental effect on all organic matrix composites was material loss due to AO erosion. AO erosion of uncoated organic matrix composites (OMC) facing the satellite ram direction was responsible for significant mechanical property degradations. Also, thermal cycling-induced microcracking was observed in some nonunidirectional reinforced OMC's. Thermal cycling and outgassing caused significant but predictable dimensional changes as measured in situ on one experiment. Some metal and metal oxide-based coatings were found to be very effective at preventing AO erosion of OMC's. However, M&D impacts and coating fractures which compromised these coatings allowed AO erosion of the underlying OMC substrates. The findings for organic matrix composites flown on the LDEF are summarized and the LEO environmental factors, their effects, and the influence on space hardware design factors for LEO applications are identified.

Mapping the CMB with the Wilkinson Microwave Anisotropy Probe

NASA Technical Reports Server (NTRS)

Hinshaw, Gary F.

2007-01-01

The data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature anisotropy and new full-sky maps of the polarization. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. These and other aspects of the mission results will be discussed and commented on. WMAP, part of NASA's Explorers program, was launched on June 30,200 1. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; University of Chicago; Brown University; University of British Columbia; and University of California, Los Angeles.

AMPTE CCE observations of Pi 2 pulsations in the inner magnetosphere

NASA Technical Reports Server (NTRS)

Takahashi, Kazue; Ohtani, Shin-Ichi; Yumoto, Kiyohumi

1992-01-01

Magnetic field data acquired with the AMPTE Charge Composition Explorer satellite in the inner magnetosphere (L = 2-5) often show Pi 2 pulsations whose waveforms match Pi 2 pulsations simultaneously observed on the ground at Kakioka (L = 1.2). From a study such events, it is found that the magnetic pulsations in the equatorial magnetosphere are dominated by poloidal-mode oscillations. The relative phase between the compressional component at CCE and the horizontal component at Kakioka is either near zero or near 180 deg, with the 180 lag observed only when the satellite is at L greater than 3. This observation implies that there is a node of a radial standing wave at L greater than 3. It is argued that the nodal structure arises from reflection of MHD fast-mode waves at some inner boundary of the magnetosphere and discuss the relevance of the nodal structure to cavity-mode resonances and oscillations in the inner magnetosphere forced by a source wave external to the inner magnetosphere.

Taking the Measure of the Universe: Cosmology from the WMAP Mission

NASA Technical Reports Server (NTRS)

Hinshaw, Gary F.

2006-01-01

The data from the first three years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature anisotropy and new full-sky maps of the polarization. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. These and other aspects of the mission will be discussed. WMAP, part of NASA's Explorers program, was launched on June 30,2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Cornel1 University; University of Chicago; Brown University; University of British Columbia; University of Pennsylvania; and University of California, Los Angeles

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Attendees watch a short video on Explorer 1 during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

NASA Tropospheric Composition Program field campagins as prototypes to advance the Integrated Observing System for Air Quality

NASA Astrophysics Data System (ADS)

Lefer, B. L.; Crawford, J. H.; Pierce, R. B.; Berkoff, T.; Swap, R.; Janz, S. J.; Ahn, J.; Al-Saadi, J. A.

2017-12-01

With the launch over the virtual constellation of earth observing satellites for atmospheric composition (e.g., TROPOMI, GEMS, TEMPO, and Sentinel-4) over the next several years, we have a unique opportunity to develop an Integrated Observing System (IOS) for air quality in the northern hemisphere. Recently, NASA's Tropospheric Composition Program (TCP) has participated in several different air quality related field campaigns as an effort to explore various prototypes of the IOS for Air Quality. The IOS for air quality could be a system were space-based observations of air quality (generally, column abundances of NO2, HCHO, O3, SO2, and AOD) are given added "value" by being integrated with: a) long-term ground-based observations;b) regional and global air quality and chemical transport models; as well as c) measurements from targeted airborne field campaigns. The recent Korea-US Air Quality Study (KORUS-AQ), the Lake Michigan Ozone Study 2017 (LMOS), and the Ozone Water-Land Environmental Transition Study (OWLETS) field campaigns were held in different locations and made measurements over different scale. However, all of these provide an opportunity to learn about how a future integrated air quality observing system can be implemented to serve a variety of air quality related objectives. NASA TCP is also exploring enchancements to our routine observations to strengthen the IOS for air quality in the future.

Near Real-Time Applications of Earth Remote Sensing for Response to Meteorological Disasters

NASA Technical Reports Server (NTRS)

Molthan, Andrew L.; Burks, Jason E.; McGrath, Kevin M.; Bell, Jordan R.

2013-01-01

Numerous on-orbit satellites provide a wide range of spatial, spectral, and temporal resolutions supporting the use of their resulting imagery in assessments of disasters that are meteorological in nature. This presentation will provide an overview of recent use of Earth remote sensing by NASA's Short-term Prediction Research and Transition (SPoRT) Center in response to disaster activities in 2012 and 2013, along with case studies supporting ongoing research and development. The SPoRT Center, with support from NASA's Applied Sciences Program, has explored a variety of new applications of Earth-observing sensors to support disaster response. In May 2013, the SPoRT Center developed unique power outage composites representing the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Subsequent ASTER, MODIS, Landsat-7 and Landsat-8 imagery help to identify the damaged area. Higher resolution imagery of Moore, Oklahoma were provided by commercial satellites and the recently available International Space Station (ISS) SERVIR Environmental Research and Visualization System (ISERV) instrument. New techniques are being explored by the SPoRT team in order to better identify damage visible in high resolution imagery, and to monitor ongoing recovery for Moore, Oklahoma. Other applications are being developed to refine light source detections with the VIIRS day-night band and to map hail during the growing season through combination of available satellite and radar imagery. The aforementioned products and support are not useful unless they are distributed in a timely manner and within an appropriate decision support system. This presentation will provide an update on ongoing activities to support inclusion of these data sets within the NOAA National Weather Service Damage Assessment Toolkit, which allows meteorologists in the field to consult available satellite imagery while performing their damage assessment.

Near Real-­Time Applications of Earth Remote Sensing for Response to Meteorological Disasters

NASA Technical Reports Server (NTRS)

Molthan, Andrew L.; Burks, Jason E.; McGrath, Kevin M.; Bell, Jordan R.

2013-01-01

Numerous on-orbit satellites provide a wide range of spatial, spectral, and temporal resolutions supporting the use of their resulting imagery in assessments of disasters that are meteorological in nature. This presentation will provide an overview of recent use of Earth remote sensing by NASA's Short-term Prediction Research and Transition (SPoRT) Center in response to disaster activities in 2012 and 2013, along with case studies supporting ongoing research and development. The SPoRT Center, with support from NASA's Applied Sciences Program, has explored a variety of new applications of Earth-observing sensors to support disaster response. In May 2013, the SPoRT Center developed unique power outage composites representing the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Subsequent ASTER, MODIS, Landsat-7 and Landsat-8 imagery help to identify the damaged area. Higher resolution imagery of Moore, Oklahoma were provided by commercial satellites and the recently available International Space Station (ISS) SERVIR Environmental Research and Visualization System (ISERV) instrument. New techniques are being explored by the SPoRT team in order to better identify damage visible in high resolution imagery, and to monitor ongoing recovery for Moore, Oklahoma. Other applications are being developed to refine light source detections with the VIIRS day-night band and to map hail during the growing season through combination of available satellite and radar imagery. The aforementioned products and support are not useful unless they are distributed in a timely manner and within an appropriate decision support system. This presentation will provide an update on ongoing activities to support inclusion of these data sets within the NOAA National Weather Service Damage Assessment Toolkit, which allows meteorologists in the field to consult available satellite imagery while performing their damage assessment.

JPL Closeup

NASA Technical Reports Server (NTRS)

1983-01-01

Voyager, Infrared Astronomical Satellite, Galileo, Viking, Solar Mesosphere Explorer, Wide-field/Planetary Camera, Venus Mapper, International Solar Polar Mission - Solar Interplanetary Satellite, Extreme Ultraviolet Explores, Starprobe, International Halley Watch, Marine Mark II, Samex, Shuttle Imaging Radar-A, Deep Space Network, Biomedical Technology, Ocean Studies and Robotics are summarized.

The Value of Photographic Observations in Improving the Accuracy of Satellite Orbits.

DTIC Science & Technology

1982-02-01

cameras in the years 1971 -3 have recently become available, particularly of the balloon-satellite Explorer 19, from the observing stations at Riga...from the Russian AFU-75 cameras in the years 1971 -1973 have recently become available, particularly of the balloon- satellite Explorer 19, from the...large numbers of observations frum the Russian AFU-75 cameras have become available, covering the years 1971 -3. The observations, made during the

A graphics approach in the design of the dual air density Explorer satellites

NASA Technical Reports Server (NTRS)

Mcdougal, D. S.

1975-01-01

A computer program was developed to generate a graphics display of the Dual Air Density (DAD) Explorer satellites which aids in the engineering and scientific design. The program displays a two-dimensional view of both spacecraft and their surface features from any direction. The graphics have been an indispensable tool in the design, analysis, and understanding of the critical locations of the various surface features for both satellites.

Recent progress in empirical modeling of ion composition in the topside ionosphere

NASA Astrophysics Data System (ADS)

Truhlik, Vladimir; Triskova, Ludmila; Bilitza, Dieter; Kotov, Dmytro; Bogomaz, Oleksandr; Domnin, Igor

2016-07-01

The last deep and prolonged solar minimum revealed shortcomings of existing empirical models, especially of parameter models that depend strongly on solar activity, such as the IRI (International Reference Ionosphere) ion composition model, and that are based on data sets from previous solar cycles. We have improved the TTS-03 ion composition model (Triskova et al., 2003) which is included in IRI since version 2007. The new model called AEIKion-13 employs an improved description of the dependence of ion composition on solar activity. We have also developed new global models of the upper transition height based on large data sets of vertical electron density profiles from ISIS, Alouette and COSMIC. The upper transition height is used as an anchor point for adjustment of the AEIKion-13 ion composition model. Additionally, we show also progress on improvements of the altitudinal dependence of the ion composition in the AEIKion-13 model. Results of the improved model are compared with data from other types of measurements including data from the Atmosphere Explorer C and E and C/NOFS satellites, and the Kharkiv and Arecibo incoherent scatter radars. Possible real time updating of the model by the upper transition height from the real time COSMIC vertical profiles is discussed. Triskova, L.,Truhlik,V., Smilauer, J.,2003. An empirical model of ion composition in the outer ionosphere. Adv. Space Res. 31(3), 653-663.

Physical properties of the natural satellites. [excluding the Moon and including Saturnian Rings

NASA Technical Reports Server (NTRS)

Morrison, D.; Cruikshank, D. P.

1974-01-01

Review of the physical nature of all of the known satellites except the moon. Following a summary of the basic data regarding the size, mass, and density of satellite systems and a description of models that have been proposed for the composition and structure of these systems, a detailed analysis is made of the satellites of Mars, the Galilean satellites, Titan, the other satellites of Saturn, the rings of Saturn, and the remaining objects, with emphasis on studies of their surfaces by imaging, photometry, spectrophotometry, polarimetry, and radiometry.

47 CFR 95.1211 - Channel use policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... in the 400.150-406.000 MHz band in the Meteorological Aids, Meteorological Satellite, or Earth... in the 400.150-406.000 MHz band in the Meteorological Aids, Meteorological Satellite, or Earth..., Meteorological Satellite, or Earth Exploration Satellite Services, or to other authorized stations operating in...

Variations in thermospheric composition: A model based on mass-spectrometer and satellite-drag data

NASA Technical Reports Server (NTRS)

Jacchia, L. G.

1973-01-01

The seasonal-latitudinal and the diurnal variations of composition observed by mass spectrometers on the OGO 6 satellite are represented by two simple empirical formulae, each of which uses only one numerical parameter. The formulae are of a very general nature and predict the behavior of these variations at all heights and for all levels of solar activity; they yield a satisfactory representation of the corresponding variations in total density as derived from satellite drag. It is suggested that a seasonal variation of hydrogen might explain the abnormally low hydrogen densities at high northern latitudes in July 1964.

Co-culture of Adult Mesenchymal Stem Cells and Nucleus Pulposus Cells in Bilaminar Pellets for Intervertebral Disc Regeneration.

PubMed

Allon, Aliza A; Schneider, Richard A; Lotz, Jeffrey C

2009-01-01

Our goal is to optimize stem cell-based tissue engineering strategies in the context of the intervertebral disc environment. We explored the benefits of co-culturing nucleus pulposus cells (NPC) and adult mesenchymal stem cells (MSC) using a novel spherical bilaminar pellet culture system where one cell type is enclosed in a sphere of the other cell type. Our 3D system provides a structure that exploits embryonic processes such as tissue induction and condensation. We observed a unique phenomenon: the budding of co-culture pellets and the formation of satellite pellets that separate from the main pellet. MSC and NPC co-culture pellets were formed with three different structural organizations. The first had random organization. The other two had bilaminar organization with either MSC inside and NPC outside or NPC inside and MSC outside. By 14 days, all co-culture pellets exhibited budding and spontaneously generated satellite pellets. The satellite pellets were composed of both cell types and, surprisingly, all had the same bilaminar organization with MSC on the inside and NPC on the outside. This organization was independent of the structure of the main pellet that the satellites stemmed from. The main pellets generated satellite pellets that spontaneously organized into a bilaminar structure. This implies that structural organization occurs naturally in this cell culture system and may be inherently favorable for cell-based tissue engineering strategies. The occurrence of budding and the organization of satellite pellets may have important implications for the use of co-culture pellets in cell-based therapies for disc regeneration. From a therapeutic point of view, the generation of satellite pellets may be a beneficial feature that would serve to spread donor cells throughout the host matrix and restore normal matrix composition in a sustainable way, ultimately renewing tissue function.

A Review of Communications Satellites and Related Spacecraft for Factors Influencing Mission Success. Volume 2

DTIC Science & Technology

1975-11-17

and control (subsystem) COMM., comm AEC Atomic Energy Commission comsat AFB Air Force Base COMSTAR ACE A-hr aerospace ground equipment ampere...array TDA Satellite Assembly Building TDAL Space and Missile Systems Organization (U.S. Air Force) TDM THIR satellite communications system TI...Satellite Control Facility (U.S. Air Force) TIROS selective chopper radiometer TLM, T/M surface composition mapping radiometer TOS TRUST

Observations of low-energy ions in the wake of a magnetospheric satellite

NASA Technical Reports Server (NTRS)

Samir, U.; Comfort, R. H.; Chappell, C. R.; Stone, N. H.

1986-01-01

Measurements of low-energy ions made by the retarding ion mass spectrometer (RIMS) onboard the Dynamics Explorer 1 (DE 1) satellite are used to study some aspects of 'body-plasma interactions' in the terrestrial plasmasphere. Preliminary results are presented, yielding the degree of H+ and He+ ion depletion in the wake of the satellite in terms of specific and average ion Mach numbers, average ion mass, body size normalized to ionic Debye length, and body potential normalized to ion thermal energy. Some results from the RIMS measurements are compared with relevant results from the Explorer 31 and the Atmosphere Explorer C ionospheric satellites. Wake depletion is found to vary approximately linearly for small bodies (R-sub-Di less than about 12) and exponentially for large bodies (R-sub-Di greater than 50).

Identifying new surface constituents of icy moons using mid-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Young, Cindy L.; Wray, James J.; Hand, Kevin P.; Poston, Michael J.; Carlson, Robert W.; Clark, Roger N.; Spencer, John R.; Jennings, Donald E.

2015-11-01

Spectroscopic compositional studies of the icy satellites can help us to better understand the formation and evolution of material in the outer solar system. The spectral complexity of the Saturnian satellite system as seen in reflected visible light suggests additional complexity may be present at mid-infrared wavelengths from which unique compositional information can be gleaned [1]. In addition, the mid-infrared is the region of the stronger fundamental diagnostic vibrational modes of many compounds. However, Cassini Composite Infrared Spectrometer (CIRS) surface compositional studies have received little attention to date.We are exploring the suitability of mid-infrared spectroscopy for discovering non-H2O compounds on icy moon surfaces. On the dark terrain of Iapetus, we find an emissivity feature at ~855 cm-1 and a potential doublet at 660 and 690 cm-1 that do not correspond to any known instrument artifacts [2]. We attribute the 855 cm-1 feature to fine-grained silicates, similar to those found in dust on Mars and in meteorites, which are nearly featureless at shorter wavelengths [3]. Although silicates on the dark terrains of Saturn’s icy moons have been suspected for decades, there have been no definitive prior detections. Serpentines measured at ambient conditions have features near 855 cm-1 and 660 cm-1 [4]. However, peaks can shift depending on temperature, pressure, and grain size, so measurements at Iapetus-like conditions are necessary for more positive identifications [e.g., 5].We measured the vacuum, low temperature (125 K) spectra of various fine-grained powdered silicates. We find that some of these materials do have emissivity features near 855 cm-1 and match the doublet. Identifying a specific silicate would provide clues into the sources and sinks of the dark material in the Saturnian system. We report on our ongoing exploration of the CIRS icy moon dataset and plans for future measurements in JPL’s Icy Worlds Simulation Lab.[1] Flasar, F.M., et al. (2004), Space Sci Rev, 115, 169.[2] Young, C.L., et al. (in review), ApJ Lett.[3] Christensen, P.R., et al. (2004), Sci, 306, 1733.[4] Bishop, J.L., et al. (2008), Clay Minerals, 43, 35.[5] Wray, J.J., et al. (2014), DPS 46th Meeting, Vol. 46.

Report of the Terrestrial Bodies Science Working Group. Volume 7: The Galilean satellites

NASA Technical Reports Server (NTRS)

Fanale, F. P.; Beckman, J. C.; Chapman, C. R.; Coroniti, F. V.; Johnson, T. V.; Malin, M. C.

1977-01-01

The formational and evolutionary history of natural satellites, their mineralogical composition and other phenomena of scientific interest are discussed. Key scientific questions about IO, Ganymede, Callisto, and Europa are posed and the measurements and instruments required for a Galilean satellite lander in the 1980's are described.

Sandmeier model based topographic correction to lunar spectral profiler (SP) data from KAGUYA satellite.

PubMed

Chen, Sheng-Bo; Wang, Jing-Ran; Guo, Peng-Ju; Wang, Ming-Chang

2014-09-01

The Moon may be considered as the frontier base for the deep space exploration. The spectral analysis is one of the key techniques to determine the lunar surface rock and mineral compositions. But the lunar topographic relief is more remarkable than that of the Earth. It is necessary to conduct the topographic correction for lunar spectral data before they are used to retrieve the compositions. In the present paper, a lunar Sandmeier model was proposed by considering the radiance effect from the macro and ambient topographic relief. And the reflectance correction model was also reduced based on the Sandmeier model. The Spectral Profile (SP) data from KAGUYA satellite in the Sinus Iridum quadrangle was taken as an example. And the digital elevation data from Lunar Orbiter Laser Altimeter are used to calculate the slope, aspect, incidence and emergence angles, and terrain-viewing factor for the topographic correction Thus, the lunar surface reflectance from the SP data was corrected by the proposed model after the direct component of irradiance on a horizontal surface was derived. As a result, the high spectral reflectance facing the sun is decreased and low spectral reflectance back to the sun is compensated. The statistical histogram of reflectance-corrected pixel numbers presents Gaussian distribution Therefore, the model is robust to correct lunar topographic effect and estimate lunar surface reflectance.

System concepts and enabling technologies for an ESA low-cost mission to Jupiter / Europa

NASA Astrophysics Data System (ADS)

Renard, P.; Koeck, C.; Kemble, Steve; Atzei, Alessandro; Falkner, Peter

2004-11-01

The European Space Agency is currently studying the Jovian Minisat Explorer (JME), as part of its Technology Reference Studies (TRS), used for its development plan of technologies enabling future scientific missions. The JME focuses on the exploration of the Jovian system and particularly of Europa. The Jupiter Minisat Orbiter (JMO) study concerns the first mission phase of JME that counts up to three missions using pairs of minisats. The scientific objectives are the investigation of Europa's global topography, the composition of its (sub)surface and the demonstration of existence of a subsurface ocean below its icy crust. The present paper describes the candidate JMO system concept, based on a Europa Orbiter (JEO) supported by a communications relay satellite (JRS), and its associated technology development plan. It summarizes an analysis performed in 2004 jointly by ESA and the EADS-Astrium Company in the frame of an industrial technical assistance to ESA.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Thomas Zurbuchen, Associate Administrator for NASA's Science Mission Directorate, speaks during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

JUPITER AS AN EXOPLANET: UV TO NIR TRANSMISSION SPECTRUM REVEALS HAZES, A Na LAYER, AND POSSIBLY STRATOSPHERIC H{sub 2}O-ICE CLOUDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montañés-Rodríguez, Pilar; González-Merino, B.; Pallé, E.

Currently, the analysis of transmission spectra is the most successful technique to probe the chemical composition of exoplanet atmospheres. However, the accuracy of these measurements is constrained by observational limitations and the diversity of possible atmospheric compositions. Here, we show the UV–VIS–IR transmission spectrum of Jupiter as if it were a transiting exoplanet, obtained by observing one of its satellites, Ganymede, while passing through Jupiter’s shadow, i.e., during a solar eclipse from Ganymede. The spectrum shows strong extinction due to the presence of clouds (aerosols) and haze in the atmosphere and strong absorption features from CH{sub 4}. More interestingly, themore » comparison with radiative transfer models reveals a spectral signature, which we attribute here to a Jupiter stratospheric layer of crystalline H{sub 2}O ice. The atomic transitions of Na are also present. These results are relevant for the modeling and interpretation of giant transiting exoplanets. They also open a new technique to explore the atmospheric composition of the upper layers of Jupiter’s atmosphere.« less

BOREAS Level-4c AVHRR-LAC Ten-Day Composite Images: Surface Parameters

NASA Technical Reports Server (NTRS)

Cihlar, Josef; Chen, Jing; Huang, Fengting; Nickeson, Jaime; Newcomer, Jeffrey A.; Hall, Forrest G. (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. Manitoba Remote Sensing Center (MRSC) and BOREAS Information System (BORIS) personnel acquired, processed, and archived data from the Advanced Very High Resolution Radiometer (AVHRR) instruments on the NOAA-11 and -14 satellites. The AVHRR data were acquired by CCRS and were provided to BORIS for use by BOREAS researchers. These AVHRR level-4c data are gridded, 10-day composites of surface parameters produced from sets of single-day images. Temporally, the 10-day compositing periods begin 11-Apr-1994 and end 10-Sep-1994. Spatially, the data cover the entire BOREAS region. The data are stored in binary image format files. Note: Some of the data files on the BOREAS CD-ROMs have been compressed using the Gzip program.

BOREAS Level-4b AVHRR-LAC Ten-Day Composite Images: At-sensor Radiance

NASA Technical Reports Server (NTRS)

Cihlar, Josef; Chen, Jing; Nickerson, Jaime; Newcomer, Jeffrey A.; Huang, Feng-Ting; Hall, Forrest G. (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. Manitoba Remote Sensing Center (MRSC) and BOREAS Information System (BORIS) personnel acquired, processed, and archived data from the Advanced Very High Resolution Radiometer (AVHRR) instruments on the National Oceanic and Atmospheric Administration (NOAA-11) and -14 satellites. The AVHRR data were acquired by CCRS and were provided to BORIS for use by BOREAS researchers. These AVHRR level-4b data are gridded, 10-day composites of at-sensor radiance values produced from sets of single-day images. Temporally, the 10- day compositing periods begin 11-Apr-1994 and end 10-Sep-1994. Spatially, the data cover the entire BOREAS region. The data are stored in binary image format files.

Simulating Future GPS Clock Scenarios with Two Composite Clock Algorithms

NASA Technical Reports Server (NTRS)

Suess, Matthias; Matsakis, Demetrios; Greenhall, Charles A.

2010-01-01

Using the GPS Toolkit, the GPS constellation is simulated using 31 satellites (SV) and a ground network of 17 monitor stations (MS). At every 15-minutes measurement epoch, the monitor stations measure the time signals of all satellites above a parameterized elevation angle. Once a day, the satellite clock estimates the station and satellite clocks. The first composite clock (B) is based on the Brown algorithm, and is now used by GPS. The second one (G) is based on the Greenhall algorithm. The composite clock of G and B performance are investigated using three ground-clock models. Model C simulates the current GPS configuration, in which all stations are equipped with cesium clocks, except for masers at USNO and Alternate Master Clock (AMC) sites. Model M is an improved situation in which every station is equipped with active hydrogen masers. Finally, Models F and O are future scenarios in which the USNO and AMC stations are equipped with fountain clocks instead of masers. Model F is a rubidium fountain, while Model O is more precise but futuristic Optical Fountain. Each model is evaluated using three performance metrics. The timing-related user range error having all satellites available is the first performance index (PI1). The second performance index (PI2) relates to the stability of the broadcast GPS system time itself. The third performance index (PI3) evaluates the stability of the time scales computed by the two composite clocks. A distinction is made between the "Signal-in-Space" accuracy and that available through a GNSS receiver.

Ionospheric Results with Sounding Rockets and the Explorer VIII Satellite (1960 )

NASA Technical Reports Server (NTRS)

Bourdeau, R. E.

1961-01-01

A review is made of ionospheric data reported since the IGY from rocket and satellite-borne ionospheric experiments. These include rocket results on electron density (RF impedance probe), D-region conductivity (Gerdien condenser), and electron temperature (Langmuir probe). Also included are data in the 1000 kilometer region on ion concentration (ion current monitor) and electron temperature from the Explorer VIII Satellite (1960 xi). The review includes suggestions for second generation experiments and combinations thereof particularly suited for small sounding rockets.

Building for the Future: China’s Progress in Space Technology During the Tenth 5-Year Plan and the U.S. Response

DTIC Science & Technology

2008-03-01

solar telescope to study solar physics. — Develop technologies for a three-satellite constellation called Kua Fu to study solar activity that will...consist of one satellite to monitor solar activity and two others to study the aurora. • International cooperation. Participate in the Sino...Russian Mars environment exploration plan, the World Space Observatory Ultraviolet Project,50 and the Sino-French Small Satellite Solar Flare Exploration

GOES Composite - El Niño Support Imagery - Satellite Products and Services

Science.gov Websites

Division/Office of Satellite and Product Operations Skip Navigation Link NESDIS banner image Information Service Home Page Default Office of Satellite and Product Operations banner image and link to OSPO MIRS MSPPS Ocean -- Coral Bleaching -- Ocean Color -- Sea/Lake Ice -- Sea Surface Height -- Sea Surface

Tracking of Environment Changes by Exploitation of Suomi-NPP VIIRS Data

NASA Astrophysics Data System (ADS)

Ibrahim, W.; Greene, E.; van Poollen, C.; Cumpton, D.

2017-12-01

NOAA's next-generation environmental satellite system, Joint Polar Satellite System (JPSS), replaces the current Polar-orbiting Operational Environmental Satellites. JPSS satellites carry sensors which collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The first JPSS satellite, Suomi National Polar-orbiting Partnership (S-NPP), was launched in 2011. The JPSS ground system is the Common Ground System (CGS), and provides command, control, and communications (C3) and data processing (DP). S-NPP satellite includes the Visible Infrared Imaging Radiometer Suite (VIIRS), a 22-band scanning radiometer that provides top-of-atmosphere radiances and reflectances at a range of visible and infrared frequencies. Data collected from VIIRS are output by CGS DP into Raw Data Records (RDRs; Level-0), Sensor Data Records (SDRs; Level-1B) and Environmental Data Records (EDRs; Level-1C). This paper presents a methodology of monitoring and tracking impact of weather conditions on environment changes by exploitation of data from S-NPP VIIRS products. Three different products created from VIIRS data, SDR M-band True-Color (TC) composite visible imagery RGB (M5, M4 and M3), SDR M-band Natural-Color (NC) composite imagery RGB (M10, M7 and M5) and Vegetation Index (VI) EDR, are used to analyze the change in springtime vegetation and snowpack in California, USA, over four years from the height of the drought in 2014 to its end in 2017. While the TC composite images are more appealing to the human observer, utilization of the NC composite images allows for tracking and monitoring the changes in the snowpack in the Sierra Nevada, the reappearance of bodies of water and the changes in the vegetation composite. The VI product uses NDVI to characterize the vegetation temporally. By combining multiple VIIRS products, complex scenes can be visualized and analyzed temporally and spatially more accurately than just using a single product. Assimilation of both imagery and EDR products allows for a better characterization of impact of weather conditions on environment changes. This method can be expanded to characterize impact of weather conditions on environment changes in sea ice, snow, forest, agricultural land, population centers, etc.

Scientific rationale for Uranus and Neptune in situ explorations

NASA Astrophysics Data System (ADS)

Mousis, O.; Atkinson, D. H.; Cavalié, T.; Fletcher, L. N.; Amato, M. J.; Aslam, S.; Ferri, F.; Renard, J.-B.; Spilker, T.; Venkatapathy, E.; Wurz, P.; Aplin, K.; Coustenis, A.; Deleuil, M.; Dobrijevic, M.; Fouchet, T.; Guillot, T.; Hartogh, P.; Hewagama, T.; Hofstadter, M. D.; Hue, V.; Hueso, R.; Lebreton, J.-P.; Lellouch, E.; Moses, J.; Orton, G. S.; Pearl, J. C.; Sánchez-Lavega, A.; Simon, A.; Venot, O.; Waite, J. H.; Achterberg, R. K.; Atreya, S.; Billebaud, F.; Blanc, M.; Borget, F.; Brugger, B.; Charnoz, S.; Chiavassa, T.; Cottini, V.; d'Hendecourt, L.; Danger, G.; Encrenaz, T.; Gorius, N. J. P.; Jorda, L.; Marty, B.; Moreno, R.; Morse, A.; Nixon, C.; Reh, K.; Ronnet, T.; Schmider, F.-X.; Sheridan, S.; Sotin, C.; Vernazza, P.; Villanueva, G. L.

2018-06-01

The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission.

Observations of subauroral ion drift (SAID) occurrence statistics and associated ionospheric conditions measured by the Defense Meteorological Satellite Program (DMSP) and Dynamics Explorer 2 (DE-2).

NASA Astrophysics Data System (ADS)

Landry, R. G.; Anderson, P. C.

2017-12-01

Subauroral ion drifts (SAID) are a phenomenon sometimes observed in the subauroral ionosphere in dusk to post-midnight magnetic local time sectors during magnetically active periods characterized by strong poleward electric fields that drive westward ion drifts greater than 1 km/s. SAIDs typically will span 1-2 degrees magnetic latitude and several hours in magnetic local time. SAIDs are often observed colocated with the midlatitude trough. The strong electric field can act to reduce the ionospheric conductivity further through enhanced recombination and vertical transport. The theory that SAIDs are generated by ionospheric Pedersen currents fed by ring current driven field-aligned currents (FAC) requires the decreased conductance associated with the midlatitude trough to produce the latitudinally narrow, large amplitude SAID electric field. Using Dynamics Explorer 2 (DE 2) plasma measurements of SAIDs from altitudes of 200 to 1000 km, we investigate the statistical variation of the ionospheric composition, temperature, and vertical ion drifts as a function of altitude. Using Defense Meteorological Satellite Program (DMSP) measurements from 1987-2012, we extend the empirical study at the DMSP altitude of 830 km to investigate how season, longitude, and any ionospheric preconditioning before SAID formation affect the likelihood of SAID occurrence and coincidence with FACs and ion density troughs.

Satellite Data Product and Data Dissemination Updates for the SPoRT Sea Surface Temperature Composite Product

NASA Technical Reports Server (NTRS)

Zavodsky, Bradley; LaFontaine, Frank; Berndt, Emily; Meyer, Paul; Jedlovec, Gary

2017-01-01

The SPoRT SST composite is a reliable and robust high-resolution product generated twice per day in near real time. It incorporates highest quality data satellite data from infrared imagers and global analysis from NESDIS and UKMO. Recent updates to the product include the inclusion of VIIRS data to extend the life of the product beyond the MODIS era. It is used by a number of users in their DSS.

VZLUSAT-1: verification of new materials and technologies for space

NASA Astrophysics Data System (ADS)

Daniel, Vladimir; Urban, Martin; Nentvich, Ondrej; Stehlikova, Veronika

2016-09-01

CubeSats are a good opportunity to test new technologies and materials on orbit. These innovations can be later used for improving of properties and life length of Cubesat or other satellites as well. VZLUSAT-1 is a small satellite from the CubeSat family, which will carry a wide scale of payloads with different purposes. The poster is focused on measuring of degradation and properties measurement of new radiation hardened composite material in orbit due to space environment. Material properties changes can be studied by many methods and in many disciplines. One payload measures mechanical changes in dependence on Young's modulus of elasticity which is got from non-destructive testing by mechanical vibrations. The natural frequencies we get using Fast Fourier Transform. The material is tested also by several thermometers which measure heat distribution through the composite, as well as reflectivity in dependence on different coatings. The satellite also will measure the material radiation shielding properties. There are PIN diodes which measure the relative shielding efficiency of composite and how it will change in time in space environment. Last one of material space testing is measurement of outgassing from tested composite material. It could be very dangerous for other parts of satellite, like detectors, when anything was outgassing, for example water steam. There are several humidity sensors which are sensitive to steam and other gases and measures temperatures as well.

Three Dimensional Spherical Display Systems and McIDAS: Tools for Science, Education and Outreach

NASA Astrophysics Data System (ADS)

Kohrs, R.; Mooney, M. E.

2010-12-01

The Space Science and Engineering Center (SSEC) and Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin are now using a 3D spherical display system and their Man computer Data Access System (McIDAS)-X and McIDAS-V as outreach tools to demonstrate how scientists and forecasters utilize satellite imagery to monitor weather and climate. Our outreach program displays orbits and data coverage of geostationary and polar satellites and demonstrates how each is beneficial for the remote sensing of Earth. Global composites of visible, infrared and water vapor images illustrate how satellite instruments collect data from different bands of the electromagnetic spectrum to monitor global weather patterns 24 hours a day. Captivating animations on spherical display systems are proving to be much more intuitive than traditional 2D displays, enabling audiences to view satellites orbiting above real-time weather systems circulating the entire globe. Complimenting the 3D spherical display system are the UNIX-based McIDAS-X and Java-based McIDAS-V software packages. McIDAS is used to composite the real-time global satellite data and create other weather related derived products. Client and server techniques used by these software packages provide the opportunity to continually update the real-time content on our globe. The enhanced functionality of McIDAS-V extends our outreach program by allowing in-depth interactive 4-dimensional views of the imagery previously viewed on the 3D spherical display system. An important goal of our outreach program is the promotion of remote sensing research and technology at SSEC and CIMSS. The 3D spherical display system has quickly become a popular tool to convey societal benefits of these endeavors. Audiences of all ages instinctively relate to recent weather events which keeps them engaged in spherical display presentations. McIDAS facilitates further exploration of the science behind the weather phenomena. Audience feedback fuels the collaborative efforts of outreach specialists and computer programmers which provides continuous evolution of the 3D displays and McIDAS. This iterative presentation strategy is proving to be beneficial to our outreach program as seen by the success of our workshops, educational lectures and temporary exhibits at high visibility venues such as Madison Children’s Museum, the Milwaukee Public Museum and EAA AirVenture Museum. 3D Spherical Display System and McIDAS-V depiction of Hurricane Wilma

Planning, Implementation, and Scientific Goals of the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) Field Missions

NASA Technical Reports Server (NTRS)

Toon, Owen B.; Maring, Hal; Dibb, Jack; Ferrare, Richard A.; Jacob, Daniel J.; Jensen, Eric J.; Luo, Z. Johnny; Mace, Gerald G.; Pan, Laura L.; Pfister, Leonhard;

Measurements of Sheath Currents and Equilibrium Potential on the Explorer VIII Satellite (1960 xi)

NASA Technical Reports Server (NTRS)

Bourdeau, R. E.; Donley, J. L.; Serbu, G. P.; Whipple, E. C., Jr.

1961-01-01

Experimental data were obtained from the Explorer VIII satellite on five parameters pertinent to the problem of the interaction of space vehicles with an ionized atmosphere. The five parameters are: photoemission current due to electrons emitted from the satellite surfaces as a result of solar radiation; electron and positive ion currents due to the diffusion of charged particles from the medium to the spacecraft; the vehicle potential relative to the medium, and the ambient electron temperature. Included in the experimental data is the aspect dependence of the photoemission and diffusion currents. On the basis of the observations, certain characteristics of the satellite's plasma sheath are postulated.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Alexander Moiseev, a research scientist at NASA's Goddard Spaceflight Center, speaks during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Michael Freilich, Director of the Earth Science Division of NASA's Science Mission Directorate, speaks during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

An Overview of the NASA Spring/Summer 2008 Arctic Campaign - ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites)

NASA Technical Reports Server (NTRS)

Jacob, Daniel J.; Clarke, Antony; Crawford, James H.; Dibbs, Jack; Ferrare, Richard A.; Hostetler, Chris A.; Maring, Hal; Russell, Philip B.; Singh, Hanwant B.

2008-01-01

ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) is a major NASA led airborne field campaign being performed in the spring and summer of 2008 at high latitudes (http://cloud1.arc.nasa.gov/arctas/). ARCTAS is a part of the International Polar Year program and its activities are closely coordinated with multiple U. S. (NOAA, DOE), Canadian, and European partners. Observational data from an ensemble of aircraft, surface, and satellite sensors are closely integrated with models of atmospheric chemistry and transport in this experiment. Principal NASA airborne platforms include a DC-8 for detailed atmospheric composition studies, a P-3 that focuses on aerosols and radiation, and a B-200 that is dedicated to remote sensing of aerosols. Satellite validation is a central activity in all these platforms and is mainly focused on CALIPSO, Aura, and Aqua satellites. Major ARCTAS themes are: (1) Long-range transport of pollution to the Arctic including arctic haze, tropospheric ozone, and persistent pollutants such as mercury; (2) Boreal forest fires and their implications for atmospheric composition and climate; (3) Aerosol radiative forcing from arctic haze, boreal fires, surface-deposited black carbon, and other perturbations; and (4) Chemical processes with focus on ozone, aerosols, mercury, and halogens. The spring deployment (April) is presently underway and is targeting plumes of anthropogenic and biomass burning pollution and dust from Asia and North America, arctic haze, stratosphere-troposphere exchange, and ozone photochemistry involving HOx and halogen radicals. The summer deployment (July) will target boreal forest fires and summertime photochemistry. The ARCTAS mission is providing a critical link to enhance the value of NASA satellite observations for Earth science. In this talk we will discuss the implementation of this campaign and some preliminary results.

Visualizing Airborne and Satellite Imagery

NASA Technical Reports Server (NTRS)

Bierwirth, Victoria A.

2011-01-01

Remote sensing is a process able to provide information about Earth to better understand Earth's processes and assist in monitoring Earth's resources. The Cloud Absorption Radiometer (CAR) is one remote sensing instrument dedicated to the cause of collecting data on anthropogenic influences on Earth as well as assisting scientists in understanding land-surface and atmospheric interactions. Landsat is a satellite program dedicated to collecting repetitive coverage of the continental Earth surfaces in seven regions of the electromagnetic spectrum. Combining these two aircraft and satellite remote sensing instruments will provide a detailed and comprehensive data collection able to provide influential information and improve predictions of changes in the future. This project acquired, interpreted, and created composite images from satellite data acquired from Landsat 4-5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper plus (ETM+). Landsat images were processed for areas covered by CAR during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCT AS), Cloud and Land Surface Interaction Campaign (CLASIC), Intercontinental Chemical Transport Experiment-Phase B (INTEXB), and Southern African Regional Science Initiative (SAFARI) 2000 missions. The acquisition of Landsat data will provide supplemental information to assist in visualizing and interpreting airborne and satellite imagery.

Planetesimal Break-Up and the Feeding of Solids to the Satellite Disk: Consequences for the Formation Timescale and Composition of the Satellites of Jupiter and Saturn

NASA Technical Reports Server (NTRS)

Mosqueira, I.; Estrada, P. R.

2003-01-01

In order to create a coherent scenario of satellite formation. the source of the solids (rock-metal and ice) that will eventually make up the satellites must be considered. While it is customary to use a solar composition mixture with a gas/solid mass ratio of about 100, at the tail end of the formation of the giant planet (when satellite formation is thought to have taken place) the fraction of solids entrained in the gas (particles with sizes lower than the decoupling size about 1 m for typical nebula parameters) is likely to be significantly lower than cosmic. In particular, in the core accretion model of giant planet formation one expects low dust and rubble content at late times due to particle coagulation leading to a collisional distribution of particle sizes with most of the mas residing in objects 1 km or larger, which are not coupled to the gas and whose dynamics must be followed independently. As a result, flow of gas into circumplanetary orbits is not sufficient to constrain the mas available to form satellites.

Monitoring and tracking the trans-Pacific transport of aerosols using multi-satellite aerosol optical depth composites

NASA Astrophysics Data System (ADS)

Naeger, Aaron R.; Gupta, Pawan; Zavodsky, Bradley T.; McGrath, Kevin M.

2016-06-01

The primary goal of this study was to generate a near-real time (NRT) aerosol optical depth (AOD) product capable of providing a comprehensive understanding of the aerosol spatial distribution over the Pacific Ocean, in order to better monitor and track the trans-Pacific transport of aerosols. Therefore, we developed a NRT product that takes advantage of observations from both low-earth orbiting and geostationary satellites. In particular, we utilize AOD products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) satellites. Then, we combine these AOD products with our own retrieval algorithms developed for the NOAA Geostationary Operational Environmental Satellite (GOES-15) and Japan Meteorological Agency (JMA) Multi-functional Transport Satellite (MTSAT-2) to generate a NRT daily AOD composite product. We present examples of the daily AOD composite product for a case study of trans-Pacific transport of Asian pollution and dust aerosols in mid-March 2014. Overall, the new product successfully tracks this aerosol plume during its trans-Pacific transport to the west coast of North America as the frequent geostationary observations lead to a greater coverage of cloud-free AOD retrievals equatorward of about 35° N, while the polar-orbiting satellites provide a greater coverage of AOD poleward of 35° N. However, we note several areas across the domain of interest from Asia to North America where the GOES-15 and MTSAT-2 retrieval algorithms can introduce significant uncertainties into the new product.

A geological basis for the exploration of the planets: Introduction

NASA Technical Reports Server (NTRS)

Greeley, R.; Carr, M. H.

1976-01-01

The geological aspects of solar-system exploration were considered by first showing how geologic data are related to space science in general, and, second, by discussing the approach used in planetary geology. The origin, evolution, and distribution of matter condensed in the form of planets, satellites, comets, and asteroids were studied. Terrestrial planets, comets, and asteroids, and the solid satellites of the outer planets are discussed. Jupiter and Saturn, in particular, have satellites of prime importance. Geophysics, geochemistry, geodesy, cartography, and other disciplines concerned with the solid planets were all included.

Ionosphere total electron content and its horizontal gradients, measured on the basis of satellite signal recordings at scattered points

DOE Office of Scientific and Technical Information (OSTI.GOV)

Misyura, V.A.; Podnos, V.A.; Kapanin, I.I.

1973-01-01

Translated from Kosm. Issled.; 11: No. 4, 581-585(1973). The integrated electron content of the ionosphere up to the level of the recording satellite, and the horizontal gradients of the integrated electron content (total, latitudinal, and longitudinal components), was obtained at scattered observation points located at medium and high latitudes, on the basis of recordings made of Doppler and Faraday effects on coherent signals from the satellites Explorer-22, Explorer-27, Interkosmos-2, Kosmos321, Kosmos-356, and Kosmos-381. (auth)

Satellite Observations for Detecting and Tracking Changes in Atmospheric Composition

EPA Science Inventory

The international scientific community's Integrated Global Atmosphere Chemistry Observation System report outlined a plan for ground-based, airborne and satellite Measurements, and models to integrate the observations into a 4-dimensional representation of the atmosphere (space a...

Miranda - Highest Resolution Color Picture

NASA Image and Video Library

1999-08-30

This color composite of the Uranian satellite Miranda was taken by NASA Voyager 2 on January 24, 1986. Miranda, just 480 km 300 mi across, is the smallest of Uranus five major satellites. http://photojournal.jpl.nasa.gov/catalog/PIA00042

Zonal average earth radiation budget measurements from satellites for climate studies

NASA Technical Reports Server (NTRS)

Ellis, J. S.; Haar, T. H. V.

1976-01-01

Data from 29 months of satellite radiation budget measurements, taken intermittently over the period 1964 through 1971, are composited into mean month, season and annual zonally averaged meridional profiles. Individual months, which comprise the 29 month set, were selected as representing the best available total flux data for compositing into large scale statistics for climate studies. A discussion of spatial resolution of the measurements along with an error analysis, including both the uncertainty and standard error of the mean, are presented.

The Europa Clipper Mission Concept

NASA Astrophysics Data System (ADS)

Pappalardo, Robert; Goldstein, Barry; Magner, Thomas; Prockter, Louise; Senske, David; Paczkowski, Brian; Cooke, Brian; Vance, Steve; Wes Patterson, G.; Craft, Kate

2014-05-01

A NASA-appointed Science Definition Team (SDT), working closely with a technical team from the Jet Propulsion Laboratory (JPL) and the Applied Physics Laboratory (APL), recently considered options for a future strategic mission to Europa, with the stated science goal: Explore Europa to investigate its habitability. The group considered several mission options, which were fully technically developed, then costed and reviewed by technical review boards and planetary science community groups. There was strong convergence on a favored architecture consisting of a spacecraft in Jupiter orbit making many close flybys of Europa, concentrating on remote sensing to explore the moon. Innovative mission design would use gravitational perturbations of the spacecraft trajectory to permit flybys at a wide variety of latitudes and longitudes, enabling globally distributed regional coverage of the moon's surface, with nominally 45 close flybys at altitudes from 25 to 100 km. We will present the science and reconnaissance goals and objectives, a mission design overview, and the notional spacecraft for this concept, which has become known as the Europa Clipper. The Europa Clipper concept provides a cost-efficient means to explore Europa and investigate its habitability, through understanding the satellite's ice and ocean, composition, and geology. The set of investigations derived from the Europa Clipper science objectives traces to a notional payload for science, consisting of: Ice Penetrating Radar (for sounding of ice-water interfaces within and beneath the ice shell), Topographical Imager (for stereo imaging of the surface), ShortWave Infrared Spectrometer (for surface composition), Neutral Mass Spectrometer (for atmospheric composition), Magnetometer and Langmuir Probes (for inferring the satellite's induction field to characterize an ocean), and Gravity Science (to confirm an ocean).The mission would also include the capability to perform reconnaissance for a future lander, with the Reconnaissance goal: Characterize safe and scientifically compelling sites for a future lander mission to Europa. To accomplish these reconnaissance objectives and the investigations that flow from them, principally to address issues of landing site safety, two additional instruments would be included in the notional payload: a Reconnaissance Camera (for high-resolution imaging) and a Thermal Imager (to characterize the surface through its thermal properties). These instruments, in tandem with the notional payload for science, could assess the science value of potential landing sites. This notional payload serves as a proof-of-concept for the Europa Clipper during its formulation stage. The actual payload would be chosen through a NASA Announcement of Opportunity. If NASA were to proceed with the mission, it could be possible to launch early in the coming decade, on an Atlas V or the Space Launch System (SLS).

Hands-on Activities Designed to Familiarize Users with Data from ABI on GOES-R and AHI on Himawari-8

NASA Astrophysics Data System (ADS)

Lindstrom, S. S.; Schmit, T.; Gerth, J.; Gunshor, M. M.; Mooney, M. E.; Whittaker, T. M.

2016-12-01

Recent and ongoing launches of next-generation geostationary satellites offer a challenge to familiarize National Weather Service (and other) forecasters with the new capabilities of different spectral channels sensed by the Advanced Baseline Imager (ABI) on GOES-R and the Advanced Himawari Imager (AHI) on Himawari-8. Hands on HTML5-based applets developed at the Cooperative Institute for Meteorological Satellite Studies allow for quick comparisons of reflectance in the visible (0.4 to 0.7 um) and near-infrared channels (0.86 to 2.2 um) and brightness temperatures in the infrared (3.9 to 13.3 um). The web apps to explore the different channels on ABI and AHI are at http://cimss.ssec.wisc.edu/goes/webapps/bandapp/; those that offer guidance on how to produce Red/Green/Blue composites are at http://cimss.ssec.wisc.edu/goes/webapps/satrgb/overview.html. This talk will briefly discuss highlights from both websites, and suggest ways the applications can be used to educate forecasters and the general public.

Vegetation impoverishment despite greening: a case study from central Senegal

USGS Publications Warehouse

Herrmann, Stefanie M.; Tappan, G. Gray

2013-01-01

Recent remote sensing studies have documented a greening trend in the semi-arid Sahel and Sudan zones of West Africa since the early 1980s, which challenges the mainstream paradigm of irreversible land degradation in this region. What the greening trend means on the ground, however, has not yet been explored. This research focuses on a region in central Senegal to examine changes in woody vegetation abundance and composition in selected sites by means of a botanical inventory of woody vegetation species, repeat photography, and perceptions of local land users. Despite the greening, an impoverishment of the woody vegetation cover was observed in the studied sites, indicated by an overall reduction in woody species richness, a loss of large trees, an increasing dominance of shrubs, and a shift towards more arid-tolerant, Sahelian species since 1983. Thus, interpretation of the satellite-derived greening trend as an improvement or recovery is not always justified. The case of central Senegal represents only one of several possible pathways of greening throughout the region, all of which result in similar satellite-derived greening signals.

The impact of earth resources exploration from space. [technology assessment/LANDSAT satellites -technological forecasting

NASA Technical Reports Server (NTRS)

Nordberg, W.

1975-01-01

The use of Earth Resources Technology Satellites in solving global problems is examined. Topics discussed are: (1) management of food, water, and fiber resources; (2) exploration and management of energy and mineral resources; (3) protection of the environment; (4) protection of life and property; and (5) improvements in shipping and navigation.

Development of a Nano-Satellite Micro-Coupling Mechanism with Characterization of a Shape Memory Alloy Interference Joint

DTIC Science & Technology

2010-12-01

satellite incorporation are explored by assembly and experimentation. Research on pseudoelastic material properties , analytical predictions, and...are explored by assembly and experimentation. Research on pseudoelastic material properties , analytical predictions, and tests of coupling strengths...20  Table 2.  Material Properties Used in Micro-Coupling Predicted Strength Calculations

Education Via Satellite: A Trinational Perspective.

ERIC Educational Resources Information Center

Shaw, Willard D.

The Rural Satellite Program of the U.S. Agency for International Development was a 6-year effort (1981-87) to explore the potential uses of two way telecommunications facilities, particularly satellite-mediated, telephone-based technologies--to support Third World Development educational endeavors. This program created three audioconferencing…

Educational Applications of Communications Satellites in Canada. New Technologies in Canadian Education Series. Paper 12.

ERIC Educational Resources Information Center

Richmond, J. Murray

Canada has explored the use of satellites as a means to provide information and communications services to geographically isolated populations since 1962. Between 1972 and 1984, five series of satellites known as Anik A, B, C, and D and Hermes were launched. Each satellite provided expanded communications services, and each led to research and…

Results of various studies made with the NCAR Thermospheric General Circulation Model (TGCM) (invited review)

NASA Technical Reports Server (NTRS)

Roble, R. G.

1986-01-01

The NCAR thermospheric general circulation model (TGCM) has been used for a variety of thermospheric dynamic studies. It has also been used to compare model predictions with measurements made from various ground-based Fabry-Perot interferometer stations, incoherent scatter radar stations and the Dynamics Explorer satellites. The various input and output features of the model are described. These include the specification of solar EUV fluxes, and descriptions of empirical models to specify auroral particle precipitation, ion drag, and magnetospheric convection. Results are presented for solstice conditions giving the model perturbation temperature and circulation response to solar heating forcing alone and also with the inclusion of magnetospheric convections for two different dawn-dusk potential drops, 20 and 60 kV respectively. Results at two constant pressure levels Z =+1 at 300 km and Z= -4 at 120 km are presented for both the winter and summer polar cap regions. The circulation over the Northern Hemisphere polar cap in both the upper and lower thermosphere are presented along with a figure showing that the circulation is mainly a non-divergent irrotational flow responding to ion drag. The results of a study made on the Southern Hemisphere polar cap during October 1981 where Dynamics Explorer satellite measurements of winds, temperature and composition are compared to TGCM predictions are also presented. A diagnostic package that has been developed to analyze the balance of forces operating in the TGCM is presented next illustrating that in the F-region ion drag and pressure provide the main force balance and in the E-region ion drag, pressure and the coriolis forces provide the main balance. The TGCM prediction for the June 10, 1983 total solar eclipse are next presented showing a thermospheric disturbance following the path of totality. Finally, results are presented giving the global circulation, temperature and composition structure of the thermosphere for solar minimum conditions at equinox with 60 kV magnetospheric convection forcing at high latitudes.

Composite sandwich lattice structure

NASA Technical Reports Server (NTRS)

Rhodes, M. D. (Inventor); Mikulas, M. M., Jr.

1977-01-01

A lattice type structural panel is described. The panel utilizes the unidirectional character of filamentary epoxy impregnated composites. The panels are stiff lightweight structures for use in constructing space satellites and the like.

Spatial Data Exploring by Satellite Image Distributed Processing

NASA Astrophysics Data System (ADS)

Mihon, V. D.; Colceriu, V.; Bektas, F.; Allenbach, K.; Gvilava, M.; Gorgan, D.

2012-04-01

Our society needs and environmental predictions encourage the applications development, oriented on supervising and analyzing different Earth Science related phenomena. Satellite images could be explored for discovering information concerning land cover, hydrology, air quality, and water and soil pollution. Spatial and environment related data could be acquired by imagery classification consisting of data mining throughout the multispectral bands. The process takes in account a large set of variables such as satellite image types (e.g. MODIS, Landsat), particular geographic area, soil composition, vegetation cover, and generally the context (e.g. clouds, snow, and season). All these specific and variable conditions require flexible tools and applications to support an optimal search for the appropriate solutions, and high power computation resources. The research concerns with experiments on solutions of using the flexible and visual descriptions of the satellite image processing over distributed infrastructures (e.g. Grid, Cloud, and GPU clusters). This presentation highlights the Grid based implementation of the GreenLand application. The GreenLand application development is based on simple, but powerful, notions of mathematical operators and workflows that are used in distributed and parallel executions over the Grid infrastructure. Currently it is used in three major case studies concerning with Istanbul geographical area, Rioni River in Georgia, and Black Sea catchment region. The GreenLand application offers a friendly user interface for viewing and editing workflows and operators. The description involves the basic operators provided by GRASS [1] library as well as many other image related operators supported by the ESIP platform [2]. The processing workflows are represented as directed graphs giving the user a fast and easy way to describe complex parallel algorithms, without having any prior knowledge of any programming language or application commands. Also this Web application does not require any kind of install for what the house-hold user is concerned. It is a remote application which may be accessed over the Internet. Currently the GreenLand application is available through the BSC-OS Portal provided by the enviroGRIDS FP7 project [3]. This presentation aims to highlight the challenges and issues of flexible description of the Grid based processing of satellite images, interoperability with other software platforms available in the portal, as well as the particular requirements of the Black Sea related use cases.

Explorer Satellite Electronics

NASA Technical Reports Server (NTRS)

Eyraud, J. P.; Richter, H. L.; Victor, W. K.

1960-01-01

A discussion is presented of the design restrictions and the philosophy which enabled the Explorer satellites to be first during the IGY to reveal the presence of a belt of intense cosmic radiation encircling the earth's equator. In addition, an indication of the amount and momentum of cosmic dust in the solar system was obtained from the Explorers. Methods used to obtain reliability in the transducing and communications system are described, together with interpretations of space-environment information as deduced from the narrow-band telemetry.

Geospace exploration project: Arase (ERG)

NASA Astrophysics Data System (ADS)

Miyoshi, Y.; Kasaba, Y.; Shinohara, I.; Takashima, T.; Asamura, K.; Matsumoto, H.; Higashio, N.; Mitani, T.; Kasahara, S.; Yokota, S.; Wang, S.; Kazama, Y.; Kasahara, Y.; Yagitani, S.; Matsuoka, A.; Kojima, H.; Katoh, Y.; Shiokawa, K.; Seki, K.; Fujimoto, M.; Ono, T.; ERG project Group

2017-06-01

The ERG (Exploration of energization and Radiation in Geospace) is Japanese geospace exploration project. The project focuses on relativistic electron acceleration mechanism of the outer belt and dynamics of space storms in the context of the cross-energy coupling via wave-particle interactions. The project consists of the satellite observation team, the ground-based network observation team, and integrated-data analysis/simulation team. The satellite was launched on December 20 2016 and has been nicknamed, “Arase”. This paper describes overview of the project and future plan for observations.

Models, figures, and gravitational moments of Jupiter's satellites Io and Europa

NASA Astrophysics Data System (ADS)

Zharkov, V. N.; Karamurzov, B. S.

2006-07-01

Two types of trial three-layer models have been constructed for the satellites Io and Europa. In the models of the first type (Io1 and E1), the cores are assumed to consist of eutectic Fe-FeS melt with the densities ρ 1 = 5.15 g cm-3 (Io1) and 5.2 g cm-3 (E1). In the models of the second type (Io3 and E3), the cores consist of FeS with an admixture of nickel and have the density ρ 1 = 4.6 g cm-3. The approach used here differs from that used previously both in chosen model chemical composition of these satellites and in boundary conditions imposed on the models. The most important question to be answered by modeling the internal structure of the Galilean satellites is that of the condensate composition at the formation epoch of Jupiter's system. Jupiter's core and the Galilean satellites were formed from the condensate. Ganymede and Callisto were formed fairly far from Jupiter in zones with temperatures below the water condensation temperature, water was entirely incorporated into their bodies, and their modeling showed the mass ratio of the icy (I) component to the rock (R) component in them to be I/R ˜ 1. The R composition must be clarified by modeling Io and Europa. The models of the second type (Io3 and E3), in which the satellite cores consist of FeS, yield 25.2 (Io3) and 22.8 (E3) for the core masses (in weight %). In discussing the R composition, we note that, theoretically, the material of which the FeS+Ni core can consist in the R accounts for ˜25.4% of the satellite mass. In this case, such an important parameter as the mantle silicate iron saturation is Fe# = 0.265. The Io3 and E3 models agree well with this theoretical prediction. The models of the first and second types differ markedly in core radius; thus, in principle, the R composition in the formation zone of Jupiter's system can be clarified by geophysical studies. Another problem studied here is that of the error made in modeling Io and Europa using the Radau-Darvin formula when passing from the Love number k 2 to the nondimensional polar moment of inertia bar C. For Io, the Radau-Darvin formula underestimates the true value of bar C by one and a half units in the third decimal digit. For Europa, this effect is approximately a factor of 3 smaller, which roughly corresponds to a ratio of the small parameters for the satellites under consideration α Io/α Europa ˜ 3.4. In modeling the internal structure of the satellites, the core radius depends strongly on both the mean moment of inertia I* and k 2. Therefore, the above discrepancy in bar C for Io is appreciable.

The effects on the ionosphere of inertia in the high latitude neutral thermosphere

NASA Technical Reports Server (NTRS)

Burns, Alan; Killeen, Timothy

1993-01-01

High-latitude ionospheric currents, plasma temperatures, densities, and composition are all affected by the time-dependent response of the neutral thermosphere to ion drag and Joule heating through a variety of complex feedback processes. These processes can best be studied numerically using the appropriate nonlinear numerical modeling techniques in conjunction with experimental case studies. In particular, the basic physics of these processes can be understood using a model, and these concepts can then be applied to more complex realistic situations by developing the appropriate simulations of real events. Finally, these model results can be compared with satellite-derived data from the thermosphere. We used numerical simulations from the National Center of Atmospheric Research Thermosphere/Ionosphere General Circulation Model (NCAR TIGCM) and data from the Dynamic Explorer 2 (DE 2) satellite to study the time-dependent effects of the inertia of the neutral thermosphere on ionospheric currents, plasma temperatures, densities, and composition. One particular case of these inertial effects is the so-called 'fly-wheel effect'. This effect occurs when the neutral gas, that has been spun-up by the large ionospheric winds associated with a geomagnetic storm, moves faster than the ions in the period after the end of the main phase of the storm. In these circumstances, the neutral gas can drag the ions along with them. It is this last effect, which is described in the next section, that we have studied under this grant.

Early Rockets

NASA Image and Video Library

1958-01-01

The modified Jupiter C (sometimes called Juno I), used to launch Explorer I, had minimum payload lifting capabilities. Explorer I weighed slightly less than 31 pounds. Juno II was part of America's effort to increase payload lifting capabilities. Among other achievements, the vehicle successfully launched a Pioneer IV satellite on March 3, 1959, and an Explorer VII satellite on October 13, 1959. Responsibility for Juno II passed from the Army to the Marshall Space Flight Center when the Center was activated on July 1, 1960. On November 3, 1960, a Juno II sent Explorer VIII into a 1,000-mile deep orbit within the ionosphere.

Ultraviolet Spectroscopy of the Surfaces of the Inner Icy Saturnian Satellites

NASA Astrophysics Data System (ADS)

Hendrix, A. R.; Hansen, C. J.

2008-12-01

The Cassini mission has provided a unique opportunity to make high-resolution, multi-spectral measurements of Saturn's icy moons, to investigate their surface compositions, processes and evolution. Here we present results from the Ultraviolet Imaing Spectrograph (UVIS). This instrument allows for the first measurements of the icy satellites in the extreme ultraviolet (EUV) to far-ultraviolet (FUV) wavelength range. The icy satellites of the Saturn system exhibit a remarkable amount of variability: Dark, battered Phoebe orbiting at a distant 200 RS, black-and-white Iapetus, the wispy streaks of Dione, cratered Rhea and Mimas, bright Tethys and geologically active Enceladus. Phoebe, Iapetus and Hyperion all orbit largely outside Saturn's magnetosphere, while the inner icy satellites Mimas, Enceladus, Dione Tethys and Rhea all orbit within the magnetosphere. Furthermore, the inner icy satellites all orbit within the E-ring - so the extent of exogenic effects on these icy satellites is wide-ranging. We present an overview of UVIS results from Tethys, Dione, Mimas, Enceladus and Rhea, focusing on surface investigations. We expect that the UV signatures of these icy satellites are strongly influenced not only by their water ice composition, but by external effects and magnetospheric environments. We study the FUV reflectance spectra to learn about the surface composition, map out water ice grain size variations, investigate effects of coating by E-ring grains, examine disk-resolved and hemispheric compositional and brightness variations, and investigate the presence of radiation products. This is new work: FUV spectra of surfaces have not been well-studied in the past. Spectra of the inner icy moons have been used to better develop spectral models, to further understand existing lab data of water ice and to help with understanding instrument performance. Analysis is challenged by a lack of laboratory data in this wavelength region, but intriguing results are being found. We find that the FUV albedo is a critical tie- point to understand the composition of these moons -- important absorptions occur in the NUV-visible region. We present disk-integrated hemispherical reflectance spectra, and show that while Tethys and Dione exhibit strong UV leading-trailing differences, Mimas, Enceladus and Rhea do not. In the UV, Mimas is nearly as bright as Enceladus. Tethys is surprisingly dark in the UV. The visible-wavelength leading-trailing hemisphere albedo differences can be attributed to coating by E-ring grains; in the UV, a process appears to darken the trailing hemisphere of Tethys. We also investigate disk-resolved Enceladus spectra to understand spectral differences between the south polar tiger stripe region and elsewhere on the surface.

Electrospun Fe3O4/TiO2 hybrid nanofibers and their in vitro biocompatibility: prospective matrix for satellite cell adhesion and cultivation.

PubMed

Amna, Touseef; Hassan, M Shamshi; Van Ba, Hoa; Khil, Myung-Seob; Lee, Hak-Kyo; Hwang, I H

2013-03-01

We report the fabrication of novel Fe3O4/TiO2 hybrid nanofibers with the improved cellular response for potential tissue engineering applications. In this study, Fe3O4/TiO2 hybrid nanofibers were prepared by facile sol-gel electrospinning using titanium isopropoxide and iron(III) nitrate nonahydrate as precursors. The obtained electrospun nanofibers were vacuum dried at 80 °C and then calcined at 500 °C. The physicochemical characterization of the synthesized composite nanofibers was carried out by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and X-ray diffraction pattern. To examine the in vitro cytotoxicity, satellite cells were treated with as-prepared Fe3O4/TiO2 and the viability of cells was analyzed by Cell Counting Kit-8 assay at regular time intervals. The morphological features of unexposed satellite cells and exposed to Fe3O4/TiO2 composite were examined with a phase contrast microscope whereas the quantification of cell viability was carried out via confocal laser scanning microscopy. The morphology of the cells attached to hybrid matrix was observed by Bio-SEM. Cytotoxicity experiments indicated that the satellite cells could attach to the Fe3O4/TiO2 composite nanofibers after being cultured. We observed that Fe3O4-TiO2 composite nanofibers could support cell adhesion and growth. Results from this study therefore suggest that Fe3O4/TiO2 composite scaffold with small diameters (approximately 200 nm) can mimic the natural extracellular matrix well and provide possibilities for diverse applications in the field of tissue engineering and regenerative medicine. Copyright © 2012 Elsevier B.V. All rights reserved.

Origin of Saturn's rings and inner moons by mass removal from a lost Titan-sized satellite.

PubMed

Canup, Robin M

2010-12-16

The origin of Saturn's rings has not been adequately explained. The current rings are more than 90 to 95 per cent water ice, which implies that initially they were almost pure ice because they are continually polluted by rocky meteoroids. In contrast, a half-rock, half-ice mixture (similar to the composition of many of the satellites in the outer Solar System) would generally be expected. Previous ring origin theories invoke the collisional disruption of a small moon, or the tidal disruption of a comet during a close passage by Saturn. These models are improbable and/or struggle to account for basic properties of the rings, including their icy composition. Saturn has only one large satellite, Titan, whereas Jupiter has four large satellites; additional large satellites probably existed originally but were lost as they spiralled into Saturn. Here I report numerical simulations of the tidal removal of mass from a differentiated, Titan-sized satellite as it migrates inward towards Saturn. Planetary tidal forces preferentially strip material from the satellite's outer icy layers, while its rocky core remains intact and is lost to collision with the planet. The result is a pure ice ring much more massive than Saturn's current rings. As the ring evolves, its mass decreases and icy moons are spawned from its outer edge with estimated masses consistent with Saturn's ice-rich moons interior to and including Tethys.

JEMRMS Small Satellite Deployment Observation

NASA Image and Video Library

2012-10-04

ISS033-E-009334 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

JEMRMS Small Satellite Deployment Observation

NASA Image and Video Library

2012-10-04

ISS033-E-009458 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

Galactic and zodiacal light surface brightness measurements with the Atmosphere Explorer satellites

NASA Technical Reports Server (NTRS)

Abreu, V. J.; Hays, P. B.; Yee, J. H.

1982-01-01

Galactic and zodiacal light surface maps based on the Atmosphere Explorer-C, -D, and -E satellite data are presented at 7320, 6300, 5577, 5200, and 4278 A. A procedure used to generate these maps, which involves separation of the individual stars and diffuse starlight from the zodiacal light, is described in detail. The maps can be used in atmospheric emission studies to correct for galactic emissions which contaminate satellite as well as ground-based photometric observations. The zodiacal light maps show enhanced features which are important for understanding the nature of interplanetary dust.

Testing command and control of the satellites in formation flight

NASA Astrophysics Data System (ADS)

Gheorghe, Popan; Gheorghe, Gh. Ion; Gabriel, Todoran

2013-10-01

The topics covered in the paper are mechatronic systems for determining the distance between the satellites and the design of the displacement system on air cushion table for satellites testing. INCDMTM has the capability to approach the collaboration within European Programms (ESA) of human exploration of outer space through mechatronic systems and accessories for telescopes, mechatronics systems used by the launchers, sensors and mechatronic systems for the robotic exploration programs of atmosphere and Mars. This research has a strong development component of industrial competitiveness many of the results of space research have direct applicability in industrial fabrication.

Project SKYLITE: A Design Exploration.

DTIC Science & Technology

1987-09-01

5. Gravity Gradient Boom The SKYLITE satellite uses gravity gradient stabilization. This technique requires a gravity gradient boom for attitude ... attitude of the satellite. To satisfy SKYLITE mission requirements, the satellite contains an array of IR sensors for evaluation of radiation from the ...3.1 Extended GAS Canister. The Orion satellite has been designed with 7 thrusters. Six thrusters are .1 lbr rated, and used for spin up and attitude

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

Brian Holz, CEO of OneWeb Satellites, speaks during the groundbreaking ceremony at Kennedy's Exploration Park for OneWeb. The company, in partnership with Airbus, is building a 150,000-square-foot factory to manufacture satellites that will connect all areas of the world to the Internet wirelessly. Photo credit: NASA/Kim Shiflett

Direct Broadcast Satellites: An Interview with Hartford Gunn.

ERIC Educational Resources Information Center

Library Hi Tech, 1984

1984-01-01

In this interview with Hartford Gunn, Vice-President of Program Development for Satellite Television Corporation (STC), the concept of direct broadcast by satellite (DBS) is explored. Allocation of radio frequencies, services provided by DBS network, home installation and purchase of dish antenna, and comparison of DBS with cable television are…

Developing and Evaluating RGB Composite MODIS Imagery for Applications in National Weather Service Forecast Offices

NASA Technical Reports Server (NTRS)

Oswald, Hayden; Molthan, Andrew L.

2011-01-01

Satellite remote sensing has gained widespread use in the field of operational meteorology. Although raw satellite imagery is useful, several techniques exist which can convey multiple types of data in a more efficient way. One of these techniques is multispectral compositing. The NASA Short-term Prediction Research and Transition (SPoRT) Center has developed two multispectral satellite imagery products which utilize data from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra and Aqua satellites, based upon products currently generated and used by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT). The nighttime microphysics product allows users to identify clouds occurring at different altitudes, but emphasizes fog and low cloud detection. This product improves upon current spectral difference and single channel infrared techniques. Each of the current products has its own set of advantages for nocturnal fog detection, but each also has limiting drawbacks which can hamper the analysis process. The multispectral product combines each current product with a third channel difference. Since the final image is enhanced with color, it simplifies the fog identification process. Analysis has shown that the nighttime microphysics imagery product represents a substantial improvement to conventional fog detection techniques, as well as provides a preview of future satellite capabilities to forecasters.

Evolution of angular velocity for defunct satellites as a result of YORP: An initial study

NASA Astrophysics Data System (ADS)

Albuja, Antonella A.; Scheeres, Daniel J.; McMahon, Jay W.

2015-07-01

Observations of defunct satellites show that these objects are generally rotating, with some having very fast rotation rates, yet the cause of these rapid rates is unknown. The observed secular change in the spin rate and spin axis orientation of asteroids is known to be caused by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, however, its effect on inactive satellites in Earth orbit remains unexplored. This paper applies the YORP effect to defunct satellites and analyzes its effect on the spin rate and obliquity of these objects. This work uses two different satellite geometries to explore the secular change of the spin rate and obliquity caused by the YORP effect for inactive Geostationary Earth Orbit (GEO) satellites. One of the model satellites has an asymmetric geometry, which leads to the classical YORP effect as originally formulated for asteroids. The other model satellite is geometrically symmetric, but relies on mass distribution asymmetry to generate the YORP effect. For both models the secular change is explored with averaged dynamics, and the solutions of the averaged theory are compared with numerical integrations of the non-averaged equations of motion. Additionally, previously published observations of inactive GEO satellites are used to estimate the YORP torque acting on those bodies. A comparison between this torque and the expected torque on a defunct satellite shows that the two are of the same order of magnitude. These results motivate further study on the YORP effect in the realm of inactive satellites.

Evaluation of Enhanced High Resolution MODIS/AMSR-E SSTs and the Impact on Regional Weather Forecast

NASA Technical Reports Server (NTRS)

Schiferl, Luke D.; Fuell, Kevin K.; Case, Jonathan L.; Jedlovec, Gary J.

2010-01-01

Over the last few years, the NASA Short-term Prediction Research and Transition (SPoRT) Center has been generating a 1-km sea surface temperature (SST) composite derived from retrievals of the Moderate Resolution Imaging Spectroradiometer (MODIS) for use in operational diagnostics and regional model initialization. With the assumption that the day-to-day variation in the SST is nominal, individual MODIS passes aboard the Earth Observing System (EOS) Aqua and Terra satellites are used to create and update four composite SST products each day at 0400, 0700, 1600, and 1900 UTC, valid over the western Atlantic and Caribbean waters. A six month study from February to August 2007 over the marine areas surrounding southern Florida was conducted to compare the use of the MODIS SST composite versus the Real-Time Global SST analysis to initialize the Weather Research and Forecasting (WRF) model. Substantial changes in the forecast heat fluxes were seen at times in the marine boundary layer, but relatively little overall improvement was measured in the sensible weather elements. The limited improvement in the WRF model forecasts could be attributed to the diurnal changes in SST seen in the MODIS SST composites but not accounted for by the model. Furthermore, cloud contamination caused extended periods when individual passes of MODIS were unable to update the SSTs, leading to substantial SST latency and a cool bias during the early summer months. In order to alleviate the latency problems, the SPoRT Center recently enhanced its MODIS SST composite by incorporating information from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) instruments as well as the Operational Sea Surface Temperature and Sea Ice Analysis. These enhancements substantially decreased the latency due to cloud cover and improved the bias and correlation of the composites at available marine point observations. While these enhancements improved upon the modeled cold bias using the original MODIS SSTs, the discernable impacts on the WRF model were still somewhat limited. This paper explores several factors that may have contributed to this result. First, the original methodology to initialize the model used the most recent SST composite available in a hypothetical real ]time configuration, often matching the forecast initial time with an SST field that was 5-8 hours offset. To minimize the differences that result from the diurnal variations in SST, the previous day fs SST composite is incorporated at a time closest to the model initialization hour (e.g. 1600 UTC composite at 1500 UTC model initialization). Second, the diurnal change seen in the MODIS SST composites was not represented by the WRF model in previous simulations, since the SSTs were held constant throughout the model integration. To address this issue, we explore the use of a water skin-temperature diurnal cycle prediction capability within v3.1 of the WRF model to better represent fluctuations in marine surface forcing. Finally, the verification of the WRF model is limited to very few over-water sites, many of which are located near the coastlines. In order to measure the open ocean improvements from the AMSR-E, we could use an independent 2-dimensional, satellite-derived data set to validate the forecast model by applying an object-based verification method. Such a validation technique could aid in better understanding the benefits of the mesoscale SST spatial structure to regional models applications.

Conservative Allowables Determined by a Tsai-Hill Equivalent Criterion for Design of Satellite Composite Parts

NASA Astrophysics Data System (ADS)

Pommatau, Gilles

2014-06-01

The present paper deals with the industrial application, via a software developed by Thales Alenia Space, of a new failure criterion named "Tsai-Hill equivalent criterion" for composite structural parts of satellites. The first part of the paper briefly describes the main hypothesis and the possibilities in terms of failure analysis of the software. The second parts reminds the quadratic and conservative nature of the new failure criterion, already presented in ESA conference in a previous paper. The third part presents the statistical calculation possibilities of the software, and the associated sensitivity analysis, via results obtained on different composites. Then a methodology, proposed to customers and agencies, is presented with its limitations and advantages. It is then conclude that this methodology is an efficient industrial way to perform mechanical analysis on quasi-isotropic composite parts.

Icy Satellites of the Planets, and the Work of V.I. Moroz

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.

2006-01-01

The satellites of the giant planets are highly varied in size and density, indicating a wide range of compositions. The principal components of these satellites are ices of many different compositions (with H2O the most abundant) and varying amounts of silicate rocky material. Many different ices have been found by spectroscopic techniques both from Earth-based observatories and from planetary spacecraft. Three of the Galilean satellites of Jupiter exhibit H2O ice on their surfaces, while small amounts of CO2 are present on Ganymede and Callisto. The volcanic satellite Io has abundant SO2 ice and frost deposits. Saturn s satellites have surfaces dominated by H2O ice, but CO2 is also present on most of them, and in the cases of the low-albedo satellites Iapetus and Phoebe, there is evidence of complex hydrocarbons mixed with the surface materials. The large Uranian satellites also have H2O-dominated surfaces, but CO2 has also been discovered on two of them. Neptune s largest satellite, Triton, show spectroscopic evidence for six different ices, including N2, CH4, CO, CO2, H2O, and C2H6. The latter ice is a photochemical product from the action of sunlight on Triton's atmosphere. Pluto is similar to Triton, although CO2 has not been found. Pluto s large satellite, Charon, shows evidence for an ammonia hydrate on part of its surface. V. I. Moroz was a pioneer in the application of near-infrared detectors to astronomical sources. Using a prism spectrometer he measured the spectra of the Galilean satellites of Jupiter, and in 1966 he published the first near-infrared spectra, noting the appearance of H2O ice as a major component of Europa and Ganymede. This discovery, and the techniques of Moroz measurements help set the stage for the broad extension of the study of planetary, satellite, and asteroid surfaces through reflectance spectroscopy in the near-infrared.

Exploring the Universe.

ERIC Educational Resources Information Center

Aviation/Space, 1982

1982-01-01

Highlights National Aeronautics and Space Administration's (NASA) space exploration studies, focusing on Voyager at Saturn, advanced Jupiter exploration, infrared observatory, space telescope, Dynamics Explorers (satellites designed to provide understanding of earth/sun energy relationship), and ozone studies. (JN)

Micromega IR, an infrared hyperspectral microscope for space exploration

NASA Astrophysics Data System (ADS)

Pilorget, C.; Bibring, J.-P.; Berthe, M.; Hamm, V.

2017-11-01

The coupling between imaging and spectrometry has proved to be one of the most promising way to study remotely planetary objects [1][2]. The next step is to use this concept for in situ analyses. MicrOmega IR has been developed within this scope. It is an ultra miniaturized near-infrared hyperspectral microscope dedicated to in situ analyses, selected to be part of the ESA/ExoMars rover and RKA/Phobos Grunt lander payload. The goal of this instrument is to characterize the composition of samples at almost their grain size scale, in a nondestructive way. Coupled to the mapping information, it provides unique clues to trace back the history of the parent body (planet, satellite or small body) [3][4].

Transverse ion energization and low-frequency plasma waves in the mid-altitude auroral zone - A case study

NASA Technical Reports Server (NTRS)

Peterson, W. K.; Shelley, E. G.; Boardsen, S. A.; Gurnett, D. A.; Ledley, B. G.; Sugiura, M.; Moore, T. E.

1988-01-01

Evidence of transverse ion energization at altitudes of several earth radii in the auroral zone was reexamined using several hundred hours of high-sensitivity and high-resolution plasma data obtained by the Dynamics Explorer 1 satellite. The data on particle environment encountered at midaltitudes in the auroral zone disclosed rapid variations in the values of total density, thermal structure, and composition of the plasma in the interval measured; the modes of low-frequency plasma waves also varied rapidly. It was not possible to unambiguously identify in these data particle and wave signature of local transverse ion energization; however, many intervals were found where local transverse ion heating was consistent with the observations.

The Final Frontier: News Media’s Use of Commercial Satellite Imagery during Wartime

DTIC Science & Technology

2006-04-01

1 The Technology and History of Commercial Satellite Imaging…………………. 4 Media Use of Satellite Imagery During U.S. Armed...explore how the mass media uses satellite imaging to gather information during wartime and determine what impact this technology has had, and will have...Enduring Freedom and Iraqi Freedom; (3) legal and regulatory issues facing both the media and the satellite-imaging industry in regards to the use of

Utilization of satellite data and regional scale numerical models in short range weather forecasting

NASA Technical Reports Server (NTRS)

Kreitzberg, C. W.

1985-01-01

Overwhelming evidence was developed in a number of studies of satellite data impact on numerical weather prediction that it is unrealistic to expect satellite temperature soundings to improve detailed regional numerical weather prediction. It is likely that satellite data over the United States would substantially impact mesoscale dynamical predictions if the effort were made to develop a composite moisture analysis system. The horizontal variability of moisture, most clearly depicited in images from satellite water vapor channels, would not be determined from conventional rawinsondes even if that network were increased by a doubling of both the number of sites and the time frequency.

Exploring Ocean-World Habitability within the Planned Europa Clipper Mission

NASA Astrophysics Data System (ADS)

Pappalardo, R. T.; Senske, D.; Korth, H.; Blaney, D. L.; Blankenship, D. D.; Collins, G. C.; Christensen, P. R.; Gudipati, M. S.; Kempf, S.; Lunine, J. I.; Paty, C. S.; Raymond, C. A.; Rathbun, J.; Retherford, K. D.; Roberts, J. H.; Schmidt, B. E.; Soderblom, J. M.; Turtle, E. P.; Waite, J. H., Jr.; Westlake, J. H.

2017-12-01

A key driver of planetary exploration is to understand the processes that lead to potential habitability across the solar system, including within oceans hosted by some icy satellites of the outer planets. In this context, it is the overarching science goal of the planned Europa Clipper mission is: Explore Europa to investigate its habitability. Following from this goal are three mission objectives: (1) Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; (2) Understand the habitability of Europa's ocean through composition and chemistry; and (3) Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities. Folded into these objectives is the desire to search for and characterize any current activity, notably plumes and thermal anomalies. A suite of nine remote-sensing and in-situ observing instruments is being developed that synergistically addresses these objectives. The remote-sensing instruments are the Europa UltraViolet Spectrograph (Europa-UVS), the Europa Imaging System (EIS), the Mapping Imaging Spectrometer for Europa (MISE), the Europa THErMal Imaging System (E-THEMIS), and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON). The instruments providing in-situ observations are the Interior Characterization of Europa using Magnetometry (ICEMAG), the Plasma Instrument for Magnetic Sounding (PIMS), the MAss Spectrometer for Planetary EXploration (MASPEX), and the SUrface Dust Analyzer (SUDA). In addition, gravity science can be achieved via the spacecraft's telecommunication system, and the planned radiation monitoring system could provide information on Europa's energetic particle environment. Working together, the mission's robust investigation suite can be used to test hypotheses and enable discoveries relevant to the interior, composition, and geology of Europa, thereby addressing the potential habitability of this intriguing ocean world.

San Marco C-2 Explorer

NASA Technical Reports Server (NTRS)

1974-01-01

The San Marco C-2 spacecraft will be launched no earlier than 18 February 1974 from the San Marco Range located off the coast of Kenya, Africa, by a Scout launch vehicle. The launch will be conducted by an Italian crew. The San Marco C-2 is the fourth cooperative satellite project between Italy and the United States. The purpose of the mission is to obtain measurements of the diurnal variations of the equatorial neutral atmosphere density, composition, and temperature and to use these data for correlation with AE-C (Explorer 51) data for studies of the physics and dynamics of the thermosphere. The San Marco C-2 project is a joint undertaking of the National Aeronautics and Space Administration (NASA) and the Italian Space Commission officially initiated with a Memorandum of Understanding in August of 1973. Project management responsibility for the Italian portion of the project has been assigned to the Centro Ricerche Aerospaziali (CRA) while the Goddard Space Flight Center (GSFC) has responsibility for the United States portion.

Explore Earth Science Datasets for STEM with the NASA GES DISC Online Visualization and Analysis Tool, GIOVANNI

NASA Astrophysics Data System (ADS)

Liu, Z.; Acker, J. G.; Kempler, S. J.

2016-12-01

The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) is one of twelve NASA Science Mission Directorate (SMD) Data Centers that provide Earth science data, information, and services to research scientists, applications scientists, applications users, and students around the world. The GES DISC is the home (archive) of NASA Precipitation and Hydrology, as well as Atmospheric Composition and Dynamics remote sensing data and information. To facilitate Earth science data access, the GES DISC has been developing user-friendly data services for users at different levels. Among them, the Geospatial Interactive Online Visualization ANd aNalysis Infrastructure (GIOVANNI, http://giovanni.gsfc.nasa.gov/) allows users to explore satellite-based data using sophisticated analyses and visualizations without downloading data and software, which is particularly suitable for novices to use NASA datasets in STEM activities. In this presentation, we will briefly introduce GIOVANNI and recommend datasets for STEM. Examples of using these datasets in STEM activities will be presented as well.

Explore Earth Science Datasets for STEM with the NASA GES DISC Online Visualization and Analysis Tool, Giovanni

NASA Technical Reports Server (NTRS)

Liu, Z.; Acker, J.; Kempler, S.

2016-01-01

The NASA Goddard Earth Sciences (GES) Data and Information Services Center(DISC) is one of twelve NASA Science Mission Directorate (SMD) Data Centers that provide Earth science data, information, and services to users around the world including research and application scientists, students, citizen scientists, etc. The GESDISC is the home (archive) of remote sensing datasets for NASA Precipitation and Hydrology, Atmospheric Composition and Dynamics, etc. To facilitate Earth science data access, the GES DISC has been developing user-friendly data services for users at different levels in different countries. Among them, the Geospatial Interactive Online Visualization ANd aNalysis Infrastructure (Giovanni, http:giovanni.gsfc.nasa.gov) allows users to explore satellite-based datasets using sophisticated analyses and visualization without downloading data and software, which is particularly suitable for novices (such as students) to use NASA datasets in STEM (science, technology, engineering and mathematics) activities. In this presentation, we will briefly introduce Giovanni along with examples for STEM activities.

Introducing the VISAGE project - Visualization for Integrated Satellite, Airborne, and Ground-based data Exploration

NASA Astrophysics Data System (ADS)

Gatlin, P. N.; Conover, H.; Berendes, T.; Maskey, M.; Naeger, A. R.; Wingo, S. M.

2017-12-01

A key component of NASA's Earth observation system is its field experiments, for intensive observation of particular weather phenomena, or for ground validation of satellite observations. These experiments collect data from a wide variety of airborne and ground-based instruments, on different spatial and temporal scales, often in unique formats. The field data are often used with high volume satellite observations that have very different spatial and temporal coverage. The challenges inherent in working with such diverse datasets make it difficult for scientists to rapidly collect and analyze the data for physical process studies and validation of satellite algorithms. The newly-funded VISAGE project will address these issues by combining and extending nascent efforts to provide on-line data fusion, exploration, analysis and delivery capabilities. A key building block is the Field Campaign Explorer (FCX), which allows users to examine data collected during field campaigns and simplifies data acquisition for event-based research. VISAGE will extend FCX's capabilities beyond interactive visualization and exploration of coincident datasets, to provide interrogation of data values and basic analyses such as ratios and differences between data fields. The project will also incorporate new, higher level fused and aggregated analysis products from the System for Integrating Multi-platform data to Build the Atmospheric column (SIMBA), which combines satellite and ground-based observations into a common gridded atmospheric column data product; and the Validation Network (VN), which compiles a nationwide database of coincident ground- and satellite-based radar measurements of precipitation for larger scale scientific analysis. The VISAGE proof-of-concept will target "golden cases" from Global Precipitation Measurement Ground Validation campaigns. This presentation will introduce the VISAGE project, initial accomplishments and near term plans.

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

A model of a OneWeb satellite like those the company will build to will connect all areas of the world to the Internet wirelessly. The company plans to launch 2,000 of the satellites as part of its constellation. The satellites will be built at a new factory at Exploration Park at NASA's Kennedy Space Center. The company held a groundbreaking ceremony for the factory. Photo credit: NASA/Kim Shiflett

TriAnd and its siblings: satellites of satellites in the Milky Way halo

NASA Astrophysics Data System (ADS)

Deason, A. J.; Belokurov, V.; Hamren, K. M.; Koposov, S. E.; Gilbert, K. M.; Beaton, R. L.; Dorman, C. E.; Guhathakurta, P.; Majewski, S. R.; Cunningham, E. C.

2014-11-01

We explore the Triangulum-Andromeda (TriAnd) overdensity in the SPLASH (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo) and SEGUE (the Sloan Extension for Galactic Understanding and Exploration) spectroscopic surveys. Milky Way main-sequence turn-off stars in the SPLASH survey reveal that the TriAnd overdensity and the recently discovered Pan-Andromeda Archaeological Survey (PAndAS) stream share a common heliocentric distance (D ˜ 20 kpc), position on the sky, and line-of-sight velocity (VGSR ˜ 50 km s-1). Similarly, A-type, giant, and main-sequence turn-off stars selected from the SEGUE survey in the vicinity of the Segue 2 satellite show that TriAnd is prevalent in these fields, with a velocity and distance similar to Segue 2. The coincidence of the PAndAS stream and Segue 2 satellite in positional and velocity space to TriAnd suggests that these substructures are all associated, and may be a fossil record of group-infall on to the Milky Way halo. In this scenario, the Segue 2 satellite and PAndAS stream are `satellites of satellites', and the large, metal-rich TriAnd overdensity is the remains of the group central.

Giant planets and their satellites: What are the relationships between their properties and how they formed

NASA Technical Reports Server (NTRS)

Stevenson, David J.

1991-01-01

The following subject areas are covered: (1) the mass distribution; (2) interior models; (3) atmospheric compositions and their implications; (4) heat flows and their implications; (5) satellite systems; (6) temperatures in the solar nebula; and (7) giant planet formation.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Michael Moloney, Director for Space and Aeronautics at the Space Studies Board and the Aeronautics and Space Engineering Board of the U.S. National Academies of Sciences, Engineering, and Medicine, delivers opening remarks during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Satellite services system analysis study. Volume 3A: Service equipment requirements, appendix

NASA Technical Reports Server (NTRS)

1981-01-01

Spacecraft descriptions and mission sequences, mission and servicing operations functional analyses, servicing requirements, and servicing equipment are discussed for five reference satellites: the X-ray Timing Explorer, the Upper Atmospheric Research Satellite, the Advanced X-ray Astrophysics Facility, the Earth Gravity Field Survey Mission, and the Orbiting Astronomical Observatory.

Improving UK Air Quality Modelling Through Exploitation of Satellite Observations

NASA Astrophysics Data System (ADS)

Pope, Richard; Chipperfield, Martyn; Savage, Nick

2014-05-01

In this work the applicability of satellite observations to evaluate the operational UK Met Office Air Quality in the Unified Model (AQUM) have been investigated. The main focus involved the AQUM validation against satellite observations, investigation of satellite retrieval error types and of synoptic meteorological-atmospheric chemistry relationships simulated/seen by the AQUM/satellite. The AQUM is a short range forecast model of atmospheric chemistry and aerosols up to 5 days. It has been designed to predict potentially hazardous air pollution events, e.g. high concentrations of surface ozone. The AQUM has only been validated against UK atmospheric chemistry recording surface stations. Therefore, satellite observations of atmospheric chemistry have been used to further validate the model, taking advantage of better satellite spatial coverage. Observations of summer and winter 2006 tropospheric column NO2 from both OMI and SCIAMACHY show that the AQUM generally compares well with the observations. However, in northern England positive biases (AQUM - satellite) suggest that the AQUM overestimates column NO2; we present results of sensitivity experiments on UK emissions datasets suspected to be the cause. In winter, the AQUM over predicts background column NO2 when compared to both satellite instruments. We hypothesise that the cause is the AQUM winter night-time chemistry, where the NO2 sinks are not substantially defined. Satellite data are prone to errors/uncertainty such as random, systematic and smoothing errors. We have investigated these error types and developed an algorithm to calculate and reduce the random error component of DOAS NO2 retrievals, giving more robust seasonal satellite composites. The Lamb Weather Types (LWT), an objective method of classifying the daily synoptic weather over the UK, were used to create composite satellite maps of column NO2 under different synoptic conditions. Under cyclonic conditions, satellite observed UK column NO2 is reduced as the indicative south-westerly flow transports it away from the UK over the North Sea. However, under anticyclonic conditions, the satellite shows that the stable conditions enhance the build-up of column NO2 over source regions. The influence of wind direction on column NO2 can also be seen from space with transport leeward of the source regions.

Vertical lifting of ionization during geomagnetic storms from satellite measurements of ion composition

NASA Technical Reports Server (NTRS)

Goel, M. K.; Rao, B. C. N.; Chandra, S.; Maier, E. J.

1977-01-01

Magnetic-storm phenomena at low latitudes are discussed based on ion-composition /O(+), H(+), He(+)/ and electron- and ion-temperature measurements from the OGO-4 and Isis-2 satellites. For the moderately severe storms considered, the effects of changes in the neutral composition and in the neutral and plasma temperatures are discussed, and it is shown that these changes would not produce the observed O(+) increase during storms at low latitudes. It is suggested that the observed increase in O(+) in the topside region is a manifestation of the vertical lifting of ionization of the F-layer. The argument in favor of vertical lifting is further substantiated by the observed changes in the F-region critical frequency and the height parameters.

"Star Light, Star Bright..."

ERIC Educational Resources Information Center

Moore, Gil; Doop, Skip; Millson, David

1998-01-01

Describes Student-Tracked Atmospheric Research Satellite for Heuristic International Networking Experiment (STARSHINE), which enables students to explore optical astronomy, orbital dynamics, space and atmospheric physics, mathematics and international cooperation by tracking a satellite. (Author)

Space plasma physics at the Applied Physics Laboratory over the past half-century

NASA Technical Reports Server (NTRS)

Potemra, Thomas A.

1992-01-01

An overview is given of space-plasma experiments conducted at the Applied Physics Laboratory (APL) at Johns Hopkins University including observational campaigns and the instrumentation developed. Specific space-plasma experiments discussed include the study of the radiation environment in the Van Allen radiation belt with solid-state proton detectors. Also described are the 5E-1 satellites which acquired particle and magnetic-field data from earth orbit. The Triad satellite and its magnetometer system were developed for high-resolution studies of the earth's magnetic field, and APL contributions to NASA's Interplanetary Monitoring Platforms are listed. The review mentions the International Ultraviolet Explorer, the Atmosphere Explorer mission, and the Active Magnetic Particle Tracer Explorers mission. Other recent programs reviewed include a high-latitude satellite, contributions to the Voyager mission, and radar studies of space plasmas.

A TT&C Performance Simulator for Space Exploration and Scientific Satellites - Architecture and Applications

NASA Astrophysics Data System (ADS)

Donà, G.; Faletra, M.

2015-09-01

This paper presents the TT&C performance simulator toolkit developed internally at Thales Alenia Space Italia (TAS-I) to support the design of TT&C subsystems for space exploration and scientific satellites. The simulator has a modular architecture and has been designed using a model-based approach using standard engineering tools such as MATLAB/SIMULINK and mission analysis tools (e.g. STK). The simulator is easily reconfigurable to fit different types of satellites, different mission requirements and different scenarios parameters. This paper provides a brief description of the simulator architecture together with two examples of applications used to demonstrate some of the simulator’s capabilities.

Early Rockets

NASA Image and Video Library

1958-01-31

This illustration shows the main characteristics of the Jupiter C launch vehicle and its payload, the Explorer I satellite. The Jupiter C, America's first successful space vehicle, launched the free world's first scientific satellite, Explorer 1, on January 31, 1958. The four-stage Jupiter C measured almost 69 feet in length. The first stage was a modified liquid fueled Redstone missile. This main stage was about 57 feet in length and 70 inches in diameter. Fifteen scaled down SERGENT solid propellant motors were used in the upper stages. A "tub" configuration mounted on top of the modified Redstone held the second and third stages. The second stage consisted of 11 rockets placed in a ring formation within the tub. Inserted into the ring of second stage rockets was a cluster of 3 rockets making up the third stage. A fourth stage single rocket and the satellite were mounted atop the third stage. This "tub", all upper stages, and the satellite were set spirning prior to launching. The complete upper assembly measured 12.5 feet in length. The Explorer I carried the radiation detection experiment designed by Dr. James Van Allen and discovered the Van Allen Radiation Belt.

On the Existence of Regular and Irregular Outer Moons Orbiting the Pluto-Charon System

NASA Astrophysics Data System (ADS)

Michaely, Erez; Perets, Hagai B.; Grishin, Evgeni

2017-02-01

The dwarf planet Pluto is known to host an extended system of five co-planar satellites. Previous studies have explored the formation and evolution of the system in isolation, neglecting perturbative effects by the Sun. Here we show that secular evolution due to the Sun can strongly affect the evolution of outer satellites and rings in the system, if such exist. Although precession due to extended gravitational potential from the inner Pluto-Charon binary quench such secular evolution up to a crit ˜ 0.0035 au (˜0.09 R Hill the Hill radius; including all of the currently known satellites), outer orbits can be significantly altered. In particular, we find that co-planar rings and satellites should not exist beyond a crit; rather, satellites and dust particles in these regions secularly evolve on timescales ranging between 104 and 106 years, and quasi-periodically change their inclinations and eccentricities through secular evolution (Lidov-Kozai oscillations). Such oscillations can lead to high inclinations and eccentricities, constraining the range where such satellites (and dust particles) can exist without crossing the orbits of the inner satellites or crossing the outer Hill stability range. Outer satellites, if such exist are therefore likely to be irregular satellites, with orbits limited to be non-circular and/or highly inclined. Current observations, including the recent data from the New-Horizons mission explored only inner regions (<0.0012 au) and excluded the existence of additional satellites; however, the irregular satellites discussed here should reside farther, in the yet uncharted regions around Pluto.

Flight Testing of a Low Cost De-Orbiting Device for Small Satellites

NASA Technical Reports Server (NTRS)

Turse, Dana; Keller, Phil; Taylor, Robert; Reavis, Mark; Tupper, Mike; Koehler, Chris

2014-01-01

Use of small and very small spacecraft is rapidly becoming more common. Methods to intentionally deorbit these spacecraft at the end of useful satellite life are required. A family of mass efficient Roll-Out De- Orbiting devices (RODEO"TM") was developed by Composite Technology Development, Inc. (CTD). RODEO"TM" consists of lightweight film attached to a simple, ultra-lightweight, roll-out composite boom structure. This system is rolled to stow within a lightweight launch canister, allowing easy integration to the small satellite bus. The device is released at the end of useful lifetime and the RODEO"TM" composite boom unrolls the drag sail in a matter of seconds. This dramatically increases the deployed surface area, resulting in the higher aerodynamic drag that significantly reduces the time until reentry. A RODEO"TM" flight demonstration was recently conducted as part of the Colorado Space Grant Consortium's (COSGC) RocketSat-8 program, a program to provide students hands-on experience in developing experiments for space flight. The experiment was ultimately a success and RODEO (trademark) is now ready for future CubeSat missions.

Intelligent systems for the autonomous exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Furfaro, Roberto; Lunine, Jonathan I.; Kargel, Jeffrey S.; Fink, Wolfgang

2008-04-01

Future planetary exploration of the outer satellites of the Solar System will require higher levels of onboard automation, including autonomous determination of sites where the probability of significant scientific findings is highest. Generally, the level of needed automation is heavily influenced by the distance between Earth and the robotic explorer(s) (e.g. spacecraft(s), rover(s), and balloon(s)). Therefore, planning missions to the outer satellites mandates the analysis, design and integration within the mission architecture of semi- and/or completely autonomous intelligence systems. Such systems should (1) include software packages that enable fully automated and comprehensive identification, characterization, and quantification of feature information within an operational region with subsequent target prioritization and selection for close-up reexamination; and (2) integrate existing information with acquired, "in transit" spatial and temporal sensor data to automatically perform intelligent planetary reconnaissance, which includes identification of sites with the highest potential to yield significant geological and astrobiological information. In this paper we review and compare some of the available Artificial Intelligence (AI) schemes and their adaptation to the problem of designing expert systems for onboard-based, autonomous science to be performed in the course of outer satellites exploration. More specifically, the fuzzy-logic framework proposed is analyzed in some details to show the effectiveness of such a scheme when applied to the problem of designing expert systems capable of identifying and further exploring regions on Titan and/or Enceladus that have the highest potential to yield evidence for past or present life. Based on available information (e.g., Cassini data), the current knowledge and understanding of Titan and Enceladus environments is evaluated to define a path for the design of a fuzzy-based system capable of reasoning over collected data and capable of providing the inference required to autonomously optimize future outer satellites explorations.

The Foundations of Radiation Belt Research

NASA Astrophysics Data System (ADS)

Ludwig, G. H.

2008-12-01

The United States undertook the launching of an artificial Earth satellite as part of its contribution to the International Geophysical Year. The Vanguard program was established to meet that commitment, and it developed a launch vehicle, ground station network, and suite of scientific payloads, including the cosmic ray experiment proposed by James A. Van Allen. Although Vanguard eventually exceeded all of its pre-stated goals, the preemptive launches of Sputniks I and II by the Soviets in October and November 1957 spurred the U.S. into a frenzy of activity, resulting in the launches of Explorers I and III in January and March of 1958. The data from those two satellites quickly revealed the lower boundary of an unexpected region of high intensity radiation trapped in the Earth's magnetic field. The original announcement in May 1958 stated that the radiation was probably composed of either protons or electrons, and that, if electrons, it was probably bremsstrahlung formed in the satellite shell. Immediately following that announcement, approval was received for what became Explorer IV, whose announced purpose was to follow up on the new discovery. Another reason for the satellite, unmentioned at the time, was its inclusion as a component of the highly classified Argos program, a covert military program to test whether the detonation of nuclear devices at high altitude would inject measurable numbers of charged particles into durable trajectories in the Earth's magnetic field. Our team at Iowa produced the satellites under the oversight of, and with assistance by, the Army Ballistic Missile Agency in Huntsville, and with the contributions of key hardware from several other government laboratories. The project was completed in the unbelievably short period of seventy-seven days from approval to launch. Launched into a higher-inclination orbit than the earlier Explorers, Explorer IV confirmed the discovery and greatly expanded our understanding of the natural phenomenon. It also provided the first hint that there were two distinct radiation belts, although that conclusion was not reached until later. Although that new information was quickly announced, the results of the high altitude nuclear detonations were kept secret until well into 1959. They clearly revealed the charged particle shells created by the Argos nuclear detonations. The next major step in mapping and understanding the high-intensity radiation involved the launch of deep space probes Pioneers III and IV in December 1958 and March 1959. Although both launches fell short in their primary objective, to reach the moon, they traveled far enough from the Earth to fully meet the needs of the scientific experiment. They very clearly showed the two-radiation belt structure, and mapped its extent. They also showed the probable effect of a magnetic storm on 25 February, thus indicating the direct influence of solar activity on the outer belt. By the end of 1959, the existence of the Van Allen Radiation Belts and their general structure were solidly established, early information about the composition of the radiation was appearing in print, and energetic work was under way to understand the physics of the processes involved.

Vehicle Motions as Inferred from Radio-signal- Strength Records

NASA Technical Reports Server (NTRS)

Pilkington, W. C.

1958-01-01

Considerable data on various parameters of a satellite and its launching vehicle can be obtained from the received-signal-strength records at the various satellite receiver stations. The doppler shifts of the satellite can be used to determine the orbital characteristics quite accurately. (Ref. 1 discusses the rapid determination of these parameters.) Information concerning the velocity increment and direction of each stage can be obtained if doppler data are received by several stations during the high-speed staging. The variations in signal strength during launch can be used to find the spin rate of the satellite before, during, and after staging, and to find variations in attitude, including precession, during launch. With spin and precession frequencies available, any changes in the ratios of moments of inertia can be determined. In this paper the launchings of the Explorer satellites will be used as a basis for the generalized conclusions concerning utilization of radio-signal-strength records. The discussion includes a description of the Explorer launching system.

Exploring Europa's Habitability: Science achieved from the Europa Orbiter and Clipper Mission Concepts

NASA Astrophysics Data System (ADS)

Senske, D. A.; Prockter, L. M.; Pappalardo, R. T.; Patterson, G. W.; Vance, S.

2012-12-01

Europa is a prime candidate in the search for present-day habitable environments in our solar system. Europa is unique among the large icy satellites because it probably has a saltwater ocean today beneath an ice shell that is geodynamically active. The combination of irradiation of its surface and tidal heating of its interior could make Europa a rich source of chemical energy for life. Perhaps most importantly, Europa's ocean is believed to be in direct contact with its rocky mantle, where conditions could be similar to those on Earth's biologically rich sea floor. Hydrothermal zones on Earth's seafloor are known to be rich with life, powered by energy and nutrients that result from reactions between the seawater and the warm rocky ocean floor. Life as we know it depends on three principal "ingredients": 1) a sustained liquid water environment; 2) essential chemical elements that are critical for building life; and 3) a source of energy that could be utilized by life. Europa's habitability requires understanding whether it possesses these three ingredients. NASA has enlisted a study team to consider Europa mission options feasible over the next decade, compatible with NASA's projected planetary science budget and addressing Planetary Decadal Survey priorities. Two Europa mission concepts (Orbiter and multiple flyby—call the "Clipper") are undergoing continued study with the goal to "Explore Europa to investigate its habitability." Each mission would address this goal in complementary ways, with high science value of its own. The Orbiter and Clipper architectures lend themselves to specific types of scientific measurements. The Orbiter concept is tailored to the unique geophysical science that requires being in orbit at Europa. This includes confirming the existence of an ocean and characterizing that ocean through geophysical measurements of Europa's gravitational tides and magnetic induction response. It also includes mapping of the global morphology and topography of the satellite to reveal its geological evolution. This architecture would provide for radiation-shielded instruments with low mass, power, and data rate, requiring limited spacecraft resources. The Clipper Mission concept concentrates on remote sensing science that can be accomplished through multiple close flybys of Europa. This includes exploring Europa's ice shell for evidence of liquid water within or beneath it, in order to understand the thickness of the ice shell and potential material pathways from the ocean to the surface and from the surface to the ocean. The mission concept also includes exploration of the surface and atmospheric composition of Europa, in order to address ocean composition and habitability. Detailed morphologic and topographic characterization of Europa's surface are included as well. This architecture would provide for radiation-shielded instruments with high mass, power, and data rate. NASA has directed the Europa team to refine, within a cost constrained budget, the ability of the Orbiter concept to characterize the ice shell and composition, and for the Clipper concept to address investigations to characterize the ocean. The status of these updated concepts will be reported.

Monthly AOD maps combining strengths of remote sensing products

NASA Astrophysics Data System (ADS)

Kinne, Stefan

2010-05-01

The mid-visible aerosol optical depth (AOD) is the most prominent property to quantify aerosol amount the atmospheric column. Almost all aerosol retrievals of satellite sensors provide estimates for this property, however, often with limited success. As sensors differ in capabilities individual retrievals have local and regional strengths and weaknesses. Focusing on individual retrieval strengths a satellite based AOD composite has been constructed. Hereby, every retrieval performance has been assessed in statistical comparisons to ground-based sun-photometry, which provide highly accurate references though only at few globally distributed monitoring sites. Based on these comparisons, which consider bias as well as spatial patterns and seasonality, the regionally best performing satellite AOD products are combined. The resulting remote sensing AOD composite provide a general reference for the spatial and temporal AOD distribution on an (almost) global basis - solely tied to sensor data.

Auroral photometry from the atmosphere Explorer satellite

NASA Technical Reports Server (NTRS)

Rees, M. H.; Abreu, V. J.

1984-01-01

Attention is given to the ability of remote sensing from space to yield quantitative auroral and ionospheric parametrers, in view of the auroral measurements made during two passes of the Explorer C satellite over the Poker Flat Optical Observatory and the Chatanika Radar Facility. The emission rate of the N2(+) 4278 A band computed from intensity measurements of energetic auroral electrons has tracked the same spetral feature that was measured remotely from the satellite over two decades of intensity, providing a stringent test for the measurement of atmospheric scattering effects. It also verifies the absolute intensity with respect to ground-based photometric measurements. In situ satellite measurments of ion densities and ground based electron density profile radar measurements provide a consistent picture of the ionospheric response to auroral input, while also predicting the observed optical emission rate.

GOCE and Future Gravity Missions for Geothermal Energy Exploitation

NASA Astrophysics Data System (ADS)

Pastorutti, Alberto; Braitenberg, Carla; Pivetta, Tommaso; Mariani, Patrizia

2016-08-01

Geothermal energy is a valuable renewable energy source the exploitation of which contributes to the worldwide reduction of consumption of fossil fuels oil and gas. The exploitation of geothermal energy is facilitated where the thermal gradient is higher than average leading to increased surface heat flow. Apart from the hydrologic circulation properties which depend on rock fractures and are important due to the heat transportation from the hotter layers to the surface, essential properties that increase the thermal gradient are crustal thinning and radiogenic heat producing rocks. Crustal thickness and rock composition form the link to the exploration with the satellite derived gravity field, because both induce subsurface mass changes that generate observable gravity anomalies. The recognition of gravity as a useful investigation tool for geothermal energy lead to a cooperation with ESA and the International Renewable Energy Agency (IRENA) that included the GOCE derived gravity field in the online geothermal energy investigation tool of the IRENA database. The relation between the gravity field products as the free air gravity anomaly, the Bouguer and isostatic anomalies and the heat flow values is though not straightforward and has not a unique relationship. It is complicated by the fact that it depends on the geodynamical context, on the geologic context and the age of the crustal rocks. Globally the geological context and geodynamical history of an area is known close to everywhere, so that a specific known relationship between gravity and geothermal potential can be applied. In this study we show the results of a systematic analysis of the problem, including some simulations of the key factors. The study relies on the data of GOCE and the resolution and accuracy of this satellite. We also give conclusions on the improved exploration power of a gravity mission with higher spatial resolution and reduced data error, as could be achieved in principle by flying an atom interferometer sensor on board a satellite.

National Space Science Data Center (NSSDC) Data Listing

NASA Technical Reports Server (NTRS)

1980-01-01

Satellite and nonsatellite data available from the National Space Science Data Center are listed. The Satellite Data listing includes the spacecraft name, launch date, and an alphabetical list of experiments. The Non-Satellite Data listing contains ground based data, models, computer routines, and composite spacecraft data. The data set name, data form code, quantity of data, and the time space covered are included in the data sets of both listings where appropriate. Geodetic tracking data sets are also included.

Chemical Composition and Dynamics of the Upper Troposphere and the Lower Stratosphere: Overview of the Project

NASA Astrophysics Data System (ADS)

Sofieva, V. F.; Liu, C.; Huang, F.; Kyrola, E.; Liu, Y.; Ialongo, I.; Hakkarainen, J.; Zhang, Y.

2016-08-01

The DRAGON-3 cooperation study on the upper troposphere and the lower stratosphere (UTLS) is based on new satellite data and modern atmospheric models. The objectives of the project are: (i) assessment of satellite data on chemical composition in UTLS, (ii) dynamical and chemical structures of the UTLS and its variability, (iii) multi-scale variability of stratospheric ozone, (iv) climatology of the stratospheric aerosol layer and its variability, and (v) updated ozone climatology and its relation to tropopause/multiple tropopauses.In this paper, we present the main results of the project.

The rheology and composition of cryovolcanic flows on icy satellites

NASA Technical Reports Server (NTRS)

Kargel, Jeffrey S.

1993-01-01

The rheologic properties of terrestrial lavas have been related to morphologic features of their flows, such as levees, banked surfaces, multilobate structures, and compressible folds. These features also have been used to determine rheologies and constrain the compositions of extraterrestrial flows. However, with rare exceptions, such features are not resolvable in Voyager images of the satellites of outer planets. Often only flow length and edge thickness of cryovolcanic flows can be measured reasonably accurately from Voyager images. The semiempirical lava-flow model presented here is a renewed effort to extract useful information from such measurements.

Thermal insulation of a cryogenic tank for a space telescope using a pretensioned suspension of Fiber Reinforced Composite (FRC)

NASA Astrophysics Data System (ADS)

Bongers, Bernd; Haider, Otmar; Tauber, Wolfgang

1990-09-01

For the thermal insulation of cryogenic tanks in satellite applications Fiber Reinforced Composite (FRC) materials are preferable because of their low thermal conductivity and high tensile strength compared to metallic materials. At the Infrared Space Observatory (ISO) satellite the main Liquid Helium (LHe) tank is suspended by one spatial framework and eight pretensioned chain strands at each side. Frameworks and chain strands are acting as a thermal barrier and therefore made of FRC. To meet the various and, in parts contractive requirements, sophisticated design approaches are chosen for the structural parts.

Outer planets satellites

NASA Technical Reports Server (NTRS)

Morrison, D.

1983-01-01

The present investigation takes into account the published literature on outer planet satellites for 1979-1982. It is pointed out that all but three (the moon and the two Martian satellites) of the known planetary satellites are found in the outer solar system. Most of these are associated with the three regular satellite systems of Jupiter, Saturn, and Uranus. The largest satellites are Titan in the Saturn system and Ganymede and Callisto in the Jupiter system. Intermediate in size between Mercury and Mars, each has a diameter of about 5000 km. Presumably each has an internal composition about 60 percent rock and 40 ice, and each is differentiated with a dense core extending out about 75 percent of the distance to the surface, with a mantle of high-pressure ice and a crust of ordinary ice perhaps 100 km thick. Attention is also given to Io, Europa, the icy satellites of Saturn, the satellites of Uranus, the small satellites of Jupiter and Saturn, Triton and the Pluto system, and plans for future studies.

VSAT: opening new horizons to oil and gas explorations

NASA Astrophysics Data System (ADS)

Al-Dhamen, Muhammad I.

2002-08-01

Whether exploring in the Empty Quarter, drilling offshore in the Gulf of Mexico, or monitoring gas pipelines or oil wells in the deserts, communications is a key element to the success of oil and gas operations. Secure, efficient communications is required between remote, isolated locations and head offices to report on work status, dispatch supplies and repairs, report on-site emergencies, transfer geophysical surveys and real-time drilling data. Drilling and exploration firms have traditionally used land-based terrestrial networks that rely on radio transmissions for voice and data communications to offshore platforms and remote deep desert drilling rigs. But these systems are inefficient and have proven inflexible with today's drilling and exploration communications demands, which include high-speed data access, telephone and video conferencing. In response, numerous oil and gas exploration entities working in deep waters and remote deep deserts have all tapped into what is an ideal solution for these needs: Very Small Aperture Terminal Systems (VSAT) for broadband access services. This led to the use of Satellite Communication Systems for a wide range of applications that were difficult to achieve in the past, such as real-time applications transmission of drilling data and seismic information. This paper provides a thorough analysis of opportunities for satellite technology solutions in support of oil and gas operations. Technologies, architecture, service, networking and application developments are discussed based upon real field experience. More specifically, the report addresses: VSAT Opportunities for the Oil and Gas Operations, Corporate Satellite Business Model Findings, Satellite Market Forecasts

Extreme Ultraviolet Explorer Science Operation Center

NASA Technical Reports Server (NTRS)

Wong, G. S.; Kronberg, F. A.; Meriwether, H. D.; Wong, L. S.; Grassi, C. L.

1993-01-01

The EUVE Science Operations Center (ESOC) is a satellite payload operations center for the Extreme Ultraviolet Explorer project, located on the Berkeley campus of the University of California. The ESOC has the primary responsibility for commanding the EUVE telescopes and monitoring their telemetry. The ESOC is one of a very few university-based satellite operations facilities operating with NASA. This article describes the history, operation, and advantages of the ESOC as an on-campus operations center.

Sun, Earth and man: The need to know. The quest for knowledge of Sun-Earth relations

NASA Technical Reports Server (NTRS)

Stafford, E. P.

1982-01-01

Solar physics and the effects of emanations from the Sun on communications and Earth's weather and climate are discussed. Scientific interest in the solar system from the old Stone Age to the present is reviewed with particular emphasis on the objectives sought and information obtained by Explorer satellites, Pioneer satellites, Skylab, Helios, ISEE, the solar maximum mission, and the Dynamics Explorer. The goals of missions planned for the 1980's are discussed including those using space shuttle, Spacelab, the Solar Mesosphere Explorer, the solar optical telescope, the upper atmosphere research satellite, and the solar probe. The objectives of the international solar polar mission and of the Origin of Plasma in Earth's Neighborhood mission are also delineated. Other missions being considered are reviewed and the prospect of taming the fusion process to provide clean, harmless electrical energy like that obtained from the Sun is entertained.

What do the data show? Fostering physical intuition with ClimateBits and NASA Earth Observations

NASA Astrophysics Data System (ADS)

Schollaert Uz, S.; Ward, K.

2017-12-01

Through data visualizations using global satellite imagery available in NASA Earth Observations (NEO), we explain Earth science concepts (e.g. albedo, urban heat island effect, phytoplankton). We also provide examples of ways to explore the satellite data in NEO within a new blog series. This is an ideal tool for scientists and non-scientists alike who want to quickly check satellite imagery for large scale features or patterns. NEO analysis requires no software or plug-ins; only a browser and an internet connection. You can even check imagery and perform simple analyses from your smart phone. NEO can be used to create graphics for presentations and papers or as a first step before acquiring data for more rigorous analysis. NEO has potential application to easily explore large scale environmental and climate patterns that impact operations and infrastructure. This is something we are currently exploring with end user groups.

Effects of space weather on GOCE electrostatic gravity gradiometer measurements

NASA Astrophysics Data System (ADS)

Ince, E. Sinem; Pagiatakis, Spiros D.

2016-12-01

We examine the presence of residual nongravitational signatures in gravitational gradients measured by GOCE electrostatic gravity gradiometer. These signatures are observed over the magnetic poles during geomagnetically active days and can contaminate the trace of the gravitational gradient tensor by up to three to five times the expected noise level of the instrument (˜ 11 mE). We investigate these anomalies in the gradiometer measurements along many satellite tracks and examine possible causes using external datasets, such as interplanetary electric field measurements from the ACE (advanced composition explorer) and WIND spacecraft, and Poynting vector (flux) estimated from equivalent ionospheric currents derived from spherical elementary current systems over North America and Greenland. We show that the variations in the east-west and vertical electrical currents and Poynting vector components at the satellite position are highly correlated with the disturbances observed in the gradiometer measurements. The results presented in this paper reveal that the disturbances are due to intense ionospheric current variations that are enhanced by increased solar activity that causes a very dynamic drag environment. Moreover, successful modelling and removal of a high percentage of these disturbances are possible using external geomagnetic field observations.

A Reflight of the Explorer-1 Science Mission: The Montana EaRth Orbiting Pico Explorer (MEROPE)

NASA Astrophysics Data System (ADS)

Klumpar, D. M.; Obland, M.; Hunyadi, G.; Jepsen, S.; Larsen, B.; Kankelborg, C.; Hiscock, W.

2001-05-01

Montana State University's interdisciplinary Space Science and Engineering Laboratory (SSEL) under support from the Montana NASA Space Grant Consortium is engaged in an earth orbiting satellite student design and flight project. The Montana EaRth Orbiting Pico Explorer (MEROPE) will carry a modern-day reproduction of the scientific payload carried on Explorer-1. On February 1, 1958 the United States launched its first earth orbiting satellite carrying a 14 kg scientific experiment built by Professor James Van Allen's group at the State University of Iowa (now The University of Iowa). The MEROPE student satellite will carry a reproduction, using current-day technology, of the scientific payload flown on Explorer-1. The CubeSat-class satellite will use currently available, low cost technologies to produce a payload-carrying satellite with a total orbital mass of 1 kg in a volume of 1 cubic liter. The satellite is to be launched in late 2001 into a 600 km, 65° inclination orbit. MEROPE will utilize passive magnetic orientation for 2-axis attitude control. A central microprocessor provides timing, controls on-board operations and switching, and enables data storage. Body mounted GaAs solar arrays are expected to provide in excess of 1.5 W. to maintain battery charge and operate the bus and payload. The Geiger counter will be operated at approximately 50% duty cycle, primarily during transits of the earth's radiation belts. Data will be stored on board and transmitted approximately twice per day to a ground station located on the Bozeman campus of the Montana State University. Owing to the 65° inclination, the instrument will also detect the higher energy portion of the electron spectrum responsible for the production of the Aurora Borealis. This paper describes both the technical implementation and design of the satellite and its payload as well as the not inconsiderable task of large team organization and management. As of March 2001, the student team consists of four graduate students and approximately 45 undergraduates in fields including Physics, Engineering, Computer Sciences, Business, and Liberal Arts. Satellites of this class have the potential to lead to low-cost constellations of sciencecraft making coordinated measurements of the highly dynamic and spatially structured space environment. While key tradeoffs between resource needs and resource availability (e.g. power, telemetry, mass, volume, and cost) constrain payload sophistication, the tremendous advantages of having even simple dispersed multipoint measurements of the Geospace environment far outweigh the loss of payload sophistication in many instances.

Low-CCN concentration air masses over the eastern North Atlantic: Seasonality, meteorology, and drivers

NASA Astrophysics Data System (ADS)

Wood, Robert; Stemmler, Jayson D.; Rémillard, Jasmine; Jefferson, Anne

2017-01-01

A 20 month cloud condensation nucleus concentration (NCCN) data set from Graciosa Island (39°N, 28°W) in the remote North Atlantic is used to characterize air masses with low cloud condensation nuclei (CCN) concentrations. Low-CCN events are defined as 6 h periods with mean NCCN<20 cm-3 (0.1% supersaturation). A total of 47 low-CCN events are identified. Surface, satellite, and reanalysis data are used to explore the meteorological and cloud context for low-CCN air masses. Low-CCN events occur in all seasons, but their frequency was 3 times higher in December-May than during June-November. Composites show that many of the low-CCN events had a common meteorological basis that involves southerly low-level flow and rather low wind speeds at Graciosa. Anomalously low pressure is situated to the west of Graciosa during these events, but back trajectories and lagged SLP composites indicate that low-CCN air masses often originate as cold air outbreaks to the north and west of Graciosa. Low-CCN events were associated with low cloud droplet concentrations (Nd) at Graciosa, but liquid water path (LWP) during low-CCN events was not systematically different from that at other times. Satellite Nd and LWP estimates from MODIS collocated with Lagrangian back trajectories show systematically lower Nd and higher LWP several days prior to arrival at Graciosa, consistent with the hypothesis that observed low-CCN air masses are often formed by coalescence scavenging in thick warm clouds, often in cold air outbreaks.

Three small deployed satellites

NASA Image and Video Library

2012-10-04

ISS033-E-009282 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment. Earth’s horizon and the blackness of space provide the backdrop for the scene.

JEMRMS Small Satellite Deployment Observation

NASA Image and Video Library

2012-10-04

ISS033-E-009315 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment. A blue and white part of Earth provides the backdrop for the scene.

DESTINY+ Trajectory Design to (3200) Phaethon

NASA Astrophysics Data System (ADS)

Sarli, Bruno Victorino; Horikawa, Makoto; Yam, Chit Hong; Kawakatsu, Yasuhiro; Yamamoto, Takayuki

2018-03-01

This work explores the target selection and trajectory design of the mission candidate for ISAS/JAXA's small science satellite series, DESTINY PLUS or DESTINY+. This mission combines unique aspects of the latest satellite technology and exploration of transition bodies to fill a technical and scientific gap in the Japanese space science program. The spacecraft is targeted to study the comet-asteroid transition body (3200) Phaethon through a combination of low-thrust propulsion and Earth Gravity Assist. The trajectory design concept is presented in details together with the launch window and flyby date analysis. Alternative targets for a possible mission extension scenario are also explored.

Temperature Dependence of Cryogenic Ammonia-Water Ice Mixtures and Implications for Icy Satellite Surfaces

NASA Technical Reports Server (NTRS)

Dalton, J. B., III; Curchin, J. M.; Clark, R. N.

2001-01-01

Infrared spectra of ammonia-water ice mixtures reveal temperature-dependent absorption bands due to ammonia. These features, at 1.04, 2.0, and 2.25 microns, may shed light on the surface compositions of the Galilean and Saturnian satellites. Additional information is contained in the original extended abstract.

Cloud-Free Satellite Image Mosaics with Regression Trees and Histogram Matching.

Treesearch

E.H. Helmer; B. Ruefenacht

2005-01-01

Cloud-free optical satellite imagery simplifies remote sensing, but land-cover phenology limits existing solutions to persistent cloudiness to compositing temporally resolute, spatially coarser imagery. Here, a new strategy for developing cloud-free imagery at finer resolution permits simple automatic change detection. The strategy uses regression trees to predict...

KSC-99pp0657

NASA Image and Video Library

1999-06-07

Workers oversee the mating of the second stage with the first stage of a Boeing Delta II rocket, which will launch the NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is NASA's Far Ultraviolet Spectroscopic Explorer satellite developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to launch June 23 at Launch Pad 17A, Cape Canaveral Air Station

On the Existence of Regular and Irregular Outer Moons Orbiting the Pluto–Charon System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michaely, Erez; Perets, Hagai B.; Grishin, Evgeni

The dwarf planet Pluto is known to host an extended system of five co-planar satellites. Previous studies have explored the formation and evolution of the system in isolation, neglecting perturbative effects by the Sun. Here we show that secular evolution due to the Sun can strongly affect the evolution of outer satellites and rings in the system, if such exist. Although precession due to extended gravitational potential from the inner Pluto–Charon binary quench such secular evolution up to a {sub crit} ∼ 0.0035 au (∼0.09 R {sub Hill} the Hill radius; including all of the currently known satellites), outer orbitsmore » can be significantly altered. In particular, we find that co-planar rings and satellites should not exist beyond a {sub crit}; rather, satellites and dust particles in these regions secularly evolve on timescales ranging between 10{sup 4} and 10{sup 6} years, and quasi-periodically change their inclinations and eccentricities through secular evolution (Lidov–Kozai oscillations). Such oscillations can lead to high inclinations and eccentricities, constraining the range where such satellites (and dust particles) can exist without crossing the orbits of the inner satellites or crossing the outer Hill stability range. Outer satellites, if such exist are therefore likely to be irregular satellites, with orbits limited to be non-circular and/or highly inclined. Current observations, including the recent data from the New-Horizons mission explored only inner regions (<0.0012 au) and excluded the existence of additional satellites; however, the irregular satellites discussed here should reside farther, in the yet uncharted regions around Pluto.« less

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

Kelvin Manning, associate director of NASA's Kennedy Space Center, talks with Brian Holz, CEO of OneWeb Satellites, following the groundbreaking ceremony at Kennedy's Exploration Park for OneWeb. The company, in partnership with Airbus, is building a 150,000-square-foot factory to manufacture satellites that will connect all areas of the world to the Internet wirelessly. Photo credit: NASA/Kim Shiflett

Monthly analysis of PM ratio characteristics and its relation to AOD.

PubMed

Sorek-Hamer, Meytar; Broday, David M; Chatfield, Robert; Esswein, Robert; Stafoggia, Massimo; Lepeule, Johanna; Lyapustin, Alexei; Kloog, Itai

2017-01-01

Airborne particulate matter (PM) is derived from diverse sources-natural and anthropogenic. Climate change processes and remote sensing measurements are affected by the PM properties, which are often lumped into homogeneous size fractions that show spatiotemporal variation. Since different sources are attributed to different geographic locations and show specific spatial and temporal PM patterns, we explored the spatiotemporal characteristics of the PM 2.5 /PM 10 ratio in different areas. Furthermore, we examined the statistical relationships between AERONET aerosol optical depth (AOD) products, satellite-based AOD, and the PM ratio, as well as the specific PM size fractions. PM data from the northeastern United States, from San Joaquin Valley, CA, and from Italy, Israel, and France were analyzed, as well as the spatial and temporal co-measured AOD products obtained from the MultiAngle Implementation of Atmospheric Correction (MAIAC) algorithm. Our results suggest that when both the AERONET AOD and the AERONET fine-mode AOD are available, the AERONET AOD ratio can be a fair proxy for the ground PM ratio. Therefore, we recommend incorporating the fine-mode AERONET AOD in the calibration of MAIAC. Along with a relatively large variation in the observed PM ratio (especially in the northeastern United States), this shows the need to revisit MAIAC assumptions on aerosol microphysical properties, and perhaps their seasonal variability, which are used to generate the look-up tables and conduct aerosol retrievals. Our results call for further scrutiny of satellite-borne AOD, in particular its errors, limitations, and relation to the vertical aerosol profile and the particle size, shape, and composition distribution. This work is one step of the required analyses to gain better understanding of what the satellite-based AOD represents. The analysis results recommend incorporating the fine-mode AERONET AOD in MAIAC calibration. Specifically, they indicate the need to revisit MAIAC regional aerosol microphysical model assumptions used to generate look-up tables (LUTs) and conduct retrievals. Furthermore, relatively large variations in measured PM ratio shows that adding seasonality in aerosol microphysics used in LUTs, which is currently static, could also help improve accuracy of MAIAC retrievals. These results call for further scrutiny of satellite-borne AOD for better understanding of its limitations and relation to the vertical aerosol profile and particle size, shape, and composition.

Optical Multiple Access Network (OMAN) for advanced processing satellite applications

NASA Technical Reports Server (NTRS)

Mendez, Antonio J.; Gagliardi, Robert M.; Park, Eugene; Ivancic, William D.; Sherman, Bradley D.

1991-01-01

An OMAN breadboard for exploring advanced processing satellite circuit switch applications is introduced. Network architecture, hardware trade offs, and multiple user interference issues are presented. The breadboard test set up and experimental results are discussed.

Obtaining Reliable Predictions of Terrestrial Energy Coupling From Real-Time Solar Wind Measurements

NASA Technical Reports Server (NTRS)

Weimer, Daniel R.

2002-01-01

Measurements of the interplanetary magnetic field (IMF) from the ACE (Advanced Composition Explorer), Wind, IMP-8 (Interplanetary Monitoring Platform), and Geotail spacecraft have revealed that the IMF variations are contained in phase planes that are tilted with respect to the propagation direction, resulting in continuously variable changes in propagation times between spacecraft, and therefore, to the Earth. Techniques for using 'minimum variance analysis' have been developed in order to be able to measure the phase front tilt angles, and better predict the actual propagation times from the L1 orbit to the Earth, using only the real-time IMF measurements from one spacecraft. The use of empirical models with the IMF measurements at L1 from ACE (or future satellites) for predicting 'space weather' effects has also been demonstrated.

Ultraviolet reflectance properties of asteroids

NASA Astrophysics Data System (ADS)

Butterworth, P. S.; Meadows, A. J.

1985-05-01

An analysis of the UV spectra of 28 asteroids obtained with the Internal Ultraviolet Explorer (IUE) satellite is presented. The spectra lie within the range 2100-3200 A. The results are examined in terms of both asteroid classification and of current ideas concerning the surface mineralogy of asteroids. For all the asteroids examined, UV reflectivity declines approximately linearly toward shorter wavelengths. In general, the same taxonomic groups are seen in the UV as in the visible and IR, although there is some evidence for asteroids with anomalous UV properties and for UV subclasses within the S class. No mineral absorption features are reported of strength similar to the strongest features in the visible and IR regions, but a number of shallow absorptions do occur and may provide valuable information on the surface composition of many asteroids.

The Formation of Life-sustaining Planets in Extrasolar Systems

NASA Technical Reports Server (NTRS)

Chambers, J. E.

2003-01-01

The spatial exploration is providing us a large quantity of information about the composition of the planets and satellites crusts. However, most of the experiences that are proposed in the guides of activities in Planetary Geology are based exclusively on the images utilization: photographs, maps, models or artistic reconstructions [1,2]. That things help us to recognize shapes and to deduce geological processes, but they says us little about the materials that they are implicated. In order to avoid this dicotomy between shapes and materials, we have designed an experience in the one which, employing of rocks and landscapes of our geological environment more next, the pupils be able to do an exercise of compared planetology analyzing shapes, processes and material of several planetary bodies of the Solar System.

On-board attitude determination for the Explorer Platform satellite

NASA Technical Reports Server (NTRS)

Jayaraman, C.; Class, B.

1992-01-01

This paper describes the attitude determination algorithm for the Explorer Platform satellite. The algorithm, which is baselined on the Landsat code, is a six-element linear quadratic state estimation processor, in the form of a Kalman filter augmented by an adaptive filter process. Improvements to the original Landsat algorithm were required to meet mission pointing requirements. These consisted of a more efficient sensor processing algorithm and the addition of an adaptive filter which acts as a check on the Kalman filter during satellite slew maneuvers. A 1750A processor will be flown on board the satellite for the first time as a coprocessor (COP) in addition to the NASA Standard Spacecraft Computer. The attitude determination algorithm, which will be resident in the COP's memory, will make full use of its improved processing capabilities to meet mission requirements. Additional benefits were gained by writing the attitude determination code in Ada.

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results

NASA Astrophysics Data System (ADS)

Jacob, D. J.; Crawford, J. H.; Maring, H.; Clarke, A. D.; Dibb, J. E.; Emmons, L. K.; Ferrare, R. A.; Hostetler, C. A.; Russell, P. B.; Singh, H. B.; Thompson, A. M.; Shaw, G. E.; McCauley, E.; Pederson, J. R.; Fisher, J. A.

2010-06-01

The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was conducted in two 3-week deployments based in Alaska (April 2008) and western Canada (June-July 2008). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1) influx of mid-latitude pollution, (2) boreal forest fires, (3) aerosol radiative forcing, and (4) chemical processes. The June-July deployment was preceded by one week of flights over California (ARCTAS-CARB) focused on (1) improving state emission inventories for greenhouse gases and aerosols, (2) providing observations to test and improve models of ozone and aerosol pollution. ARCTAS involved three aircraft: a DC-8 with a detailed chemical payload, a P-3 with an extensive aerosol and radiometric payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft data augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train. The spring phase (ARCTAS-A) revealed pervasive Asian pollution throughout the Arctic as well as significant European pollution below 2 km. Unusually large Siberian fires in April 2008 caused high concentrations of carbonaceous aerosols and also affected ozone. Satellite observations of BrO column hotspots were found not to be related to Arctic boundary layer events but instead to tropopause depressions, suggesting the presence of elevated inorganic bromine (5-10 pptv) in the lower stratosphere. Fresh fire plumes from Canada and California sampled during the summer phase (ARCTAS-B) indicated low NOx emission factors from the fires, rapid conversion of NOx to PAN, no significant secondary aerosol production, and no significant ozone enhancements except when mixed with urban pollution.

Multi-Wavelength investigation of the co-orbital moons Dione and Helene

NASA Astrophysics Data System (ADS)

Royer, Emilie M.; Hendrix, Amanda R.; Howett, Carly; Spilker, Linda

2017-10-01

The icy satellites Dione and Helene share the same orbit, at 6.26 Saturn radii from the giant planet, which is within Saturn’s diffuse E ring. Helene is one of Dione’s two Trojan moons, located in the leading Lagrangian point L4 of Dione’s orbit. We present here preliminary results on the investigation of the Dione-Helene duo in term of origin, formation and evolution. Specifically, the key objectives are to retrieve the photometric properties and composition of the moons to answer questions such as: Are the Dione and Helene surfaces made of the same material? Did they form in the same region of the Solar System? Is one satellite older than the other? Have they experienced the same amount of space weathering?To provide the most complete evaluation of the Dione and Helene surfaces and advance our understanding of how exogenic processes affect the surfaces of icy satellites we use the synergy of four of the Cassini instruments: UVIS (Ultraviolet Imaging Spectrograph), ISS (Imaging Science Subsystem), VIMS (Visual and Infrared Mapping Spectrometer) and CIRS (Composite Infrared Spectrometer). Composite disk-integrated spectra of both moons have been produced to conduct spectral modeling over a large wavelength range from the ultraviolet to the infrared, from 111nm to 1mm. Until now, most investigations have focused only on one wavelength domain, telling only part of the story. A multi-wavelength analysis allows an in-depth investigation of the surfaces of the Saturnian satellites as each wavelength probes a different layer of the surface. Special attention is directed toward the search for correlations of basic properties (albedo, scattering properties, texture, grain size, composition, porosity, thermal properties) between Dione and Helene.

Integrated Satellite Control in REIMEI (INDEX) Satellite

NASA Astrophysics Data System (ADS)

Fukuda, Seisuke; Mizuno, Takahide; Sakai, Shin-Ichiro; Fukushima, Yousuke; Saito, Hirobumi

REIMEI/INDEX (INnovative-technology Demonstration EXperiment) is a 70kg class small satellite which the Institute of Space and Astronautical Science, Japan Exploration Agency, ISAS/JAXA, has developed for observation of auroral small-scale dynamics as well as demonstration of advanced satellite technologies. An important engineering mission of REIMEI is integrated satellite control using commercial RISC CPUs with a triple voting system in order to ensure fault-tolerance against radiation hazards. Software modules concerning every satellite function, such as attitude control, data handling, and mission applications, work cooperatively so that highly sophisticated satellite control can be performed. In this paper, after a concept of the integrated satellite control is introduced, the Integrated Controller Unit (ICU) is described in detail. Also unique topics in developing the integrated control system are shown.

Satellite-derived mineral mapping and monitoring of weathering, deposition and erosion

PubMed Central

Cudahy, Thomas; Caccetta, Mike; Thomas, Matilda; Hewson, Robert; Abrams, Michael; Kato, Masatane; Kashimura, Osamu; Ninomiya, Yoshiki; Yamaguchi, Yasushi; Collings, Simon; Laukamp, Carsten; Ong, Cindy; Lau, Ian; Rodger, Andrew; Chia, Joanne; Warren, Peter; Woodcock, Robert; Fraser, Ryan; Rankine, Terry; Vote, Josh; de Caritat, Patrice; English, Pauline; Meyer, Dave; Doescher, Chris; Fu, Bihong; Shi, Pilong; Mitchell, Ross

2016-01-01

The Earth’s surface comprises minerals diagnostic of weathering, deposition and erosion. The first continental-scale mineral maps generated from an imaging satellite with spectral bands designed to measure clays, quartz and other minerals were released in 2012 for Australia. Here we show how these satellite mineral maps improve our understanding of weathering, erosional and depositional processes in the context of changing weather, climate and tectonics. The clay composition map shows how kaolinite has developed over tectonically stable continental crust in response to deep weathering during northwardly migrating tropical conditions from 45 to 10 Ma. The same clay composition map, in combination with one sensitive to water content, enables the discrimination of illite from montmorillonite clays that typically develop in large depositional environments over thin (sinking) continental crust such as the Lake Eyre Basin. Cutting across these clay patterns are sandy deserts that developed <10 Ma and are well mapped using another satellite product sensitive to the particle size of silicate minerals. This product can also be used to measure temporal gains/losses of surface clay caused by periodic wind erosion (dust) and rainfall inundation (flood) events. The accuracy and information content of these satellite mineral maps are validated using published data. PMID:27025192

The Fixed-bias Langmuir Probe on the Communication-navigation Outage Forecast System Satellite: Calibration and Validation

NASA Technical Reports Server (NTRS)

Klenzing, Jeffrey H.; Rowland, Douglas E.

2012-01-01

A fixed-bias spherical Langmuir probe is included as part of the Vector Electric Field Instrument (VEFI) suite on the Communication Navigation Outage Forecast System (CNOFS) satellite.CNOFS gathers data in the equatorial ionosphere between 400 and 860 km, where the primary constituent ions are H+ and O+. The ion current collected by the probe surface per unit plasmadensity is found to be a strong function of ion composition. The calibration of the collected current to an absolute density is discussed, and the performance of the spherical probe is compared to other in situ instruments on board the CNOFS satellite. The application of the calibration is discussed with respect to future xed-bias probes; in particular, it is demonstrated that some density fluctuations will be suppressed in the collected current if the plasma composition rapidly changes along with density. This is illustrated in the observation of plasma density enhancements on CNOFS.

The dust cloud of the century

NASA Astrophysics Data System (ADS)

Robock, A.

1983-02-01

The structure and composition of the dust cloud from the 4 April 1982 eruption of the El Chichon volcano in Chiapas state, Mexico, is examined and the possible effects of the dust cloud on the world's weather patterns are discussed. Observations of the cloud using a variety of methods are evaluated, including data from the GOES and NOAA-7 weather satellites, vertically pointing lidar measurements, the SME satellite, and the Nimbus-7 satellite. Studies of the gaseous and particulate composition of the cloud reveal the presence of large amounts of sulfuric acid particles, which have a long mean residence time in the atmosphere and have a large effect on the amount of solar radiation received at the earth's surface by scattering several percent of the radiation back to space. Estimates of the effect of this cloud on surface air temperature changes are presented based on findings from climate models.

Biogeochemical and Optical Analysis of Coastal DOM for Satellite Retrieval of Terrigenous DOM in the U.S. Middle Atlantic Bight

NASA Technical Reports Server (NTRS)

Mannino, A.; Dyda, R. Y.; Hernes, P. J.; Hooker, Stan; Hyde, Kim; Novak, Mike

2012-01-01

Estuaries and coastal ocean waters experience a high degree of variability in the composition and concentration of particulate and dissolved organic matter (DOM) as a consequence of riverine/estuarine fluxes of terrigenous DOM, sediments, detritus and nutrients into coastal waters and associated phytoplankton blooms. Our approach integrates biogeochemical measurements (elemental content, molecular analyses), optical properties (absorption) and remote sensing to examine terrestrial DOM contributions into the U.S. Middle Atlantic Bight (MAB). We measured lignin phenol composition, DOC and CDOM absorption within the Chesapeake and Delaware Bay mouths, plumes and adjacent coastal ocean waters to derive empirical relationships between CDOM and biogeochemical measurements for satellite remote sensing application. Lignin ranged from 0.03 to 6.6 ug/L between estuarine and outer shelf waters. Our results demonstrate that satellite-derived CDOM is useful as a tracer of terrigenous DOM in the coastal ocean

Satellite Observations of the Effect of Natural and Anthropogenic Aerosols on Clouds

NASA Technical Reports Server (NTRS)

Kaufman, Yoram J.

2006-01-01

Our knowledge of atmospheric aerosols (smoke, pollution, dust or sea salt particles, small enough to be suspended in the air), their evolution, composition, variability in space and time and interaction with clouds and precipitation is still lacking despite decades of research. Understanding the global aerosol system is critical to quantifying anthropogenic climate change, to determine climate sensitivity from observations and to understand the hydrological cycle. While a single instrument was used to demonstrate 50 years ago that the global CO2 levels are rising, posing threat of global warming, we need an array of satellites and field measurements coupled with chemical transport models to understand the global aerosol system. This complexity of the aerosol problem results from their short lifetime (1 week) and variable chemical composition. A new generation of satellites provides exciting opportunities to measure the global distribution of aerosols, distinguishing natural from anthropogenic aerosol and measuring their interaction with clouds and climate.

The first Earth Resources Technology Satellite - Nearly two years of operation

NASA Technical Reports Server (NTRS)

Nordberg, W.

1974-01-01

A brief status report is given of the ERTS-1 satellite system as of June, 1974, and some applications of the ERTS-1 images are discussed. The multispectral images make it possible to identify or measure the quality and composition of water, the potential water content of snow, the moisture and possible composition of soils, the types and state of vegetation cover, and factors relating to stresses on the environment. The orthographic view of the earth provided by the satellite makes it possible to rapidly produce thematic maps, on a scale of 1:250,000, of most areas of the world. The regular, repetitive coverage provided by ERTS-1 every 18 days is important in areas such as water-supply and flood-damage studies. The use of ERTS-1 imagery for land-use planning, wetlands surveying, assessing marine resources, and observing processes such as desertification in the African Sahel is discussed.

A discussion on mobile satellite system and the myths of CDMA and diversity revealed

NASA Technical Reports Server (NTRS)

Hart, Nicholas; Goerke, Thomas; Jahn, Axel

1995-01-01

The paper explores the myths and facts surrounding: link margins and constellation designs; the use of satellite diversity in a mobile satellite channel; trade-offs in multiple access technique. Different satellite constellations are presented, which are comparable with those used by the big LEO proponents, with the associated trade-offs in the system design. Propagation data and results from various narrowband and wideband measurement campaigns are used to illustrate the expected differences in service performance.

PhoneSat - The Smartphone Nanosatellite

NASA Technical Reports Server (NTRS)

Cockrell, James J.; Yost, Bruce; Petro, Andrew

2013-01-01

NASAs PhoneSat project will test whether spacecraft can be built using smartphones to launch the lowest-cost satellites ever flown in space. Each PhoneSat nanosatellite is one cubesat unit - a satellite in a 10 cm (approx. 4 inches) cube or about the size of a tissue box - and weighs approximately three pounds. Engineers believe PhoneSat technology will enable NASA to launch multiple new satellites capable of conducting science and exploration missions at a small fraction of the cost of conventional satellites.

PhoneSat - The Smartphone Nanosatellite

NASA Technical Reports Server (NTRS)

Cockrell, James J.; Yost, Bruce; Petro, Andrew

2013-01-01

NASA's PhoneSat project tests whether spacecraft can be built using smartphones to launch the lowest-cost satellites ever flown in space. Each PhoneSat nanosatellite is one cubesat unit - a satellite in a 10 cm (approx. 4 inches) cube or about the size of a tissue box - and weighs approximately 1 kg (2.2 pounds). Engineers believe PhoneSat technology will enable NASA to launch multiple new satellites capable of conducting science and exploration missions at a small fraction of the cost of conventional satellites.

Carbon Observations from Geostationary Earth Orbit as Part of an Integrated Observing System for Atmospheric Composition

NASA Astrophysics Data System (ADS)

Edwards, D. P.

2015-12-01

This presentation describes proposed satellite carbon measurements from the CHRONOS mission. The primary goal of this experiment is to measure the atmospheric pollutants carbon monoxide (CO) and methane (CH4) from geostationary orbit, with hourly observations of North America at high spatial resolution. CHRONOS observations would provide measurements not currently available or planned as part of a surface, suborbital and satellite integrated observing system for atmospheric composition over North America. Carbon monoxide is produced by combustion processes such as urban activity and wildfires, and serves as a proxy for other combustion pollutants that are not easily measured. Methane has diverse anthropogenic sources ranging from fossil fuel production, animal husbandry, agriculture and waste management. The impact of gas exploration in the Western States of the USA and oil extraction from the Canadian tar sands will be particular foci of the mission, as will the poorly-quantified natural CH4 emissions from wetlands and thawing permafrost. In addition to characterizing pollutant sources, improved understanding of the domestic CH4 budget is a priority for policy decisions related to short-lived climate forcers. A primary motivation for targeting CO is its value as a tracer of atmospheric pollution, and CHRONOS measurements will provide insight into local and long-range transport across the North American continent, as well as the processes governing the entrainment and venting of pollution in and out of the planetary boundary layer. As a result of significantly improved characterization of diurnal changes in atmospheric composition, CHRONOS observations will find direct societal applications for air quality regulation and forecasting. We present a quantification of this expected improvement in the prediction of near-surface concentrations when CHRONOS measurements are used in Observation System Simulation Experiments (OSSEs). If CHRONOS and the planned NASA Earth Venture TEMPO (Tropospheric Emissions: Monitoring of Pollution) mission were implemented concurrently, the resulting measurement suite would efficiently and expeditiously serve to address the science goals of the Decadal Survey proposed GEO-CAPE mission.

A practical system for regional mobile satellite services

NASA Technical Reports Server (NTRS)

Glein, Randall; Leverson, Denis; Olmstead, Dean

1993-01-01

The Regional Mobile Satellite (MSAT) concept proposes a worldwide, interconnected mobile satellite service (MSS) network in which MSAT-type satellites provide the space segment services to separate regions (i.e., one or a few countries). Using this concept, mobile communications users across entire continents can now be served by a handful of regionally controlled satellites in geostationary earth orbit (GEO). All requirements, including hand-held telephone capabilities, can be cost-effectively provided using proven technologies. While other concepts of regional or global mobile communications continue to be explored, the Hughes Regional MSAT system demonstrates the near-term viability of the GEO approach.

NASA satellite to track North Pole expedition

NASA Technical Reports Server (NTRS)

1978-01-01

The proposed expedition of a lone explorer and the use of Nimbus 6 (NASA meteorological research satellite) to track his journey is reported. The journey is scheduled to start March 4, 1978, and will cover a distance of 6.000 Km (3,728 miles) from northern Canada to the North Pole and return, traveling the length of Greenland's isolated interior. The mode of transportation for the explorer will be by dog sled. Instrumentation and tracking techniques are discussed.

Constraints on Galactic Cosmic-Ray Origins from Elemental Composition Measurements

NASA Astrophysics Data System (ADS)

Binns, W. R.; Christian, E. R.; Cummings, A. C.; Denolfo, G. A.; Israel, M. H.; Lave, K. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.; Wiedenbeck, M. E.

2017-01-01

We present measurements of the abundances of ultra-heavy (Z>29) cosmic rays made by the CRIS instrument on NASA's Advanced Composition Explorer satellite. The data set corresponds to 6413 days of data collection between December 4, 1997 and May 31, 2016. The charge resolution that we obtain is excellent, exhibiting essentially complete separation of adjacent charges in the Z>28 range. We detected 196 events over the charge range of Z =30-40. Our measured abundances show that the ordering of refractory and volatile elements with atomic mass is greatly improved when compared to a mix of massive star outflow and SN ejecta with normal ISM, rather than pure ISM. Additionally, the refractory and volatile elements have similar slopes and refractory elements are preferentially accelerated by a factor of 4. The measured abundances support a model in which 20% of cosmic ray source material is from massive star outflow and ejecta and 80% is from normal ISM. Our abundances show generally good agreement with the TIGER and SuperTIGER results. This research is supported by NASA under Grant # NNX13AH66G.

DebriSat - A Planned Laboratory-Based Satellite Impact Experiment for Breakup Fragment Characterizations

NASA Technical Reports Server (NTRS)

Liou, Jer-Chyi; Clark, S.; Fitz-Coy, N.; Huynh, T.; Opiela, J.; Polk, M.; Roebuck, B.; Rushing, R.; Sorge, M.; Werremeyer, M.

2013-01-01

The goal of the DebriSat project is to characterize fragments generated by a hypervelocity collision involving a modern satellite in low Earth orbit (LEO). The DebriSat project will update and expand upon the information obtained in the 1992 Satellite Orbital Debris Characterization Impact Test (SOCIT), which characterized the breakup of a 1960 s US Navy Transit satellite. There are three phases to this project: the design and fabrication of DebriSat - an engineering model representing a modern, 60-cm/50-kg class LEO satellite; conduction of a laboratory-based hypervelocity impact to catastrophically break up the satellite; and characterization of the properties of breakup fragments down to 2 mm in size. The data obtained, including fragment size, area-to-mass ratio, density, shape, material composition, optical properties, and radar cross-section distributions, will be used to supplement the DoD s and NASA s satellite breakup models to better describe the breakup outcome of a modern satellite.

The German joint research project "concepts for future gravity satellite missions"

NASA Astrophysics Data System (ADS)

Reubelt, Tilo; Sneeuw, Nico; Fichter, Walter; Müller, Jürgen

2010-05-01

Within the German joint research project "concepts for future gravity satellite missions", funded by the Geotechnologies programme of the German Federal Ministry of Education and Research, options and concepts for future satellite missions for precise (time-variable) gravity field recovery are investigated. The project team is composed of members from science and industry, bringing together experts in geodesy, satellite systems, metrology, sensor technology and control systems. The majority of team members already contributed to former gravity missions. The composition of the team guarantees that not only geodetic aspects and objectives are investigated, but also technological and financial constraints are considered. Conversely, satellite, sensor and system concepts are developed and improved in a direct exchange with geodetic and scientific claims. The project aims to develop concepts for both near and mid-term future satellite missions, taking into account e.g. advanced satellite formations and constellations, improved orbit design, innovative metrology and sensor systems and advances in satellite systems.

(?) The Air Force Geophysics Laboratory: Aeronomy, aerospace instrumentation, space physics, meteorology, terrestrial sciences and optical physics

NASA Astrophysics Data System (ADS)

McGinty, A. B.

1982-04-01

Contents: The Air Force Geophysics Laboratory; Aeronomy Division--Upper Atmosphere Composition, Middle Atmosphere Effects, Atmospheric UV Radiation, Satellite Accelerometer Density Measurement, Theoretical Density Studies, Chemical Transport Models, Turbulence and Forcing Functions, Atmospheric Ion Chemistry, Energy Budget Campaign, Kwajalein Reference Atmospheres, 1979, Satellite Studies of the Neutral Atmosphere, Satellite Studies of the Ionosphere, Aerospace Instrumentation Division--Sounding Rocket Program, Satellite Support, Rocket and Satellite Instrumentation; Space Physics Division--Solar Research, Solar Radio Research, Environmental Effects on Space Systems, Solar Proton Event Studies, Defense Meteorological Satellite Program, Ionospheric Effects Research, Spacecraft Charging Technology; Meteorology Division--Cloud Physics, Ground-Based Remote-Sensing Techniques, Mesoscale Observing and Forecasting, Design Climatology, Aircraft Icing Program, Atmospheric Dynamics; Terrestrial Sciences Division--Geodesy and Gravity, Geokinetics; Optical Physics Division--Atmospheric Transmission, Remote Sensing, INfrared Background; and Appendices.

Remote Sensing of Drought: Progress and Opportunities for Improving Drought Monitoring and Prediction

NASA Astrophysics Data System (ADS)

AghaKouchak, A.; Huning, L. S.; Love, C. A.; Farahmand, A.

2017-12-01

This presentation surveys current and emerging drought monitoring approaches using satellite remote sensing observations from climatological and ecosystem perspectives. Satellite observations that are not currently used for operational drought monitoring, such as near-surface air relative humidity and water vapor, provide opportunities to improve early drought warning. Current and future satellite missions offer opportunities to develop composite and multi-indicator drought models. This presentation describes how different satellite observations can be combined for overall drought development and impact assessment. Finally, we provide an overview of the research gaps and challenges that are facing us ahead in the remote sensing of drought.

Exploring the possibility of following the movements of a bird from an artificial earth satellite

NASA Technical Reports Server (NTRS)

Mackay, R. S.

1974-01-01

The development of a harness to hold the transmitter is discussed along with satellite systems for monitoring the flight paths of the birds, and incorporating biological information into the tracking signal.

Testing the use of a land cover map for habitat ranking in boreal forests.

PubMed

Hilli, Milla; Kuitunen, Markku T

2005-04-01

Habitat loss and modification is one of the major threats to biodiversity and the preservation of conservation values. We use the term ''conservation value'' to mean the benefit of nature or habitats for species. The importance of identifying and preserving conservation values has increased with the decline in biodiversity and the adoption of more stringent environmental legislation. In this study, conservation values were considered in the context of land-use planning and the rapidly increasing demand for more accurate methods of predicting and identifying these values. We used a k-nearest neighbor interpreted satellite (Landsat TM) image classified in 61 classes to assess sites with potential conservation values at the regional and landscape planning scale. Classification was made at the National Land Survey of Finland for main tree species, timber volume, land-use type, and soil on the basis of spectral reflectance in satellite image together with broad numerical reference data. We used the number and rarity of vascular plant species observed in the field as indicators for potential conservation values. We assumed that significant differences in the species richness, rarity, or composition of flora among the classes interpreted in the satellite image would also mean a difference in conservation values among these classes. We found significant differences in species richness among the original satellite image classes. Many of the classes examined could be distinguished by the number of plant species. Species composition also differed correspondingly. Rare species were most abundant in old spruce forests (>200 m3/ha), raising the position of such forests in the ranking of categories according to conservation values. The original satellite image classification was correct for 70% of the sites studied. We concluded that interpreted satellite data can serve as a useful source for evaluating habitat categories on the basis of plant species richness and rarity. Recategorization of original satellite image classification into such new conservation value categories is challenging because of the variation in species composition among the new categories. However, it does not represent a major problem for the purposes of early-stage land-use planning. Benefits of interpreted satellite image recategorization as a rapid conservation value assessment tool for land-use planners would be great.

The QBO Impact on Stratospheric Composition as Revealed by the MERRA-2 GMI Simulation and NASA Satellite Observations

NASA Astrophysics Data System (ADS)

Oman, L.; Strahan, S. E.

2017-12-01

The Quasi-Biennial Oscillation (QBO) is the dominant mode of variability in the tropical stratosphere on interannual time scales. It has been shown to impact both stratospheric dynamics and important trace gas constituent distributions. The QBO timing with respect to the seasonal cycle in each hemisphere is significant in determining its impact on up to decadal scale variability. The composition response to the QBO is examined using the new MERRA-2 GMI "Replay" simulation, an atmospheric composition community resource, run at the native MERRA-2 approximately ½° horizontal resolution on the cubed sphere. MERRA-2 GMI is driven by the online use of key MERRA-2 meteorological quantities (i.e. U, V, T, and P) with all other variables calculated in response to those and boundary condition forcings from 1980-2016. The simulation combined with NASA's UARS and Aura satellite measurements have allowed us to quantify the impact of the QBO on stratospheric composition in more detail than was ever possible before. Revealing preferential pathways and transport timings necessary in understanding the QBO impact on composition throughout the stratosphere.

The composite nature of the peculiar star HR 6560 (HD 159870)

NASA Technical Reports Server (NTRS)

Wegner, Gary; Cowley, Charles R.

1992-01-01

Ground-based high-dispersion photographic spectra and ultraviolet spectra obtained with the IUE satellite are described and employed to determine the nature of the peculiar star HR 6560 (HD 159870). Previously this object had been described as both a composite system and as a strong Fm star. The UBVRI, Stromgren, and ultraviolet colors of HR 6560 are compared with objects classified composite from the Bright Star Catalogue and normal dwarfs and giants. The colors of HR 6560 are not unusual for a composite and are consistent with a late-A dwarf, combined with a late-G or early-K giant. The ultraviolet satellite clearly shows the presence of an A component, but its precise spectral type is difficult to assign. The IUE and TD-1 data suggest that the ultraviolet is dominated by light from an A5 V secondary and the visual from a GO III primary. This does not agree well with the most plausible model that fits the visual photometry. The peculiar nature of HR 6560's spectrum is most likely due to its composite nature.

Three small deployed satellites

NASA Image and Video Library

2012-10-04

ISS033-E-009286 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment. A portion of the station’s solar array panels and a blue and white part of Earth provide the backdrop for the scene.

Three small deployed satellites

NASA Image and Video Library

2012-10-04

ISS033-E-009285 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment. A portion of the station’s solar array panels and a blue and white part of Earth provide the backdrop for the scene.

Developing spectral, structural, and phenological diversity proxies for monitoring biodiversity change across space and time using ESA's Sentinel satellites

NASA Astrophysics Data System (ADS)

Ma, X.; Mahecha, M. D.; Migliavacca, M.; Luo, Y.; Urban, M.; Bohn, F. J.; Huth, A.; Reichstein, M.

2017-12-01

A key challenge for monitoring biodiversity change is the lack of consistent measures of biodiversity across space and time. This challenge may be addressed by exploring the potentials provided by novel remote sensing observations. By continuously observing broad-scale patterns of vegetation and land surface parameters, remote sensing can complement the restricted coverage afforded by field measurements. Here we develop methods to infer spatial patterns of biodiversity at ecosystem level from ESA's next-generation Sentinel sensors (Sentinel-1: C-band radar & Sentinel-2: multispectral). Both satellites offer very high spatial (10 m) and temporal resolutions (5 days) measurements with global coverage. We propose and test several ecosystem biodiversity proxies, including landscape spectral diversity, phenological diversity, and canopy structural diversity. These diversity proxies are highly related to some key aspects of essential biodiversity variables (EBVs) as defined by GEO-BON, such as habitat structure, community composition, ecosystem function and structure. We verify spaceborne retrievals of these biodiversity proxies with in situ measurements from drone (spectral diversity), phenocam (phenological diversity), and airborne LiDAR (canopy structural diversity) over multiple flux tower sites within the Mediterranean region. We further compare our remote sensing retrievals of biodiversity proxies against several biodiversity indices as derived from field measurements (incl. ⍺-/β- diversity and Shannon-index) to explore the limitations and potentials of extending the RS proxies to a greater spatial extent. We expect the new concept as to maximize the potential of remote sensing information might help to monitor key aspects of EBVs on a global scale.

Remote sensing of electron density and ion composition using nonducted whistler observations on OGO 1 and Van Allen Probes

NASA Astrophysics Data System (ADS)

Sonwalkar, V. S.; Butler, J.; Reddy, A.

2017-12-01

We present a new method to remotely measure magnetospheric electron density and ion composition using lightning generated nonducted whistlers observed on a satellite. Electron and ion densities play important roles in magnetospheric processes such as wave-particle interactions in the equatorial region and ion-neutral dynamics in the ionosphere, and are important for calculating space weather effects such as particle precipitation, GPS scintillations, and satellite drag. The nonducted whistler resulting from a single lightning appears on a spectrogram as a series of magnetospherically reflected traces with characteristic dispersion (time delay versus frequency) and upper and lower cut off frequencies. Ray tracing simulations show that these observed characteristics depend on the magnetospheric electron density and ion composition. The cut off frequencies depend on both electron density and ion composition. The dispersion depends strongly on electron density, but weakly on ion composition. Using an iterative process to fit the measured dispersion and cutoff frequencies to those obtained from ray tracing simulations, it is possible to construct the electron and ion density profiles of the magnetosphere. We demonstrate our method by applying it to nonducted whistlers observed on OGO 1 and Van Allen probe satellites. In one instance (08 Nov 1965), whistler traces observed on OGO 1 (L = 2.4, λm = -6°) displayed a few seconds of dispersion and cutoff frequencies in the 1-10 kHz range. Ray tracing analysis showed that a diffusive equilibrium density model with the following parameters can reproduce the observed characteristics of the whistler traces: 1900 el/cc at L=2.4 and the equator, 358,000 el/cc at F2 peak (hmF2 = 220 km), the relative ion concentrations αH+ = 0.2, αHe+ = 0.2, and αO+ = 0.6 at 1000 km, and temperature 1600 K. The method developed here can be applied to whistlers observed on the past, current, and future magnetospheric satellite missions carrying wave instrument (e.g. OGO, ISEE 1, DE 1, POLAR, CLUSTER, Van Allen Probes). The method can be easily extended to make tomographic measurements of magnetospheric electron and ion density by analyzing a series of whistlers observed along the satellite orbit.

Quasi-isotropic VHF antenna array design study for the International Ultraviolet Explorer satellite

NASA Technical Reports Server (NTRS)

Raines, J. K.

1975-01-01

Results of a study to design a quasi-isotropic VHF antenna array for the IUE satellite are presented. A free space configuration was obtained that has no nulls deeper than -6.4 dbi in each of two orthogonal polarizations. A computer program named SOAP that analyzes the electromagnetic interaction between antennas and complicated conducting bodies, such as satellites was developed.

Citizen Explorer. 1; An Earth Observer With New Small Satellite Technology

NASA Technical Reports Server (NTRS)

Allen, Zachary; Dunn, Catherine E.

2003-01-01

Citizen Explorer-I (CX-I), designed and built by students at Colorado Space Grant Consortium in Boulder to provide global ozone monitoring, employs a unique mission architecture and several innovative technologies during its mission. The mission design allows K-12 schools around the world to be involved as ground stations available to receive science data and telemetry from CX-I. Another important technology allows the spacecraft to be less reliant on ground operators. Spacecraft Command Language (SCL) allows mission designers to set constraints on the satellite operations. The satellite then automatically adheres to the constraints when the satellite is out of contact with Mission Operations. In addition to SCL, a low level of artificial intelligence will be supplied to the spacecraft through the use of the Automated Scheduling and Planning ENvironment (ASPEN). ASPEN is used to maintain a spacecraft schedule in order to achieve the objectives a mission operator would normally have to complete. Within the communications system of CX-I, internet of CX-I, internet protocols are the main method for communicating with the satellite. As internet protocols have not been widely used in satellite communication, CX-I provides an opportunity to study the effectiveness of using internet protocols over radio links. The Attitude Determination and Control System (ADCS) on CX-I uses a gravity gradient boom as a means of orienting the satellite's science instruments toward nadir. The boom design is unique because it is constructed of tape measure material. These new technologies' effectiveness will be tested for use on future small satellite projects within the space satellite industry.

The CEOS WGISS Atmospheric Composition Portal

NASA Technical Reports Server (NTRS)

Lynnes, Chris

2010-01-01

Goal: Demonstrate the feasibility of connecting distributed atmospheric composition data and analysis tools into a common and shared web framework. Initial effort focused on: a) Collaboratively creating a web application within WDC-RSAT for comparison of satellite derived atmospheric composition datasets accessed from distributed data sources. b) Implementation of data access and interoperability standards. c) Sollicit feedback from paternal users; Especially from ACC participants.

Current Usage and Future Prospects of Multispectral (RGB) Satellite Imagery in Support of NWS Forecast Offices and National Centers

NASA Technical Reports Server (NTRS)

Molthan, Andrew; Fuell, Kevin; Knaff, John; Lee, Thomas

2012-01-01

What is an RGB Composite Image? (1) Current and future satellite instruments provide remote sensing at a variety of wavelengths. (2) RGB composite imagery assign individual wavelengths or channel differences to the intensities of the red, green, and blue components of a pixel color. (3) Each red, green, and blue color intensity is related to physical properties within the final composite image. (4) Final color assignments are therefore related to the characteristics of image pixels. (5) Products may simplify the interpretation of data from multiple bands by displaying information in a single image. Current Products and Usage: Collaborations between SPoRT, CIRA, and NRL have facilitated the use and evaluation of RGB products at a variety of NWS forecast offices and National Centers. These products are listed in table.

Characterizing the Asian Tropopause Aerosol Layer using in situ balloon measurements: the BATAL campaigns of 2014-2017

NASA Astrophysics Data System (ADS)

Fairlie, T. D.; Vernier, J. P.; Deshler, T.; Pandit, A. K.; Ratnam, M. V.; Gadhavi, H. S.; Liu, H.; Natarajan, M.; Jayaraman, A.; Kumar, S.; Singh, A. K.; Stenchikov, G. L.; Wienhold, F.; Vignelles, D.; Bedka, K. M.; Avery, M. A.

2017-12-01

We present in situ balloon observations of the Asian Tropopause Aerosol Layer (ATAL), a summertime accumulation of aerosols in the upper troposphere and lower stratosphere (UTLS), associated with Asian Summer Monsoon (ASM). The ATAL was first revealed by CALIPSO satellite data, and has been linked with deep convection of boundary layer pollution into the UTLS. The ATAL has potential implications for regional cloud properties, radiative transfer, and chemical processes in the UTLS. The "Balloon measurements of the Asian Tropopause Aerosol Layer (BATAL)" field campaigns to India and Saudi Arabia in were designed to characterize the physical and optical properties of the ATAL, to explore its composition, and its relationship with clouds in the UTLS. We launched 55 balloon flights from 4 locations, in summers 2014-2016. We return to India to make more balloon flights in summer 2017. Balloon payloads range from 500g to 50 kg, making measurements of meteorological parameters, ozone, water vapor, aerosol optical properties, concentration, volatility, and composition in the UTLS region. This project represents the most important effort to date to study UTLS aerosols during the ASM, given few in situ observations. We complement the in situ data presented with 3-d chemical transport simulations, designed to further explore the ATAL's chemical composition, the sensitivity of such to scavenging in parameterized deep convection, and the relative contribution of regional vs. rest-of-the-world pollution sources. The BATAL project has been a successful partnership between institutes in the US, India, Saudi Arabia, and Europe, and continues for the next 3-4 years, sponsored by the NASA Upper Atmosphere Research program. This partnership may provide a foundation for potential high-altitude airborne measurement studies during the ASM in the future.

Satellite imagery and discourses of transparency

NASA Astrophysics Data System (ADS)

Harris, Chad Vincent

In the last decade there has been a dramatic increase in satellite imagery available in the commercial marketplace and to the public in general. Satellite imagery systems and imagery archives, a knowledge domain formally monopolized by nation states, have become available to the public, both from declassified intelligence data and from fully integrated commercial vendors who create and market imagery data. Some of these firms have recently launched their own satellite imagery systems and created rather large imagery "architectures" that threaten to rival military reconnaissance systems. The increasing resolution of the imagery and the growing expertise of software and imagery interpretation developers has engendered a public discourse about the potentials for increased transparency in national and global affairs. However, transparency is an attribute of satellite remote sensing and imagery production that is taken for granted in the debate surrounding the growing public availability of high-resolution satellite imagery. This paper examines remote sensing and military photo reconnaissance imagery technology and the production of satellite imagery in the interests of contemplating the complex connections between imagery satellites, historically situated discourses about democratic and global transparency, and the formation and maintenance of nation state systems. Broader historical connections will also be explored between satellite imagery and the history of the use of cartographic and geospatial technologies in the formation and administrative control of nation states and in the discursive formulation of national identity. Attention will be on the technology itself as a powerful social actor through its connection to both national sovereignty and transcendent notions of scientific objectivity. The issues of the paper will be explored through a close look at aerial photography and satellite imagery both as communicative tools of power and as culturally relevant historical artifacts.

NASA Space Astronomy Update 6: Unconventional Windows on the Universe

NASA Technical Reports Server (NTRS)

1992-01-01

Professor Stu Bowyer (University of California at Berkeley) explains the Extreme Ultraviolet Explorer and its telescope in this video. Both instrument and satellite are kept in perfect working condition. The satellite picks up extra galactic objects outside our galaxy.

Command and data handling for Atmosphere Explorer satellite

NASA Technical Reports Server (NTRS)

Fuldner, W. V.

1974-01-01

The command and data-handling subsystem of the Atmosphere Explorer satellite provides the necessary controls for the instrumentation and telemetry, and also controls the satellite attitude and trajectory. The subsystem executes all command information within the spacecraft, either in real time (as received over the S-band command transmission link) or remote from the command site (as required by the orbit operations schedule). Power consumption in the spacecraft is optimized by suitable application and removal of power to various instruments; additional functions include control of magnetic torquers and of the orbit-adjust propulsion subsystem. Telemetry data from instruments and the spacecraft equipment are formatted into a single serial bit stream. Attention is given to command types, command formats, decoder operation, and command processing functions.

The search for crustal resources - MAGSAT and beyond

NASA Technical Reports Server (NTRS)

Taylor, P. T.; Hinze, W. J.; Ravat, D. N.

1992-01-01

In the decade since global satellite magnetic field data have been available from MAGSAT, notable progress has been made in processing these data for purposes of mapping crustal anomalies. Several regional magnetic anomaly maps compiled using these new techniques (e.g. Kursk region, U.S.S.R.; central Africa; Kiruna, Sweden; and the U.S.A. midcontinent) provide insight into the nature and tectonic evolution of the crust that contribute to conceptual crustal models useful in regional resource exploration. A recent mail survey of geopotential-field specialists involved in resource exploration indicates interest in MAGSAT data and future satellite missions with improved resolution. It is apparent that magnetic anomalies derived from satellite observations can aid in the search for crustal resources.

Into the thermosphere: The atmosphere explorers

NASA Technical Reports Server (NTRS)

Burgess, Eric; Torr, Douglass

1987-01-01

The need to study the lower thermosphere with the new instrument, data handling, and spacecraft technology available in the 1960s led to the formulation and establishment of the Atmospheric Explorer program. This book provides an overview of this program with particular emphasis on the AE3, AE4, and AE5 satellites, which represent early examples of problem-dedicated missions. Both the satellites and their instrumentation on the one hand and the experimental and scientific considerations in studying the thermosphere on the other are discussed.

Kagawa Satellite “STARS” in Shikoku

NASA Astrophysics Data System (ADS)

Nohmi, Masahiro; Yamamoto, Takeshi; Andatsu, Akira; Takagi, Yohei; Nishikawa, Yusuke; Kaneko, Takashi; Kunitom, Daisuke

The Space Tethered Autonomous Robotic Satellite (STARS) is being developed in Kagawa University, and it will be launched by the H-IIA rocket by Japan Aerospace Exploration Agency (JAXA) in summer 2008. STARS is the first satellite developed in Shikoku, and its specific characteristics are: (i) mother and daughter satellites, which have basic satellite system respectively, and those are launched at the same time; (ii) large space system more than 5m by extending tether; (iii) robotic system, the daughter satellite controls its arm link and the mother satellite controls tether extension. Development of STARS in Kagawa University demonstrates space technology in local community, which has been considered to be a national project. Also, it promotes popularization, enlightenment, and understanding of space technology in local area of the Kagawa prefecture and around it.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farkas-Takács, A.; Kiss, Cs.; Pál, A.

In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel /PACS and Spitzer /MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranianmore » irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.« less

Development of Multi-Sensor Global Cloud and Radiance Composites for DSCOVR EPIC Imager with Subpixel Definition

NASA Technical Reports Server (NTRS)

Khlopenkov, Konstantin V.; Duda, David; Thieman, Mandana; Sun-mack, Szedung; Su, Wenying; Minnis, Patrick; Bedka, Kristopher

2017-01-01

The Deep Space Climate Observatory (DSCOVR) enables analysis of the daytime Earth radiation budget via the onboard Earth Polychromatic Imaging Camera (EPIC) and National Institute of Standards and Technology Advanced Radiometer (NISTAR). EPIC delivers adequate spatial resolution imagery but only in shortwave bands (317-780 nm), while NISTAR measures the top-of-atmosphere (TOA) whole-disk radiance in shortwave and longwave broadband windows. Accurate calculation of albedo and outgoing longwave flux requires a high-resolution scene identification such as the radiance observations and cloud properties retrievals from low earth orbit (LEO, including NASA Terra and Aqua MODIS, Suomi-NPP VIIRS, and NOAA AVHRR) and geosynchronous (GEO, including GOES east and west, METEOSAT, INSAT-3D, MTSAT-2, and Himawari-8) satellite imagers. The cloud properties are derived using the Clouds and the Earth's Radiant Energy System (CERES) mission Cloud Subsystem group algorithms. These properties have to be co-located with EPIC pixels to provide the scene identification and to select anisotropic directional models (ADMs), which are then used to adjust the NISTAR-measured radiance and subsequently obtain the global daytime shortwave and longwave fluxes. This work presents an algorithm for optimal merging of selected radiance and cloud property parameters derived from multiple satellite imagers to obtain seamless global hourly composites at 5-km resolution. Selection of satellite data for each 5-km pixel is based on an aggregated rating that incorporates five parameters: nominal satellite resolution, pixel time relative to the EPIC time, viewing zenith angle, distance from day/night terminator, and probability of sun glint. To provide a smoother transition in the merged output, in regions where candidate pixel data from two satellite sources have comparable aggregated rating, the selection decision is defined by the cumulative function of the normal distribution so that abrupt changes in the visual appearance of the composite data are avoided. Higher spatial accuracy in the composite product is achieved by using the inverse mapping with gradient search during reprojection and bicubic interpolation for pixel resampling.

Dynamics of phytoplankton community composition in the western Gulf of Maine

NASA Astrophysics Data System (ADS)

Moore, Timothy S.

This dissertation is founded on the importance of phytoplankton community composition to marine biogeochemistry and ecosystem processes and motivated by the need to understand their distributions on regional to global scales. The ultimate goal was to predict surface phytoplankton communities using satellite remote sensing by relating marine habitats--defined through a statistical description of environmental properties--to different phytoplankton communities. While phytoplankton community composition is governed by the interplay of abiotic and biotic interactions, the strategy adopted here was to focus on the physical abiotic factors. This allowed for the detection of habitats from ocean satellites based on abiotic factors that were linked to associated phytoplankton communities. The research entailed three studies that addressed different aspects of the main goal using a dataset collected in the western Gulf of Maine over a 3-year period. The first study evaluated a chemotaxonomic method that quantified phytoplankton composition from pigment data. This enabled the characterization of three phytoplankton communities, which were defined by the relative abundance of diatoms and flagellates. The second study examined the cycles of these communities along with environmental variables, and the results revealed that the three phytoplankton communities exhibited an affinity to different hydrographic regimes. The third study focused on the implementation of a classifier that predicted phytoplankton communities from environmental variables. Its ability to differentiate communities dominated by diatoms versus flagellates was shown to be high. However, the increase in data imprecision when using satellite data led to lowered performance and favored an approach that incorporated fuzzy logic. The fuzzy method is well suited to characterize the uncertainties in phytoplankton community prediction, and provides a measure of confidence on predicted communities. The final product of the overall dissertation was a time series of maps generated from satellite observations depicting the likelihood of three phytoplankton communities. This dissertation reached the main goal and, moreover, demonstrated that improvements in the predictive power of the method can be achieved with increased precision and more advanced satellite-derived products. The results of this research can benefit present bio-optical and primary productivity models, and ecosystem-based models of the marine environment.

Multidisciplinary studies of the social, economic and political impact resulting from recent advances in satellite meteorology, volume 1

NASA Technical Reports Server (NTRS)

1971-01-01

The multidisciplinary studies explore and evaluate the impact of the meteorological satellite and the concomitant impact of the data derived from it on various user groups. As expected, the primary impact related to those who would use satellite data for weather prediction and related purposes. A secondary impact was in the area of international concerns where GARP and other international meteorological activities were affected and international law was developed. A tertiary impact was exemplified by satellite photographs utilized in advertisements and related materials. The case studies, supporting studies, and independent studies all emphasize the potential of the meteorological satellite.

DOD Pico-Satellite known as ANDE released from the STS-116 shuttle payload bay

NASA Image and Video Library

2006-12-21

S116-E-07837 (21 Dec. 2006) --- As seen through windows on the aft flight deck of Space Shuttle Discovery, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment (ANDE) is released from the shuttle's payload bay by STS-116 crewmembers. ANDE consists of two micro-satellites which will measure the density and composition of the low Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

DOD Pico-Satellite known as ANDE released from the STS-116 shuttle payload bay

NASA Image and Video Library

2006-12-21

S116-E-07831 (21 Dec. 2006) --- As seen through windows on the aft flight deck of Space Shuttle Discovery, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment (ANDE) is released from the shuttle's payload bay by STS-116 crewmembers. ANDE consists of two micro-satellites which will measure the density and composition of the low Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

DOD Pico-Satellite known as ANDE released from the STS-116 shuttle payload bay

NASA Image and Video Library

2006-12-21

S116-E-07838 (21 Dec. 2006) --- As seen through windows on the aft flight deck of Space Shuttle Discovery, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment (ANDE) is released from the shuttle's payload bay by STS-116 crewmembers. ANDE consists of two micro-satellites which will measure the density and composition of the low Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

Frequency addressable beams for land mobile communications

NASA Technical Reports Server (NTRS)

Thompson, J. D.; Dubellay, G. G.

1988-01-01

Satellites used for mobile communications need to serve large numbers of small, low cost terminals. The most important parameters affecting the capacity of such systems are the satellite equivalent isotropically radiated power (EIRP) and gain to noise temperature ratio (G/T) and available bandwidth. Satellites using frequency addressed beams provide high EIRP and G/T with high-gain antenna beams that also permit frequency reuse over the composite coverage area. Frequency addressing is easy to implement and compatible with low-cost terminals and offers higher capacity than alternative approaches.

Interstellar matter research with the Copernicus satellite

NASA Technical Reports Server (NTRS)

Spitzer, L., Jr.

1976-01-01

The use of the Copernicus satellite in an investigation of interstellar matter makes it possible to study absorption lines in the ultraviolet range which cannot be observed on the ground because of atmospheric absorption effects. A brief description is given of the satellite and the instrument used in the reported studies of interstellar matter. The results of the studies are discussed, giving attention to interstellar molecular hydrogen, the chemical composition of the interstellar gas, the coronal gas between the stars, and the interstellar abundance ratio of deuterium to hydrogen.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003876 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are featured in this image photographed by an Expedition 38 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module's robotic arm on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan’s fourth H-II Transfer Vehicle, Kounotori-4.

SSOD on JEM RMS

NASA Image and Video Library

2012-10-04

ISS033-E-009269 (4 Oct. 2012) --- A Small Satellite Orbital Deployer (SSOD) attached to the Japanese module’s robotic arm is featured in this image photographed by an Expedition 33 crew member on the International Space Station. Several tiny satellites were released outside the Kibo laboratory using the SSOD on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

The Feasibility of a Galileo-Style Tour of the Uranian Satellites

NASA Technical Reports Server (NTRS)

Heaton, Andrew F.; Longuski, James M.; Vanhooser, Teresa B. (Technical Monitor)

2001-01-01

Gravity-assist trajectories have been a key to outer Solar System exploration. In particular, the gravity-assist tour of the Jovian satellites has contributed significantly to the success of the Galileo mission. A comparison of the Jovian system to the Uranian system reveals that the two possess similar satellite/planet mass ratios. Tisserand graphs of the Uranian system also indicate the potential for tours at Uranus. In this paper. We devise tour strategies and design a prototypical tour of the Uranian satellites, proving that tours at Uranus are feasible.

Use of communications. [satellite communication

NASA Technical Reports Server (NTRS)

1975-01-01

Progress in the field of satellite communications is reviewed, and useful services which may be provided by future satellite communications systems are considered. Recommendations are made with regard to mobile communications for use on land and at sea, position determination, mineral and energy exploration, the possibility of using electronic means to assist in main delivery, education and health-care experiments, and the use of satellite telecommunications to enhance the quality of life in rural areas by making available a full range of educational and entertainment programs. The needs of the amateur radio community are also considered.

Satellite Observations for Detecting and Tracking Changes in Atmospheric Composition

NASA Technical Reports Server (NTRS)

Neil, Doreen O.; Kondragunbta, Shobha; Osterman, Gregory; Pickering, Kenneth; Pinder, Robert W.; Prados, Ana I.; Szykman, James

2009-01-01

The satellite observations provide constraints on detailed atmospheric modeling, including emissions inventories, indications of transport, harmonized data over vast areas suitable for trends analysis, and a link between spatial scales ranging from local to global, and temporal scales from diurnal to interannual. 1 The National Oceanic and Atmospheric Administration's (NOAA) long-term commitments help provide these observations in cooperation with international meteorological organizations. NASA s long-term commitments will advance scientifically important observations as part of its Earth Science Program, and will assist the transition of the science measurements to applied analyses through the Applied Science Program. Both NASA and NOAA have begun to provide near realtime data and tools to visualize and analyze satellite data,2 while maintaining data quality, validation, and standards. Consequently, decision-makers can expect satellite data services to support air quality decision making now and in the future. The international scientific community's Integrated Global Atmosphere Chemistry Observation System Report3 outlined a plan for ground-based, airborne and satellite measurements and models to integrate the observations into a four-dimensional representation of the atmosphere (space and time) to support assessment and policy information needs. This plan is being carried out under the Global Earth Observation System of Systems (GEOSS). Demonstrations of such an integrated capability4 provide new understanding of the changing atmosphere and link policy decisions to benefits for society. In this article, we highlight the use of satellite data to constrain biomass burning emissions, to assess oxides of nitrogen (NO(x)) emission reductions, and to contribute to state implementation plans, as examples of the use of satellite observations for detecting and tracking changes in atmospheric composition.

Satellite Interconnection and Distance Delivery in Alaska: Toward the 21st Century. Summary and Recommendations of the Satellite Interconnection Project under the Direction of the Telecommunications Information Council.

ERIC Educational Resources Information Center

Alaska Public Broadcasting Commission, Juneau.

The Satellite Interconnection Project was created for the purpose of investigating the interest and need for improved interconnection, faster and of greater capacity than the capability of present systems, especially among Alaska state-supported users of video and audio transmissions. The intent was to explore the cost-benefit and the potential…

Steady Motions of Rigid Body Satellites in a Central Gravitational Field

DTIC Science & Technology

1993-12-01

been explored for several centuries. Orbiting bodies investigated include point masses, spheres, cylinders, rods, ball-and-socket connected objects...of the satellite model relative to its orbit radius could lead to 5 its treatment as a point mass, doing so would prevent analysis of satellite...8217 librational ’ motion ... and internal elastic forces in the structure balance the orbital dynamic accelerations tending to separate masses orbiting at

A two-step nearest neighbors algorithm using satellite imagery for predicting forest structure within species composition classes

Treesearch

Ronald E. McRoberts

2009-01-01

Nearest neighbors techniques have been shown to be useful for predicting multiple forest attributes from forest inventory and Landsat satellite image data. However, in regions lacking good digital land cover information, nearest neighbors selected to predict continuous variables such as tree volume must be selected without regard to relevant categorical variables such...

Combining forest inventory, satellite remote sensing, and geospatial data for mapping forest attributes of the conterminous United States

Treesearch

Mark Nelson; Greg Liknes; Charles H. Perry

2009-01-01

Analysis and display of forest composition, structure, and pattern provides information for a variety of assessments and management decision support. The objective of this study was to produce geospatial datasets and maps of conterminous United States forest land ownership, forest site productivity, timberland, and reserved forest land. Satellite image-based maps of...

Properties of the Irregular Satellite System around Uranus Inferred from K2, Herschel, and Spitzer Observations

NASA Astrophysics Data System (ADS)

Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Mommert, M.; Szakáts, R.; Müller, T.; Kiss, L. L.

2017-09-01

In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel/PACS and Spitzer/MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranian irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.

Design Considerations for a Dedicated Gravity Recovery Satellite Mission Consisting of Two Pairs of Satellites

NASA Technical Reports Server (NTRS)

Wiese, D. N.; Nerem, R. S.; Lemoine, F. G.

2011-01-01

Future satellite missions dedicated to measuring time-variable gravity will need to address the concern of temporal aliasing errors; i.e., errors due to high-frequency mass variations. These errors have been shown to be a limiting error source for future missions with improved sensors. One method of reducing them is to fly multiple satellite pairs, thus increasing the sampling frequency of the mission. While one could imagine a system architecture consisting of dozens of satellite pairs, this paper explores the more economically feasible option of optimizing the orbits of two pairs of satellites. While the search space for this problem is infinite by nature, steps have been made to reduce it via proper assumptions regarding some parameters and a large number of numerical simulations exploring appropriate ranges for other parameters. A search space originally consisting of 15 variables is reduced to two variables with the utmost impact on mission performance: the repeat period of both pairs of satellites (shown to be near-optimal when they are equal to each other), as well as the inclination of one of the satellite pairs (the other pair is assumed to be in a polar orbit). To arrive at this conclusion, we assume circular orbits, repeat groundtracks for both pairs of satellites, a 100-km inter-satellite separation distance, and a minimum allowable operational satellite altitude of 290 km based on a projected 10-year mission lifetime. Given the scientific objectives of determining time-variable hydrology, ice mass variations, and ocean bottom pressure signals with higher spatial resolution, we find that an optimal architecture consists of a polar pair of satellites coupled with a pair inclined at 72deg, both in 13-day repeating orbits. This architecture provides a 67% reduction in error over one pair of satellites, in addition to reducing the longitudinal striping to such a level that minimal post-processing is required, permitting a substantial increase in the spatial resolution of the gravity field products. It should be emphasized that given different sets of scientific objectives for the mission, or a different minimum allowable satellite altitude, different architectures might be selected.

Rotational Dynamics of Inactive Satellites as a Result of the YORP Effect

NASA Astrophysics Data System (ADS)

Albuja, Antonella A.

Observations of inactive satellites in Earth orbit show that these objects are generally rotating, some with very fast rotation rates. In addition, observations indicate that the rotation rate at which defunct satellites spin tends to evolve over time. However, the cause for this behavior is unknown. The observed secular change in the spin rate and spin axis orientation of asteroids is known to be caused by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, which results in a torque that is created from reflected thermal energy and sunlight from the surface of an asteroid. This thesis explores the effect of YORP on defunct satellites in Earth orbit and offers this as a potential cause for the observed rotation states of inactive satellites. In this work, several different satellite models are developed to represent inactive satellites in Geostationary Earth Orbit (GEO). The evolution of the spin rate and obliquity for each satellite is then explored using Euler's equations of motion as well as spin and year averaged dynamics. This results in the dynamics being analyzed to understand the secular changes that occur, as well as the variations that result from short period terms over the course of a year. Some of the model satellites have asymmetric geometries, leading to the classical YORP effect as originally formulated for asteroids. One model satellite is geometrically symmetric, but relies on mass distribution asymmetry to generate the YORP effect. Because the YORP effect is directly dependent on geometric, optical and thermal properties of the satellite, varying these parameters can lead to different long-term rotational behavior. A sensitivity study is done by varying these parameters and analyzing its effect on the long-term dynamics of a satellite. Additionally, available observation data of inactive GEO satellites are used to estimate the YORP torque acting on those bodies. A comparison between this torque and the expected torque on a defunct satellite shows that the two are of the same order of magnitude, demonstrating that YORP could be a cause for the observed behavior.

Exploring the Opportunities of a Balloon-Satellite in Bangladesh for Weather Data Collection and Vegetative Analysis

NASA Astrophysics Data System (ADS)

Shafique, Md. Ishraque Bin; Razzaq Halim, M. A.; Rabbi, Fazle; Khalilur Rhaman, Md.

2016-07-01

For a third world country like Bangladesh, satellite and space research is not feasible due to lack of funding. Therefore, in order to imitate the principles of such a satellite Balloon Satellite can easily and inexpensively be setup. Balloon satellites are miniature satellites, which are cheap and easy to construct. This paper discusses a BalloonSat developed using a Raspberry Pi, IMU module, UV sensor, GPS module, Camera and XBee Module. An interactive GUI was designed to display all the data collected after processing. To understand nitrogen concentration of a plant, a leaf color chart is used. This paper attempts to digitalize this process, which is applied on photos taken by the BallonSat.

Earth

NASA Image and Video Library

2012-01-30

Behold one of the more detailed images of the Earth yet created. This Blue Marble Earth montage shown above -- created from photographs taken by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on board the new Suomi NPP satellite -- shows many stunning details of our home planet. The Suomi NPP satellite was launched last October and renamed last week after Verner Suomi, commonly deemed the father of satellite meteorology. The composite was created from the data collected during four orbits of the robotic satellite taken earlier this month and digitally projected onto the globe. Many features of North America and the Western Hemisphere are particularly visible on a high resolution version of the image. http://photojournal.jpl.nasa.gov/catalog/PIA18033

Extension of surface data by use of meteorological satellites

NASA Technical Reports Server (NTRS)

Giddings, L. E.

1976-01-01

Ways of using meteorological satellite data to extend surface data are summarized. Temperature models are prepared from infrared data from ITOS/NOAA, NIMBUS, SMS/GOES, or future LANDSAT satellites. Using temperatures for surface meteorological stations as anchors, an adjustment is made to temperature values for each pixel in the model. The result is an image with an estimated temperature for each pixel. This provides an economical way of producing detailed temperature information for data-sparse areas, such as are found in underdeveloped countries. Related uses of these satellite data are also given, including the use of computer prepared cloud-free composites to extend climatic zones, and their use in discrimination of reflectivity-thermal regime zones.

Ocean Compositions on Europa and Ganymede

NASA Astrophysics Data System (ADS)

Leitner, M. A.; Bothamy, N.; Choukroun, M.; Pappalardo, R. T.; Vance, S.

2014-12-01

The ocean compositions of icy Galilean satellites Europa and Ganymede are highly uncertain. Spectral observations of the satellites' surfaces provide clues for the interior composition. Putative sulfate hydration features in Galileo near-infrared reflectance spectra suggest fractionation of Na and Mg sulfates from a subsurface reservoir (McCord et al. 1998, Sci. 278, 271; McCord et al. 1998, Sci. 280, 1242; Dalton et al. 2005, Icarus, 177, 472). Recent spatially resolved spectral mapping of Europa hints at possible partitioning of near-surface brines in Europa's low-lying planes (Shirley et al. 2010; Icarus, 210, 358; Dalton et al. 2012; J. Geophys. Res. 117, E03003). Surface materials can be modified by the delivery of material from impacts and Io's active volcanoes as well as intense irradiation from Jupiter's magnetic field interaction with the jovian magnetosphere. These factors, combined with observations of high Cl/K ratios in Europa's exosphere, have led other investigators to suggest that Europa's ocean is dominated by dissolved chloride rather than sulfate (Brown and Hand 2013; Astr. J. 145, 110). There is still much uncertainty regarding how well the surface composition approximates the interior ocean composition. Exogenic materials, seafloor hydrothermal processes, and fractional crystallization during ice formation will determine the abundances of species in the ocean and by extension those present on Europa's surface. We develop a bottom-up model for oceans on Europa and Ganymede, assuming initial compositions of chondritic and cometary materials including an Fe core for Europa and an Fe-FeS eutectic core for Ganymede. We calculate an ocean composition by employing a Bulk Silicate Earth approach, also used by Zolotov and Shock (2001; J. Geophys. Res. 106, 32815) at Europa, which assess element partitioning between the rocky mantle, Fe-rich core, and water ocean. Partitioning factors are based on terrestrial estimates for Earth. The resulting ocean composition is used to assess solid precipitation into the ocean and ice shell using FREZCHEM modeling software (Marion et al. 2010; Icarus, 207, 675). These results are then compared with measured compositions of brines on Europa's surface. We develop the model in a way that permits ready application to other icy satellites, such as Titan or Enceladus.

NASA's Advanced Solar Sail Propulsion System for Low-Cost Deep Space Exploration and Science Missions that Use High Performance Rollable Composite Booms

NASA Technical Reports Server (NTRS)

Fernandez, Juan M.; Rose, Geoffrey K.; Younger, Casey J.; Dean, Gregory D.; Warren, Jerry E.; Stohlman, Olive R.; Wilkie, W. Keats

2017-01-01

Several low-cost solar sail technology demonstrator missions are under development in the United States. However, the mass saving derived benefits that composites can offer to such a mass critical spacecraft architecture have not been realized yet. This is due to the lack of suitable composite booms that can fit inside CubeSat platforms and ultimately be readily scalable to much larger sizes, where they can fully optimize their use. With this aim, a new effort focused at developing scalable rollable composite booms for solar sails and other deployable structures has begun. Seven meter booms used to deploy a 90 m2 class solar sail that can fit inside a 6U CubeSat have already been developed. The NASA road map to low-cost solar sail capability demonstration envisioned, consists of increasing the size of these composite booms to enable sailcrafts with a reflective area of up to 2000 m2 housed aboard small satellite platforms. This paper presents a solar sail system initially conceived to serve as a risk reduction alternative to Near Earth Asteroid (NEA) Scout's baseline design but that has recently been slightly redesigned and proposed for follow-on missions. The features of the booms and various deployment mechanisms for the booms and sail, as well as ground support equipment used during testing, are introduced. The results of structural analyses predict the performance of the system under microgravity conditions. Finally, the results of the functional and environmental testing campaign carried out are shown.

Non-destructive testing of satellite nozzles made of carbon fibre ceramic matrix composite, C/SiC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rebelo Kornmeier, J.; Hofmann, M.; Schmidt, S.

Carbon fibre ceramic matrix composite materials, C/SiC, are excellent candidates as lightweight structural materials for high performance hot structures such as in aerospace applications. Satellite nozzles are manufactured from C/SiC, using, for instance, the Liquid Polymer Infiltration (LPI) process. In this article the applicability of different non-destructive analysis methods for the characterisation of C/SiC components will be discussed. By using synchrotron and neutron tomography it is possible to characterise the C/SiC material in each desired location or orientation. Synchrotron radiation using tomography on small samples with a resolution of 1.4 {mu}m, i.e. the fibre scale, was used to characterise threemore » dimensionally fibre orientation and integrity, matrix homogeneity and dimensions and distributions of micro pores. Neutron radiation tomography with a resolution of about 300 {mu}m was used to analyse the over-all C/SiC satellite nozzle component with respect to the fibre content. The special solder connection of a C/SiC satellite nozzle to a metallic ring was also successfully analysed by neutron tomography. In addition, the residual stress state of a temperature tested satellite nozzle was analysed non-destructively in depth by neutron diffraction. The results revealed almost zero stress for the principal directions, radial, axial and tangential, which can be considered to be the principal directions.« less

Hinode Satellite Captures Total Solar Eclipse Video Aug. 21

NASA Image and Video Library

2017-08-21

The Japan Aerospace Exploration Agency, the National Astronomical Observatory of Japan and NASA released this video of Aug. 21 total solar eclipse taken by the X-ray telescope aboard the Hinode joint solar observation satellite as it orbited high above the Pacific Ocean.

ESPA-Based Multiple Satellite Architecture for Mars Science and Exploration

NASA Astrophysics Data System (ADS)

Lo, A. S.; Griffin, K.; Hanson, M.; Lee, G.

2012-06-01

We propose a LCROSS-based approach, enabled by ts innovative use of the ESPA ring. Exploiting this architecture for Mars mission can use the upcoming Mars launch opportunities to inject multiple satellites that can support the wide range of NASA’s goals.

Using satellite-based measurements to explore spatiotemporal scales and variability of drivers of new particle formation

EPA Science Inventory

New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently ...

Twenty-Second Lunar and Planetary Science Conference

NASA Technical Reports Server (NTRS)

1991-01-01

The papers in this collection were written for general presentation, avoiding jargon and unnecessarily complex terms. Some of the topics covered include: planetary evolution, planetary satellites, planetary composition, planetary surfaces, planetary geology, volcanology, meteorite impacts and composition, and cosmic dust. Particular emphasis is placed on Mars and the Moon.

Evaluation of Thematic Mapper Performance as Applied to Hydrocarbon Exploration. [Ontario, Canada; Cement, Oklahoma; and Death Valley, California

NASA Technical Reports Server (NTRS)

Everett, J. R.; Sheffield, C.; Dykstra, J.

1985-01-01

The role data from the first three LANDSAT satellites have in geologic exploration and their current level of acceptance is reviewed and the advantages of LANDSAT 4 TM data over MSS data are discussed. Specially enhanced Thematic Mapper imager can make a very significant contribution to the oil and gas and mineral exploration industries. The TM's increased spatial resolution enables the production of larger scale imagery, which greatly increases the amount of geomorphic and structural information interpretable. TM's greater spectral resolution, combined with the smaller, more homogeneous pixels, should enable a far greater confidence in mapping lithologies and detecting geobotanical anomalies from space. The results from its applications to hydrocarbon and mineral exploration promise to bring the majority of the geologic exploration community into that final stage of acceptance and routine application of the satellite data.

Petroleum exploration in Africa from space

NASA Astrophysics Data System (ADS)

Gianinetto, Marco; Frassy, Federico; Aiello, Martina; Rota Nodari, Francesco

2017-10-01

Hydrocarbons are nonrenewable resources but today they are the cheaper and easier energy we have access and will remain the main source of energy for this century. Nevertheless, their exploration is extremely high-risk, very expensive and time consuming. In this context, satellite technologies for Earth observation can play a fundamental role by making hydrocarbon exploration more efficient, economical and much more eco-friendly. Complementary to traditional geophysical methods such as gravity and magnetic (gravmag) surveys, satellite remote sensing can be used to detect onshore long-term biochemical and geochemical alterations on the environment produced by invisible small fluxes of light hydrocarbons migrating from the underground deposits to the surface, known as microseepage effect. This paper describes two case studies: one in South Sudan and another in Mozambique. Results show how remote sensing is a powerful technology for detecting active petroleum systems, thus supporting hydrocarbon exploration in remote or hardly accessible areas and without the need of any exploration license.

Shuttle Atlantis to deploy Galileo probe toward Jupiter

NASA Technical Reports Server (NTRS)

1989-01-01

The objectives of Space Shuttle Mission STS-34 are described along with major flight activities, prelaunch and launch operations, trajectory sequence of events, and landing and post-landing operations. The primary objective of STS-34 is to deploy the Galileo planetary exploration spacecraft into low earth orbit. Following deployment, Galileo will be propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist (VEEGA), by an inertial upper stage (IUS). The objectives of the Galileo mission are to study the chemical composition, state, and dynamics of the Jovian atmosphere and satellites, and investigate the structure and physical dynamics of the Jovian magnetosphere. Secondary STS-34 payloads include the Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument; the Mesoscale Lightning Experiment (MLE); and various other payloads involving polymer morphology, the effects of microgravity on plant growth hormone, and the growth of ice crystals.

Color Survey of the Irregular Planetary Satellites

NASA Astrophysics Data System (ADS)

Graykowski, Ariel; Jewitt, David

2017-10-01

Irregular planetary satellites are characterized by their large orbital distance from their planet, their high eccentricity and their high inclination, all indicating that they were captured. However, the mechanism of capture and the source region of the satellites remain subjects of conjecture. This work presents the optical magnitudes and colors from a photometric survey of 42 irregular satellites with data obtained from the LRIS instrument on the 10-meter telescope at the Keck Observatory in Hawaii. Color is used as a proxy for composition. We compare the satellite populations of different planets and compare the satellites as a whole with other solar system small-body populations. For instance, if irregular satellites were captured from the Kuiper Belt, as is commonly proposed, then some might contain the ultrared material that is common in the trans-Neptunian and Centaur populations. Overall our data show that the irregular satellites lack ultrared matter. They are color-wise more similar to the comets, giant planet Trojans and other bodies of the middle solar system. Implications of our observations, and comparisons with previous color work, will be discussed.

Comparison of Landsat MSS and merged MSS/RBV data for analysis of natural vegetation

NASA Technical Reports Server (NTRS)

Roller, N. E. G.; Cox, S.

1980-01-01

Improved resolution could make satellite remote sensing data more useful for surveys of natural vegetation. Although improved satellite/sensor systems appear to be several years away, one potential interim solution to the problem of achieving greater resolution without sacrificing spectral sensitivity is through the merging of Landsat RBV and MSS data. This paper describes the results of a study performed to obtain a preliminary evaluation of the usefulness of two types of products that can be made by merging Landsat RBV and MSS data. The products generated were a false color composite image and a computer recognition map. Of these two products, the false color composite image appears to be the most useful.

Near-earth asteroids - Possible sources from reflectance spectroscopy

NASA Technical Reports Server (NTRS)

Mcfadden, L. A.; Gaffey, M. J.; Mccord, T. B.

1985-01-01

The diversity of reflectance spectra noted among near-earth asteroids that were compared with selected asteroids, planets and satellites to determine possible source regions is indicative of different mineralogical composition and, accordingly, of more than one source region. Spectral signatures that are similar to those of main belt asteroids support models deriving some of these asteroids from the 5:2 Kirkwood gap and the Flora family, by way of gravitational perturbations. The differences in composition found between near-earth asteroids and planetary and satellite surfaces are in keeping with theoretical arguments that such bodies should not be sources. While some near-earth asteroids furnish portions of the earth's meteorite flux, other sources must also contribute.

Evaluation of a moderate resolution, satellite-based impervious surface map using an independent, high-resolution validation data set

USGS Publications Warehouse

Jones, J.W.; Jarnagin, T.

2009-01-01

Given the relatively high cost of mapping impervious surfaces at regional scales, substantial effort is being expended in the development of moderate-resolution, satellite-based methods for estimating impervious surface area (ISA). To rigorously assess the accuracy of these data products high quality, independently derived validation data are needed. High-resolution data were collected across a gradient of development within the Mid-Atlantic region to assess the accuracy of National Land Cover Data (NLCD) Landsat-based ISA estimates. Absolute error (satellite predicted area - "reference area") and relative error [satellite (predicted area - "reference area")/ "reference area"] were calculated for each of 240 sample regions that are each more than 15 Landsat pixels on a side. The ability to compile and examine ancillary data in a geographic information system environment provided for evaluation of both validation and NLCD data and afforded efficient exploration of observed errors. In a minority of cases, errors could be explained by temporal discontinuities between the date of satellite image capture and validation source data in rapidly changing places. In others, errors were created by vegetation cover over impervious surfaces and by other factors that bias the satellite processing algorithms. On average in the Mid-Atlantic region, the NLCD product underestimates ISA by approximately 5%. While the error range varies between 2 and 8%, this underestimation occurs regardless of development intensity. Through such analyses the errors, strengths, and weaknesses of particular satellite products can be explored to suggest appropriate uses for regional, satellite-based data in rapidly developing areas of environmental significance. ?? 2009 ASCE.

Communication satellite applications

NASA Astrophysics Data System (ADS)

Pelton, Joseph N.

The status and future of the technologies, numbers and services provided by communications satellites worldwide are explored. The evolution of Intelsat satellites and the associated earth terminals toward high-rate all-digital telephony, data, facsimile, videophone, videoconferencing and DBS capabilities are described. The capabilities, services and usage of the Intersputnik, Eutelsat, Arabsat and Palapa systems are also outlined. Domestic satellite communications by means of the Molniya, ANIK, Olympus, Intelsat and Palapa spacecraft are outlined, noting the fast growth of the market and the growing number of different satellite manufacturers. The technical, economic and service definition issues surrounding DBS systems are discussed, along with presently operating and planned maritime and aeronautical communications and positioning systems. Features of search and rescue and tracking, data, and relay satellite systems are summarized, and services offered or which will be offered by every existing or planned communication satellite worldwide are tabulated.

The Use of NASA near Real-time and Archived Satellite Data to Support Disaster Assessment

NASA Technical Reports Server (NTRS)

McGrath, Kevin M.; Molthan, Andrew; Burks, Jason

2014-01-01

With support from a NASA's Applied Sciences Program, The Short-term Prediction Research and Transition (SPoRT) Center has explored a variety of techniques for utilizing archived and near real-time NASA satellite data to support disaster assessment activities. MODIS data from the NASA Land Atmosphere Near Real-time Capability for EOS currently provides true color and other imagery for assessment and potential applications including, but not limited to, flooding, fires, and tornadoes. In May 2013, the SPoRT Center developed unique power outage composites using the VIIRS Day/Night Band to represent the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Pre-event imagery provided by the NASA funded Web-Enabled Landsat Data project offer a basis of comparison for monitoring post-disaster recovery efforts. Techniques have also been developed to generate products from higher resolution imagery from the recently available International Space Station SERVIR Environmental Research and Visualization System instrument. Of paramount importance is to deliver these products to end users expeditiously and in formats compatible with Decision Support Systems (DSS). Delivery techniques include a Tile Map Service (TMS) and a Web Mapping Service (WMS). These mechanisms allow easy integration of satellite products into DSS's, including the National Weather Service's Damage Assessment Toolkit for use by personnel conducting damage surveys. This poster will present an overview of the developed techniques and products and compare the strengths and weaknesses of the TMS and WMS.

Redefining climate regions in the United States of America using satellite remote sensing and machine learning for public health applications.

PubMed

Liss, Alexander; Koch, Magaly; Naumova, Elena N

2014-12-01

Existing climate classification has not been designed for an efficient handling of public health scenarios. This work aims to design an objective spatial climate regionalization method for assessing health risks in response to extreme weather. Specific climate regions for the conterminous United States of America (USA) were defined using satellite remote sensing (RS) data and compared with the conventional Köppen-Geiger (KG) divisions. Using the nationwide database of hospitalisations among the elderly (≥65 year olds), we examined the utility of a RS-based climate regionalization to assess public health risk due to extreme weather, by comparing the rate of hospitalisations in response to thermal extremes across climatic regions. Satellite image composites from 2002-2012 were aggregated, masked and compiled into a multi-dimensional dataset. The conterminous USA was classified into 8 distinct regions using a stepwise regionalization approach to limit noise and collinearity (LKN), which exhibited a high degree of consistency with the KG regions and a well-defined regional delineation by annual and seasonal temperature and precipitation values. The most populous was a temperate wet region (10.9 million), while the highest rate of hospitalisations due to exposure to heat and cold (9.6 and 17.7 cases per 100,000 persons at risk, respectively) was observed in the relatively warm and humid south-eastern region. RS-based regionalization demonstrates strong potential for assessing the adverse effects of severe weather on human health and for decision support. Its utility in forecasting and mitigating these effects has to be further explored.

Interplanetary Small Satellite Conference 2017 Program

NASA Technical Reports Server (NTRS)

Dalle, Derek Jordan

2017-01-01

The Interplanetary Small Satellite Conference will be held at San Jose State University on May 1 and 2, 2017. The program attached here contains logistical information for attendees, the agenda, and abstracts of the conference presentations. All abstracts were reviewed by their authors' home institute and approved for public release prior to inclusion in the program booklet. The ISSC explores mission concepts, emerging technologies, and fosters outside the box thinking critical to future interplanetary small satellite missions.

Drag on a Satellite Moving across a Spherical Galaxy: Tidal and Frictional Forces in Short-lived Encounters

NASA Astrophysics Data System (ADS)

Colpi, Monica; Pallavicini, Andrea

1998-07-01

The drag force on a satellite of mass M moving with speed V in the gravitational field of a spherically symmetric background of stars is computed. During the encounter, the stars are subject to a time-dependent force that alters their equilibrium. The resulting distortion in the stellar density field acts back to produce a force FΔ that decelerates the satellite. This force is computed using a perturbative technique known as linear response theory. In this paper, we extend the formalism of linear response to derive the correct expression for the back-reaction force FΔ that applies when the stellar system is described by an equilibrium one-particle distribution function. FΔ is expressed in terms of a suitable correlation function that couples the satellite dynamics to the unperturbed dynamics of the stars. At time t, the force depends upon the whole history of the composite system. In the formalism, we account for the shift of the stellar center of mass resulting from linear momentum conservation. The self-gravity of the response is neglected since it contributes to a higher order in the perturbation. Linear response theory applies also to the case of a satellite orbiting outside the spherical galaxy. The case of a satellite moving on a straight line, at high speed relative to the stellar dispersion velocity, is explored. We find that the satellite during its passage raises (1) global tides in the stellar distribution and (2) a wake, i.e., an overdense region behind its trail. If the satellite motion is external to the galaxy, it suffers a dissipative force that is not exclusively acting along V but acquires a component along R, the position vector relative to the center of the spherical galaxy. We derive the analytical expression of the force in the impulse approximation. In penetrating short-lived encounters, the satellite moves across the stellar distribution and the transient wake excited in the density field is responsible for most of the deceleration. We find that dynamical friction arises from a memory effect involving only those stars perturbed along the path. The force can be written in terms of an effective Coulomb logarithm that now depends upon time. The value of ln Λ is computed for two simple equilibrium density distributions; it is shown that the drag increases as the satellite approaches the denser regions of the stellar distribution and attains a maximum after pericentric passage. When the satellite crosses the edge of the galaxy, the force does not vanish since the galaxy keeps memory of the perturbation induced and declines on a time comparable to the dynamical time of the stellar system. In the case of a homogeneous cloud, we compute the total energy loss. In evaluating the contribution resulting from friction, we derive self-consistently the maximum impact parameter, which is found to be equal to the length traveled by the satellite within the system. Tides excited by the satellite in the galaxy reduce the value of the energy loss by friction; in close encounters, this value is decreased by a factor of ~1.5.

The Fixed-Bias Langmuir Probe on the Communication-Navigation Outage Forecast System Satellite: Calibration and Validation

NASA Technical Reports Server (NTRS)

Klenzing, J.; Rowland, D.

2012-01-01

A fixed-bias spherical Langmuir probe is included as part of the Vector Electric Field Instrument (VEFI) suite on the Communication Navigation Outage Forecast System (CNOFS) satellite.CNOFS gathers data in the equatorial ionosphere between 400 and 860 km, where the primary constituent ions are H+ and O+. The ion current collected by the probe surface per unit plasma density is found to be a strong function of ion composition. The calibration of the collected current to an absolute density is discussed, and the performance of the spherical probe is compared to other in situ instruments on board the CNOFS satellite. The application of the calibration is discussed with respect to future fixed-bias probes; in particular, it is demonstrated that some density fluctuations will be suppressed in the collected current if the plasma composition rapidly changes along with density. This is illustrated in the observation of plasma density enhancements on CNOFS.

Continental land cover classification using meteorological satellite data

NASA Technical Reports Server (NTRS)

Tucker, C. J.; Townshend, J. R. G.; Goff, T. E.

1983-01-01

The use of the National Oceanic and Atmospheric Administration's advanced very high resolution radiometer satellite data for classifying land cover and monitoring of vegetation dynamics over an extremely large area is demonstrated for the continent of Africa. Data from 17 imaging periods of 21 consecutive days each were composited by a technique sensitive to the in situ green-leaf biomass to provide cloud-free imagery for the whole continent. Virtually cloud-free images were obtainable even for equatorial areas. Seasonal variation in the density and extent of green leaf vegetation corresponded to the patterns of rainfall associated with the inter-tropical convergence zone. Regional variations, such as the 1982 drought in east Africa, were also observed. Integration of the weekly satellite data with respect to time produced a remotely sensed assessment of biological activity based upon density and duration of green-leaf biomass. Two of the 21-day composited data sets were used to produce a general land cover classification. The resultant land cover distributions correspond well to those of existing maps.

Exploration for fossil and nuclear fuels from orbital altitudes

NASA Technical Reports Server (NTRS)

Short, N. M.

1977-01-01

The paper discusses the application of remotely sensed data from orbital satellites to the exploration for fossil and nuclear fuels. Geological applications of Landsat data are described including map editing, lithologic identification, structural geology, and mineral exploration. Specific results in fuel exploration are reviewed and a series of related Landsat images is included.

Satellite Remote Sensing For Aluminum And Nickel Laterites

NASA Astrophysics Data System (ADS)

Henderson, Frederick B.; Penfield, Glen T.; Grubbs, Donald K.

1984-08-01

The new LANDSAT-4,-5/Thematic Mapper (TM) land observational satellite remote sensing systems are providing dramatically new and important short wave infrared (SWIR) data, which combined with Landsat's Multi-Spectral Scanner (MSS) visible (VIS), very near infrared (VNIR), and thermal infrared (TI) data greatly improves regional geological mapping on a global scale. The TM will significantly improve clay, iron oxide, aluminum, and nickel laterite mapping capabilities over large areas of the world. It will also improve the ability to discriminate vegetation stress and species distribution associated with lateritic environments. Nickel laterites on Gag Island, Indonesia are defined by MSS imagery. Satellite imagery of the Cape Bougainville and the Darling Range, Australia bauxite deposits show the potential use of MSS data for exploration and mining applications. Examples of satellite syn-thetic aperture radar (SAR) for Jamaica document the use of this method for bauxite exploration. Thematic Mapper data will be combined with the French SPOT satellite's high spatial resolution and stereoscopic digital data, and U.S., Japanese, European, and Canadian Synthetic Aperture Radar (SAR) data to assist with logistics, mine development, and environ-mental concerns associated with aluminum and nickel lateritic deposits worldwide.

Scientific Objectives of China-Russia Joint Mars Exploration Program YH-1

NASA Astrophysics Data System (ADS)

Wu, Ji; Zhu, Guang-Wu; Zhao, Hua; Wang, Chi; Li, Lei; Sun, Yue-Qiang; Guo, Wei; Huang, Cheng-Li

2010-04-01

Compared with other planets, Mars is a planet most similar with the earth and most possible to find the extraterrestrial life on it, and therefore especially concerned about by human beings. In recent years, some countries have launched Mars probes and announced their manned Mars exploration programs. China has become the fifth country in the world to launch independently artificial satellites, and the third country able to carry out an independent manned space program. However, China is just at the beginning of deep space explorations. In 2007, China and Russia signed an agreement on a joint Mars exploration program by sending a Chinese micro-satellite Yinghuo-1 (YH-1) to the Mars orbit. Once YH-1 enters its orbit, it will carry out its own exploration, as well as the joint exploration with the Russian Phobos-Grunt probe. This paper summarizes the scientific background and objectives of YH-1 and describes briefly its payloads for realizing these scientific objectives. In addition, the main exploration tasks of YH-1 and a preliminary prospect on its exploration results are also given.

The Chinese FY-1 Meteorological Satellite Application in Observation on Oceanic Environment

NASA Astrophysics Data System (ADS)

Weimin, S.

meteorological satellite is stated in this paper. exploration of the ocean resources has been a very important question of global strategy in the world. The exploration of the ocean resources includes following items: Making full use of oceanic resources and space, protecting oceanic environment. to observe the ocean is by using of satellite. In 1978, US successfully launched the first ocean observation satellite in the world --- Sea Satellite. It develops ancient oceanography in to advanced space-oceanography. FY-1 B and FY- IC respectively. High quality data were acquired at home and abroad. FY-1 is Chinese meteorological satellite, but with 0.43 ~ 0.48 μm ,0.48 ~ 0.53 μm and 0.53 ~ 0.58 μm three ocean color channels, actually it is a multipurpose remote sensing satellite of meteorology and oceanography. FY-1 satellite's capability of observation on ocean partly, thus the application field is expanded and the value is increased. With the addition of oceanic channels on FY-1, the design of the satellite is changed from the original with meteorological observation as its main purpose into remote sensing satellite possessing capability of observing meteorology and ocean as well. Thus, the social and economic benefit of FY-1 is increased. the social and economic benefit of the development of the satellite is the key technique in the system design of the satellite. technically feasible but also save the funds in researching and manufacturing of the satellite, quicken the tempo of researching and manufacturing satellite. the scanning radiometer for FY-1 is conducted an aviation experiment over Chinese ocean. This experiment was of vital importance to the addition of oceanic observation channel on FY-1. FY-1 oceanic channels design to be correct. detecting ocean color. This is the unique character of Chinese FY-1 meteorological satellite. meteorological remote sensing channel on FY-1 to form detecting capability of three visible channels: red, yellow and blue spectrum bands. Thus FY-1 satellite can be used for observation on ocean color experiment. This experiment is successful, a lot of data were acquired. Good application results were obtained in the field of oceanic science research. Therefore, it makes FY-1 a remote sensing satellite used for observation on meteorology and ocean. This is the unique character of Chinese FY-1 meteorological satellite, it is widely noticed all over the world. Chinese meteorological satellite has been realized the aim of using one satellite for multipurpose applications and brought more and more social and economic benefit. oceanic channel in Chinese meteorological satellites is also foreseen to expand the application field in Chinese meteorological satellites. Key Word : Meteorological Satellite Oceanic Remote Sensing

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

Florida Governor Rick Scott speaks during the groundbreaking ceremony at Kennedy's Exploration Park for OneWeb. The company, in partnership with Airbus, is building a 150,000-square-foot factory to manufacture satellites that will connect all areas of the world to the Internet wirelessly. Photo credit: NASA/Kim Shiflett

Composite Technology for Exploration

NASA Technical Reports Server (NTRS)

Fikes, John

2017-01-01

The CTE (Composite Technology for Exploration) Project will develop and demonstrate critical composites technologies with a focus on joints that utilize NASA expertise and capabilities. The project will advance composite technologies providing lightweight structures to support future NASA exploration missions. The CTE project will demonstrate weight-saving, performance-enhancing bonded joint technology for Space Launch System (SLS)-scale composite hardware.

The YORP effect on the GOES 8 and GOES 10 satellites: A case study

NASA Astrophysics Data System (ADS)

Albuja, Antonella A.; Scheeres, Daniel J.; Cognion, Rita L.; Ryan, William; Ryan, Eileen V.

2018-01-01

The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a proposed explanation for the observed rotation behavior of inactive satellites in Earth orbit. This paper further explores the YORP effect for highly asymmetric inactive satellites. Satellite models are developed to represent the GOES 8 and GOES 10 satellites, both of which are currently inactive in geosynchronous Earth orbit (GEO). A simple satellite model for the GOES 8 satellite is used to analyze the short period variations of the angular velocity and obliquity as a result of the YORP effect. A more complex model for the rotational dynamics of the GOES 8 and GOES 10 satellites are developed to probe their sensitivity and to match observed spin periods and states of these satellites. The simulated rotation periods are compared to observations for both satellites. The comparison between YORP theory and observed rotation rates for both satellites show that the YORP effect could be the cause for the observed rotational behavior. The YORP model also predicts a novel state for the GOES 8 satellite, namely that it could periodically fall into a tumbling rotation state. Recent observations of this satellite are consistent with this prediction.

Report of the Terrestrial Bodies Science Working Group. Volume 1: Executive summary. [Terrestrial planets, Galilean satellites, Comets, Asteroids, and the Moon

NASA Technical Reports Server (NTRS)

1977-01-01

Current knowledge of Mercury, Venus, Mars, the Moon, asteroids, comets, and the Galilean satellites were reviewed along with related NASA programs and available mission concepts. Exploration plans for the 1980 to 1990 period are outlined and recommendations made. Topics discussed include: scientific objectives and goals, exploration strategy and recommended mission plans, supporting research and technology, Earth-based and Earth-orbital investigations, data analysis and synthesis, analysis of extraterrestrial materials, broadening the science support base, and international cooperation.

Tethered satellite system dynamics and control review panel and related activities, phase 3

NASA Technical Reports Server (NTRS)

1991-01-01

Two major tests of the Tethered Satellite System (TSS) engineering and flight units were conducted to demonstrate the functionality of the hardware and software. Deficiencies in the hardware/software integration tests (HSIT) led to a recommendation for more testing to be performed. Selected problem areas of tether dynamics were analyzed, including verification of the severity of skip rope oscillations, verification or comparison runs to explore dynamic phenomena observed in other simulations, and data generation runs to explore the performance of the time domain and frequency domain skip rope observers.

Machine Learning Algorithms for Automated Satellite Snow and Sea Ice Detection

NASA Astrophysics Data System (ADS)

Bonev, George

The continuous mapping of snow and ice cover, particularly in the arctic and poles, are critical to understanding the earth and atmospheric science. Much of the world's sea ice and snow covers the most inhospitable places, making measurements from satellite-based remote sensors essential. Despite the wealth of data from these instruments many challenges remain. For instance, remote sensing instruments reside on-board different satellites and observe the earth at different portions of the electromagnetic spectrum with different spatial footprints. Integrating and fusing this information to make estimates of the surface is a subject of active research. In response to these challenges, this dissertation will present two algorithms that utilize methods from statistics and machine learning, with the goal of improving on the quality and accuracy of current snow and sea ice detection products. The first algorithm aims at implementing snow detection using optical/infrared instrument data. The novelty in this approach is that the classifier is trained using ground station measurements of snow depth that are collocated with the reflectance observed at the satellite. Several classification methods are compared using this training data to identify the one yielding the highest accuracy and optimal space/time complexity. The algorithm is then evaluated against the current operational NASA snow product and it is found that it produces comparable and in some cases superior accuracy results. The second algorithm presents a fully automated approach to sea ice detection that integrates data obtained from passive microwave and optical/infrared satellite instruments. For a particular region of interest the algorithm generates sea ice maps of each individual satellite overpass and then aggregates them to a daily composite level, maximizing the amount of high resolution information available. The algorithm is evaluated at both, the individual satellite overpass level, and at the daily composite level. Results show that at the single overpass level for clear-sky regions, the developed multi-sensor algorithm performs with accuracy similar to that of the optical/infrared products, with the advantage of being able to also classify partially cloud-obscured regions with the help of passive microwave data. At the daily composite level, results show that the algorithm's performance with respect to total ice extent is in line with other daily products, with the novelty of being fully automated and having higher resolution.

A series of small scientific satellite with flexible standard bus

NASA Astrophysics Data System (ADS)

Saito, Hirobumi; Sawai, Syujiro; Sakai, Shin-ichiro; Fukuda, Seisuke; Kitade, Kenji

2009-11-01

Japan Aerospace Exploration Agency has a plan to develop the small satellite standard bus for various scientific missions and disaster monitoring missions. The satellite bus is a class of 250-400 kg mass with three-axis control capability of 0.02∘ accuracy. The science missions include X-ray astronomy missions, planetary telescope missions, and magnetosphere atmosphere missions. In order to adapt the wide range of mission requirements, the satellite bus has to be provided with flexibility. The concepts of modularization, reusability, and product line are applied to the standard bus system. This paper describes the characteristics of the small satellite standard bus which will be firstly launched in 2011.

Advanced Earth Observation System Instrumentation Study (aeosis)

NASA Technical Reports Server (NTRS)

White, R.; Grant, F.; Malchow, H.; Walker, B.

1975-01-01

Various types of measurements were studied for estimating the orbit and/or attitude of an Earth Observation Satellite. An investigation was made into the use of known ground targets in the earth sensor imagery, in combination with onboard star sightings and/or range and range rate measurements by ground tracking stations or tracking satellites (TDRSS), to estimate satellite attitude, orbital ephemeris, and gyro bias drift. Generalized measurement equations were derived for star measurements with a particular type of star tracker, and for landmark measurements with a multispectral scanner being proposed for an advanced Earth Observation Satellite. The use of infra-red horizon measurements to estimate the attitude and gyro bias drift of a geosynchronous satellite was explored.

Active Control of NITINOL-Reinforced Structural Composites

DTIC Science & Technology

1992-10-12

useful in many critical structures that are intended to operate autonomously for long durations in isolated environments such as defense vehicles , space...durations in isolated environment such as defense vehicles , space structures and satellites. ACKNOWLEDGEMENTS This work is funded by a grant from the US Army...are intended to operate autonomously for long durations in isolated environment such as defense vehicles , space structures and satellites. REFERENCES

Multispectral Analysis of NMR Imagery

NASA Technical Reports Server (NTRS)

Butterfield, R. L.; Vannier, M. W. And Associates; Jordan, D.

1985-01-01

Conference paper discusses initial efforts to adapt multispectral satellite-image analysis to nuclear magnetic resonance (NMR) scans of human body. Flexibility of these techniques makes it possible to present NMR data in variety of formats, including pseudocolor composite images of pathological internal features. Techniques do not have to be greatly modified from form in which used to produce satellite maps of such Earth features as water, rock, or foliage.

The composition of phobos: evidence for carbonaceous chondrite surface from spectral analysis.

PubMed

Pang, K D; Pollack, J B; Veverka, J; Lane, A L; Ajello, J M

1978-01-06

A reflectance spectrum of Phobos (from 200 to 1100 nanometers) has been compiled from the Mariner 9 ultraviolet spectrometer, Viking lander imaging, and ground-based photometric data. The reflectance of the martian satellite is approximately constant at 5 percent from 1100 to 400 nanometers but drops sharply below 400 nanometers, reaching a value of 1 percent at 200 nanometers. The spectral albedo of Phobos bears a striking resemblance to that of asteroids (1) Ceres and (2) Pallas. Comparison of the reflectance spectra of asteroids with those of meteorites has shown that the spectral signature of Ceres is indicative of a carbonaceous chondritic composition. A physical explanation of how the compositional information is imposed on the reflectance spectrum is given. On the basis of a good match between the reflectance spectra of Phobos and Ceres and the extensive research that has been done to infer the composition of Ceres, it seems reasonable to believe that the surface composition of Phobos is similar to that of carbonaceous chondrites. This suggestion is consistent with the recently determined low density of Mars's inner satellite. Our result and recent Viking noble gas measurements suggest different modes of origin for Mars and Phobos.

Latest Progress In Novel High Conductivity And Highly Stable Composite Structure Developments For Satellite Applications

NASA Astrophysics Data System (ADS)

Klebor, Maximillian; Reichmann, Olaf; Pfeiffer, Ernst K.; Ihle, Alexander; Linke, Stefan; Tschepe, Christoph; Roddecke, Susanne; Richter, Ines; Berrill, Mark; Santiago-Prowald, Julian

2012-07-01

Materials such as aluminium, titanium and carbon fibre based composites are indispensable in space business. However, special demands on spaceborne applications require both new ideas and new concepts but also powerful novel materials. These days the trend is to substitute aluminium for CFRP basically in order to safe mass or to decrease thermal expansions. Nevertheless there are upcoming requirements that cannot be met using standard CFRP materials. In this connection innovative composites have to be introduced. In the frame of this paper three major applications for such material requests are considered, i.e.: • antennas • satellite platform structural panels • radiators. The new composites need to cope with the following challenges and demands: high operational temperature range, high stiffness, high strength, high thermal conductivity, vacuum compatibility, low mass, high in- orbit stability, compatibility with metallic parts and many more. Some of these demands have to be fulfilled in conjunction. Herein the innovative composites cover new raw materials and their combination, manufacturing process enhancement as well as new inspection and test methods. It has been observed that by using the developed CFRPs it is possible to satisfy and excel the needs. However, these materials feature a different behaviour than conventional composites which has to be taken into account during future design.

IT Middleware Services for an 'Exploration Web'

NASA Technical Reports Server (NTRS)

Lamarra, Norm

2003-01-01

This slide presentation reviews the application of middleware in space exploration, and satellite communications. The aim of the use of Space middleware is ot use remote sensors and other resources more efficiently.

Energy dissipation/transfer and stable attitude of spatial on-orbit tethered system

NASA Astrophysics Data System (ADS)

Hu, Weipeng; Song, Mingzhe; Deng, Zichen

2018-01-01

For the Tethered Satellite System, the coupling between the platform system and the solar panel is a challenge in the dynamic analysis. In this paper, the coupling dynamic behaviors of the Tethered Satellite System that is idealized as a planar flexible damping beam-spring-mass composite system are investigated via a structure-preserving method. Considering the coupling between the plane motion of the system, the oscillation of the spring and the transverse vibration of the beam, the dynamic model of the composite system is established based on the Hamiltonian variational principle. A symplectic dimensionality reduction method is proposed to decouple the dynamic system into two subsystems approximately. Employing the complex structure-preserving approach presented in our previous work, numerical iterations are performed between the two subsystems with weak damping to study the energy dissipation/transfer in the composite system, the effect of the spring stiffness on the energy distribution and the effect of the particle mass on the stability of the composite system. The numerical results show that: the energy transfer approach is uniquely determined by the initial attitude angle, while the energy dissipation speed is mainly depending on the initial attitude angle and the spring stiffness besides the weak damping. In addition, the mass ratio between the platform system and the solar panel determines the stable state as well as the time needed to reach the stable state of the composite system. The numerical approach presented in this paper provides a new way to deal with the coupling dynamic system and the conclusions obtained give some useful advices on the overall design of the Tethered Satellite System.

Global Interconnectivity Between Mobile Satellite and Terrestrial Users: Call Signalling Issues and Challenges

NASA Technical Reports Server (NTRS)

Estabrook, Polly; Moon, Todd; Spade, Rob

1996-01-01

This paper will discuss some of the challenges in connecting mobile satellite users and mobile terrestrial users in a cost efficient manner and with a grade of service comparable to that of satellite to fixed user calls. Issues arising from the translation between the mobility management protocols resident at the satellite Earth station and those resident at cellular switches - either GSM (Group Special Mobile) or IS-41 (used by U.S. digital cellular systems) type - will be discussed. The impact of GSM call routing procedures on the call setup of a satellite to roaming GSM user will be described. Challenges facing provision of seamless call handoff between satellite and cellular systems will be given. A summary of the issues explored in the paper are listed and future work outlined.

Development of the Lunar and Solar Perturbations in the Motion of an Artificial Satellite

NASA Technical Reports Server (NTRS)

Musen, P.; Bailie, A.; Upton, E.

1961-01-01

Problems relating to the influence of lunar and solar perturbations on the motion of artificial satellites are analyzed by an extension of Cayley's development of the perturbative function in the lunar theory. In addition, the results are modified for incorporation into the Hansen-type theory used by the NASA Space Computing Center. The theory is applied to the orbits of the Vanguard I and Explorer VI satellites, and the results of detailed computations for these satellites are given together with a physical description of the perturbations in terms of resonance effects.

Building technological capability within satellite programs in developing countries

NASA Astrophysics Data System (ADS)

Wood, Danielle; Weigel, Annalisa

2011-12-01

This paper explores the process of building technological capability in government-led satellite programs within developing countries. The key message is that these satellite programs can learn useful lessons from literature in the international development community. These lessons are relevant to emerging satellite programs that leverage international partnerships in order to establish local capability to design, build and operate satellites. Countries with such programs include Algeria, Nigeria, Turkey, Malaysia and the United Arab Emirates. The paper first provides background knowledge about space activity in developing countries, and then explores the nuances of the lessons coming from the international development literature. Developing countries are concerned with satellite technology because satellites provide useful services in the areas of earth observation, communication, navigation and science. Most developing countries access satellite services through indirect means such as sharing data with foreign organizations. More countries, however, are seeking opportunities to develop satellite technology locally. There are objective, technically driven motivations for developing countries to invest in satellite technology, despite rich debate on this topic. The paper provides a framework to understand technical motivations for investment in satellite services, hardware, expertise and infrastructure in both short and long term. If a country decides to pursue such investments they face a common set of strategic decisions at the levels of their satellite program, their national context and their international relationships. Analysis of past projects shows that countries have chosen diverse strategies to address these strategic decisions and grow in technological capability. What is similar about the historical examples is that many countries choose to leverage international partnerships as part of their growth process. There are also historical examples from outside the space arena in which organizations have pursued technological capability. Scholars have analyzed these examples and developed insightful frameworks. The paper draws key concepts from this literature about the nature of development, technology, knowledge and organizational learning. These concepts are relevant to learning in new satellite programs, but the ideas must be applied cautiously because of the nature of satellite technology. The paper draws three major lessons from the international development literature regarding absorptive capacity, tacit knowledge and organizational learning; it synthesizes these lessons into a cohesive, original framework. The closing section proposes future work on a detailed study of technological learning in specific government satellite programs.

Real-time Identification and Control of Satellite Signal Impairments Solution and Application of the Stratonovich Equation Part 1. Theoretical Development

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2016-01-01

As satellite communications systems become both more complex and reliant with respect to their operating environment, it has become imperative to be able to identify, during real-time operation, the onset of one or more impairments to the quality of overall communications system integrity. One of the most important aspects to monitor of a satellite link operating within the Earth's atmosphere is the signal fading due to the occurrence of rain and/or phase scintillations. This, of course, must be done in the presence of the associated measurement uncertainty or potentially faulty measurement equipment such as in the Advanced Communication Technology Satellite (ACTS) experiment. In the present work, an approach originally suggested in 1991, and apparently still considered iconoclastic, will be significantly developed and applied to the satellite communications link on which the deleterious composite signal fade is the result of one or many component fade mechanisms. Through the measurement (with the attendant uncertainty or 'error' in the measurement) of such a composite fading satellite signal, it is desired to extract the level of each of the individual fading mechanisms so they can be appropriately mitigated before they impact the overall performance of the communications network. Rather than employing simple-minded deterministic filtering to the real-time fading, the present approach is built around all the models and/or descriptions used to describe the individual fade components, including their dynamic evolution. The latter is usually given by a first-order Langevin equation. This circumstance allows the description of the associated temporal transition probability densities of each of the component processes. By using this description, along with the real-time measurements of the composite fade (along with the measurement errors), one can obtain statistical estimates of the levels of each of the component fading mechanisms as well as their predicted values into the future. This is all accomplished by the use of the well-known Stratonovich integro-differential equation that results from the model of the measured signal fade that is also tailored to adaptively adjust the values of the parameters used in the statistical models of the individual fade mechanisms. Three examples of increasing complexity are addressed and solved for the iterative determination of fade component levels from the measured composite signal fade in the presence of measurement error and, in the last case, with uncertainty in the model parameters.

Exoplanet exploration for brown dwarfs with infrared astrometry

NASA Astrophysics Data System (ADS)

Yamaguchi, Masaki

The astrometry is one of the oldest method for the exoplanet exploration. However, only one exoplanet has been found with the method. This is because the planet mass is sufficiently smaller than the mass of the central star, so that it is hard to observe the fluctuation of the central star by the planet. Therefore, we investigate the orbital period and mass of planets which we can discover by the future astrometric satellites for brown dwarfs, with the mass less than a tenth of the solar mass. So far five planetary systems of brown dwarfs have been found, whose mass ratios are larger than a tenth. For example, for the system whose distance, orbital period and mass ratio are 10 pc, 1 year and a tenth, respectively, the apparent semi-major axis reaches 3 milli-arcsecond, which can be well detected with the future astrometric satellites such as Small-JASMINE and Gaia. With these satellite, we can discover even super-Earth for the above system. We further investigate where in the period-mass plane we can explore the planet for individual brown dwarf with Small-JASMINE and Gaia. As a result, we find that we can explore a wide region where period and mass are within 5 years and larger than 3 earth mass. In addition, we can explore the region around 0.1 day and 10 Jovian mass, where planets have never found for any central star, and where we can explore only with Small-JASMINE for most target brown dwarfs.

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

Jim Kuzma, COO of Space Florida, speaks during the groundbreaking ceremony at Kennedy's Exploration Park for OneWeb. The company, in partnership with Airbus, is building a 150,000-square-foot factory to manufacture satellites that will connect all areas of the world to the Internet wirelessly. Photo credit: NASA/Kim Shiflett

Telelearning for Extension Agents: The Virginia Experience.

ERIC Educational Resources Information Center

Murphy, William F., Jr.

The creation of the Virginia Tech Teleport Facility and the installation of a nine-meter (diameter) C-Band satellite uplink antenna provided the initial impetus for the Virginia Cooperative Extension Service (VCES) to explore the use of satellite technology for information and program delivery. The $600,000 uplink became operational in September…

Catastrophic disruption of asteriods and satellites; Proceedings of the International Workshop, Pisa, Italy, July 30-August 2, 1985

NASA Astrophysics Data System (ADS)

Davis, D. R.; Farinella, P.; Paolicchi, P.; Zappala, V.

Theoretical, numerical, and experimental investigations of the violent disruption of asteroids or planetary satellites are discussed in reviews and reports. Topics examined include acceleration techniques and results of experiments simulating catastrophic fragmentation events; laboratory simulations of catastrophic impact; scaling laws for the catastrophic collisions of asteroids; asteroid collisional history, the origin of the Hirayama families, and disruption of small satellites; and the implications of the inferred compositions of a steroids for their collisional evolution. Diagrams, graphs, tables, and a summary of the discussion at the workshop are provided.

Catastrophic disruption of asteriods and satellites; Proceedings of the International Workshop, Pisa, Italy, July 30-August 2, 1985

NASA Technical Reports Server (NTRS)

Davis, D. R. (Editor); Farinella, P. (Editor); Paolicchi, P. (Editor); Zappala, V. (Editor)

1986-01-01

Theoretical, numerical, and experimental investigations of the violent disruption of asteroids or planetary satellites are discussed in reviews and reports. Topics examined include acceleration techniques and results of experiments simulating catastrophic fragmentation events; laboratory simulations of catastrophic impact; scaling laws for the catastrophic collisions of asteroids; asteroid collisional history, the origin of the Hirayama families, and disruption of small satellites; and the implications of the inferred compositions of a steroids for their collisional evolution. Diagrams, graphs, tables, and a summary of the discussion at the workshop are provided.

Saturn's satellites - Near-infrared spectrophotometry (0.65-2.5 microns) of the leading and trailing sides and compositional implications

NASA Technical Reports Server (NTRS)

Steele, A.; Clark, R. N.; Brown, R. H.; Owensby, P. D.

1984-01-01

Water ice absorptions at 2.0, 1.5, and 1.25 microns are noted in near-IR spectra of Tethys, Dione, Rhea, Iapetus, and Hyperion, and the weak 1.04-micron ice absorption, which is detected for Rhea and Dione, is studied to establish band depth upper limits. The leading-trailing side 1.04-micron ice band depth differences on Saturn's satellites are similar to those for the Galilean satellites, indicating possible surface modification by magnetospheric charged particle bombardment. Limits are obtained for the amounts of particulates, trapped gases, and ammonium hydroxide on the surface. With the exception of the dark side of Iapetus, the surfaces of all of Saturn's satellites are nearly pure ice water.

Proceedings of the 38th Lunar and Planetary Science Conference

NASA Technical Reports Server (NTRS)

2007-01-01

The sessions in the conference include: Titan, Mars Volcanism, Mars Polar Layered Deposits, Early Solar System Isotopes, SPECIAL SESSION: Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Achondrites: Exploring Oxygen Isotopes and Parent-Body Processes, Solar System Formation and Evolution, SPECIAL SESSION: SMART-1, . Impact Cratering: Observations and Experiments, SPECIAL SESSION: Volcanism and Tectonism on Saturnian Satellites, Solar Nebula Composition, Mars Fluvial Geomorphology, Asteroid Observations: Spectra, Mostly, Mars Sediments and Geochemistry: View from the Surface, Mars Tectonics and Crustal Dichotomy, Stardust: Wild-2 Revealed, Impact Cratering from Observations and Interpretations, Mars Sediments and Geochemistry: The Map View, Chondrules and Their Formation, Enceladus, Asteroids and Deep Impact: Structure, Dynamics, and Experiments, Mars Surface Process and Evolution, Martian Meteorites: Nakhlites, Experiments, and the Great Shergottite Age Debate, Stardust: Mainly Mineralogy, Astrobiology, Wind-Surface Interactions on Mars and Earth, Icy Satellite Surfaces, Venus, Lunar Remote Sensing, Space Weathering, and Impact Effects, Interplanetary Dust/Genesis, Mars Cratering: Counts and Catastrophes?, Chondrites: Secondary Processes, Mars Sediments and Geochemistry: Atmosphere, Soils, Brines, and Minerals, Lunar Interior and Differentiation, Mars Magnetics and Atmosphere: Core to Ionosphere, Metal-rich Chondrites, Organics in Chondrites, Lunar Impacts and Meteorites, Presolar/Solar Grains, Topics for Print Only papers are: Outer Planets/Satellites, Early Solar System, Interplanetary Dust, Comets and Kuiper Belt Objects, Asteroids and Meteoroids, Chondrites, Achondrites, Meteorite Related, Mars Reconnaissance Orbiter, Mars, Astrobiology, Planetary Differentiation, Impacts, Mercury, Lunar Samples and Modeling, Venus, Missions and Instruments, Global Warming, Education and Public Outreach, Poster sessions are: Asteroids/Kuiper Belt Objects, Galilean Satellites: Geology and Mapping, Titan, Volcanism and Tectonism on Saturnian Satellites, Early Solar System, Achondrite Hodgepodge, Ordinary Chondrites, Carbonaceous Chondrites, Impact Cratering from Observations and Interpretations, Impact Cratering from Experiments and Modeling, SMART-1, Planetary Differentiation, Mars Geology, Mars Volcanism, Mars Tectonics, Mars: Polar, Glacial, and Near-Surface Ice, Mars Valley Networks, Mars Gullies, Mars Outflow Channels, Mars Sediments and Geochemistry: Spirit and Opportunity, Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Mars Reconnaissance Orbiter: Geology, Layers, and Landforms, Oh, My!, Mars Reconnaissance Orbiter: Viewing Mars Through Multicolored Glasses; Mars Science Laboratory, Phoenix, and ExoMars: Science, Instruments, and Landing Sites; Planetary Analogs: Chemical and Mineral, Planetary Analogs: Physical, Planetary Analogs: Operations, Future Mission Concepts, Planetary Data, Imaging, and Cartography, Outer Solar System, Presolar/Solar Grains, Stardust Mission; Interplanetary Dust, Genesis, Asteroids and Comets: Models, Dynamics, and Experiments, Venus, Mercury, Laboratory Instruments, Methods, and Techniques to Support Planetary Exploration; Instruments, Techniques, and Enabling Techologies for Planetary Exploration; Lunar Missions and Instruments, Living and Working on the Moon, Meteoroid Impacts on the Moon, Lunar Remote Sensing, Lunar Samples and Experiments, Lunar Atmosphere, Moon: Soils, Poles, and Volatiles, Lunar Topography and Geophysics, Lunar Meteorites, Chondrites: Secondary Processes, Chondrites, Martian Meteorites, Mars Cratering, Mars Surface Processes and Evolution, Mars Sediments and Geochemistry: Regolith, Spectroscopy, and Imaging, Mars Sediments and Geochemistry: Analogs and Mineralogy, Mars: Magnetics and Atmosphere, Mars Aeolian Geomorphology, Mars Data Processing and Analyses, Astrobiology, Engaging Student Educators and the Public in Planetary Science,

Scientific and synergistic lessons learned from the Cassini-Huygens mission

NASA Astrophysics Data System (ADS)

Coustenis, Athena

The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. Titan is also rich in organic molecules—more so in its surface and atmosphere than anyplace in the solar system, including Earth [2-4]. These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. I will discuss our current understanding of Titan's complex environment in view of the Cassini-Huygens mission results [1-8], which demonstrated the power of synergistic remote and in situ exploration. I will focus on the atmospheric structure (temperature and composition), and the surface nature. I will show how these and other elements can give us clues as to the origin and evolution of the satellite, and how they connect to the observations of the other satellites, Enceladus in particular. Future space missions to Titan can help us understand the kronian and also our Solar System as a whole. Finally, I will describe the future exploration of Titan and the Saturnian System with TSSM, a mission studied jointly by ESA and NASA in 2008 and prioritized second for a launch around 2023-2025. References 1. Coustenis, A., Hirtzig, M., 2009. Cassini-Huygens results on Titan's surface. Research in Astronomy and Astrophysics 9, 249-268. 2. Coustenis et al., 2010, Titan trace gaseous composition from CIRS at the end of the Cassini-Huygens prime mission Icarus, in press. 3. Flasar, F. M., et al., 2005. Titan's atmospheric temperatures, winds, and composition. Science, 308, 975-978. 4. Fulchignoni, M., et al, 2005. In situ measurements of the physical characteristics of Titan's environment. Nature, 438, 785-791, doi:10.1038/nature04126. 5. Lebreton, J-P., Coustenis, A., et al., 2009. Results from the Huygens probe on Titan. Astron. & Astrophys. Rev. 17, 149-179. 6. Tomasko, M. G., et al., 2005. Rain, winds and haze during the Huygens probe's descent to Titan's surface. Nature, 438, 765-778, doi:10.1038/nature04126.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003874 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are deployed from a Small Satellite Orbital Deployer (SSOD) attached to the Kibo laboratory's robotic arm at 7:10 a.m. (EST) on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan's fourth H-II Transfer Vehicle, Kounotori-4.

Spatial and Temporal Varying Thresholds for Cloud Detection in Satellite Imagery

NASA Technical Reports Server (NTRS)

Jedlovec, Gary; Haines, Stephanie

2007-01-01

A new cloud detection technique has been developed and applied to both geostationary and polar orbiting satellite imagery having channels in the thermal infrared and short wave infrared spectral regions. The bispectral composite threshold (BCT) technique uses only the 11 micron and 3.9 micron channels, and composite imagery generated from these channels, in a four-step cloud detection procedure to produce a binary cloud mask at single pixel resolution. A unique aspect of this algorithm is the use of 20-day composites of the 11 micron and the 11 - 3.9 micron channel difference imagery to represent spatially and temporally varying clear-sky thresholds for the bispectral cloud tests. The BCT cloud detection algorithm has been applied to GOES and MODIS data over the continental United States over the last three years with good success. The resulting products have been validated against "truth" datasets (generated by the manual determination of the sky conditions from available satellite imagery) for various seasons from the 2003-2005 periods. The day and night algorithm has been shown to determine the correct sky conditions 80-90% of the time (on average) over land and ocean areas. Only a small variation in algorithm performance occurs between day-night, land-ocean, and between seasons. The algorithm performs least well. during he winter season with only 80% of the sky conditions determined correctly. The algorithm was found to under-determine clouds at night and during times of low sun angle (in geostationary satellite data) and tends to over-determine the presence of clouds during the day, particularly in the summertime. Since the spectral tests use only the short- and long-wave channels common to most multispectral scanners; the application of the BCT technique to a variety of satellite sensors including SEVERI should be straightforward and produce similar performance results.

DCERP Defense Coastal/Estuarine Research Program Workshop Proceedings

DTIC Science & Technology

2005-02-01

indicators, both in terms of ecological health and human impacts. • Phytoplankton and benthic microalgae species, especially bloom-forming ones that...composition) Chlorophyll a and other diagnostic photopigments Phytoplankton /zooplankton community composition Primary production (Photosynthesis...Satellite imagery for phytoplankton and higher plant communities Aerial sensors for submerged aquatic vegetation, salt marshes, ocean color 22 IR

Assessing the effects of land use spatial structure on urban heat islands using HJ-1B remote sensing imagery in Wuhan, China

NASA Astrophysics Data System (ADS)

Wu, Hao; Ye, Lu-Ping; Shi, Wen-Zhong; Clarke, Keith C.

2014-10-01

Urban heat islands (UHIs) have attracted attention around the world because they profoundly affect biological diversity and human life. Assessing the effects of the spatial structure of land use on UHIs is essential to better understanding and improving the ecological consequences of urbanization. This paper presents the radius fractal dimension to quantify the spatial variation of different land use types around the hot centers. By integrating remote sensing images from the newly launched HJ-1B satellite system, vegetation indexes, landscape metrics and fractal dimension, the effects of land use patterns on the urban thermal environment in Wuhan were comprehensively explored. The vegetation indexes and landscape metrics of the HJ-1B and other remote sensing satellites were compared and analyzed to validate the performance of the HJ-1B. The results have showed that land surface temperature (LST) is negatively related to only positive normalized difference vegetation index (NDVI) but to Fv across the entire range of values, which indicates that fractional vegetation (Fv) is an appropriate predictor of LST more than NDVI in forest areas. Furthermore, the mean LST is highly correlated with four class-based metrics and three landscape-based metrics, which suggests that the landscape composition and the spatial configuration both influence UHIs. All of them demonstrate that the HJ-1B satellite has a comparable capacity for UHI studies as other commonly used remote sensing satellites. The results of the fractal analysis show that the density of built-up areas sharply decreases from the hot centers to the edges of these areas, while the densities of water, forest and cropland increase. These relationships reveal that water, like forest and cropland, has a significant effect in mitigating UHIs in Wuhan due to its large spatial extent and homogeneous spatial distribution. These findings not only confirm the applicability and effectiveness of the HJ-1B satellite system for studying UHIs but also reveal the impacts of the spatial structure of land use on UHIs, which is helpful for improving the planning and management of the urban environment.

Visualization of Space-Time Ambiguities to be Explored by the NASA GEC Mission with a Critique of Synthesized Measurements for Different GEC Mission Scenarios

NASA Technical Reports Server (NTRS)

Sojka, Jan J.; Zhu, Lie; Fuller-Rowell, Timothy J.

2005-01-01

The objective of this grant was to study how a multi-satellite mission configuration can be optimized for maximum exploratory scientific return. NASA's Solar Terrestrial Probe (STP) concept mission Geospace Electrodynamic Connections (GEC) was the target mission for this pilot study. GEC prime mission characteristics were two fold: (i) a series of three satellites in the same orbit plane with differential spacing, and (ii) a deep-dipping phase in which these satellites could dip to altitudes as low as 130 km to explore the lower ionosphere and thermosphere. Each satellite would carry a full suite of plasma and neutral in-situ sensors and have the same dipping capability. This latter aspect would be envisaged as a series, up to 10, of deep-dipping campaigns, each lasting 10 days during which the perigee would be lowered to the desired probing depth. The challenge in optimization is to establish the scientific problems that can best be addressed by varying or selecting satellite spacing during a two-year mission while also interspersing, in this two year time frame, the deep-dipping campaigns. Although this sounds like a straightforward trade-off situation, it is complicated by the orbit precession in local time, the location of perigee, and that even the dipping campaigns will have preferred satellite spacing requirements.

Investigating the origins of the Irregular satellites using Cladistics

NASA Astrophysics Data System (ADS)

Holt, Timothy; Horner, Jonti; Tylor, Christopher; Nesvorny, David; Brown, Adrian; Carter, Brad

2017-10-01

The irregular satellites of Jupiter and Saturn are thought to be objects captured during a period of instability in the early solar system. However, the precise origins of these small bodies remain elusive. We use cladistics, a technique traditionally used by biologists, to help constrain the origins of these bodies. Our research contributes to a growing body of work that uses cladistics in astronomy, collectively called astrocladistics. We present one of the first instances of cladistics being used in a planetary science context. The analysis uses physical and compositional characteristics of three prograde Jovian irregular satellites (Themisto, Leda & Himalia), five retrograde Jovian irregular satellites (Ananke, Carme, Pasiphae, Sinope & Callirrhoe), along with Phoebe, a retrograde irregular satellite of Saturn, and several other regular Jovian and Saturnian satellites. Each of these members are representatives of their respective taxonomic groups. The irregular satellites are compared with other well-studied solar system bodies, including satellites, terrestrial planets, main belt asteroids, comets, and minor planets. We find that the Jovian irregular satellites cluster with asteroids and Ceres. The Saturnian satellites studied here are found to form an association with the comets, adding to the narrative of exchange between the outer solar system and Saturnian orbital space. Both of these results demonstrate the utility of cladistics as an analysis tool for the planetary sciences.

First micro-satellite and new enhanced small satellite series in DFH Satellite Co. Ltd.

NASA Astrophysics Data System (ADS)

Zhang, Xiaomin; Xie, Bin; Dai, Shoulun; Zhang, Weiwen; Hu, Gefeng; Lan, Ding

2007-06-01

As one important department of CAST (Chinese Academy of Space Technology), with responsibility for small and micro-satellite development, DFH Satellite Co. Ltd. (DFHSat) manufactured and launched six small satellites from 2000 to 2004. Nowadays, DFHSat is developing micro-satellite and new enhanced small satellite series. The first micro-satellite as a basic type is named HummerSat-1. HummerSat-1 is three-axis stabilized with orbit control capability. Information and power control are implemented through an on-board network, GaAs solar cell and Li-ion battery are adopted to obtain and storage power, S-band TT&C and data transmission works are used. The payload of HummerSat-1 has a weight of 60 kg and power consumption of 200 W. The enhanced small satellite series based on technology of HummerSat-1 is planned by DFHSat. It would be aiming to form a continuative product spectrum of 80-200 kg. The enhanced series is focused on satisfying different missions, including earth remote sensing, communication, science exploration, etc.

One-Dimensional Hybrid Satellite Track Model for the Dynamics Explorer 2 (DE 2) Satellite

NASA Technical Reports Server (NTRS)

Deng, Wei; Killeen, T. L.; Burns, A. G.; Johnson, R. M.; Emery, B. A.; Roble, R. G.; Winningham, J. D.; Gary, J. B.

1995-01-01

A one-dimensional hybrid satellite track model has been developed to calculate the high-latitude thermospheric/ionospheric structure below the satellite altitude using Dynamics Explorer 2 (DE 2) satellite measurements and theory. This model is based on Emery et al. satellite track code but also includes elements of Roble et al. global mean thermosphere/ionosphere model. A number of parameterizations and data handling techniques are used to input satellite data from several DE 2 instruments into this model. Profiles of neutral atmospheric densities are determined from the MSIS-90 model and measured neutral temperatures. Measured electron precipitation spectra are used in an auroral model to calculate particle impact ionization rates below the satellite. These rates are combined with a solar ionization rate profile and used to solve the O(+) diffusion equation, with the measured electron density as an upper boundary condition. The calculated O(+) density distribution, as well as the ionization profiles, are then used in a photochemical equilibrium model to calculate the electron and molecular ion densities. The electron temperature is also calculated by solving the electron energy equation with an upper boundary condition determined by the DE 2 measurement. The model enables calculations of altitude profiles of conductivity and Joule beating rate along and below the satellite track. In a first application of the new model, a study is made of thermospheric and ionospheric structure below the DE 2 satellite for a single orbit which occurred on October 25, 1981. The field-aligned Poynting flux, which is independently obtained for this orbit, is compared with the model predictions of the height-integrated energy conversion rate. Good quantitative agreement between these two estimates has been reached. In addition, measurements taken at the incoherent scatter radar site at Chatanika (65.1 deg N, 147.4 deg W) during a DE 2 overflight are compared with the model calculations. A good agreement was found in lower thermospheric conductivities and Joule heating rate.

Satellite accretion on to massive galaxies with central black holes

NASA Astrophysics Data System (ADS)

Boylan-Kolchin, Michael; Ma, Chung-Pei

2007-02-01

Minor mergers of galaxies are expected to be common in a hierarchical cosmology such as Λ cold dark matter. Though less disruptive than major mergers, minor mergers are more frequent and thus have the potential to affect galactic structure significantly. In this paper, we dissect the case-by-case outcome from a set of numerical simulations of a single satellite elliptical galaxy accreting on to a massive elliptical galaxy. We take care to explore cosmologically relevant orbital parameters and to set up realistic initial galaxy models that include all three relevant dynamical components: dark matter haloes, stellar bulges, and central massive black holes (BHs). The effects of several different parameters are considered, including orbital energy and angular momentum, satellite density and inner density profile, satellite-to-host mass ratio, and presence of a BH at the centre of the host. BHs play a crucial role in protecting the shallow stellar cores of the hosts, as satellites merging on to a host with a central BH are more strongly disrupted than those merging on to hosts without BHs. Orbital parameters play an important role in determining the degree of disruption: satellites on less-bound or more-eccentric orbits are more easily destroyed than those on more-bound or more-circular orbits as a result of an increased number of pericentric passages and greater cumulative effects of gravitational shocking and tidal stripping. In addition, satellites with densities typical of faint elliptical galaxies are disrupted relatively easily, while denser satellites can survive much better in the tidal field of the host. Over the range of parameters explored, we find that the accretion of a single satellite elliptical galaxy can result in a broad variety of changes, in both signs, in the surface brightness profile and colour of the central part of an elliptical galaxy. Our results show that detailed properties of the stellar components of merging satellites can strongly affect the properties of the remnants.

JUpiter ICy moons Explorer (JUICE): An ESA mission to orbit Ganymede and to characterise the Jupiter system

NASA Astrophysics Data System (ADS)

Grasset, O.; Dougherty, M. K.; Coustenis, A.; Bunce, E. J.; Erd, C.; Titov, D.; Blanc, M.; Coates, A.; Drossart, P.; Fletcher, L. N.; Hussmann, H.; Jaumann, R.; Krupp, N.; Lebreton, J.-P.; Prieto-Ballesteros, O.; Tortora, P.; Tosi, F.; Van Hoolst, T.

2013-04-01

Past exploration of Jupiter's diverse satellite system has forever changed our understanding of the unique environments to be found around gas giants, both in our solar system and beyond. The detailed investigation of three of Jupiter's Galilean satellites (Ganymede, Europa, and Callisto), which are believed to harbour subsurface water oceans, is central to elucidating the conditions for habitability of icy worlds in planetary systems in general. The study of the Jupiter system and the possible existence of habitable environments offer the best opportunity for understanding the origins and formation of the gas giants and their satellite systems. The JUpiter ICy moons Explorer (JUICE) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015-2025, will perform detailed investigations of Jupiter and its system in all their inter-relations and complexity with particular emphasis on Ganymede as a planetary body and potential habitat. The investigations of the neighbouring moons, Europa and Callisto, will complete a comparative picture of the Galilean moons and their potential habitability. Here we describe the scientific motivation for this exciting new European-led exploration of the Jupiter system in the context of our current knowledge and future aspirations for exploration, and the paradigm it will bring in the study of giant (exo) planets in general.

Cloud cover determination in polar regions from satellite imagery

NASA Technical Reports Server (NTRS)

Barry, R. G.; Key, J.

1989-01-01

The objectives are to develop a suitable validation data set for evaluating the effectiveness of the International Satellite Cloud Climatology Project (ISCCP) algorithm for cloud retrieval in polar regions, to identify limitations of current procedures and to explore potential means to remedy them using textural classifiers, and to compare synoptic cloud data from model runs with observations. Toward the first goal, a polar data set consisting of visible, thermal, and passive microwave data was developed. The AVHRR and SMMR data were digitally merged to a polar stereographic projection with an effective pixel size of 5 sq km. With this data set, two unconventional methods of classifying the imagery for the analysis of polar clouds and surfaces were examined: one based on fuzzy sets theory and another based on a trained neural network. An algorithm for cloud detection was developed from an early test version of the ISCCP algorithm. This algorithm includes the identification of surface types with passive microwave, then temporal tests at each pixel location in the cloud detection phase. Cloud maps and clear sky radiance composites for 5 day periods are produced. Algorithm testing and validation was done with both actural AVHRR/SMMR data, and simulated imagery. From this point in the algorithm, groups of cloud pixels are examined for their spectral and textural characteristics, and a procedure is developed for the analysis of cloud patterns utilizing albedo, IR temperature, and texture. In a completion of earlier work, empirical analyses of arctic cloud cover were explored through manual interpretations of DMSP imagery and compared to U.S. Air Force 3D-nephanalysis. Comparisons of observed cloudiness from existing climatologies to patterns computed by the GISS climate model were also made.

Outer planets and icy satellites

NASA Technical Reports Server (NTRS)

Drobyshevski, E. M.

1991-01-01

The resources offered by the outer bodies in the Solar System, starting with the main belt asteroids and Jovian System, are not only larger and more diverse but may even be easier to reach than, say, those of Mars. The use of their material, including water and organic matter, depends exclusively on the general strategy of exploration of the Solar System. Of major interest in this respect are the large ice satellites - Titan, Ganymede, and Callisto. Motion through the planetary magnetospheres excites in their ice envelopes megampere currents which, in the presence of rocky, etc., inclusions with electronic conduction should lead to the bulk electrolysis of ice and accumulation in it of 2H2 + O2 in the form of a solid solution. With the concentration of 2H2 + O2 reaching about 15 wt. percent, the solution becomes capable of detonation by a strong meteoritic impact. An explosion of Ganymede's ice envelope about 0.5 By ago could account for the formation of the Trojans and irregular satellites, all known differences between Ganymede and Callisto, and many other things. The explosion of a small icy planet with M approx less than 0.5 Moon created the asteroid belt. Two to three explosions occurred on Io, and two on Europa. The specific features of the longperiod comets close to Saturn's orbit permit dating Titan's envelope explosion as 10,000 yr ago, which produced its thick atmosphere, young Saturn's rings, as well as a reservoir of ice fragments saturated by 2H2 + O2, i.e., cometary nuclei between the orbits of Jupiter and Saturn. Thus these nuclei should contain, besides organic matter, also 2H2 + O2, which could be used for their transportation as well as for fuel for spaceships. Ices of such composition can reside deep inside Deimos, the Trojans, C-asteroids, etc. The danger of a future explosion of Callisto's electrolyzed ices, which would result in a catastrophic bombardment of the Earth by comets, may be high enough to warrant a revision of the priorities and strategy of space exploration.

Outer planets and icy satellites

NASA Astrophysics Data System (ADS)

Drobyshevski, E. M.

The resources offered by the outer bodies in the Solar System, starting with the main belt asteroids and Jovian System, are not only larger and more diverse but may even be easier to reach than, say, those of Mars. The use of their material, including water and organic matter, depends exclusively on the general strategy of exploration of the Solar System. Of major interest in this respect are the large ice satellites - Titan, Ganymede, and Callisto. Motion through the planetary magnetospheres excites in their ice envelopes megampere currents which, in the presence of rocky, etc., inclusions with electronic conduction should lead to the bulk electrolysis of ice and accumulation in it of 2H2 + O2 in the form of a solid solution. With the concentration of 2H2 + O2 reaching about 15 wt. percent, the solution becomes capable of detonation by a strong meteoritic impact. An explosion of Ganymede's ice envelope about 0.5 By ago could account for the formation of the Trojans and irregular satellites, all known differences between Ganymede and Callisto, and many other things. The explosion of a small icy planet with M approx less than 0.5 Moon created the asteroid belt. Two to three explosions occurred on Io, and two on Europa. The specific features of the longperiod comets close to Saturn's orbit permit dating Titan's envelope explosion as 10,000 yr ago, which produced its thick atmosphere, young Saturn's rings, as well as a reservoir of ice fragments saturated by 2H2 + O2, i.e., cometary nuclei between the orbits of Jupiter and Saturn. Thus these nuclei should contain, besides organic matter, also 2H2 + O2, which could be used for their transportation as well as for fuel for spaceships. Ices of such composition can reside deep inside Deimos, the Trojans, C-asteroids, etc. The danger of a future explosion of Callisto's electrolyzed ices, which would result in a catastrophic bombardment of the Earth by comets, may be high enough to warrant a revision of the priorities and strategy of space exploration.

Variations/Changes in Daily Precipitation Extremes Derived from Satellite-Based Products

NASA Astrophysics Data System (ADS)

Gu, G.; Adler, R. F.

2017-12-01

Interannual/decadal-scale variations/changes in daily precipitation extremes are investigated by means of satellite-based high-spatiotemporal resolution precipitation products, including TRMM-TMPA, PERSIANN-CDR-Daily, GPCP 1DD, etc. Extreme precipitation indices at grids are first defined, including the maximum daily precipitation amount (Rx1day), the simple precipitation intensity index (SDII), the conditional (Rcond) daily precipitation rate (Pr>0 mm day-1), and monthly frequencies of rainy (FOCc) and wet (FOCw) days. Other two precipitation intensity indices, i.e., mean daily precipitation rates for Pr ≥10 mm day-1 (Pr10II) and for Pr ≥ 20 mm day-1 (Pr20II), are also constructed. Consistency analyses of daily extreme indices among these data sets are then performed by comparing corresponding averages over large domains such as tropical (30oN-30oS) land, ocean, land+ocean, for their common period (post-1997). This can provide a preliminary uncertainty analysis of these data sets in describing daily extreme precipitation events. Discrepancies can readily be found among these products regarding the magnitudes of area-averaged extreme indices. However, generally consistent temporal variations can be found among the indices derived from different satellite products. Interannual variability in daily precipitation extremes are then examined and compared at grids by exploring their relations with the El Nino-Southern Oscillation (ENSO). Linear correlation and composite analyses are used to examine the impact of ENSO on these extreme indices at grids and over large domains during the post-1997 period. Decadal-scale variability/change in daily extreme events is further examined by using the PERSIANN-CDR-Daily that can cover the entire post-1983 period, based on its general consistency with other two products during the post-1979 period. We specifically focus on exploring and discriminating the effects of decadal-scale internal variability such as the Pacific Decadal Oscillation (PDO) and anthropogenic forcings including the greenhouse-gases (GHG) related warming. Comparisons are also made over global land with the results from two gridded daily rain-gauge products, GPCC Full-record daily (1988-2013) and NOAA/CPC Unified daily (1979-present).

Surface Composition and Physical Mixture State of the Regoliths of Outer Solar System Satellites: The Role of Scattering and Absorption by the non-Ice Components and Implications for Rayleigh Absorption and Rayleigh Scattering

NASA Astrophysics Data System (ADS)

Clark, R. N.; Perlman, Z. S.; Pearson, N.; Hendrix, A. R.; Cuzzi, J. N.; Cruikshank, D. P.; Bradley, E. T.; Filacchione, G.; Nicholson, P. D.; Hedman, M. M.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Sotin, C.; Nelson, R. M.

2014-12-01

Many outer Solar System satellites have surfaces dominated by water ice and a mysterious material(s) causing strong visible to ultraviolet absorption along with trace other compounds with infrared absorptions, including CO2 and organics. Various mechanisms have been proposed for the UV absorber, including tholins, iron oxides, and nano-sized metallic iron particles (e.g. see Clark et al., 2012, Icarus v218 p831, and references therein). We have constructed extensive laboratory analog measurements and radiative transfer modeling of the materials and scattering conditions that can contribute to the optical properties seen on outer Solar System satellites. We have successfully modeled Rayleigh absorption and Rayleigh scattering to produce spectral shapes typical of those seen in spectra of icy Solar System satellites, including those in the Saturn system observed with the Cassini UVIS and VIMS instruments. While it is easy to create these absorptions with radiative transfer modeling, it has been more difficult to do with laboratory analogs. We are finding that laboratory analogs refine and restricts the possible mixing states of the UV absorber in icy satellite surfaces. We have found that just because a particle is highly absorbing, as in metallic iron, if the particle is not embedded in another matrix, scattering will dominate over absorption and Rayleigh absorption will not be observed. Further, the closer the indices of refraction match between the absorbing particle and the matrix, there will be less scattering and more absorption will occur. But we have also found this to be true with other absorbing material, like Tholins. It is very difficult to obtain the very low reflectances observed in the UV in icy satellite spectra using traditional intimate mixtures, as scattering and first surface reflections contribute significantly to the reflectance. The solution, both from radiative transfer modeling and laboratory analogs point to embedded absorbing materials. For example, nano-phase metallic iron embedded in a less absorbing silicate matrix as meteoritic dust infall onto satellitesurfaces is one explanation. An alternative would be tholins embedded in the ice. Spectral features should be able to distinguish between these and other possibilities and will be explored.

Satellite telemetry and prey sampling reveal contaminant sources to Pacific Northwest Ospreys.

PubMed

Elliott, John E; Morrissey, Christy A; Henny, Charles J; Inzunza, Ernesto Ruelas; Shaw, Patrick

2007-06-01

Migratory behavior can be an important factor in determining contaminant exposure in avian populations. Accumulation of organochlorine (OC) pesticides while birds are wintering in tropical regions has been cited often as the reason for high concentrations in migrant populations. To explore this issue, we satellite tracked 16 Ospreys (Pandion haliaetus) over the period 1996-2003 from breeding sites in British Columbia, Canada, and integrated the results into a database on 15 Ospreys that were satellite tracked over the period 1995-1999, from breeding locations in Washington and Oregon, USA. Data on wintering sites of 31 Ospreys in Mexico and Central America were used for spatially targeted sampling of prey fish. Concentrations of the main organochlorine contaminant, p,p'-dichloro-diphenyl-dichloroethylene (DDE), in fish composites from Mexico ranged from 0.005 to 0.115 nicrog/g wet mass. Significant differences existed among fish families in p,p'-DDE, total dichloro-diphenyl-trichloroethane (sigmaDDT), sigmachlordanes, and total polychlorinated biphenyls (sigmaPCBs). Catfish (family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, sigmachlordanes, sigmaPCBs, and hexachlorobenzene. Eggs collected from 16 nests throughout the Pacific Northwest (nine from British Columbia, seven from Oregon and Washington) where Ospreys had been satellite tagged, showed marked variation in levels of DDT metabolites (p,p'-DDE; range 0.02-10.14 microg/g). Wintering site had no significant effect on contaminant concentrations in sample eggs from those specific Ospreys; rather concentrations of p,p'-DDE, were predicted by breeding sites with highest levels in eggs of Ospreys breeding in the lower Columbia River, consistent with published reports of continued high concentrations of DDT and related compounds in that system.

Satellite telemetry and prey sampling reveal contaminant sources to pacific northwest ospreys

USGS Publications Warehouse

Elliott, J.E.; Morrissey, C.A.; Henny, C.J.; Inzunza, E.R.; Shaw, P.

2007-01-01

Migratory behavior can be an important factor in determining contaminant exposure in avian populations. Accumulation of organochlorine (OC) pesticides while birds are wintering in tropical regions has been cited often as the reason for high concentrations in migrant populations. To explore this issue, we satellite tracked 16 Ospreys (Pandion haliaetus) over the period 1996-2003 from breeding sites in British Columbia, Canada, and integrated the results into a database on 15 Ospreys that were satellite tracked over the period 1995-1999, from breeding locations in Washington and Oregon, USA. Data on wintering sites of 31 Ospreys in Mexico and Central America were used for spatially targeted sampling of prey fish. Concentrations of the main organochlorine contaminant, p,p???-dichloro-diphenyl-dichloroethylene (DDE), in fish composites from Mexico ranged from 0.005 to 0.115 ??g/g wet mass. Significant differences existed among fish families in p,p???-DDE, total dichloro- diphenyltrichloroethane (??DDT), ??chlordanes, and total polychlorinated biphenyls (??PCBs). Catfish (family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, ??chlordanes, ??PCBs, and hexachlorobenzene. Eggs collected from 16 nests throughout the Pacific Northwest (nine from British Columbia, seven from Oregon and Washington) where Ospreys had been satellite tagged, showed marked variation in levels of DDT metabolites (p,p???-DDE; range 0.02-10.14 ??g/g). Wintering site had no significant effect on contaminant concentrations in sample eggs from those specific Ospreys; rather concentrations of p,p???-DDE, were predicted by breeding sites with highest levels in eggs of Ospreys breeding in the lower Columbia River, consistent with published reports of continued high concentrations of DDT and related compounds in that system. ?? 2007 by the Ecological Society of America.

Influence of monsoon-related riparian phenology on yellow-billed cuckoo habitat selection in Arizona

USGS Publications Warehouse

Wallace, Cynthia S.A.; Villarreal, Miguel; van Riper, Charles

2013-01-01

Aim: The western yellow-billed cuckoo (Coccyzus americanus occidentalis), a Neotropical migrant bird, is facing steep population declines in its western breeding grounds owing primarily to loss of native habitat. The favoured esting habitat for the cuckoo in the south-western United States is low-elevation riparian forests and woodlands. Our aim was to explore relationships between vegetation phenology patterns captured by satellite phenometrics and the distribution of the yellow-billed cuckoo, and to use this information to map cuckoo habitat. Location: Arizona, USA. Methods: Land surface phenometrics were derived from satellite Advanced Very High-Resolution Radiometer (AVHRR), bi-weekly time-composite, ormalized difference vegetation index (NDVI) data for 1998 and 1999 at a resolution of 1 km. Fourier harmonics were used to analyse the waveform of the annual NDVI profile in each pixel. To create the models, we coupled 1998 satellite phenometrics with 1998 field survey data of cuckoo presence or absence and with point data that sampled riparian and cottonwood–willow vegetation types. Our models were verified and refined using field and satellite data collected in 1999. Results: The models reveal that cuckoos prefer areas that experience peak greenness 29 days later, are 36% more dynamic and slightly (< 1%) more productive than their average cottonwood–willow habitat. The results support a scenario in which cuckoos migrate northwards, following the greening of riparian corridors and surrounding landscapes in response to monsoon precipitation, but then select a nesting site based on optimizing the near-term foraging potential of the neighbourhood. Main conclusions: The identification of preferred phenotypes within recognized habitat can be used to refine future habitat models, inform habitat response to climate change, and suggest adaptation strategies. For example, models of phenotype preferences can guide management actions by identifying and prioritizing for conservation those landscapes that reliably exhibit highly preferred phenometrics on a consistent basis.

Recent changes in stratospheric aerosol budget from ground-based and satellite observations

NASA Astrophysics Data System (ADS)

Khaykin, Sergey; Godin-Beekmann, Sophie; Keckhut, Philippe; Hauchecorne, Alain; Portafaix, Thierry; Begue, Nelson; Vernier, Jean-Paul; DeLand, Matthew; Bhartia, Pawan K.; Leblanc, Thierry

2017-04-01

Stratospheric aerosol budget plays an important role in climate variability and ozone chemistry. Observations of stratospheric aerosol by ground-based lidars represent a particular value as they ensure the continuity and coherence of stratospheric aerosol record. Ground-based lidars remain indispensable for complementing and validating satellite instruments and for filling gaps between satellite missions. On the other hand, geophysical interpretation of local observations is complicated without the knowledge of global distribution of stratospheric aerosol, which calls for a combined analysis of ground-based and space-borne observations. The present study aims at characterizing global and regional variability of stratospheric aerosol over the last 5 years using various sets of observations. We use the data provided by three lidars operated within NDACC (Network for Detection of Atmospheric Composition Change) at Haute-Provence, (44° N), Mauna Loa (21° N) and Maido (21° S) sites together with quasi-global-coverage aerosol measurements by CALIOP and OMPS satellite instruments. The local and space-borne measurements are shown to be in good agreement allowing for their synergetic use. Since the late 2012 stratospheric aerosol remained at background levels throughout the globe. Eruptions of Kelud volcano at 4° S in February 2014 and Calbuco volcano at 41° S in April 2015 resulted in a remarkable enhancement of stratospheric AOD at a wide latitude range. We explore meridional dispersion and lifetime of volcanic plumes in consideration of global atmospheric circulation. A focus is made on the poleward transport of volcanic aerosol and its detection at the mid-latitude Haute-Provence observatory. We show that the moderate eruptions in the Southern hemisphere leave a measurable imprint on the Northern mid-latitude aerosol loading. Having identified the volcanically-perturbed periods from local and global observations we examine the evolution of non-volcanic (background) aerosol by comparing the recent observations with historical data available from 23-yr observations at Haute-Provence and Mauna-Loa.

A Study on the Potential Applications of Satellite Data in Air Quality Monitoring and Forecasting

NASA Technical Reports Server (NTRS)

Li, Can; Hsu, N. Christina; Tsay, Si-Chee

2011-01-01

In this study we explore the potential applications of MODIS (Moderate Resolution Imaging Spectroradiometer) -like satellite sensors in air quality research for some Asian regions. The MODIS aerosol optical thickness (AOT), NCEP global reanalysis meteorological data, and daily surface PM(sub 10) concentrations over China and Thailand from 2001 to 2009 were analyzed using simple and multiple regression models. The AOT-PM(sub 10) correlation demonstrates substantial seasonal and regional difference, likely reflecting variations in aerosol composition and atmospheric conditions, Meteorological factors, particularly relative humidity, were found to influence the AOT-PM(sub 10) relationship. Their inclusion in regression models leads to more accurate assessment of PM(sub 10) from space borne observations. We further introduced a simple method for employing the satellite data to empirically forecast surface particulate pollution, In general, AOT from the previous day (day 0) is used as a predicator variable, along with the forecasted meteorology for the following day (day 1), to predict the PM(sub 10) level for day 1. The contribution of regional transport is represented by backward trajectories combined with AOT. This method was evaluated through PM(sub 10) hindcasts for 2008-2009, using ohservations from 2005 to 2007 as a training data set to obtain model coefficients. For five big Chinese cities, over 50% of the hindcasts have percentage error less than or equal to 30%. Similar performance was achieved for cities in northern Thailand. The MODIS AOT data are responsible for at least part of the demonstrated forecasting skill. This method can be easily adapted for other regions, but is probably most useful for those having sparse ground monitoring networks or no access to sophisticated deterministic models. We also highlight several existing issues, including some inherent to a regression-based approach as exemplified by a case study for Beijing, Further studies will be necessa1Y before satellite data can see more extensive applications in the operational air quality monitoring and forecasting.

Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

NASA Astrophysics Data System (ADS)

Lainer, M.; Kämpfer, N.; Tschanz, B.; Nedoluha, G. E.; Ka, S.; Oh, J. J.

2015-08-01

The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change). Keeping in mind that the instruments are based on different hardware and calibration setups, a height-dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different data sets, the Microwave Limb Sounder (MLS) on the Aura satellite is used to serve as a kind of traveling standard. A domain-averaging TM (trajectory mapping) method is applied which simplifies the subsequent validation of the quality of the trajectory-mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW) accompanied by the polar vortex breakdown; a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high potential of a network of ground-based remote sensing instruments to synthesize hemispheric maps of water vapor.

Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

NASA Astrophysics Data System (ADS)

Lainer, M.; Kämpfer, N.; Tschanz, B.; Nedoluha, G. E.; Ka, S.; Oh, J. J.

2015-04-01

The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change). Keeping in mind that the instruments are based on different hardware and calibration setups, a height dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different datasets, the Microwave Limb Sounder (MLS) on the Aura satellite is used to serve as a kind of travelling standard. A domain-averaging TM (trajectory mapping) method is applied which simplifies the subsequent validation of the quality of the trajectory mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW) accompanied by the polar vortex breakdown, a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high potential of a network of ground-based remote sensing instruments to synthesize hemispheric maps of water vapor.

Investigation of water vapor motion winds from geostationary satellites

NASA Technical Reports Server (NTRS)

Velden, Christopher

1993-01-01

Motions deduced in animated water vapor imagery from geostationary satellites can be used to infer wind fields in cloudless regimes. For the past several years, CIMSS has been exploring this potentially important source of global-scale wind information. Recently, METEOSAT-3 data has become routinely available to both the U.S. operational and research community. Compared with the current GOES satellite, the METEOSAT has a superior resolution (5 km vs. 16 km) in its water vapor channel. Preliminary work: at CIMSS has demonstrated that wind sets derived from METEOSAT water vapor imagery can provide important upper-tropospheric wind information in data void areas, and can positively impact numerical model guidance in meteorological applications. Specifically, hurricane track forecasts can be improved. Currently, we are exploring methods to further improve the derivation and quality of the water vapor wind sets.

Development of reference practices for the calibration and validation of atmospheric composition satellites

NASA Astrophysics Data System (ADS)

Lambert, Jean-Christopher; Bojkov, Bojan

The Committee on Earth Observation Satellites (CEOS)/Working Group on Calibration and Validation (WGCV) is developing a global data quality strategy for the Global Earth Obser-vation System of Systems (GEOSS). In this context, CEOS WGCV elaborated the GEOSS Quality Assurance framework for Earth Observation (QA4EO, http://qa4eo.org). QA4EO en-compasses a documentary framework and a set of ten guidelines, which describe the top-level approach of QA activities and key requirements that drive the QA process. QA4EO is appli-cable virtually to all Earth Observation data. Calibration and validation activities are a cornerstone of the GEOSS data quality strategy. Proper uncertainty assessment of the satellite measurements and their derived data products is essential, and needs to be continuously monitored and traceable to standards. As a practical application of QA4EO, CEOS WGCV has undertaken to establish a set of best practices, methodologies and guidelines for satellite calibration and validation. The present paper reviews current developments of best practices and guidelines for the vali-dation of atmospheric composition satellites. Aimed as a community effort, the approach is to start with current practices that could be improved with time. The present review addresses current validation capabilities, achievements, caveats, harmonization efforts, and challenges. Terminologies and general principles of validation are reminded. Going beyond elementary def-initions of validation like the assessment of uncertainties, the specific GEOSS context requires considering also the validation of individual service components and against user requirements.

Climatology and Impact of Convection on the Tropical Tropopause Layer

NASA Technical Reports Server (NTRS)

Robertson, Franklin; Pittman, Jasna

2007-01-01

Water vapor plays an important role in controlling the radiative balance and the chemical composition of the Tropical Tropopause Layer (TTL). Mechanisms ranging from slow transport and dehydration under thermodynamic equilibrium conditions to fast transport in convection have been proposed as regulators of the amount of water vapor in this layer. However,.details of these mechanisms and their relative importance remain poorly understood, The recently completed Tropical Composition, Cloud, and Climate Coupling (TC4) campaign had the opportunity to sample the.TTL over the Eastern Tropical Pacific using ground-based, airborne, and spaceborne instruments. The main goal of this study is to provide the climatological context for this campaign of deep and overshooting convective activity using various satellite observations collected during the summertime. We use the Microwave Humidity Sensor (MRS) aboard the NOAA-18 satellite to investigate the horizontal extent.and the frequency of convection reaching and penetrating into the TTL. We use the Moderate Resolution I1l1aging Spectroradiometer (MODIS) aboard the Aqua satellite to investigate the frequency distribution of daytime cirrus clouds. We use the Tropical Rainfall Measuring Mission(TRMM) and CloudSat to investigate the vertical structure and distribution of hydrometeors in the convective cells, In addition to cloud measurements; we investigate the impact that convection has on the concentration of radiatively important gases such as water vapor and ozone in the TTL by examining satellite measurement obtained from the Microwave Limb Sounder(MLS) aboard the Aura satellite.

Techniques to minimize adjacent band emissions from Earth Exploration Satellites to protect the Space Research (Category B) Earth Stations in the 8400-8450 MHz band

NASA Technical Reports Server (NTRS)

Wang, Charles C.; Sue, Miles K.; Manshadi, Farzin

2004-01-01

The Earth Exploration Satellites operating in the 8025-8400 MHz band can have strong adjacent band emissions on the8400-8450 MHz band which is allocated for Space Research (Category-B). The unwanted emission may exceed the protection criterion establish by the ITU-R for the protection of the Space Research (Category B) earth stations, i.e., deep-space earth stations. An SFCG Action Item (SF 23/14) was created during the 23rd SFCG meeting to explore technical and operational techniques to reduce the adjacent band emissions. In response to this action item, a study was conducted and results are presented in this document.

Inhibition of the Activin Receptor Type-2B Pathway Restores Regenerative Capacity in Satellite Cell-Depleted Skeletal Muscle.

PubMed

Formicola, Luigi; Pannérec, Alice; Correra, Rosa Maria; Gayraud-Morel, Barbara; Ollitrault, David; Besson, Vanessa; Tajbakhsh, Shahragim; Lachey, Jennifer; Seehra, Jasbir S; Marazzi, Giovanna; Sassoon, David A

2018-01-01

Degenerative myopathies typically display a decline in satellite cells coupled with a replacement of muscle fibers by fat and fibrosis. During this pathological remodeling, satellite cells are present at lower numbers and do not display a proper regenerative function. Whether a decline in satellite cells directly contributes to disease progression or is a secondary result is unknown. In order to dissect these processes, we used a genetic model to reduce the satellite cell population by ~70-80% which leads to a nearly complete loss of regenerative potential. We observe that while no overt tissue damage is observed following satellite cell depletion, muscle fibers atrophy accompanied by changes in the stem cell niche cellular composition. Treatment of these mice with an Activin receptor type-2B (AcvR2B) pathway blocker reverses muscle fiber atrophy as expected, but also restores regenerative potential of the remaining satellite cells. These findings demonstrate that in addition to controlling fiber size, the AcvR2B pathway acts to regulate the muscle stem cell niche providing a more favorable environment for muscle regeneration.

Iodine Propulsion Advantages for Low Cost Mission Applications and the Iodine Satellite (ISAT) Technology Demonstration

NASA Technical Reports Server (NTRS)

Dankanich, John W.; Schumacher, Daniel M.

2015-01-01

The NASA Marshall Space Flight Center Science and Technology Office is continuously exploring technology options to increase performance or reduce cost and risk to future NASA missions including science and exploration. Electric propulsion is a prevalent technology known to reduce mission costs by reduction in launch costs and spacecraft mass through increased post launch propulsion performance. The exploration of alternative propellants for electric propulsion continues to be of interest to the community. Iodine testing has demonstrated comparable performance to xenon. However, iodine has a higher storage density resulting in higher ?V capability for volume constrained systems. Iodine's unique properties also allow for unpressurized storage yet sublimation with minimal power requirements to produce required gas flow rates. These characteristics make iodine an ideal propellant for secondary spacecraft. A range of mission have been evaluated with a focus on low-cost applications. Results highlight the potential for significant cost reduction over state of the art. Based on the potential, NASA has been developing the iodine Satellite for a near-term iodine Hall propulsion technology demonstration. Mission applications and progress of the iodine Satellite project are presented.

Exploring quantum computing application to satellite data assimilation

NASA Astrophysics Data System (ADS)

Cheung, S.; Zhang, S. Q.

2015-12-01

This is an exploring work on potential application of quantum computing to a scientific data optimization problem. On classical computational platforms, the physical domain of a satellite data assimilation problem is represented by a discrete variable transform, and classical minimization algorithms are employed to find optimal solution of the analysis cost function. The computation becomes intensive and time-consuming when the problem involves large number of variables and data. The new quantum computer opens a very different approach both in conceptual programming and in hardware architecture for solving optimization problem. In order to explore if we can utilize the quantum computing machine architecture, we formulate a satellite data assimilation experimental case in the form of quadratic programming optimization problem. We find a transformation of the problem to map it into Quadratic Unconstrained Binary Optimization (QUBO) framework. Binary Wavelet Transform (BWT) will be applied to the data assimilation variables for its invertible decomposition and all calculations in BWT are performed by Boolean operations. The transformed problem will be experimented as to solve for a solution of QUBO instances defined on Chimera graphs of the quantum computer.

Usefulness of ERTS-1 satellite imagery as a data-gathering tool by resource managers in the Bureau of Land Management. [Arizona, California, Oregon, and Alaska

NASA Technical Reports Server (NTRS)

Bentley, R. G.

1974-01-01

ERTS-1 satellite imagery can be an effective data-gathering tool for resource managers. Techniques are developed which allow managers to visually analyze simulated color infrared composite images to map perennial and ephemeral (annual) plant communities. Tentative results indicate that ephemeral plant growth and development and potential to produce forage can be monitored.

Precise Orbit Determination Of Low Earth Satellites At AIUB Using GPS And SLR Data

NASA Astrophysics Data System (ADS)

Jaggi, A.; Bock, H.; Thaller, D.; Sosnica, K.; Meyer, U.; Baumann, C.; Dach, R.

2013-12-01

An ever increasing number of low Earth orbiting (LEO) satellites is, or will be, equipped with retro-reflectors for Satellite Laser Ranging (SLR) and on-board receivers to collect observations from Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS) and the Russian GLONASS and the European Galileo systems in the future. At the Astronomical Institute of the University of Bern (AIUB) LEO precise orbit determination (POD) using either GPS or SLR data is performed for a wide range of applications for satellites at different altitudes. For this purpose the classical numerical integration techniques, as also used for dynamic orbit determination of satellites at high altitudes, are extended by pseudo-stochastic orbit modeling techniques to efficiently cope with potential force model deficiencies for satellites at low altitudes. Accuracies of better than 2 cm may be achieved by pseudo-stochastic orbit modeling for satellites at very low altitudes such as for the GPS-based POD of the Gravity field and steady-state Ocean Circulation Explorer (GOCE).

Precision Viticulture from Multitemporal, Multispectral Very High Resolution Satellite Data

NASA Astrophysics Data System (ADS)

Kandylakis, Z.; Karantzalos, K.

2016-06-01

In order to exploit efficiently very high resolution satellite multispectral data for precision agriculture applications, validated methodologies should be established which link the observed reflectance spectra with certain crop/plant/fruit biophysical and biochemical quality parameters. To this end, based on concurrent satellite and field campaigns during the veraison period, satellite and in-situ data were collected, along with several grape samples, at specific locations during the harvesting period. These data were collected for a period of three years in two viticultural areas in Northern Greece. After the required data pre-processing, canopy reflectance observations, through the combination of several vegetation indices were correlated with the quantitative results from the grape/must analysis of grape sampling. Results appear quite promising, indicating that certain key quality parameters (like brix levels, total phenolic content, brix to total acidity, anthocyanin levels) which describe the oenological potential, phenolic composition and chromatic characteristics can be efficiently estimated from the satellite data.

Regulation of centriolar satellite integrity and its physiology.

PubMed

Hori, Akiko; Toda, Takashi

2017-01-01

Centriolar satellites comprise cytoplasmic granules that are located around the centrosome. Their molecular identification was first reported more than a quarter of a century ago. These particles are not static in the cell but instead constantly move around the centrosome. Over the last decade, significant advances in their molecular compositions and biological functions have been achieved due to comprehensive proteomics and genomics, super-resolution microscopy analyses and elegant genetic manipulations. Centriolar satellites play pivotal roles in centrosome assembly and primary cilium formation through the delivery of centriolar/centrosomal components from the cytoplasm to the centrosome. Their importance is further underscored by the fact that mutations in genes encoding satellite components and regulators lead to various human disorders such as ciliopathies. Moreover, the most recent findings highlight dynamic structural remodelling in response to internal and external cues and unexpected positive feedback control that is exerted from the centrosome for centriolar satellite integrity.

Simultaneous assimilation of satellite NO2, O3, CO, and HNO3 data for the analysis of the tropospheric chemical composition

NASA Astrophysics Data System (ADS)

Miyazaki, K.; Eskes, H.; Sudo, K.

2012-04-01

Carbon monoxide (CO) and nitrogen oxides (NOx) play an important role in tropospheric chemistry through their influences on the ozone and hydroxyl radical (OH). The simultaneous optimization of various chemical components is expected to improve the emission inversion through the better description of the chemical feedbacks in the NOx- and CO-chemistry. This study aims to reproduce chemical composition distributions in the troposphere by combining information obtained from multiple satellite data sets. The emissions of CO and NOx, together with the 3D concentration fields of all forecasted chemical species in the global CTM CHASER have been simultaneously optimized using the ensemble Kalman filter (EnKF) data assimilation technique, and NO2, O3, CO, and HNO3 data obtained from OMI, TES, MOPITT, and MLS satellite measurements. The performance is evaluated against independent data from ozone sondes, aircraft measurements, GOME-2, and SCIAMACHY satellite data. Observing System Experiments (OSEs) have been carried out. These OSEs quantify the relative importance of each data set on constraining the emissions and concentrations. We confirmed that the simultaneous data assimilation improved the agreement with these independent data sets. The combined analysis of multiple data sets by means of advanced data assimilation system can provide a useful framework for the air quality research.

Nature, Origin, Potential Composition, and Climate Impact of the Asian Tropopause Aerosol Layer (ATAL)

NASA Technical Reports Server (NTRS)

Fairlie, T. D.; Vernier, J.-P.; Thomason, L. W.; Natarajan, M.; Bedka, K.; Wienhold, F.; Bian J.; Martinsson, B.

2015-01-01

Satellite observations from SAGE II and CALIPSO indicate that summertime aerosol extinction has more than doubled in the Asian Tropopause Aerosol Layer (ATAL) since the late 1990s. Here we show remote and in-situ observations, together with results from a chemical transport model (CTM), to explore the likely composition, origin, and radiative forcing of the ATAL. We show in-situ balloon measurements of aerosol backscatter, which support the high levels observed by CALIPSO since 2006. We also show in situ measurements from aircraft, which indicate a predominant carbonaceous contribution to the ATAL (Carbon/Sulfur ratios of 2- 10), which is supported by the CTM results. We show that the peak in ATAL aerosol lags by 1 month the peak in CO from MLS, associated with deep convection over Asia during the summer monsoon. This suggests that secondary formation and growth of aerosols in the upper troposphere on monthly timescales make a significant contribution to ATAL. Back trajectory calculations initialized from CALIPSO observations provide evidence that deep convection over India is a significant source for ATAL through the vertical transport of pollution to the upper troposphere.

Satellite-map position estimation for the Mars rover

NASA Technical Reports Server (NTRS)

Hayashi, Akira; Dean, Thomas

1989-01-01

A method for locating the Mars rover using an elevation map generated from satellite data is described. In exploring its environment, the rover is assumed to generate a local rover-centered elevation map that can be used to extract information about the relative position and orientation of landmarks corresponding to local maxima. These landmarks are integrated into a stochastic map which is then matched with the satellite map to obtain an estimate of the robot's current location. The landmarks are not explicitly represented in the satellite map. The results of the matching algorithm correspond to a probabilistic assessment of whether or not the robot is located within a given region of the satellite map. By assigning a probabilistic interpretation to the information stored in the satellite map, researchers are able to provide a precise characterization of the results computed by the matching algorithm.

Optimal Location of Piezoelectric Patch on Composite Structure using Viewing Method

NASA Astrophysics Data System (ADS)

Samyal, Rahul; Bagha, Ashok K.

2017-08-01

A useful material which is manufactured by mixing of two or three different materials in homogeneous level is termed as composite material. In now day’s composite materials are used in wide area such as aerospace, automobiles, satellite, bullet proof jackets, rotor blades etc. In this paper modal analysis of composite material, mixture of polyester as matrix and glass as fiber, is carried out by using ABAQUS software. The modal analysis of composite material for fiber orientation 450 is carried out. In this paper by viewing the different mode shapes of the composite material, the optimal location of piezoelectric patch is carried out.

Dynamic system simulation of small satellite projects

NASA Astrophysics Data System (ADS)

Raif, Matthias; Walter, Ulrich; Bouwmeester, Jasper

2010-11-01

A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for modeling and dynamic simulation of satellite systems has been developed called dynamic system simulation (DySyS). DySyS is based on the platform independent description language SysML to model a small satellite project with respect to the system composition and dynamic behavior. A library of specific building blocks and possible relations between these blocks have been developed. From this library a system model of the satellite of interest can be created. A mapping into a C++ simulation allows the creation of an executable system model with which simulations are performed to observe the dynamic behavior of the satellite. In this paper DySyS is used to model and simulate the dynamic behavior of small satellites, because small satellite projects can act as a precursor to demonstrate the feasibility of a system model since they are less complex compared to a large scale satellite project.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003870 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are deployed from a Small Satellite Orbital Deployer (SSOD) attached to the Kibo laboratory’s robotic arm at 7:10 a.m. (EST) on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan’s fourth H-II Transfer Vehicle, Kounotori-4.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003869 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are deployed from a Small Satellite Orbital Deployer (SSOD) attached to the Kibo laboratory’s robotic arm at 7:10 a.m. (EST) on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan’s fourth H-II Transfer Vehicle, Kounotori-4.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003871 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are deployed from a Small Satellite Orbital Deployer (SSOD) attached to the Kibo laboratory’s robotic arm at 7:10 a.m. (EST) on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan’s fourth H-II Transfer Vehicle, Kounotori-4.

Small Cube Satellite Deploy

NASA Image and Video Library

2013-11-19

ISS038-E-003872 (19 Nov. 2013) --- Three nanosatellites, known as Cubesats, are deployed from a Small Satellite Orbital Deployer (SSOD) attached to the Kibo laboratory’s robotic arm at 7:10 a.m. (EST) on Nov. 19, 2013. Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. The Cubesats were delivered to the International Space Station Aug. 9, aboard Japan’s fourth H-II Transfer Vehicle, Kounotori-4.

NASA SCaN Overview and Ka-Band Actvities

NASA Technical Reports Server (NTRS)

Stegeman, James D.; Midon, Marco Mario; Davarian, Faramaz; Geldzahler, Barry

2014-01-01

The Ka- and Broadband Communications Conference is an international forum attended by worldwide experts in the area of Ka-Band Propagation and satellite communications. Since its inception, NASA has taken the initiative of organizing and leading technical sections on RF Propagation and satellite communications, solidifying its worldwide leadership in the aforementioned areas. Consequently, participation in this conference through the contributions described below will maintain NASA leadership in Ka- and above RF Propagation as it relates to enhancing current and future satellite communication systems supporting space exploration.

ITOS/space shuttle study

NASA Technical Reports Server (NTRS)

1971-01-01

The results are reported of a study to explore the potential cost reductions in the operational ITOS weather satellite program as a consequence of shuttle/bug availability for satellite placement and retrieval, and satellite servicing and maintenance. The study program was divided into shuttle impact on equipment and testing costs, and shuttle impact on overall future ITOS operational program costs, and shuttle impact on configuration. It is concluded that savings in recurring spacecraft costs can be realized in the 1978 ITOS program, if a space shuttle is utilized.

Launch of NASA's FUSE satellite from CCAS.

NASA Technical Reports Server (NTRS)

1999-01-01

The Boeing Delta II rocket carrying NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite clears the tower after liftoff at 11:44 a.m. EDT from Launch Pad 17A, Cape Canaveral Air Station. FUSE was developed to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

Launch of NASA's FUSE satellite from CCAS.

NASA Technical Reports Server (NTRS)

1999-01-01

NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite sits on Launch Pad 17A, Cape Canaveral Air Station, aboard the Boeing Delta II rocket waiting for launch. Liftoff is scheduled for 11:39 a.m. EDT. FUSE was developed to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

Geosynchronous earth orbit/low earth orbit space object inspection and debris disposal: A preliminary analysis using a carrier satellite with deployable small satellites

NASA Astrophysics Data System (ADS)

Crockett, Derick

Detailed observations of geosynchronous satellites from earth are very limited. To better inspect these high altitude satellites, the use of small, refuelable satellites is proposed. The small satellites are stationed on a carrier platform in an orbit near the population of geosynchronous satellites. A carrier platform equipped with deployable, refuelable SmallSats is a viable option to inspect geosynchronous satellites. The propellant requirement to transfer to a targeted geosynchronous satellite, perform a proximity inspection mission, and transfer back to the carrier platform in a nearby orbit is determined. Convex optimization and traditional optimization techniques are explored, determining minimum propellant trajectories. Propellant is measured by the total required change in velocity, delta-v. The trajectories were modeled in a relative reference frame using the Clohessy-Wiltshire equations. Mass estimations for the carrier platform and the SmallSat were determined by using the rocket equation. The mass estimates were compared to the mass of a single, non-refuelable satellite performing the same geosynchronous satellite inspection missions. From the minimum delta-v trajectories and the mass analysis, it is determined that using refuelable SmallSats and a carrier platform in a nearby orbit can be more efficient than using a single non-refuelable satellite to perform multiple geosynchronous satellite inspections.

Small Explorer project: Submillimeter Wave Astronomy Satellite (SWAS). Mission operations and data analysis plan

NASA Technical Reports Server (NTRS)

Melnick, Gary J.

1990-01-01

The Mission Operations and Data Analysis Plan is presented for the Submillimeter Wave Astronomy Satellite (SWAS) Project. It defines organizational responsibilities, discusses target selection and navigation, specifies instrument command and data requirements, defines data reduction and analysis hardware and software requirements, and discusses mission operations center staffing requirements.

Dual assimilation of satellite soil moisture to improve flood prediction in ungauged catchments

USDA-ARS?s Scientific Manuscript database

This paper explores the use of active and passive satellite soil moisture products for improving stream flow prediction within 4 large (>5,000km2) semi-arid catchments. We use the probability distributed model (PDM) under a data-scarce scenario and aim at correcting two key controlling factors in th...

Communications Satellite Tariffs for Television. IBI Monograph Number 3.

ERIC Educational Resources Information Center

Passell, Peter; Ross, Leonard

Dealing with the experiences of and the conditions for international and intercontinental satellite transmissions as they have been carried out during the past decade, this paper focuses on the rules and practices applied within the Intelsat system. The purpose of the paper is to explore the issues involved in establishing tariffs in accord with…

Exploring the Airways for Adult Education. Section 310, Final Report.

ERIC Educational Resources Information Center

Morris, Betty

Intended to enable an individual to converse with satellite antenna dealers and to select a dealer and acquire an antenna to suit his/her needs at the lowest cost, this edited version of a final project report provides detailed guidelines for purchasing of communications satellites distance education delivery systems and specific technical…

One Web Satellites Ground Breaking

NASA Image and Video Library

2017-03-16

Cissy Procter, executive director of the Florida Department of Economic Activity, speaks during the groundbreaking ceremony at Kennedy's Exploration Park for OneWeb. The company, in partnership with Airbus, is building a 150,000-square-foot factory to manufacture satellites that will connect all areas of the world to the Internet wirelessly. Photo credit: NASA/Kim Shiflett

Conclusions and recommendations: Exploration of the Saturn system

NASA Technical Reports Server (NTRS)

Hunten, D. M.

1978-01-01

Saturn missions have the following principal goals, in order of importance: (1) Intensive investigation of the atmosphere of Saturn; (2) determination of regional surface chemistry and properties of the surface features of satellites and properties of ring particles; (3) intensive investigation of Titan; and (4) atmospheric dynamics and structure of Saturn satellites and Saturn rings.

A study of large, medium and small scale structures in the topside ionosphere

NASA Technical Reports Server (NTRS)

Gross, Stanley H.; Kuo, Spencer P.; Shmoys, Jerry

1986-01-01

Alouette and ISIS data were studied for large, medium, and small scale structures in the ionosphere. Correlation was also sought with measurements by other satellites, such as the Atmosphere Explorer C and E and the Dynamic Explorer 2 satellites, of both neutrals and ionization, and with measurements by ground facilities, such as the incoherent scatter radars. Large scale coherent wavelike structures were found from ISIS 2 electron density contours from above the F peak to nearly the satellite altitude. Such structures were also found to correlate with the observation by AE-C below the F peak during a conjunction of the two satellites. Vertical wavefronts found in the upper F region suggest the dominance of diffusion along field lines as well. Also discovered were multiple, evenly spaced field-aligned ducts in the F region that, at low latitudes, extended to the other hemisphere and were in the form of field-aligned sheets in the east-west direction. Low latitude heating events were discovered that could serve as sources for waves in the ionosphere.

Objectives for Atmospheres and Ring Science for the Jupiter Icy Moons Orbiter

NASA Astrophysics Data System (ADS)

Ingersoll, A.; Simon-Miller, A.

2003-12-01

The Solar System Exploration Decadal Survey was made public in draft form in June 2002. It lists 12 key scientific questions, of which 4 are most relevant to the planet Jupiter: 1. Over what period did the gas giants form, and how did the birth of the ice giants (Uranus, Neptune) differ from that of Jupiter and its gas-giant sibling, Saturn? 2. What is the history of volatile compounds, especially water, across our solar system? 3. How do the processes that shape the contemporary character of planetary bodies operate and interact? 4. What does our solar system tell us about the development and evolution of extrasolar planetary systems, and vice versa? The Decadal Survey, which was asked to provide a prioritized list of the most promising avenues for flight investigations, recommended a Jupiter Orbiter with Probes (JPOP) as the highest priority giant planets mission in the New Frontiers line. The goals of that mission are: 1. Determine if Jupiter has a central core to constrain ideas of its formation 2. Determine the planetary water abundance 3. Determine if the winds persist into Jupiter's interior or are confined to the weather layer 4. Assess the structure of Jupiter's magnetic field to learn how the internal dynamo works 5. Measure the polar magnetosphere to understand its rotation and relation to the aurora JPOP was proposed as a high inclination orbiter whose low equatorial perijove enabled it to make detailed measurements of the gravitational and magnetic fields as well as the polar magnetosphere. The probes mainly addressed the water abundance and deep winds. The gravitational field measurement also addressed the deep winds as well as the central core. The JIMO opportunity arose after the Decadal Survey report was written, and is different from the opportunity afforded by a New Frontiers mission. JIMO offers a potential breakthrough in remote sensing: The 1-3 Mbps data rate is 2 orders of magnitude greater than that of previous missions. The circular orbit offers continuous planet viewing during the 3 months between satellite encounters. The 10-30 kW of power offers advantages for radio occultations and other active sensors. In addition, JIMO can carry a probe, which can determine the water abundance, deep winds, and thermal structure to 100 bars. At the Forum on Concepts and Approaches for JIMO in Houston, Texas on June 14-15, 2003, the Atmospheres and Rings Subgroup came up with the following prioritized list of objectives: 1. Composition, structure, chemistry, and dynamics of Jupiter's atmosphere. 2. Composition, structure, and dynamics of icy moon atmospheres. 3. Composition, structure, dynamics, and time variability of the atmosphere of Io. 4. Nature of the interaction between magnetosphere, satellites, and Jupiter. 5. Structure, composition, energy budget, and variability of satellite tori. 6. Structure and particle properties of the Jovian ring system Each objective has several prioritized investigations, and each investigation has a prioritized list of measurements. These will be presented at the meeting. Some of the measurements require a probe; others can be done from the JIMO orbiter. With or without a probe, the JIMO mission can answer fundamental questions about atmospheres, rings, and satellite tori in the Jupiter system.

International Ultraviolet Explorer (IUE) satellite mission analysis

NASA Technical Reports Server (NTRS)

Cook, R. A.; Griffin, J. H.

1975-01-01

The results are presented of the mission analysis performed by Computer Sciences Corporation (CSC) in support of the International Ultraviolet Explorer (IUE) satellite. The launch window is open for three separate periods (for a total time of 7 months) during the year extending from July 20, 1977, to July 20, 1978. The synchronous orbit shadow constraint limits the launch window to approximately 88 minutes per day. Apogee boost motor fuel was computed to be 455 pounds (206 kilograms) and on-station weight was 931 pounds (422 kilograms). The target orbit is elliptical synchronous, with eccentricity 0.272 and 24 hour period.

Strategy for exploration of the outer planets: 1986-1996

NASA Technical Reports Server (NTRS)

1986-01-01

Over the past decade COMPLEX has published three strategy reports which, taken together, encompass the entire planetary system and recommend a coherent program of planetary exploration. The highest priority for outer planet exploration during the next decade is intensive study of Saturn (the planet, satellites, rings, and magnetosphere) as a system. The Committee additionally recommends that NASA engage in the following supporting activities: increased support of laboratory and theoretical studies; pursuit of earth-based and earth-orbital observations; commitment to continued operation of productive spacecraft; implementation of the instrument development plan as appropriate for the outer solar system; studies of deep atmospheric probes; development of penetrators or other hard landers; development of radiation-hardened spacecraft; and development of low-thrust propulsion systems. Longer-term objectives include exploration and intensive study of: the Uranus and Neptune systems; planetology of the Galilean satellites and Titan; and the inner Jovian system.

Research on lunar and planet development and utilization

NASA Astrophysics Data System (ADS)

Iwata, Tsutomu; Etou, Takao; Imai, Ryouichi; Oota, Kazuo; Kaneko, Yutaka; Maeda, Toshihide; Takano, Yutaka

1992-08-01

Status of the study on unmanned and manned lunar missions, unmanned Mars missions, lunar resource development and utilization missions, remote sensing exploration missions, survey and review to elucidate the problems of research and development for lunar resource development and utilization, and the techniques and equipment for lunar and planet exploration are presented. Following items were studied respectively: (1) spacecraft systems for unmanned lunar missions, such as lunar observation satellites, lunar landing vehicles, lunar surface rovers, lunar surface hoppers, and lunar sample retrieval; (2) spacecraft systems for manned lunar missions, such as manned lunar bases, lunar surface operation robots, lunar surface experiment systems, manned lunar take-off and landing vehicles, and lunar freight transportation ships; (3) spacecraft systems for Mars missions, such as Mars satellites, Phobos and Deimos sample retrieval vehicles, Mars landing explorers, Mars rovers, Mars sample retrieval; (4) lunar resource development and utilization; and (5) remote sensing exploration technologies.

Atmospheric Climate Experiment Plus

NASA Astrophysics Data System (ADS)

Lundahl, K.

ACE+ is an atmospheric sounding mission using radio occultation techniques and is a combination of the two Earth Explorer missions ACE and WATS earlier proposed to ESA. ACE was highly rated by ESA in the Call for Earth Explorer Opportunity Missions in 1999 and was prioritised as number three and selected as a "hot-stand-by". A phase A study was carried out during 2000 and 2001. ACE will observe atmospheric parameters using radio occultations from an array of 6 micro-satellites which track the L- band signal of GPS satellites to map the detailed refractivity and thermal structure of the global atmosphere from surface to space. Water vapour and wind in Atmospheric Troposphere and Stratosphere WATS was the response to ESA's Call for Ideas for the next Earth Explorer Core Missions in 2001. WATS combines ACE GPS atmospheric occultations and LEO-LEO cross-link occultations. Cross-links strongly enhance the capability of measuring humidity relative to the ACE mission. The Earth Science Advisory Committée at ESA noted that the LEO-GNSS occultation technique is already well established through several missions in recent years and could not recommend WATS for a Phase A study as an Earth Explorer Core Mission. The ESAC was, however, deeply impressed by the LEO-LEO component of the WATS proposal and would regard it as regrettable if this science would be lost and encourages the ACE/WATS team to explore other means to achieve its scientific goal. ACE+ is therefore the response to ESA's 2nd Call for Earth Explorer Opportunity Missions in 2001 and will contribute in a significant manner to ESA's Living Planet Programme. ACE+ will considerably advance our knowledge about atmosphere physics and climate change processes. The mission will demonstrate a highly innovative approach using radio occultations for globally measuring profiles of humidity and temperature throughout the atmosphere and stratosphere. A constellation of 4 small satellites, tracking L-band GPS/GALILEO signals and X/K-band LEO-LEO cross-link signals, will be launched in 2 counter-rotating orbits with 2 satellites in each at 650 and 850 km respectively. Several aspects drive the spacecraft design. The GRAS+ and CALL+ instruments have a relatively high power consumption. The pointing and stability requirements call for a fully capable 3-axis attitude control system. Satellite characteristics include a mass of 130 kg, and available power of 80 W. The bus is based on the SMART-1 satellite from Swedish Space Corporation. In order to meet the cost envelope of the Earth Explorer Opportunity Missions the spacecraft should be a simple and robust design and makes use of the latest, but proven, technical developments as CAN-bus, GaAs solar cells and Li-Ion batteries. Low cost launch with a mix of START-1 and Rockot is also foreseen and could take place in 2006-2007. This paper describes mission characteristics and technical solutions for ACE+ .

The Arctic Regional Communications Small SATellite (ARCSAT)

NASA Technical Reports Server (NTRS)

Casas, Joseph; Kress, Martin; Sims, William; Spehn, Stephen; Jaeger, Talbot; Sanders, Devon

2013-01-01

Traditional satellite missions are extremely complex and expensive to design, build, test, launch and operate. Consequently many complementary operational, exploration and research satellite missions are being formulated as a growing part of the future space community capabilities using formations of small, distributed, simple to launch and inexpensive highly capable small scale satellites. The Arctic Regional Communications small SATellite (ARCSAT) initiative would launch a Mini-Satellite "Mothership" into Polar or Sun Sync low-earth-orbit (LEO). Once on orbit, the Mothership would perform orbital insertion of four internally stored independently maneuverable nanosatellites, each containing electronically steerable antennas and reconfigurable software-defined radios. Unlike the traditional geostationary larger complex satellite communication systems, this LEO communications system will be comprised of initially a five small satellite formation that can be later incrementally increased in the total number of satellites for additional data coverage. ARCSAT will provide significant enabling capabilities in the Arctic for autonomous voice and data communications relay, Maritime Domain Awareness (MDA), data-extraction from unattended sensors, and terrestrial Search & Rescue (SAR) beacon detection missions throughout the "data starved desert" of the Arctic Region.

Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

NASA Technical Reports Server (NTRS)

Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.;

Laboratory spectroscopy and space astrophysics: A tribute to Joe Reader

NASA Astrophysics Data System (ADS)

Leckrone, David S.

2013-07-01

Beginning with the launch of the Copernicus Satellite in 1973, and continuing with the International Ultraviolet Explorer (IUE), and the state-of-the-art spectrographs on the Hubble Space Telescope (GHRS, FOS, STIS and COS), astrophysics experienced dramatic advancements in capabilities to study the composition and physical properties of planets, comets, stars, nebulae, the interstellar medium, galaxies, quasars and the intergalactic medium at visible and ultraviolet wavelengths. It became clear almost immediately that the available atomic data needed to calibrate and quantitatively analyze these superb spectroscopic observations, obtained at great cost from space observatories, was not up to that task. Over the past 3+ decades, Joe Reader and his collaborators at NIST have provided, essentially "on demand", laboratory observations and analyses of extraordinary quality to help astrophysicists extract the maximum possible physical understanding of objects in the cosmos from their space observations. This talk is one scientist's grateful retrospective about these invaluable collaborations.

New objective of the "New Horizons" in the Kuiper belt

NASA Astrophysics Data System (ADS)

Vidmachenko, A. P.

2018-05-01

The scientific purpose of the study of the small planet 2014 MU69 is to obtain characteristics on its geology and morphology, to perform mapping of the surface composition: the search for ammonia, carbon monoxide, methane, water ice, etc. Also, it is planned to study its surface, the history of formation and development, measure the temperature, display the 3D topography in order to find out what it looks like, and by what it is differ, for example, from cometary nuclei, asteroids, dwarf planets, such as Pluto; search for any signs of activity, such as commas, to search for and explore possible satellites and / or rings, determine the mass, and so on. The spacecraft will visit MU69 1.01.2019. It is planned to get closer to its surface at a distance of about 3500 km. This will allow obtaining images of the surface with a resolution of up to 30 m.

Damage accumulation in closed cross-section, laminated, composite structures

NASA Technical Reports Server (NTRS)

Bucinell, Ronald B.

1996-01-01

The need for safe, lightweight, less expensive, and more reliable launch vehicle components is being driven by the competitiveness of the commercial launch market. The United States has lost 2/3 of the commercial lunch market to Europe. As low cost Russian and Chinese vehicles become available, the US market share could be reduced even further. This international climate is driving the Single Stage To Orbit (SSTO) program at NASA. The goal of the SSTO program is to radically reduce the cost of safe, routine transportation to and from space with a totally reusable launch vehicle designed for low-cost aircraft-like operations. Achieving this goal will require more efficient uses of materials. Composite materials can provide this program with the material and structural efficiencies needed to stay competitive in the international launch market place. In satellite systems the high specific properties, design flexibility, improved corrosion and wear resistance, increased fatigue life, and low coefficient of thermal expansion that are characteristic of composite materials can all be used to improve the overall satellite performance. Some of the satellites that may be able to take advantage of these performance characteristics are the Tethered Satellite Systems (TOSCIFER, AIRSEDS, TSS2, SEDS1, and SEDS2), AXAF, GRO, and the next generation Hubble Space Telescope. These materials can also be utilized in projects at the NASAIMSFC Space Optics Technology and System Center of Excellence. The successful implementation of composite materials requires accurate performance characterization. Materials characterization data for composite materials is typically generated using flat coupons of finite width. At the free edge of these coupons the stress state is exacerbated by the presence of stiffness and geometric discontinuities. The exacerbated stress state has been shown to dominate the damage accumulation in these materials and to have a profound affect on the material constants. Space structures typically have closed cross-sections, absent of free edges. As a result, composite material characterization data generated using finite width flat specimens does not accurately reflect the performance of the composite materials used in a closed cross-section structural configuration. Several investigators have recognized the need to develop characterization techniques for composite materials in closed cross-sectioned structures. In these investigations test methods were developed and cylindrical specimens were evaluated. The behavior of the cylindrical specimens were observed to depart from behavior typical of flat coupons. However, no attempts were made to identify and monitor the progression of damage in these cylindrical specimens during loading. The identification and monitoring of damage is fundamental to the characterization of composite materials in closed cross-section configurations. In the study reported here, a closed cross-sectioned test method was developed to monitor damage progression in 2 in. diameter cylindrical specimens and 1.5 in. finite width flat coupons subjected to quasi-static, tensile loading conditions. Damage in these specimen configurations was monitored using pulse echo ultrasonic, acoustic emission, and X-ray techniques.

Exploration cost-cutting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huttrer, J.

This presentation by Jerry Huttrer, President, Geothermal Management Company, discusses the general state of exploration in the geothermal industry today, and mentions some ways to economize and perhaps save costs of geothermal exploration in the future. He suggests an increased use of satellite imagery in the mapping of geothermal resources and the identification of hot spots. Also, coordinating with oil and gas exploration efforts, the efficiency of the exploration task could be optimized.

Assessment of MODIS-EVI, MODIS-NDVI and VEGETATION-NDVI composite data using agricultural measurements: an example at corn fields in western Mexico.

PubMed

Chen, Pei-Yu; Fedosejevs, Gunar; Tiscareño-López, Mario; Arnold, Jeffrey G

2006-08-01

Although several types of satellite data provide temporal information of the land use at no cost, digital satellite data applications for agricultural studies are limited compared to applications for forest management. This study assessed the suitability of vegetation indices derived from the TERRA-Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and SPOT-VEGETATION (VGT) sensor for identifying corn growth in western Mexico. Overall, the Normalized Difference Vegetation Index (NDVI) composites from the VGT sensor based on bi-directional compositing method produced vegetation information most closely resembling actual crop conditions. The NDVI composites from the MODIS sensor exhibited saturated signals starting 30 days after planting, but corresponded to green leaf senescence in April. The temporal NDVI composites from the VGT sensor based on the maximum value method had a maximum plateau for 80 days, which masked the important crop transformation from vegetative stage to reproductive stage. The Enhanced Vegetation Index (EVI) composites from the MODIS sensor reached a maximum plateau 40 days earlier than the occurrence of maximum leaf area index (LAI) and maximum intercepted fraction of photosynthetic active radiation (fPAR) derived from in-situ measurements. The results of this study showed that the 250-m resolution MODIS data did not provide more accurate vegetation information for corn growth description than the 500-m and 1000-m resolution MODIS data.

A satellite view of aerosols in the climate system

NASA Technical Reports Server (NTRS)

Kaufman, Yoram J.; Tanre, Didier; Boucher, Olivier

2002-01-01

Anthropogenic aerosols are intricately linked to the climate system and to the hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight. Depending on their composition, aerosols can also absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process. These effects of aerosols on the temperature profile, along with the role of aerosols as cloud condensation nuclei, impact the hydrologic cycle, through changes in cloud cover, cloud properties and precipitation. Unravelling these feedbacks is particularly difficult because aerosols take a multitude of shapes and forms, ranging from desert dust to urban pollution, and because aerosol concentrations vary strongly over time and space. To accurately study aerosol distribution and composition therefore requires continuous observations from satellites, networks of ground-based instruments and dedicated field experiments. Increases in aerosol concentration and changes in their composition, driven by industrialization and an expanding population, may adversely affect the Earth's climate and water supply.

The Satellite Telescope Nina for Nuclear and Isotopic Investigations in Space

NASA Astrophysics Data System (ADS)

Circella, M.; Bidoli, V.; Casolino, M.; de Pascale, M. P.; Morselli, A.; Furano, G.; Picozza, P.; Scoscini, A.; Sparvoli, R.; Barbiellini, G.; Bonvicini, W.; Cirami, R.; Schiavon, P.; Vacchi, A.; Zampa, N.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Ciacio, F.; de Marzo, C.; Bartalucci, S.; Giuntoli, S.; Ricci, M.; Papini, P.; Piccardi, S.; Spillantini, P.; Bakaldin, A.; Batishev, A.; Galper, A. M.; Koldashov, S.; Mikhailov, V.; Murashov, A.; Voronov, S.; Boezio, M.

2000-09-01

NINA is a satellite silicon detector designed to perform measurements of the nuclear and isotopic composition of the galactic and anomalous components of cosmic rays, as well as of the energetic particles associated with solar flares. It has been orbiting the Earth onboard the Russian satellite Resource 01 n. 4 since July 1998. It can perform nuclear discrimination from hydrogen to iron as well as isotopic analyses at least up to the beryllium isotopes in a large energy range. NINA is the first step of the wide scientific program WiZard-RIM, which includes the design and deployment of the PAMELA magnet spectrometer.

History of telescopic observations of the Martian satellites

NASA Astrophysics Data System (ADS)

Pascu, D.; Erard, S.; Thuillot, W.; Lainey, V.

2014-11-01

This article intends to review the different studies of the Mars satellites Phobos and Deimos realized by means of ground-based telescopic observations as well in the astrometry and dynamics domain as in the physical one. This study spans the first period of investigations of the Martian satellites since their discovery in 1877 through the astrometry and the spectrometry methods, mainly before the modern period of the space era. It includes also some other observations performed thanks to the Hubble Space Telescope. The different techniques used and the main results obtained for the positionning, the size estimate, the albedo and surface composition are described.

Stability of an optically contacted etalon to cosmic radiation. [aboard Dynamics Explorer satellite

NASA Technical Reports Server (NTRS)

Killeen, T. L.; Dettman, D. L.; Hays, P. B.

1980-01-01

An investigation has been completed to determine the effects of prolonged exposure to cosmic radiation on Zerodur spacing elements used between two dielectric reflectors on silica substrates in the plane Fabry-Perot etalon selected for flight in the Dynamics Explorer satellite. The measured radiation expansion coefficient for Zerodur is approximately -4.0 x 10 to the -12th/rad. In addition to the overall change in gap dimension, test data indicate a degradation in etalon parallelism, which is ascribed to the different doses received by the three spacers due to their differing distances from a Co-60 source. The effect is considered to be of practical use in the tuning and parallelism adjustment of fixed gap etalons. The variation is small enough not to pose a problem for the satellite instrument where expected radiation doses are less than 10,000 rads.

The political and legal aspects of space applications

NASA Technical Reports Server (NTRS)

Hanessian, J., Jr.

1972-01-01

The political and legal repercussions of space programs both domestic and foreign are explored. Emphasis are placed on earth resources exploration (exploration based on information rights), jurisdictional problems, problems of sharing space benefits with other countries, criminal launch and use of satellites, intrusion into territorial sovereignty, and problems of establishing data ownership.

Assimilation of GMS-5 satellite winds using nudging method with MM5

NASA Astrophysics Data System (ADS)

Gao, Shanhong; Wu, Zengmao; Yang, Bo

2006-09-01

With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and National Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental forecasts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

Signature of Europa's Ocean Density on Gravity Data

NASA Astrophysics Data System (ADS)

Castillo, J. C.; Rambaux, N.

2015-12-01

Observations by the Galileo mission at Europa and Cassini-Huygens mission at Europa, Ganymede, Callisto, Enceladus, and Titan have found deep oceans at these objects with evidence for the presence of salts. Salt compounds are the products of aqueous alteration of the rock phase under hydrothermal conditions and have been predicted theoretically for these objects per analogy with carbonaceous chondrite parent bodies. Evidence for salt enrichment comes from magnetometer measurements (Galilean satellites), direct detection in the case of Enceladus, and inversion of the gravity data obtained at Titan. While there is direct detection for the presence of chlorides in icy grains ejected from Enceladus, the chemistry of the oceans detected so far, or even their densities, remain mostly unconstrained. However the increased ocean density impacts the interpretation of the tidal Love number k2and this may introduce confusion in the inference of the icy shell thickness from that parameter. We will present estimates of k2for a range of assumptions on Europa's hydrospheric structure that build on geophysical observations obtained by the Galileo mission combined with new models of Europa's interior. These models keep track of the compositions of the hydrated core and oceanic composition in a self-consistent manner. We will also estimate the electrical conductivity corresponding to the modeled oceanic composition. Finally we will explore how combining electromagnetic, topographic, and gravity data can decouple the signatures of the shell thickness and ocean composition on these geophysical observations. Acknowledgement: This work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.

Discriminating Type 1a and 1b PSCs in Satellite Data

NASA Technical Reports Server (NTRS)

Strawa, Anthony W.; Drdla, Katja; Fromm, Michael; Hoppel, Karl W.; Pueschel, Rudolf; Browell, Edward V.; Hostetler, Chris A.; Hamill, Patrick; Gore, Warren J. (Technical Monitor)

2000-01-01

We explore the use of satellite observations in discriminating types of PSCs and their ramifications. Polar Stratospheric Clouds (PSCs), which form in the winter polar vortex, have been identified as effecting ozone loss. One major result from the recent SOLVE mission is in-situ evidence of the existence of very large particles that contain nitric acid. These particles are consistent with Type la PSCs. The significance of this finding is that these large particles will have appreciable sedimentation velocities, taking nitric acid out of the stratospheric regions, causing denitrification. Since nitric acid typically mitigates ozone loss, denitrification leads to increased ozone loss. Type lb PSCs are smaller and do not sediment to any appreciable degree. Satellite measurements are made continuously throughout the winter, and offer more global coverage than in situ measurements. Thus, it would very useful to be able to discriminate PSC types from satellite measurements. Our long-term goals are to better understand the formation mechanisms and effects of PSCs. Discriminating PSC type using satellite data will give us a very important tool in this effort. A multi-wavelength analysis of POAM aerosol extinction during SOLVE has revealed differences in the radiative characteristics of PSC events. We explore the use of POAM observations to discriminate between Type la and lb Pscs. A trajectory model is used to simulate PSC la and lb particles. Calculated radiative properties act as a guide for discriminating the satellite occultation measurements. Aircraft based PSC observations are-used as confirmation of these observations.

Method of steering the gain of a multiple antenna global positioning system receiver

NASA Astrophysics Data System (ADS)

Evans, Alan G.; Hermann, Bruce R.

1992-06-01

A method for steering the gain of a multiple antenna Global Positioning System (GPS) receiver toward a plurality of a GPS satellites simultaneously is provided. The GPS signals of a known wavelength are processed digitally for a particular instant in time. A range difference or propagation delay between each antenna for GPS signals received from each satellite is first resolved. The range difference consists of a fractional wavelength difference and an integer wavelength difference. The fractional wavelength difference is determined by each antenna's tracking loop. The integer wavelength difference is based upon the known wavelength and separation between each antenna with respect to each satellite position. The range difference is then used to digitally delay the GPS signals at each antenna with respect to a reference antenna. The signal at the reference antenna is then summed with the digitally delayed signals to generate a composite antenna gain. The method searches for the correct number of integer wavelengths to maximize the composite gain. The range differences are also used to determine the attitude of the array.

Cosmic Ray-Air Shower Measurement from Space

NASA Technical Reports Server (NTRS)

Takahashi, Yoshiyuki

1997-01-01

A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (Air)-Shower Satellite (MASS), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of MASS could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the MASS/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, MASS could determine the energy spectrum, the mass composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and air-shower arrays. MASS/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray flux to the decay of topological defects. Very wide FOV optics system of MASS/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV MASS optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations.

Beyond the Ionosphere: Fifty Years of Satellite Communication

NASA Technical Reports Server (NTRS)

Butrica, Andrew J. (Editor)

1997-01-01

The three overlapping stages of satellite communications development outlined provide the three-part framework for the organization of the papers contained in this book. Part 1, 'Passive Origins,' treats the first stage of satellite communications development, extending from the 1940s into the early 1960s, when passive artificial and natural satellites funded by the military and private enterprise established the field. Part 2, 'Creating the Global, Regional, and National Systems,' addresses events that constituted the second stage of development. Early in this stage, which stretched from the 1960s into the 1970s, satellite systems began to make their appearance in the United States, while domestic and international efforts sought to bring order to this new but chaotic, field in the form of Comsat and Intelsat. Part 3, 'The Unfolding of the World System,' explores the development of satellite communications in the remainder of the world, with a strong emphasis on Asia.

Self-supervised learning as an enabling technology for future space exploration robots: ISS experiments on monocular distance learning

NASA Astrophysics Data System (ADS)

van Hecke, Kevin; de Croon, Guido C. H. E.; Hennes, Daniel; Setterfield, Timothy P.; Saenz-Otero, Alvar; Izzo, Dario

2017-11-01

Although machine learning holds an enormous promise for autonomous space robots, it is currently not employed because of the inherent uncertain outcome of learning processes. In this article we investigate a learning mechanism, Self-Supervised Learning (SSL), which is very reliable and hence an important candidate for real-world deployment even on safety-critical systems such as space robots. To demonstrate this reliability, we introduce a novel SSL setup that allows a stereo vision equipped robot to cope with the failure of one of its cameras. The setup learns to estimate average depth using a monocular image, by using the stereo vision depths from the past as trusted ground truth. We present preliminary results from an experiment on the International Space Station (ISS) performed with the MIT/NASA SPHERES VERTIGO satellite. The presented experiments were performed on October 8th, 2015 on board the ISS. The main goals were (1) data gathering, and (2) navigation based on stereo vision. First the astronaut Kimiya Yui moved the satellite around the Japanese Experiment Module to gather stereo vision data for learning. Subsequently, the satellite freely explored the space in the module based on its (trusted) stereo vision system and a pre-programmed exploration behavior, while simultaneously performing the self-supervised learning of monocular depth estimation on board. The two main goals were successfully achieved, representing the first online learning robotic experiments in space. These results lay the groundwork for a follow-up experiment in which the satellite will use the learned single-camera depth estimation for autonomous exploration in the ISS, and are an advancement towards future space robots that continuously improve their navigation capabilities over time, even in harsh and completely unknown space environments.

Ion Velocity Measurements for the Ionospheric Connections Explorer

NASA Astrophysics Data System (ADS)

Heelis, R. A.; Stoneback, R. A.; Perdue, M. D.; Depew, M. D.; Morgan, W. A.; Mankey, M. W.; Lippincott, C. R.; Harmon, L. L.; Holt, B. J.

2017-10-01

The Ionospheric Connections Explorer (ICON) payload includes an Ion Velocity Meter (IVM) to provide measurements of the ion drift motions, density, temperature and major ion composition at the satellite altitude near 575 km. The primary measurement goal for the IVM is to provide the meridional ion drift perpendicular to the magnetic field with an accuracy of 7.5 m s-1 for all daytime conditions encountered by the spacecraft within 15° of the magnetic equator. The IVM will derive this parameter utilizing two sensors, a retarding potential analyzer (RPA) and an ion drift meter (IDM) that have a robust and successful flight heritage. The IVM described here incorporates improvements in the design and operation to produce the most sensitive device that has been fielded to date. It will specify the ion drift vector, from which the component perpendicular to the magnetic field will be derived. In addition it will specify the total ion density, the ion temperature and the fractional ion composition. These data will be used in conjunction with measurements from the other ICON instruments to uncover the important connections between the dynamics of the neutral atmosphere and the ionosphere through the generation of dynamo currents perpendicular to the magnetic field and collisional forces parallel to the magnetic field. Here the configuration and operation of the IVM instrument are described, as well as the procedures by which the ion drift velocity is determined. A description of the subsystem characteristics, which allow a determination of the expected uncertainties in the derived parameters, is also given.

Enabling Science and Deep Space Exploration through Space Launch System (LSL) Secondary Payload Opportunities

NASA Technical Reports Server (NTRS)

Singer, Jody; Pelfrey, Joseph; Norris, George

2016-01-01

For the first time in almost 40 years, a NASA human-rated launch vehicle has completed its Critical Design Review (CDR). By reaching this milestone, NASA's Space Launch System (SLS) and Orion spacecraft are on the path to launch a new era of deep space exploration. NASA is making investments to expand science and exploration capability of the SLS by developing the capability to deploy small satellites during the trans-lunar phase of the mission trajectory. Exploration Mission 1 (EM-1), currently planned for launch no earlier than July 2018, will be the first mission to carry such payloads on the SLS. The EM-1 launch will include thirteen 6U Cubesat small satellites that will be deployed beyond low earth orbit. By providing an earth-escape trajectory, opportunities are created for advancement of small satellite subsystems, including deep space communications and in-space propulsion. This SLS capability also creates low-cost options for addressing existing Agency strategic knowledge gaps and affordable science missions. A new approach to payload integration and mission assurance is needed to ensure safety of the vehicle, while also maintaining reasonable costs for the small payload developer teams. SLS EM-1 will provide the framework and serve as a test flight, not only for vehicle systems, but also payload accommodations, ground processing, and on-orbit operations. Through developing the requirements and integration processes for EM-1, NASA is outlining the framework for the evolved configuration of secondary payloads on SLS Block upgrades. The lessons learned from the EM-1 mission will be applied to processes and products developed for future block upgrades. In the heavy-lift configuration of SLS, payload accommodations will increase for secondary opportunities including small satellites larger than the traditional Cubesat class payload. The payload mission concept of operations, proposed payload capacity of SLS, and the payload requirements for launch and deployment will be described to provide potential payload users an understanding of this unique exploration capability.

Compositional Analyses and Implications of Visible/Near-Infrared Spectra of Outer Irregular Jovian Satellites

NASA Astrophysics Data System (ADS)

Vilas, Faith; Hendrix, Amanda

2017-10-01

The existence of a visible-near infrared absorption feature attributed to aqueous alteration products has been suggested in both grey and reddened broadband photometry of some outer irregular jovian satellites. Moderate resolution VNIR narrowband spectroscopy was obtained of the jovian irregular satellites JVI Himalia, JVII Elara, JVIII Pasiphae, JIX Sinope, JX Lysithea, JXI Carme, JXII Ananke and JXVII Callirrhoe in 2006, 2008, 2009, and 2010 using the MMT Observatory facility Red Channel spectrograph to confirm the presence of this feature. The spectra are centered near 0.64 μm in order to cover the 0.7-μm feature entirely (generally ranging from 0.57 to 0.83 μm). The spectra generally have a dispersion/element of ~0.6 nm (6Å) some spectra are smoothed. These spectra sample three prograde (i = 28o), four retrograde (i = 149o, 165o) and one independent satellite.We observe these findings among the spectra:- An absorption feature centered near 0.7 µm exists in the spectra of the three prograde (i = 28o) satellites. This feature is spectrally broader than the 0.7-µm feature observed in C-complex asteroids. None appears spectrally reddened. This suggests that these prograde satellites have a common parent body.- A different absorption feature appears in the spectra of the three retrograde (i = 149o) satellites, also suggesting a common parent body. Varying reddening is observed. This feature is similar in spectral location and width to the 0.7-µm feature.- Reddening is observed in the individual observation of JXI Carme (i = 165o), and independent satellite JIX Sinope, similar to the D-class asteroid spectra dominating the Trojan population. A suggested absorption feature is being investigated.Mixing modeling of combinations of both expected and proposed compositions including carbonaceous materials, phyllosilicates, mafic silicates, and other opaque materials, is currently underway. Results will be reported and discussed at the meeting.Acknowledgments: The MMT Observatory is a joint facility of the University of Arizona and the Smithsonian Institution. This research has been supported by SSERVI CLASS.

Research in space physics at the University of Iowa

NASA Technical Reports Server (NTRS)

Vanallen, J. A.

1972-01-01

The research is reported for current projects. Topics discussed include: study and analysis of data from Explorer 40, 43, and small scientific satellites; and the planned missions for Helios, UK-4, Pioneer R and H, and Hawkeye satellites. The progress in the theoretical studies of electron density of the solar corona, spectrophotometry, and interferometry are also reported.

Gravity waves in the thermosphere observed by the AE satellites

NASA Technical Reports Server (NTRS)

Gross, S. H.; Reber, C. A.; Huang, F. T.

1983-01-01

Atmospheric Explorer (AE) satellite data were used to investigate the spectra characteristics of wave-like structure observed in the neutral and ionized components of the thermosphere. Power spectral analysis derived by the maximum entropy method indicate the existence of a broad spectrum of scale sizes for the fluctuations ranging from tens to thousands of kilometers.

First results of the COBE satellite measurement of the anisotropy of the cosmic microwave background radiation

NASA Technical Reports Server (NTRS)

Smoot, G. F.; Aymon, J.; De Amici, G.; Bennett, C. L.; Kogut, A.; Gulkis, S.; Backus, C.; Galuk, K.; Jackson, P. D.; Keegstra, P.

1991-01-01

The concept and operation of the Differential Microwave Radiometers (DMR) instrument aboard NASA's Cosmic Background Explorer satellite are reviewed, with emphasis on the software identification and subtraction of potential systematic effects. Preliminary results obtained from the first six months of DMR data are presented, and implications for cosmology are discussed.

Recommended satellite imagery capabilities for disaster management

NASA Technical Reports Server (NTRS)

Richards, P. B.; Robinove, C. J.; Wiesnet, D. R.; Salomonson, V. V.; Maxwell, M. S.

1982-01-01

This study explores the role that satellite imaging systems might play in obtaining information needed in the management of natural and manmade disasters. Information requirements which might conceivably be met by satellite were identified for over twenty disasters. These requirements covered pre-disaster mitigation and preparedness activities, disaster response activities, and post-disaster recovery activities. The essential imaging satellite characteristics needed to meet most of the information requirements are 30 meter (or finer) spatial resolution, frequency of observations of one week or less, data delivery times of one day or less, and stereo, synoptic all-weather coverage of large areas in the visible, near infrared, thermal infrared and microwave bands. Of the current and planned satellite systems investigated for possible application to disaster management, Landsat-D and SPOT appear to have the greatest potential during disaster mitigation and preparedness activities, but all satellites studied have serious deficiencies during response and recovery activities. Several strawman concepts are presented for a satellite system optimized to support all disaster management activities.

The Galilean Satellites

NASA Image and Video Library

1997-11-18

This composite includes the four largest moons of Jupiter which are known as the Galilean satellites. From left to right, the moons shown are Ganymede, Callisto, Io, and Europa. The Galilean satellites were first seen by the Italian astronomer Galileo Galilei in 1610. In order of increasing distance from Jupiter, Io is closest, followed by Europa, Ganymede, and Callisto. The order of these satellites from the planet Jupiter helps to explain some of the visible differences among the moons. Io is subject to the strongest tidal stresses from the massive planet. These stresses generate internal heating which is released at the surface and makes Io the most volcanically active body in our solar system. Europa appears to be strongly differentiated with a rock/iron core, an ice layer at its surface, and the potential for local or global zones of water between these layers. Tectonic resurfacing brightens terrain on the less active and partially differentiated moon Ganymede. Callisto, furthest from Jupiter, appears heavily cratered at low resolutions and shows no evidence of internal activity. North is to the top of this composite picture in which these satellites have all been scaled to a common factor of 10 kilometers (6 miles) per picture element. The Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft obtained the Io and Ganymede images in June 1996, while the Europa images were obtained in September 1996. Because Galileo focuses on high resolution imaging of regional areas on Callisto rather than global coverage, the portrait of Callisto is from the 1979 flyby of NASA's Voyager spacecraft. http://photojournal.jpl.nasa.gov/catalog/PIA00601

Uncontrolled re-entry of satellite parts after finishing their mission in LEO: Titanium alloy degradation by thermite reaction energy

NASA Astrophysics Data System (ADS)

Monogarov, K. A.; Pivkina, A. N.; Grishin, L. I.; Frolov, Yu. V.; Dilhan, D.

2017-06-01

Analytical and experimental studies conducted at Semenov Institute of Chemical Physics for investigating the use of pyrotechnic compositions, i.e., thermites, to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth are described. The main idea was the use of passive heating during uncontrolled re-entry to ignite thermite composition, fixed on the titanium surface, with the subsequent combustion energy release to be sufficient to perforate the titanium cover. It is supposed, that thus destructed satellite parts will lose their streamline shape, and will burn out being aerodynamically heated during further descending in atmosphere (patent FR2975080). On the base of thermodynamic calculations the most promising thermite compositions have been selected for the experimental phase. The unique test facilities have been developed for the testing of the efficiency of thermite charges to perforate the titanium TA6V cover of 0.8 mm thickness under temperature/pressure conditions duplicated the uncontrolled re-entry of titanium tank after its mission on LEO. Experiments with the programmed laser heating inside the vacuum chamber revealed the only efficient thermite composition among preliminary selected ones to be Al/Co3O4. Experimental searching of the optimal aluminum powder between spherical and flaked nano- and micron-sized ones revealed the possibility to adjust the necessary ignition delay time, according to the titanium cover temperature dependency on deorbiting time. For the titanium tank the maximum temperature is 1100 °C at altitude 68 km and pressure 60 Pa. Under these conditions Al/Co3O4 formulations with nano-Al spherical particles provide the ignition time to be 13.3 s, and ignition temperature as low as 592±5 °C, whereas compositions with the micron-sized spherical Al powder reveal these values to be much higher, i.e., 26.3 s and 869±5 °C, respectively. The analytical and experimental studies described in this paper provide a portion of the basic information required for the development of pyrotechnic device to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth.

Address by James C. Fletcher, Administrator National Aeronautics and Space Administration at the National Academy of Engineering, Washington, D.C., 10 November 1975

NASA Technical Reports Server (NTRS)

1975-01-01

Future plans and programs of the space agency are discussed. Topics discussed include solar energy, space stations, planetary exploration, interstellar exploration, the space shuttles, and satellites.

Ultraviolet Spectra of Comets Observed with the International Ultraviolet Explorer Satellite Observatory.

NASA Astrophysics Data System (ADS)

Weaver, Harold Anthony, Jr.

Ultraviolet spectra of seven comets observed with the International Ultraviolet Explorer (IUE) satellite are presented. Observations of comet Bradfield (1979 X) made in early 1980 allow a comprehensive study of the production of water by this comet. By comparing the observations to the predictions of two water models of the coma (Haser and vectorial), it is determined that these measurements support the idea of a comet composed principally of water ice. The vaporization of the water has a rather unexpected heliocentric variation, decreasing as r('-3.7) over the entire range of observations. Atomic carbon is relatively abundant in the coma of comet Bradfield; the production rate of carbon is roughly 5-10% of the water production rate. Analysis of the spatial brightness profiles of the strongest atomic carbon emission does not reveal the identity of the source of the observed carbon, but the data are apparently inconsistent with a photodissociation source that is either CO or CO(,2). A comparison of the ultraviolet spectrum of periodic comet Encke, recorded by the IUE between 1980 October 24 and November 5, with similar spectra of short and long period comets shows the gaseous composition of P/Encke to be virtually identical to that of the other comets. If P/Encke is indeed the remains of a once giant comet, this similarity implies a homogeneous structure for the cometary ice nucleus. The OH(0,0) band brightness distribution shows a spatial variation similar to the visible fan-shaped image of the comet. Comets P/Tuttle (1980h), P/Stephan-Oterma (1980g), and Meier (1980q) were observed during November-December 1980 with IUE, while comets P/Borrelly (1980i) and Panther (1980u) were observed with IUE on 6 March 1981. The spectra of these comets are compared with those of comets Bradfield (1979 X) and P/Encke, as well as with each other. In order to simplify the interpretation of the data and to minimize the dependence upon a specific model, the spectra are compared at approximately the same value of heliocentric distance whenever possible. Effects due to helicentric velocity, geocentric distance, and optical depth are also discussed. All of the cometary spectra are remarkably similar, which suggests that these comets may have a common composition and origin.

Badhwar - O'Neill galactic cosmic ray model update based on Advanced Composition Explorer (ACE) energy spectra from 1997 to present

NASA Astrophysics Data System (ADS)

O'Neill, P.

Accurate knowledge of the interplanetary Galactic Cosmic Ray (GCR) environment is critical to planning and operating manned space flight to the moon and beyond. In the early 1990's Badhwar and O'Neill developed a GCR model based on balloon and satellite data from 1954 to 1992. This model accurately accounts for solar modulation of each element (hydrogen -- iron) by propagating the Local Interplanetary Spectrum (LIS) of each element through the heliosphere by solving the Fokker -- Planck diffusion, convection, energy loss boundary value problem. A single value of the deceleration parameter describes the modulation of each of the elements and determines the GCR energy spectrum at any distance from the sun for a given level of solar cycle modulation. Since August 1997 the Advanced Composition Explorer (ACE) stationed at the Earth-Sun L1 libration point (about 1.5 million km from earth) has provided GCR energy spectra for boron - nickel. The Cosmic Ray Isotope Spectrometer (CRIS) provides ``quiet time'' spectra in the range of highest modulation ˜ 50 -- 500 MeV / nucleon. The collection power of CRIS is much larger than any of the previous satellite or balloon GCR instruments: 250 cm**2 --sr compared to <10 cm**2-sr! This new data was used to update the original Badhwar -- O'Neill Model and greatly improve the interplanetary GCR prediction accuracy. When the new -- highly precise ACE CRIS data was analyzed it became obvious that the LIS spectrum for each element precisely fit a very simple analytical energy power-law that was suggested by Leonard Fisk over 30 years ago. The updated Badhwar -- O'Neill Model is shown to be accurate to within 5%, for elements such as oxygen, which have sufficient abundance that over 1000 ions are captured in each energy bin within a 30 day period. The paper clearly demonstrates the statistical relationship between the number of ions captured by the instrument in a given time and the precision of the model for each element. This is a significant model upgrade that should provide interplanetary mission planners with highly accurate GCR environment data for radiation protection for astronauts and radiation hardness assurance for electronic equipment.

Relationships among vegetation structure, canopy composition, and avian richness patterns across an aspen-conifer forest gradient

Treesearch

Charles E. Swift; Kerri T. Vierling; Andrew T. Hudak; Lee A. Vierling

2017-01-01

Ecologists have a long-term interest in understanding the relative influence of vegetation composition and vegetation structure on avian diversity. LiDAR remote sensing is useful in studying local patterns of avian diversity because it characterizes fine-scale vegetation structure across broad extents. We used LiDAR, aerial and satellite imagery, and avian field data...

Autonomous Navigation Above the GNSS Constellations and Beyond: GPS Navigation for the Magnetospheric Multiscale Mission and SEXTANT Pulsar Navigation Demonstration

NASA Technical Reports Server (NTRS)

Winternitz, Luke

2017-01-01

This talk will describe two first-of-their-kind technology demonstrations attached to ongoing NASA science missions, both of which aim to extend the range of autonomous spacecraft navigation far from the Earth. First, we will describe the onboard GPS navigation system for the Magnetospheric Multiscale (MMS) mission which is currently operating in elliptic orbits reaching nearly halfway to the Moon. The MMS navigation system is a key outgrowth of a larger effort at NASA Goddard Space Flight Center to advance high-altitude Global Navigation Satellite System (GNSS) navigation on multiple fronts, including developing Global Positioning System receivers and onboard navigation software, running simulation studies, and leading efforts to characterize and protect signals at high-altitude in the so-called GNSS Space-Service Volume (SSV). In the second part of the talk, we will describe the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) mission that aims to make the first in-space demonstration of X-ray pulsar navigation (XNAV). SEXTANT is attached to the NASA astrophysics mission Neutron-star Interior Composition ExploreR (NICER) whose International Space Station mounted X-ray telescope is investigating the fundamental physics of extremes in gravity, material density, and electromagnetic fields found in neutron stars, and whose instrument provides a nearly ideal navigation sensor for XNAV.

The Multispectral Microscopic Imager: Integrating Microimaging with Spectroscopy for the In-Situ Exploration of the Moon

NASA Technical Reports Server (NTRS)

Nunez, J. I.; Farmer, J. D.; Sellar, R. G.; Allen, Carlton C.

2010-01-01

To maximize the scientific return, future robotic and human missions to the Moon will need to have in-situ capabilities to enable the selection of the highest value samples for returning to Earth, or a lunar base for analysis. In order to accomplish this task efficiently, samples will need to be characterized using a suite of robotic instruments that can provide crucial information about elemental composition, mineralogy, volatiles and ices. Such spatially-correlated data sets, which place mineralogy into a microtextural context, are considered crucial for correct petrogenetic interpretations. . Combining microscopic imaging with visible= nearinfrared reflectance spectroscopy, provides a powerful in-situ approach for obtaining mineralogy within a microtextural context. The approach is non-destructive and requires minimal mechanical sample preparation. This approach provides data sets that are comparable to what geologists routinely acquire in the field, using a hand lens and in the lab using thin section petrography, and provide essential information for interpreting the primary formational processes in rocks and soils as well as the effects of secondary (diagenetic) alteration processes. Such observations lay a foundation for inferring geologic histories and provide "ground truth" for similar instruments on orbiting satellites; they support astronaut EVA activities and provide basic information about the physical properties of soils required for assessing associated health risks, and are basic tools in the exploration for in-situ resources to support human exploration of the Moon.

Exploration of the Saturn System by the Cassini Mission: Observations with the Cassini Infrared Spectrometer

NASA Technical Reports Server (NTRS)

Abbas, Mian M.

2014-01-01

The Cassini mission is a joint NASA-ESA international mission, launched on October 17, 1997 with 12 instruments on board, for exploration of the Saturn system. A composite Infrared Spectrometers is one of the major instruments. Successful insertion of the spacecraft in Saturn's orbit for an extended orbital tour occurred on July 1, 2004. The French Huygens-Probe on board, with six instruments was programmed for a soft landing on Titan's surface occurred in January 2005. The broad range scientific objectives of the mission are: Exploration of the Saturn system for investigations of the origin, formation, & evolution of the solar system, with an extensive range of measurements and the analysis of the data for scientific interpretations. The focus of research dealing with the Cassini mission at NASA/MSFC in collaboration with the NASA/Goddard Space Flight Center, JPL, as well as the research teams at Oxford/UK and Meudon Observatory/France, involves the Infrared observations of Saturn and its satellites, for measurements of the thermal structure and global distributions of the atmospheric constituents. A brief description of the Cassini spacecraft, the instruments, the objectives, in particular with the infrared observations of the Saturn system will be given. The analytical techniques for infrared radiative transfer and spectral inversion programs, with some selected results for gas constituent distributions will be presented.

Applications of Satellite Observations to Aerosol Analyses and Forecasting using the NAAPS Model and the DataFed Distributed Data System

NASA Astrophysics Data System (ADS)

Husar, R. B.; Hoijarvi, K.; Westphal, D. L.; Scheffe, R.; Keating, T.; Frank, N.; Poirot, R.; DuBois, D. W.; Bleiweiss, M. P.; Eberhard, W. L.; Menon, R.; Sethi, V.; Deshpande, A.

2012-12-01

Near-real-time (NRT) aerosol characterization, forecasting and decision support is now possible through the availability of (1) surface-based monitoring of regional PM concentrations, (2) global-scale columnar aerosol observations through satellites; (3) an aerosol model (NAAPS) that is capable of assimilating NRT satellite observations; and (4) an emerging cyber infrastructure for processing and distribution of data and model results (DataFed) for a wide range of users. This report describes the evolving NRT aerosol analysis and forecasting system and its applications at Federal and State and other AQ Agencies and groups. Through use cases and persistent real-world applications in the US and abroad, the report will show how satellite observations along with surface data and models are combined to aid decision support for AQ management, science and informing the public. NAAPS is the U.S. Navy's global aerosol and visibility forecast model that generates operational six-day global-scale forecasts for sulfate, dust, sea salt, and smoke aerosol. Through NAVDAS-AOD, NAAPS operationally assimilates filtered and corrected MODIS MOD04 aerosol optical depths and uses satellite-derived FLAMBÉ smoke emissions. Washington University's federated data system, DataFed, consist of a (1) data server which mediates the access to AQ datasets from distributed providers (NASA, NOAA, EPA, etc.,); (2) an AQ Data Catalog for finding and accessing data; and (3) a set of application programs/tools for browsing, exploring, comparing, aggregating, fusing data, evaluating models and delivering outputs through interactive visualization. NAAPS and DataFed are components of the Global Earth Observation System of Systems (GEOSS). Satellite data support the detection of long-range transported wind-blown dust and biomass smoke aerosols on hemispheric scales. The AQ management and analyst communities use the satellite/model data through DataFed and other channels as evidence for Exceptional Events (EE) as defined by EPA; i.e., Sahara dust impact on Texas and Florida, local dusts events in the Southwestern U.S. and Canadian smoke events over the Northeastern U.S. Recent applications include the impact analysis of a major Saudi Arabian dust event on Mumbai, India air quality. The NAAPS model and the DataFed tools can visualize the dynamic AQ events as they are manifested through the different sensors. Satellite-derived aerosol observations assimilated into NAAPS provide estimates of daily emission rates for dust and biomass fire sources. Tuning and reconciliation of the observations, emissions and models constitutes a key and novel contribution yielding a convergence toward the true five-dimensional (X, Y, Z, T, Composition) characterization of the atmospheric aerosol data space. This observation-emission-model reconciliation effort is aided by model evaluation tools and supports the international HTAP program. The report will also discuss some of the challenges facing multi-disciplinary, multi-agency, multi-national applications of integrated observation-modeling system of systems that impede the incorporation of satellite observations into AQ management decision support systems.

Inhibition of the Activin Receptor Type-2B Pathway Restores Regenerative Capacity in Satellite Cell-Depleted Skeletal Muscle

PubMed Central

Formicola, Luigi; Pannérec, Alice; Correra, Rosa Maria; Gayraud-Morel, Barbara; Ollitrault, David; Besson, Vanessa; Tajbakhsh, Shahragim; Lachey, Jennifer; Seehra, Jasbir S.; Marazzi, Giovanna; Sassoon, David A.

2018-01-01

Degenerative myopathies typically display a decline in satellite cells coupled with a replacement of muscle fibers by fat and fibrosis. During this pathological remodeling, satellite cells are present at lower numbers and do not display a proper regenerative function. Whether a decline in satellite cells directly contributes to disease progression or is a secondary result is unknown. In order to dissect these processes, we used a genetic model to reduce the satellite cell population by ~70–80% which leads to a nearly complete loss of regenerative potential. We observe that while no overt tissue damage is observed following satellite cell depletion, muscle fibers atrophy accompanied by changes in the stem cell niche cellular composition. Treatment of these mice with an Activin receptor type-2B (AcvR2B) pathway blocker reverses muscle fiber atrophy as expected, but also restores regenerative potential of the remaining satellite cells. These findings demonstrate that in addition to controlling fiber size, the AcvR2B pathway acts to regulate the muscle stem cell niche providing a more favorable environment for muscle regeneration. PMID:29881353

Pluto.

ERIC Educational Resources Information Center

Binzel, Richard P.

1990-01-01

Discussed are details of what is known about the composition, physical characteristics, and formation of the planet Pluto and its satellite, Charon. Alignments of these bodies and details of their rotations and revolutions are described. (CW)

The OICETS mission

NASA Astrophysics Data System (ADS)

Jono, Takashi; Arai, Katsuyoshi

2017-11-01

The Optical Inter-orbit Communications Engineering Test Satellite (OICETS) was successfully launched on 23th August 2005 and thrown into a circular orbit at the altitude of 610 km. The main mission is to demonstrate the free-space inter satellite laser communications with the cooperation of the Advanced Relay and Technology Mission (ARTEMIS) geostationary satellite developed by the European Space Agency. This paper presents the overview of the OICETS and laser terminal, a history of international cooperation between Japan Aerospace Exploration Agency (JAXA) and ESA and typical results of the inter-orbit laser communication experiment carried out with ARTEMIS.

The ERG Science Center

NASA Astrophysics Data System (ADS)

Miyoshi, Yoshizumi; Hori, Tomoaki; Shoji, Masafumi; Teramoto, Mariko; Chang, T. F.; Segawa, Tomonori; Umemura, Norio; Matsuda, Shoya; Kurita, Satoshi; Keika, Kunihiro; Miyashita, Yukinaga; Seki, Kanako; Tanaka, Yoshimasa; Nishitani, Nozomu; Kasahara, Satoshi; Yokota, Shoichiro; Matsuoka, Ayako; Kasahara, Yoshiya; Asamura, Kazushi; Takashima, Takeshi; Shinohara, Iku

2018-06-01

The Exploration of energization and Radiation in Geospace (ERG) Science Center serves as a hub of the ERG project, providing data files in a common format and developing the space physics environment data analysis software and plug-ins for data analysis. The Science Center also develops observation plans for the ERG (Arase) satellite according to the science strategy of the project. Conjugate observations with other satellites and ground-based observations are also planned. These tasks contribute to the ERG project by achieving quick analysis and well-organized conjugate ERG satellite and ground-based observations.

Greenhouse gases observation from space: overview of TANSO and GOSAT

NASA Astrophysics Data System (ADS)

Hamazaki, Takashi

2017-11-01

Japan Aerospace Exploration Agency (JAXA) is developing Greenhouse gases Observing Satellite (GOSAT). GOSAT is the first satellite to monitor the columnar density of carbon dioxide and methane operationally from space. The GOSAT is the joint endeavor with JAXA, National Institute for Environmental Studies and Ministry of the Environment. The GOSAT will be launched with the H-IIA launch vehicle in early 2009. This paper shows the overview of GOSAT and its mission instrument, TANSO. Mission objectives, sensor and satellite design, its performance and summary of ground test results are also provided.

Effects of optical and geometrical properties on YORP effect for inactive satellites

NASA Astrophysics Data System (ADS)

Albuja, A.; Scheeres, D.

2014-09-01

With the increasing number of space debris in Earth orbit, it is important to understand the dynamics of these objects. Initial studies have demonstrated that the Yarkovsky, O'Keefe, Radzievskii, Paddack (YORP) effect on inactive satellite needs to be further explored as it could be noticeably affecting the rotational dynamics of these Earth orbiting objects. The YORP effect is created by torques resulting from light and thermal energy being re-emitted from the surface of a body. This effect has been well studied and observed to affect the spin states of asteroids. The purpose of this paper is to further investigate YORP in the realm of large inactive Geosynchronous Earth Orbit (GEO) satellites. The forces that cause the YORP effect are highly dependent on the optical, thermal and geometrical properties of the facets making up the surface of the body being analyzed. This paper focuses on exploring the effect of these properties on the YORP effect for inactive satellite. Two different satellite models that represent bus types of inactive satellites in GEO are used for this study. By varying the optical, thermal and geometrical properties of these models, in a manner that remains consistent with realistic satellite parameters, we can understand the relationship between these properties and the torques created by YORP. Having this knowledge allows for better understanding of the possible attitude states (spin rate and obliquity) for uncontrolled satellites in GEO. This information can then be used to make predictions of the long-term behavior of the rotation rate and obliquity of these objects. Categories of potential final states for defunct GEO satellites can then be created based on geometrical and optical properties (e.g. spin up continuously, spin down continuously, etc.). This allows the population of inactive GEO satellites to be studied in a more general sense and final attitude states for these objects can be quickly identified. Furthermore, an understanding of the sensitivity of YORP to each individual parameter is gained through this paper. Having knowledge of the attitude dynamics for these objects is key for accurate prediction of the orbital dynamics as these two are closely coupled when torques such as YORP are acting on the body.

Aged Muscle Demonstrates Fiber-Type Adaptations in Response to Mechanical Overload, in the Absence of Myofiber Hypertrophy, Independent of Satellite Cell Abundance

PubMed Central

Lee, Jonah D.; Fry, Christopher S.; Mula, Jyothi; Kirby, Tyler J.; Jackson, Janna R.; Liu, Fujun; Yang, Lin; Dupont-Versteegden, Esther E.; McCarthy, John J.

2016-01-01

Although sarcopenia, age-associated loss of muscle mass and strength, is neither accelerated nor exacerbated by depletion of muscle stem cells, satellite cells, we hypothesized that adaptation in sarcopenic muscle would be compromised. To test this hypothesis, we depleted satellite cells with tamoxifen treatment of Pax7CreER-DTA mice at 4 months of age, and 20 months later subjected the plantaris muscle to 2 weeks of mechanical overload. We found myofiber hypertrophy was impaired in aged mice regardless of satellite cell content. Even in the absence of growth, vehicle-treated mice mounted a regenerative response, not apparent in tamoxifen-treated mice. Further, myonuclear accretion occurred in the absence of growth, which was prevented by satellite cell depletion, demonstrating that myonuclear addition is insufficient to drive myofiber hypertrophy. Satellite cell depletion increased extracellular matrix content of aged muscle that was exacerbated by overload, potentially limiting myofiber growth. These results support the idea that satellite cells regulate the muscle environment, and that their loss during aging may contribute to fibrosis, particularly during periods of remodeling. Overload induced a fiber-type composition improvement, independent of satellite cells, suggesting that aged muscle is very responsive to exercise-induced enhancement in oxidative capacity, even with an impaired hypertrophic response. PMID:25878030

Restoration and Archiving of Data from the Plasma Composition Experiment on the International Sun-Earth Explorer One (ISEE 1)

NASA Technical Reports Server (NTRS)

Lennartsson, O. W.

1997-01-01

The objective of this project has been to complete the archiving of energetic (10 eV/epsilon - 18 keV/epsilon) ion composition data from the Lockheed Plasma Composition Experiment on the International Sun-Earth Explorer One (ISEE 1) satellite, using a particular data format that had previously been approved by NASA and the NSSDC. That same format, a combination of ion velocity moments and differential flux spectra, had been used in 1991 to archive, at the NSSDC, the first 28 months (the "Prime" period of ISEE investigations) of data from the Lockheed instrument under NASA Contract NAS5-33047. With the completion of this project, the almost 4 1/2-year time span of these unique data is now covered by a very compact set, approximately 1 gigabyte in total, of electronic files with physical quantities, all in ASCII. The files are organized by data type and time of data acquisition, in Universal Time, and named according to year and day of year. Each calendar day has five separate files (five types of data), the lengths of which vary from day to day, depending on the instrument mode of operation. The data format and file structure are described in detail in appendices 1 and 2. The physical medium consists of high-density (6250 cpi) 9-track magnetic tapes, complemented by a set of hardcopy line plots of certain plasma parameters. In this case there are five tapes, to be added to the six previous ones from 1991, and 25 booklets of plots, one per month, to be added to the previous 28. The tapes, including an extra standard-density (1600 cpi) tape with electronic versions of the Data User's Guide and self-guiding VAX/VMS command files, and the hardcopy plots are being boxed for shipment to the NSSDC.

Deployment of ANDE-2

NASA Image and Video Library

2009-07-30

S127-E-012895 (30 July 2009) --- A Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment 2 (ANDE-2) is photographed after its release from Space Shuttle Endeavour's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which will measure the density and composition of the low-Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

J6 Himalia: New Compositional Evidence and Interpretations for the Origin of Jupiter's Small Satellites

NASA Technical Reports Server (NTRS)

Vilas, Faith; Jarvis, K.; Larson, S.; Gaffey, M.

1999-01-01

New narrowband spectrophotometric data of J6 Himalia, some of which are spatially resolved, support its C-type classification. The new spectra confirm the presence of a weak absorption feature centered near 0.7 micron attributed to oxidized iron in phyllosilicates, products of aqueous alteration, which varies in depth on opposite sides of the satellite. Evaluation of older UBV photometry of J6 and J7 Elara compared to UBV photometry of C-class (and subclass) asteroids showing spectral evidence of the 0.7-microns absorption feature suggests that J6 Himalia is an F-class asteroid. We propose that the parent body of the prograde Jovian satellites originated as part of the Nysa asteroid family. Evolutionary models of the Jovian system are used to address the capture and dispersal of the irregular satellites.

Employment of satellite snowcover observations for improving seasonal runoff estimates. [Indus River and Wind River Range, Wyoming

NASA Technical Reports Server (NTRS)

Rango, A.; Salomonson, V. V.; Foster, J. L.

1975-01-01

Low resolution meteorological satellite and high resolution earth resources satellite data were used to map snowcovered area over the upper Indus River and the Wind River Mountains of Wyoming, respectively. For the Indus River, early Spring snowcovered area was extracted and related to April through June streamflow from 1967-1971 using a regression equation. Composited results from two years of data over seven Wind River Mountain watersheds indicated that LANDSAT-1 snowcover observations, separated on the basis of watershed elevation, could also be related to runoff in significant regression equations. It appears that earth resources satellite data will be useful in assisting in the prediction of seasonal streamflow for various water resources applications, nonhazardous collection of snow data from restricted-access areas, and in hydrologic modeling of snowmelt runoff.

Investigation of atomic oxygen-surface interactions related to measurements with dual air density explorer satellites

NASA Technical Reports Server (NTRS)

Wood, B. J.; Ablow, C. M.; Wise, H.

1973-01-01

For a number of candidate materials of construction for the dual air density explorer satellites the rate of oxygen atom loss by adsorption, surface reaction, and recombination was determined as a function of surface and temperature. Plain aluminum and anodized aluminum surfaces exhibit a collisional atom loss probability alpha .01 in the temperature range 140 - 360 K, and an initial sticking probability. For SiO coated aluminum in the same temperature range, alpha .001 and So .001. Atom-loss on gold is relatively rapid alpha .01. The So for gold varies between 0.25 and unity in the temperature range 360 - 140 K.

The Cosmic Background Explorer

NASA Technical Reports Server (NTRS)

Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

1990-01-01

The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

Key Issues for Navigation and Time Dissemination in NASA's Space Exploration Program

NASA Technical Reports Server (NTRS)

Nelson, R. A.; Brodsky, B.; Oria, A. J.; Connolly, J. W.; Sands, O. S.; Welch, B. W.; Ely T.; Orr, R.; Schuchman, L.

2006-01-01

The renewed emphasis on robotic and human missions within NASA's space exploration program warrants a detailed consideration of how the positions of objects in space will be determined and tracked, whether they be spacecraft, human explorers, robots, surface vehicles, or science instrumentation. The Navigation Team within the NASA Space Communications Architecture Working Group (SCAWG) has addressed several key technical issues in this area and the principle findings are reported here. For navigation in the vicinity of the Moon, a variety of satellite constellations have been investigated that provide global or regional surface position determination and timely services analogous to those offered by GPS at Earth. In the vicinity of Mars, there are options for satellite constellations not available at the Moon due to the gravitational perturbations from Earth, such as two satellites in an aerostationary orbit. Alternate methods of radiometric navigation as considered, including one- and two-way signals, as well as autonomous navigation. The use of a software radio capable of receiving all available signal sources, such as GPS, pseudolites, and communication channels, is discussed. Methods of time transfer and dissemination are also considered in this paper.

A multimission three-axis stabilized spacecraft flight dynamics ground support system

NASA Technical Reports Server (NTRS)

Langston, J.; Krack, K.; Reupke, W.

1993-01-01

The Multimission Three-Axis Stabilized Spacecraft (MTASS) Flight Dynamics Support System (FDSS) has been developed in an effort to minimize the costs of ground support systems. Unlike single-purpose ground support systems, which attempt to reduce costs by reusing software specifically developed for previous missions, the multimission support system is an intermediate step in the progression to a fully generalized mission support system in which numerous missions may be served by one general system. The benefits of multimission attitude ground support systems extend not only to the software design and coding process, but to the entire system environment, from specification through testing, simulation, operations, and maintenance. This paper reports the application of an MTASS FDSS to multiple scientific satellite missions. The satellites are the Upper Atmosphere Research Satellite (UARS), the Extreme Ultraviolet Explorer (EUVE), and the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX). Both UARS and EUVE use the multimission modular spacecraft (MMS) concept. SAMPEX is part of the Small Explorer (SMEX) series and uses a much simpler set of attitude sensors. This paper centers on algorithm and design concepts for a multimission system and discusses flight experience from UARS.

Exploration of the Kinetics of Toehold-Mediated Strand Displacement via Plasmon Rulers.

PubMed

Li, Mei-Xing; Xu, Cong-Hui; Zhang, Nan; Qian, Guang-Sheng; Zhao, Wei; Xu, Jing-Juan; Chen, Hong-Yuan

2018-04-24

DNA/RNA strand displacement is one of the most fundamental reactions in DNA and RNA circuits and nanomachines. In this work, we reported an exploration of the dynamic process of the toehold-mediated strand displacement via core-satellite plasmon rulers at the single-molecule level. Applying plasmon rulers with unlimited lifetime, single-strand displacement triggered by the invader that resulted in stepwise leaving of satellite from the core was continuously monitored by changes of scattering signal for hours. The kinetics of strand displacement in vitro with three different toehold lengths have been investigated. Also, the study revealed the difference in the kinetics of strand displacement between DNA/RNA and DNA/DNA duplexes. For the kinetics study in vivo, influence from the surrounding medium has been evaluated using both phosphate buffer and cell lysate. Applying core-satellite plasmon rulers with high signal/noise ratio, kinetics study in living cells proceeded for the first time, which was not possible by conventional methods with a fluorescent reporter. The plasmon rulers, which are flexible, easily constructed, and robust, have proven to be effective tools in exploring the dynamical behaviors of biochemical reactions in vivo.

From the Icy Satellites to Small Moons and Rings: Spectral Indicators by Cassini-VIMS Unveil Compositional Trends in the Saturnian System

NASA Astrophysics Data System (ADS)

Filacchione, G.; Capaccioni, F.; Ciarniello, M.; Nicholson, P. D.; Clark, R. N.; Cuzzi, J. N.; Buratti, B. B.; Cruikshank, D. P.; Brown, R. H.

2017-01-01

Despite water ice being the most abundant species on Saturn satellites' surfaces and ring particles, remarkable spectral differences in the 0.35-5.0 μm range are observed among these objects. Here we report about the results of a comprehensive analysis of more than 3000 disk-integrated observations of regular satellites and small moons acquired by VIMS aboard Cassini mission between 2004 and 2016. These observations, taken from very different illumination and viewing geometries, allow us to classify satellites' and rings' compositions by means of spectral indicators, e.g. 350-550 nm - 550-950 nm spectral slopes and water ice band parameters [1,2,3]. Spectral classification is further supported by indirect retrieval of temperature by means of the 3.6 μm I/F peak wavelength [4,5]. The comparison with syntethic spectra modeled by means of Hapke's theory point to different compositional classes where water ice, amorphous carbon, tholins and CO2 ice in different quantities and mixing modalities are the principal endmembers [3, 6]. When compared to satellites, rings appear much more red at visible wavelengths and show more intense 1.5-2.0 μm band depths [7]. Our analysis shows that spectral classes are detected among the principal satellites with Enceladus and Tethys the ones with stronger water ice band depths and more neutral spectral slopes while Rhea evidences less intense band depths and more red visible spectra. Even more intense reddening in the 0.55-0.95 μm range is observed on Iapetus leading hemisphere [8] and on Hyperion [9]. With an intermediate reddening, the minor moons seems to be the spectral link between the principal satellites and main rings [10]: Prometheus and Pandora appear similar to Cassini Division ring particles. Epimetheus shows more intense water ice bands than Janus. Epimetheus' visible colors are similar to water ice rich moons while Janus is more similar to C ring particles. Finally, Dione and Tethys lagrangian satellites show a very flat reflectance in the visible, making them remarkably different with respect to the other small moons. Moreover, we have observed that the two Tethys' lagrangian moons appear spectrally different, with Calypso characterized by more intense water ice bands than Telesto. Conversely, at visible wavelengths Polydeuces, Telesto and Methone are in absolute the more blue objects in the Saturn's system. The red slopes measured in the visible range on disk-integrated spectral data, showing varying degrees on all of the satellites, could be caused more by exogenic processes than by geologic and endogenic events which are operating on more localized scales. The principal exogenic processes active in the Saturn's system [11] which alter the satellites and rings surfaces are the E ring particles bombardment, the interaction with corotating plasma and energetic particles, the bombardment of exogenic dark material [12] and the water ice photolysis. A discussion about the correlations between these processes and the o bserved spectral classes is given. With the approaching of the Cassini "Gran Finale" orbits, VIMS will unveil with unprecedented spatial resolution the spectral properties of many small moons and rings. These data will be extremely valuable to improve our classification of the Saturn's satellites and rings.

Ionospheric ion temperature forecasting in multiples of 27 days

NASA Astrophysics Data System (ADS)

Sojka, Jan J.; Schunk, Robert W.; Nicolls, Michael J.

2014-03-01

The ionospheric variability found at auroral locations is usually assumed to be unpredictable. The magnetosphere, which drives this ionospheric variability via storms and substorms, is at best only qualitatively describable. In this study we demonstrate that over a 3 year period, ionospheric variability observed from Poker Flat, Alaska, has, in fact, a high degree of long-term predictability. The observations used in this study are (a) the solar wind high speed stream velocity measured by the NASA Advanced Composition Explorer satellite, used to define the corotating interaction region (CIR), and (b) the ion temperature at 300 km altitude measured by the National Science Foundation Poker Flat Incoherent Scatter Radar over Poker Flat, Alaska. After determining a seasonal and diurnal climatology for the ion temperature, we show that the residual ion temperature heating events occur synchronously with CIR-geospace interactions. Furthermore, we demonstrate examples of ion temperature forecasting at 27, 54, and 81 days. A rudimentary operational forecasting scenario is described for forecasting recurrence 27 days ahead for the CIR-generated geomagnetic storms. These forecasts apply specifically to satellite tracking operations (thermospheric drag) and emergency HF-radio communications (ionospheric modifications) in the polar regions. The forecast is based on present-day solar and solar wind observations that can be used to uniquely identify the coronal hole and its CIR. From this CIR epoch, a 27 day forecast is then made.

African Easterly Waves and Their Association with Precipitation

NASA Technical Reports Server (NTRS)

Gu, Guo-Jun; Adler, Robert F.; Huffman, George J.; Curtis, Scott

2003-01-01

Summer tropical synoptic-scale waves over West Africa are quantified by the 850 mb meridional wind component from the NCEP/NCAR reanalysis project. Their relationships with surface precipitation patterns are further explored by applying the data from the Tropical Rainfall Measuring Mission (TRMM) satellite in combination with other satellite observations during 1998-2002. Evident wavelet spectral power peaks are seen within a period of 2.5 - 6 days in both meridional wind and precipitation. The most intense wave signals in meridional wind are concentrated along 15 deg N- 25 deg N. Wave signals in precipitation and corresponding wavelet cross-spectral signals between these two variables, however, are primarily located at 5 deg N- 15 deg N, the latitudes of major summer rain events. There is a tendency for the perturbations in meridional wind component to lag (lead) precipitation signals south (north) of 15 deg N. In some cases, either an in-phase or out-of-phase relationship can even be found between these two variables, suggesting a latitude-dependent horizontal structure for these waves and probably implying two distinct wave-convective coupling mechanisms. Moreover, the lagging relationship (and/or the out-of-phase tendency) is only observed south of 15 deg N during July-September, indicating a strong seasonal preference. This phase relationship is generally consistent with the horizontal wave structures from a composite analysis.

Characterization of Satellite DNA Sequences from the Commercially Important Marine Rotifers Brachionus rotundiformis and Brachionus plicatilis.

PubMed

Boehm; Gibson; Lubzens

2000-01-01

This study was initiated to search for species-specific and strain-specific satellite DNA sequences for which oligonucleotide primers could be designed to differentiate between various commercially important strains of the marine monogonont rotifers Brachionus rotundiformis and Brachionus plicatilis. Two unrelated, highly reiterated satellite sequences were cloned and characterized. The eight sequenced monomers from B. rotundiformis and six from B. plicatilis had low intrarepeat variability and were similar in their overall lengths, A + T compositions, and high degrees of repeated motif substructure. However, hybridizations to 19 representative strains, sequence characterizations, and GenBank searches indicated that these two satellites are morphotype-specific and population-specific, respectively, and share little homology to each other or to other characterized sequences in the database. Primer pairs designed for the B. rotundiformis satellite confirmed hybridization specificities on polymerase chain reaction and could serve as a useful molecular diagnostic tool to identify strains belonging to the SS morphotype, which are gaining widespread usage as first feeds for marine fish in commercial production.

A Platform for Scalable Satellite and Geospatial Data Analysis

NASA Astrophysics Data System (ADS)

Beneke, C. M.; Skillman, S.; Warren, M. S.; Kelton, T.; Brumby, S. P.; Chartrand, R.; Mathis, M.

2017-12-01

At Descartes Labs, we use the commercial cloud to run global-scale machine learning applications over satellite imagery. We have processed over 5 Petabytes of public and commercial satellite imagery, including the full Landsat and Sentinel archives. By combining open-source tools with a FUSE-based filesystem for cloud storage, we have enabled a scalable compute platform that has demonstrated reading over 200 GB/s of satellite imagery into cloud compute nodes. In one application, we generated global 15m Landsat-8, 20m Sentinel-1, and 10m Sentinel-2 composites from 15 trillion pixels, using over 10,000 CPUs. We recently created a public open-source Python client library that can be used to query and access preprocessed public satellite imagery from within our platform, and made this platform available to researchers for non-commercial projects. In this session, we will describe how you can use the Descartes Labs Platform for rapid prototyping and scaling of geospatial analyses and demonstrate examples in land cover classification.

Effects of plasma drag on low Earth orbiting satellites due to solar forcing induced perturbations and heating

NASA Astrophysics Data System (ADS)

Nwankwo, Victor U. J.; Chakrabarti, Sandip K.; Weigel, Robert S.

2015-07-01

The upper atmosphere changes significantly in temperature, density and composition as a result of solar cycle variations, which causes severe storms and flares, and increases in the amount of absorbed solar radiation from solar energetic events. Satellite orbits are consequently affected by this process, especially those in low Earth orbit (LEO). In this paper, we present a model of atmospheric drag effects on the trajectory of two hypothetical LEO satellites of different ballistic coefficients, initially injected at h = 450 km. We investigate long-term trends of atmospheric drag on LEO satellites due to solar forcing induced atmospheric perturbations and heating at different phases of the solar cycle, and during short intervals of strong geomagnetic disturbances or magnetic storms. We show dependence of orbital decay on the severity of both solar cycle and phase and the extent of geomagnetic perturbations. The result of the model compares well with observed decay profile of some existing LEO satellites and provide a justification of the theoretical considerations used here.

Senator Barbara Mikulski Visits NASA Goddard

NASA Image and Video Library

2017-12-08

Sen. Barbara Mikulski participated in a ribbon cutting at NASA’s Goddard Space Flight Center on January 6th, 2016, to officially open the new Robotic Operations Center (ROC) developed by the Satellite Servicing Capabilities Office (SSCO). Within the ROC's black walls, NASA is testing technologies and operational procedures for science and exploration missions, including the Restore-L satellite servicing mission and also the Asteroid Redirect Mission. Here, she receives an overview of a robotic console station used to practice satellite servicing activities. During her tour of the ROC, Sen. Mikulski saw first-hand an early version of the NASA Servicing Arm, a 2-meter-class robot with the dexterity to grasp and refuel a satellite on orbit. She also heard a description of Raven, a payload launching to the International Space Station that will demonstrate real-time, relative space navigation technology. The robotic technologies that NASA is developing within the ROC also support the Journey to Mars. Learn more about NASA’s satellite servicing technologies at ssco.gsfc.nasa.gov/. Image credit: NASA/Desiree Stover NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Science and Reconnaissance from the Europa Clipper Mission Concept: Exploring Europa's Habitability

NASA Astrophysics Data System (ADS)

Pappalardo, Robert; Senske, David; Prockter, Louise; Paczkowski, Brian; Vance, Steve; Goldstein, Barry; Magner, Thomas; Cooke, Brian

2015-04-01

Europa is recognized by the Planetary Science De-cadal Survey as a prime candidate to search for a pre-sent-day habitable environment in our solar system. As such, NASA has pursued a series of studies, facilitated by a Europa Science Definition Team (SDT), to define a strategy to best advance our scientific understanding of this icy world with the science goal: Explore Europa to investigate its habitability. (In June of 2014, the SDT completed its task of identifying the overarching science objectives and investigations.) Working in concert with a technical team, a set of mission archi-tectures were evaluated to determine the best way to achieve the SDT defined science objectives. The fa-vored architecture would consist of a spacecraft in Ju-piter orbit making many close flybys of Europa, con-centrating on remote sensing to explore the moon. In-novative mission design would use gravitational per-turbations of the spacecraft trajectory to permit flybys at a wide variety of latitudes and longitudes, enabling globally distributed regional coverage of Europa's sur-face, with nominally 45 close flybys, typically at alti-tudes from 25 to 100 km. This concept has become known as the Europa Clipper. The Europa SDT recommended three science ob-jectives for the Europa Clipper: Ice Shell and Ocean: Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; Composition: Understand the habitability of Europa's ocean through composition and chemistry; and Geology: Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities. The Europa SDT also considered implications of the Hubble Space Telescope detection of possible plumes at Europa. To feed forward to potential subsequent future ex-ploration that could be enabled by a lander, it was deemed that the Europa Clipper mission concept should provide the capability to perform reconnais-sance for a future lander. In consultation with NASA Headquarters, the SDT developed a reconnaissance goal: Characterize Scientifically Compelling Sites, and Hazards, for a Potential Future Landed Mission to Europa. This leads to two reconnaissance objectives: Site Safety: Assess the distribution of surface hazards, the load-bearing capacity of the surface, the structure of the subsurface, and the regolith thickness; and Sci-ence Value: Assess the composition of surface materi-als, the geologic context of the surface, the potential for geological activity, the proximity of near surface water, and the potential for active upwelling of ocean material. The Europa Clipper mission concept provides an efficient means to explore Europa and investigate its habitability through understanding the satellite's ice shell and ocean, composition, and geology. It also provides for surface reconnaissance for potential future landed exploration of Europa. Development of the Eu-ropa Clipper mission concept is ongoing, with current studies focusing on spacecraft design trades and re-finements, launch vehicle options (EELV and SLS), and power source (MMRTG and solar), to name a few. We will provide an update on status of the science and reconnaissance effort, as well as the results of trade studies as relevant to the science and reconnaissance potential of the mission concept.

Adaptive arrays for satellite communications

NASA Technical Reports Server (NTRS)

Gupta, I. J.; Ksienski, A. A.

1984-01-01

The suppression of interfering signals in a satellite communication system was studied. Adaptive arrays are used to suppress interference at the reception site. It is required that the interference be suppressed to very low levels and a modified adaptive circuit is used which accomplishes the desired objective. Techniques for the modification of the transmit patterns to minimize interference with neighboring communication links are explored.

Using satellite and airborne LiDAR to model woodpecker habitat occupancy at the landscape scale

Treesearch

Lee A. Vierling; Kerri T. Vierling; Patrick Adam; Andrew T. Hudak

2013-01-01

Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. LiDAR can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based LiDAR...

Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation

EPA Science Inventory

The wealth of air quality information provided by satellite infrared observations of ammonia (NH3), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH3OH) is currently being explored and used for a number of applications, especially at regional or global scales. These ap...

Planning Alternative Organizational Frameworks For a Large Scale Educational Telecommunications System Served by Fixed/Broadcast Satellites. Memorandum Number 73/3.

ERIC Educational Resources Information Center

Walkmeyer, John

Considerations relating to the design of organizational structures for development and control of large scale educational telecommunications systems using satellites are explored. The first part of the document deals with four issues of system-wide concern. The first is user accessibility to the system, including proximity to entry points, ability…

Measuring Forest Area Loss Over Time Using FIA Plots and Satellite Imagery

Treesearch

Michael L. Hoppus; Andrew J. Lister

2005-01-01

How accurately can FIA plots, scattered at 1 per 6,000 acres, identify often rare forest land loss, estimated at less than 1 percent per year in the Northeast? Here we explore this question mathematically, empirically, and by comparing FIA plot estimates of forest change with satellite image based maps of forest loss. The mathematical probability of exactly estimating...

Space-based solar power conversion and delivery systems study. Volume 2: Engineering analysis of orbital systems

NASA Technical Reports Server (NTRS)

1976-01-01

Program plans, schedules, and costs are determined for a synchronous orbit-based power generation and relay system. Requirements for the satellite solar power station (SSPS) and the power relay satellite (PRS) are explored. Engineering analysis of large solar arrays, flight mechanics and control, transportation, assembly and maintenance, and microwave transmission are included.

Autonomous Object Characterization with Large Datasets

DTIC Science & Technology

2015-10-18

desk, where a substantial amount of effort is required to transform raw photometry into a data product, minimizing the amount of time the analyst has...were used to explore concepts in satellite characterization and satellite state change. The first algorithm provides real- time stability estimation... Timely and effective space object (SO) characterization is a challenge, and requires advanced data processing techniques. Detection and identification

Solar power satellite system definition study. Part 3: Preferred concept system definition

NASA Technical Reports Server (NTRS)

1978-01-01

A concise but complete system description for the preferred concept of the Solar Power Satellite System is presented. Significant selection decisions included the following: (1) single crystal silicon solar cells; (2) glass encapsulated solar cell blankets; (3) concentration ratio 1; (4) graphite composite materials for primary structure; (5) electric propulsion for attitude control; (6) klystron RF amplifier tubes for the transmitter; (7) one kilometer diameter transmitter with a design trans mission link output power of 5,000 megawatts; (8) construction in low earth orbit with self-powered transfer of satellite modules to geosynchronous orbit; and (9) two-stage winged fully reusable rocket vehicle for transportation to low earth orbit.

Performance of optical fibers in space radiation environment

NASA Astrophysics Data System (ADS)

Alam, M.; Abramczyk, J.; Manyam, U.; Farroni, J.; Guertin, D.

2017-11-01

The use of optical fibers in low earth orbiting (LEO) satellites is a source of concern due to the radiation environment in which these satellites operate and the reliability of devices based on these fibers. Although radiation induced damage in optical fibers cannot be avoided, it can certainly be minimized by intelligent engineering. Qualifying fibers for use in space is both time consuming and expensive, and manufacturers of satellites and their payloads have started to ask for radiation performance data from optical fiber vendors. Over time, Nufern has developed fiber designs, compositions and processes to make radiation hard fibers. Radiation performance data of a variety of fibers that find application in space radiation environment are presented.

Research of the key technology in satellite communication networks

NASA Astrophysics Data System (ADS)

Zeng, Yuan

2018-02-01

According to the prediction, in the next 10 years the wireless data traffic will be increased by 500-1000 times. Not only the wireless data traffic will be increased exponentially, and the demand for diversified traffic will be increased. Higher requirements for future mobile wireless communication system had brought huge market space for satellite communication system. At the same time, the space information networks had been greatly developed with the depth of human exploration of space activities, the development of space application, the expansion of military and civilian application. The core of spatial information networks is the satellite communication. The dissertation presented the communication system architecture, the communication protocol, the routing strategy, switch scheduling algorithm and the handoff strategy based on the satellite communication system. We built the simulation platform of the LEO satellites networks and simulated the key technology using OPNET.

Evaluation of Composite Structures Technologies for Application to NASA's Vision for Space Exploration (CoSTS)

NASA Technical Reports Server (NTRS)

Deo, Ravi; Wang, Donny; Bohlen, Jim; Fukuda, Cliff

2008-01-01

A trade study was conducted to determine the suitability of composite structures for weight and life cycle cost savings in primary and secondary structural systems for crew exploration vehicles, crew and cargo launch vehicles, landers, rovers, and habitats. The results of the trade study were used to identify and rank order composite material technologies that can have a near-term impact on a broad range of exploration mission applications. This report recommends technologies that should be developed to enable usage of composites on Vision for Space Exploration vehicles towards mass and life-cycle cost savings.

Long Term Association of Tropospheric Trace gases over Pakistan by exploiting satellite observations and development of Econometric Regression based Model

NASA Astrophysics Data System (ADS)

Zeb, Naila; Fahim Khokhar, Muhammad; Khan, Saud Ahmed; Noreen, Asma; Murtaza, Rabbia

2017-04-01

Air pollution is the expected key environmental issue of Pakistan as it is ranked among top polluted countries in the region. Ongoing rapid economic growth without any adequate measures is leading to worst air quality over time. The study aims to monitor long term atmospheric composition and association of trace gases over Pakistan. Tropospheric concentrations of CO, TOC, NO2 and HCHO derived from multiple satellite instruments are used for study from year 2005 to 2014. The study will provide first database for tropospheric trace gases over Pakistan. Spatio-temporal assessment identified hotspots and possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60 % of the Pakistan's population) sector of the country. The expected sources are the agricultural fires, biomass/fossil fuel burning for heating purposes, urbanization, industrialization and meteorological variations. Seasonal variability is observed to explore seasonal patterns over the decade. Well defined seasonal cycles of trace gases are observed over the whole study period. The observed seasonal patterns also showed some noteworthy association among trace gases, which is further explored by different statistical tests. Seasonal Mann Kendall test is applied to test the significance of trend in series whereas correlation is carried out to measure the strength of association among trace gases. Strong correlation is observed for trace gases especially between CO and TOC. Partial Mann Kendall test is used to ideally identify the impact of each covariate on long term trend of CO and TOC by partialling out each correlating trace gas (covariate). It is observed that TOC, NO2 and HCHO has significant impact on long term trend of CO whereas, TOC critically depends on NO2 concentrations for long term increase over the region. Furthermore to explore causal relation, regression analysis is employed to estimate model for CO and TOC. This model numerically estimated the long term association of trace gases over the region.

Pioneer 11's New Saturn.

ERIC Educational Resources Information Center

Science News, 1979

1979-01-01

New findings about the planet, Saturn and its environs, as collected by Pioneer 11 are detailed. Topics discussed include: the composition of the planet's interior, the search for new satellites, and the planet's magnetic field. (BT)

Deployment of ANDE-2

NASA Image and Video Library

2009-07-30

S127-E-012919 (30 July 2009) --- Backdropped by a blue and white Earth, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment 2 (ANDE-2) is photographed after its release from Space Shuttle Endeavour's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which will measure the density and composition of the low-Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

View of ANDE release from orbiter Discovery payload bay

NASA Image and Video Library

2006-12-21

S116-E-07828 (21 Dec. 2006) --- As seen through windows on the aft flight deck of Space Shuttle Discovery, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment (ANDE) is released from the shuttle's payload bay by STS-116 crewmembers. ANDE consists of two micro-satellites which will measure the density and composition of the low Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

Deployment of ANDE-2

NASA Image and Video Library

2009-07-30

S127-E-012934 (30 July 2009) --- Backdropped by Earth’s horizon and the blackness of space, a Department of Defense pico-satellite known as Atmospheric Neutral Density Experiment 2 (ANDE-2) is photographed after its release from Space Shuttle Endeavour's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which will measure the density and composition of the low-Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.

New horizons mapping of Europa and Ganymede.

PubMed

Grundy, W M; Buratti, B J; Cheng, A F; Emery, J P; Lunsford, A; McKinnon, W B; Moore, J M; Newman, S F; Olkin, C B; Reuter, D C; Schenk, P M; Spencer, J R; Stern, S A; Throop, H B; Weaver, H A

2007-10-12

The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.

Compositional Remote Sensing of Icy Planets and Satellites Beyond Jupiter

NASA Technical Reports Server (NTRS)

Roush, T. L.

2002-01-01

The peak of the solar energy distribution occurs at visual wavelengths and falls off rapidly in the infrared. This fact, improvements in infrared detector technology, and the low surface temperatures for most icy objects in the outer solar system have resulted in the bulk of telescopic and spacecraft observations being performed at visual and near-infrared wavelengths. Such observations, begun in the early 1970's and continuing to present, have provided compositional information regarding the surfaces of the satellites of Saturn and Uranus, Neptune's moon Triton, Pluto, Pluto's moon Charon, Centaur objects, and Kuiper belt objects. Because the incident sunlight penetrates the surface and interacts with the materials present there, the measured reflected sunlight contains information regarding the surface materials, and the ratio of the reflected to incident sunlight provides a mechanism of identifying the materials that are present.

Bulk density of asteroid 243 Ida from the orbit of its satellite Dactyl

USGS Publications Warehouse

Belton, M.J.S.; Chapmant, C.R.; Thomas, P.C.; Davies, M.E.; Greenberg, R.; Klaasen, K.; Byrnes, D.; D'Amario, L.; Synnott, S.; Johnson, T.V.; McEwen, A.; Merline, W.J.; Davis, D.R.; Petit, J.-M.; Storrs, A.; Veverka, J.; Zellner, B.

1995-01-01

DURING its reconnaissance of the asteroid 243 Ida, the Galileo spacecraft returned images of a second object, 1993(243)1 Dactyl1 - the first confirmed satellite of an asteroid. Sufficient data were obtained on the motion of Dactyl to determine its orbit as a function of Ida's mass. Here we apply statistical and dynamical arguments to constrain the range of possible orbits, and hence the mass of Ida. Combined with the volume of Ida2, this yields a bulk density of 2.6??0.5 g cm-3. Allowing for the uncertainty in the porosity of Ida, this density range is consistent with a bulk chondritic composition, and argues against some (but not all) classes of meteoritic igneous rock types that have been suggested as compositionally representative of S-type asteroids like Ida.

Bulk density of asteroid 243 Ida from the orbit of its satellite Dactyl

USGS Publications Warehouse

Belton, M.J.S.; Chapman, C.R.; Thomas, P.C.; Davies, M.E.; Greenberg, R.; Klaasen, K.; Byrnes, D.; D'Amario, L.; Synnott, S.; Johnson, T.V.; McEwen, A.; Merline, W.J.; Davis, D.R.; Petit, J.-M.; Storrs, A.; Veverka, J.; Zellner, B.

1995-01-01

DURING its reconnaissance of the asteroid 243 Ida, the Galileo spacecraft returned images of a second object, 1993(243)1 Dactyl1 - the first confirmed satellite of an asteroid. Sufficient data were obtained on the motion of Dactyl to determine its orbit as a function of Ida's mass. Here we apply statistical and dynamical arguments to constrain the range of possible orbits, and hence the mass of Ida. Combined with the volume of Ida2, this yields a bulk density of 2.6 ?? 0.5 g cm-3. Allowing for the uncertainty in the porosity of Ida, this density range is consistent with a bulk chon-dritic composition, and argues against some (but not all) classes of meteoritic igneous rock types that have been suggested as compositionally representative of S-type asteroids like Ida. ?? 2002 Nature Publishing Group.

Compositional maps of Saturn's moon Phoebe from imaging spectroscopy

USGS Publications Warehouse

Clark, R.N.; Brown, R.H.; Jaumann, R.; Cruikshank, D.P.; Nelson, R.M.; Buratti, B.J.; McCord, T.B.; Lunine, J.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Formisano, V.; Langevin, Y.; Matson, D.L.; Mennella, V.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Hoefen, T.M.; Curchin, J.M.; Hansen, G.; Hibbits, K.; Matz, K.-D.

2005-01-01

The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within the sub-nebula in which Saturn itself formed. Here we report imaging spectroscopy of Phoebe resulting from the Cassini-Huygens spacecraft encounter on 11 June 2004. We mapped ferrous-iron-bearing minerals, bound water, trapped CO2, probable phyllosilicates, organics, nitriles and cyanide compounds. Detection of these compounds on Phoebe makes it one of the most compositionally diverse objects yet observed in our Solar System. It is likely that Phoebe's surface contains primitive materials from the outer Solar System, indicating a surface of cometary origin.

Properties of the moon, Mars, Martian satellites, and near-earth asteroids

NASA Technical Reports Server (NTRS)

Taylor, Jeffrey G.

1989-01-01

Environments and surface properties of the moon, Mars, Martian satellites, and near-earth asteroids are discussed. Topics include gravity, atmospheres, surface properties, surface compositions, seismicity, radiation environment, degradation, use of robotics, and environmental impacts. Gravity fields vary from large fractions of the earth's field such as 1/3 on Mars and 1/6 on the moon to smaller fractions of 0.0004 g on an asteroid 1 km in diameter. Spectral data and the analogy with meteor compositions suggest that near-earth asteroids may contain many resources such as water-rich carbonaceous materials and iron-rich metallic bodies. It is concluded that future mining and materials processing operations from extraterrestrial bodies require an investment now in both (1) missions to the moon, Mars, Phobos, Deimos, and near-earth asteroids and (2) earth-based laboratory research in materials and processing.