Science.gov

Sample records for handling collision debris

  1. Orbital debris-debris collision avoidance

    NASA Astrophysics Data System (ADS)

    Mason, James; Stupl, Jan; Marshall, William; Levit, Creon

    2011-11-01

    We focus on preventing collisions between debris and debris, for which there is no current, effective mitigation strategy. We investigate the feasibility of using a medium-powered (5 kW) ground-based laser combined with a ground-based telescope to prevent collisions between debris objects in low-Earth orbit (LEO). The scheme utilizes photon pressure alone as a means to perturb the orbit of a debris object. Applied over multiple engagements, this alters the debris orbit sufficiently to reduce the risk of an upcoming conjunction. We employ standard assumptions for atmospheric conditions and the resulting beam propagation. Using case studies designed to represent the properties (e.g. area and mass) of the current debris population, we show that one could significantly reduce the risk of nearly half of all catastrophic collisions involving debris using only one such laser/telescope facility. We speculate on whether this could mitigate the debris fragmentation rate such that it falls below the natural debris re-entry rate due to atmospheric drag, and thus whether continuous long-term operation could entirely mitigate the Kessler syndrome in LEO, without need for relatively expensive active debris removal.

  2. Modeling collisions in circumstellar debris disks

    NASA Astrophysics Data System (ADS)

    Nesvold, Erika

    2015-10-01

    Observations of resolved debris disks show a spectacular variety of features and asymmetries, including inner cavities and gaps, inclined secondary disks or warps, and eccentric, sharp-edged rings. Embedded exoplanets could create many of these features via gravitational perturbations, which sculpt the disk directly and by generating planetesimal collisions. In this thesis, I present the Superparticle Model/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. I show that SMACK is stable to numerical viscosity and numerical heating over 107 yr, and that it can reproduce analytic models of disk evolution. As an example of the algorithm's capabilities, I use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit and demonstrate that differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring. To demonstrate SMACK's utility in studying debris disk physics, I apply SMACK to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (alpha = 2/7). I find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index alpha of the power law depends on the age of the system t relative to the collisional timescale t coll of the disk by alpha = 0.32(t/ tcoll)-0.04, with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion

  3. Contribution of explosion and future collision fragments to the orbital debris environment

    NASA Technical Reports Server (NTRS)

    Su, S.-Y.; Kessler, D. J.

    1985-01-01

    The time evolution of the near-earth man-made orbital debris environment modeled by numerical simulation is presented in this paper. The model starts with a data base of orbital debris objects which are tracked by the NORAD ground radar system. The current untrackable small objects are assumed to result from explosions and are predicted from data collected from a ground explosion experiment. Future collisions between earth orbiting objects are handled by the Monte Carlo method to simulate the range of collision possibilities that may occur in the real world. The collision fragmentation process between debris objects is calculated using an empirical formula derived from a laboratory spacecraft impact experiment to obtain the number versus size distribution of the newly generated debris population. The evolution of the future space debris environment is compared with the natural meteoroid background for the relative spacecraft penetration hazard.

  4. Evasive Maneuvers in Route Collision With Space Debris Cloud

    NASA Astrophysics Data System (ADS)

    Jesus, A. D. C.; Sousa, R. R.; Neto, E. V.

    2015-10-01

    Collisions between operational vehicles and space debris can completely derail the continuity of space missions, especially if there is chain collisions between debris, which generate even smaller fragments. In this paper, we investigate the dynamics on between an operational vehicle and space debris that form a cloud, considering the possibility of collisions between debris during an evasive maneuver the vehicle. For a radius of 3 km celestial sphere, we find possibilities of collision between debris up to 10 m, while the vehicle performs an evasive maneuver in time 3,000 s range. These results depend on the time collision, the angular positions of the collisional objects and the amount of debris that form the cloud.

  5. Space debris collision and production analytic estimates

    SciTech Connect

    Canavan, G.H.

    1996-08-01

    Analytic estimates provide useful estimates of collision rates, fragment production rates, and average collision masses and numbers in good agreement with analytic and numerical estimates for the principal quantities of interest.

  6. On the Nature of Debris and Collision Growth Estimates

    NASA Astrophysics Data System (ADS)

    Combs, R.; Koch, J.; Vandrey, N.

    2013-09-01

    Orbital debris growth estimates are used for a variety of purposes, including resource allocation for debris field tracking, allocation of research and development funds, as well as considerations on collision risk and debris elimination. More accurate projections would enable better resource allocation. Contemporary estimates and models of debris growth take a linear form where growth is a constant number of objects per year, or they take a geometric growth rate of about 1-2%. Examination of empirical data reveals that growth is not linear, but geometric, and that historical projections have underestimated growth and debris by wide margins. Measurements reveal that debris field growth rates appear to be closer to 5% than 2%. Measurements of debris size and population reveal an inverse log-log relationship, so it is possible to estimate the debris population of any size by measuring the population at a given size. The U.S. Space Catalog is the most reliable measure of the objects with a minimum diameter on the order of 50 cm. The space catalog has grown at an average rate of 3.5% per annum in the last decade, and 3.8% per annum since 1980. Space Catalog growth rate is only loosely correlated (0.55) with the global launch rate. New detection methods are being fielded like Space Based Space Surveillance and the Space Fence, objects as small as 5 cm will be reliably tracked in the near future. In 2010, the space catalog was estimated to grow from a current 20,000 object catalog to a 100,000 object catalog by 2023, yielding an 8.5% per year. Given that debris growth rates exceed contemporary estimates, it is not surprising collision rates exceed estimates as well. The number of known or suspected collisions exceeds the numbers projected by Kessler in 1978. Modern and brute-force collision projection methods reveal the use of a flat or linear rate of >100cm object conjunctions. The actual conjunction rate appears to grow geometrically as well.

  7. Debris from terrestrial planet formation: the Moon-forming collision

    NASA Astrophysics Data System (ADS)

    Jackson, Alan P.; Wyatt, Mark C.

    2012-09-01

    We study the evolution of debris created in the giant impacts expected during the final stages of terrestrial planet formation. The starting point is the debris created in a simulation of the Moon-forming impact. The dynamical evolution is followed for 10 Myr including the effects of Earth, Venus, Mars and Jupiter. The spatial distribution evolves from a clump in the first few months to an asymmetric ring for the first 10 kyr and finally becoming an axisymmetric ring by about 1 Myr after the impact. By 10 Myr after the impact 20 per cent of the particles have been accreted on to Earth and 17 per cent on to Venus, with 8 per cent ejected by Jupiter and other bodies playing minor roles. However, the fate of the debris also depends strongly on how fast it is collisionally depleted, which depends on the poorly constrained size distribution of the impact debris. Assuming that the debris is made up of 30 per cent by mass mm-cm-sized vapour condensates and 70 per cent boulders up to 500 km, we find that the condensates deplete rapidly on ˜1000 yr time-scales, whereas the boulders deplete predominantly dynamically. By considering the luminosity of dust produced in collisions within the boulder-debris distribution we find that the Moon-forming impact would have been readily detectable around other stars in Spitzer 24 μm surveys for around 25 Myr after the impact, with levels of emission comparable to many known hot dust systems. The vapour condensates meanwhile produce a short-lived, optically thick, spike of emission. We use these surveys to make an estimate of the fraction of stars that form terrestrial planets, FTPF. Since current terrestrial planet formation models invoke multiple giant impacts, the low fraction of 10-100 Myr stars found to have warm (>rsim150 K) dust implies that FTPF≲10 per cent. For this number to be higher, it would require that either terrestrial planets are largely fully formed when the protoplanetary disc disperses, or that impact generated

  8. Process Knowledge Summary Report for Materials and Fuels Complex Contact-Handled Transuranic Debris Waste

    SciTech Connect

    R. P. Grant; P. J. Crane; S. Butler; M. A. Henry

    2010-02-01

    This Process Knowledge Summary Report summarizes the information collected to satisfy the transportation and waste acceptance requirements for the transfer of transuranic (TRU) waste between the Materials and Fuels Complex (MFC) and the Advanced Mixed Waste Treatment Project (AMWTP). The information collected includes documentation that addresses the requirements for AMWTP and the applicable portion of their Resource Conservation and Recovery Act permits for receipt and treatment of TRU debris waste in AMWTP. This report has been prepared for contact-handled TRU debris waste generated by the Idaho National Laboratory at MFC. The TRU debris waste will be shipped to AMWTP for purposes of supercompaction. This Process Knowledge Summary Report includes information regarding, but not limited to, the generation process, the physical form, radiological characteristics, and chemical contaminants of the TRU debris waste, prohibited items, and packaging configuration. This report, along with the referenced supporting documents, will create a defensible and auditable record for waste originating from MFC.

  9. An analytic method of space debris cloud evolution and its collision evaluation for constellation satellites

    NASA Astrophysics Data System (ADS)

    Zhang, Binbin; Wang, Zhaokui; Zhang, Yulin

    2016-09-01

    When a debris cloud is formed in the neighborhood of a constellation, the constellation satellites will face a serious threat of collision. In order to evaluate the collision probability in a long time scale, first we build an analytic model to describe the evolution process of the debris cloud. Under the perturbations of atmospheric drag, nonspherical gravity field, etc., results of numerical simulation indicate that after the breakup of an object, the distribution of debris cloud will evolve into a relatively stable band. Based on the stable distribution characteristic of the debris cloud, fragments are divided into several groups according their orbital heights and area-mass ratios. For each debris group, the dynamics of the distribution process under the perturbation of atmosphere drag is described by a partial differential equation (PDE). Solutions of those PDEs are obtained. And the distribution of the debris cloud can be easily propagated over long time scales. Applying this analytic model, the collision probability between a debris cloud and the Globalstar satellites is analyzed and computed. Results show that the collision probability is nearly 10,000 times of the average collision probability in the near Earth environment. Moreover, as the band distribution of the space debris cloud is stable, the collisional risk on constellation satellites will last for quite a long time.

  10. Fraction of space debris collisions that are catastrophic

    SciTech Connect

    Canavan, G.H.

    1996-08-01

    Analytic calculations estimate the fraction of catalog collisions that are catastrophic by a modification of collision rates. Most catalog collisions are catastrophic. Impactors of 60 kg or larger participate in about half of the catastrophic collisions. Analytic estimates give accurate values for catastrophic collisions, which are complicated numerically.

  11. The Kuiper Belt, Exozodiacal Dust, Debris Disks: It's All About Collisions

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2010-01-01

    Debris disks around other stars, like the disks around Fomalhaut, Vega, and Epsilon Eridani, are often described as more massive versions of the Kuiper Belt. But for a long time, it's been hard to test this notion, because grain-grain collisions dominate the grain lifetimes and we lacked the tools to model the effect of collisions on the appearance of the disks. I'll describe a new breakthrough that has allowed us to make 3-D models of collisions in debris disks and exozodiacal clouds for the first time, and I'll show the latest supercomputer simulations of these systems, illustrating the effects of planets and collisions in sculpting these disks. These models will be the key to interpreting debris disk images from HST, Herschel, SOFIA, JWST, and ALMA, as well as understanding the exozodiacal dust backgrounds for direct imaging of exo-Earths.

  12. Signatures of massive collisions in debris discs. A self-consistent numerical model

    NASA Astrophysics Data System (ADS)

    Kral, Q.; Thébault, P.; Augereau, J.-C.; Boccaletti, A.; Charnoz, S.

    2015-01-01

    Context. Violent stochastic collisional events have been invoked as a possible explanation for some debris discs displaying pronounced azimuthal asymmetries or having a luminosity excess exceeding that expected for systems at collisional steady-state. So far, no thorough modelling of the consequences of such stochastic events has been carried out, mainly because of the extreme numerical challenge of coupling the dynamical and collisional evolution of the released dust. Aims: We perform the first fully self-consistent modelling of the aftermath of massive breakups in debris discs. We follow the collisional and dynamical evolution of dust released after the breakup of a Ceres-sized body at 6 AU from its central star. We investigate the duration, magnitude, and spatial structure of the signature left by such a violent event, as well as its observational detectability. Methods: We use the recently developed LIDT-DD code, which handles the coupled collisional and dynamical evolution of debris discs. The main focus is placed on the complex interplay between destructive collisions, Keplerian dynamics, and radiation pressure forces. We use the GRaTer package to estimate the system's luminosity at different wavelengths. Results: The breakup of a Ceres-sized body at 6 AU creates an asymmetric dust disc that is homogenized by the coupled action of collisions and dynamics on a timescale of a few 105 years. After a transient period where it is very steep, the particle size distribution in the system relaxes to a collisional steady-state law after ~104 years. The luminosity excess in the breakup's aftermath should be detectable by mid-IR photometry, from a 30 pc distance, over a period of ~106 years that exceeds the duration of the asymmetric phase of the disc (a few 105 years). As for the asymmetric structures, we derive synthetic images for the VLT/SPHERE and JWST/MIRI instruments, showing that they should be clearly visible and resolved from a 10 pc distance. Images at 1.6

  13. Collision-less Coupling between Explosive Debris Plasma and Magnetized Ambient Plasma

    NASA Astrophysics Data System (ADS)

    Bondarenko, Anton Sergeivich

    The explosive expansion of a dense debris plasma cloud into relatively tenuous, magnetized, ambient plasma characterizes a wide variety of astrophysical and space environments, including supernova remnants, interplanetary coronal mass ejections, and ionospheric explosions. In these and other related phenomena, collision-less electro-magnetic processes rather than Coulomb collisions typically mediate the transfer of momentum and energy from the debris plasma to the ambient plasma. In an effort to better understand the detailed physics of collision-less coupling mechanisms, compliment in situ measurements, and provide validation of previous computational and theoretical work, the present research utilizes a unique experimental platform at the University of California, Los Angeles (UCLA) to study the interaction of explosive debris plasma with magnetized ambient plasma in a reproducible laboratory setting. Specifically, by jointly employing the Large Plasma Device (LAPD) and the Phoenix laser facility, the super-Alfvenic, quasi-perpendicular expansion of laser-produced carbon (C) and hydrogen (H) debris plasma through preformed, magnetized helium (He) ambient plasma is investigated via a variety of sophisticated diagnostics, including emission spectroscopy, wavelength-filtered imaging, a magnetic flux probe, and a Langmuir probe. The key result is the direct observation of collision-less coupling via large Doppler shifts in a He II ion spectral line, which indicate that the ambient ions accelerate in response to the explosive debris plasma. Specifically, the He II ions accelerate along a trajectory that qualitatively corresponds to the large-scale laminar electric field generated by the debris expansion. A custom computational approach is utilized to simulate the initial He II ion response to the explosive debris plasma, and a synthetic Doppler-shifted wavelength spectrum constructed from the simulated ion velocities excellently reproduces the experimental

  14. CURRENT APPLICATIONS OF THREE MILE ISLAND-2 CORE AND DEBRIS HANDLING AT THE IDAHO NATIONAL LABORATORY

    SciTech Connect

    Carmack, William Jonathan; Braase, Lori Ann

    2015-09-01

    Fuel recovery from severe accidents requires careful planning and execution. The Idaho National Laboratory played a key role in the Three Mile Island (TMI) fuel and core recovery. This involved technology development to locate and handle the damaged fuel; characterization of fuel and debris; analysis of fuel interaction with structural components and materials; development of fuel drying technology for long-term storage. However, one of the critical activities from the TMI project was the extensive effort document all the activities and archive the reports and photos. A historical review of the TMI project at the INL leads to the identification of current applications and considerations for facility designs, fuel handling, robotic applications, material characterization, etc.

  15. Collision frequency of artificial satellites - The creation of a debris belt

    NASA Technical Reports Server (NTRS)

    Kessler, D. J.; Cour-Palais, B. G.

    1978-01-01

    The probability of satellite collisions increases with the number of satellites. In the present paper, possible time scales for the growth of a debris belt from collision fragments are determined, and possible consequences of continued unrestrained launch activities are examined. Use is made of techniques formerly developed for studying the evolution (growth) of the asteroid belt. A model describing the flux from the known earth-orbiting satellites is developed, and the results from this model are extrapolated in time to predict the collision frequency between satellites. Hypervelocity impact phenomena are then examined to predict the debris flux resulting from collisions. The results are applied to design requirements for three types of future space missions.

  16. SMACK: A New Algorithm for Modeling Collisions and Dynamics of Planetesimals in Debris Disks

    NASA Technical Reports Server (NTRS)

    Nesvold, Erika Rose; Kuchner, Marc J.; Rein, Hanno; Pan, Margaret

    2013-01-01

    We present the Superparticle Model/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. We show that SMACK is stable to numerical viscosity and numerical heating over 10(exp 7) yr, and that it can reproduce analytic models of disk evolution. We use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit. Differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring.

  17. SMACK: A NEW ALGORITHM FOR MODELING COLLISIONS AND DYNAMICS OF PLANETESIMALS IN DEBRIS DISKS

    SciTech Connect

    Nesvold, Erika R.; Kuchner, Marc J.; Pan, Margaret; Rein, Hanno E-mail: Marc.Kuchner@nasa.gov E-mail: rein@ias.edu

    2013-11-10

    We present the Superparticle-Method/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in three dimensions, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. We show that SMACK is stable to numerical viscosity and numerical heating over 10{sup 7} yr and that it can reproduce analytic models of disk evolution. We use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit. Differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring.

  18. NASA's Orbital Debris Conjuction Assessment and Collision Avoidance Strategy

    NASA Technical Reports Server (NTRS)

    Gavin, Richard T.

    2010-01-01

    NASA has successfully used debris avoidance maneuvers to protect our spacecraft for more than 20 . years. This process which started out using parametric data and maneuver boxes has seen considerable evolution and now allows us to continue nominal operations for all but the most threatening objects. This has greatly reduced the interruptions to the critical mission objectives being pursued by NASA s Space Station, Space Shuttle, and robotic satellites.

  19. Operational Impact of Improved Space Tracking on Collision Avoidance in the Future LEO Space Debris Environment

    NASA Astrophysics Data System (ADS)

    Sibert, D.; Borgeson, D.; Peterson, G.; Jenkin, A.; Sorge, M.

    2010-09-01

    Even if global space policy successfully curtails on orbit explosions and ASAT demonstrations, studies indicate that the number of debris objects in Low Earth Orbit (LEO) will continue to grow solely from debris on debris collisions and debris generated from new launches. This study examines the threat posed by this growing space debris population over the next 30 years and how improvements in our space tracking capabilities can reduce the number of Collision Avoidance (COLA) maneuvers required keep the risk of operational satellite loss within tolerable limits. Particular focus is given to satellites operated by the Department of Defense (DoD) and Intelligence Community (IC) in Low Earth Orbit (LEO). The following debris field and space tracking performance parameters were varied parametrically in the experiment to study the impact on the number of collision avoidance maneuvers required: - Debris Field Density (by year 2009, 2019, 2029, and 2039) - Quality of Track Update (starting 1 sigma error ellipsoid) - Future Propagator Accuracy (error ellipsoid growth rates - Special Perturbations in 3 axes) - Track Update Rate for Debris (stochastic) - Track Update Rate for Payloads (stochastic) Baseline values matching present day tracking performance for quality of track update, propagator accuracy, and track update rate were derived by analyzing updates to the unclassified Satellite Catalog (SatCat). Track update rates varied significantly for active payloads and debris and as such we used different models for the track update rates for military payloads and debris. The analysis was conducted using the System Effectiveness Analysis Simulation (SEAS) an agent based model developed by the United States Air Force Space Command’s Space and Missile Systems Center to evaluate the military utility of space systems. The future debris field was modeled by The Aerospace Corporation using a tool chain which models the growth of the 10cm+ debris field using high fidelity

  20. Constraints on Planetesimal Collision Models in Debris Disks

    NASA Astrophysics Data System (ADS)

    MacGregor, Meredith A.; Wilner, David J.; Chandler, Claire; Ricci, Luca; Maddison, Sarah T.; Cranmer, Steven R.; Andrews, Sean M.; Hughes, A. Meredith; Steele, Amy

    2016-06-01

    Observations of debris disks offer a window into the physical and dynamical properties of planetesimals in extrasolar systems through the size distribution of dust grains. In particular, the millimeter spectral index of thermal dust emission encodes information on the grain size distribution. We have made new VLA observations of a sample of seven nearby debris disks at 9 mm, with 3\\prime\\prime resolution and ∼5 μJy beam‑1rms. We combine these with archival ATCA observations of eight additional debris disks observed at 7 mm, together with up-to-date observations of all disks at (sub)millimeter wavelengths from the literature, to place tight constraints on the millimeter spectral indices and thus grain size distributions. The analysis gives a weighted mean for the slope of the power-law grain size distribution, n(a)\\propto {a}-q, of < q> =3.36+/- 0.02, with a possible trend of decreasing q for later spectral type stars. We compare our results to a range of theoretical models of collisional cascades, from the standard self-similar, steady-state size distribution (q = 3.5) to solutions that incorporate more realistic physics such as alternative velocity distributions and material strengths, the possibility of a cutoff at small dust sizes from radiation pressure, and results from detailed dynamical calculations of specific disks. Such effects can lead to size distributions consistent with the data, and plausibly the observed scatter in spectral indices. For the AU Mic system, the VLA observations show clear evidence of a highly variable stellar emission component; this stellar activity obviates the need to invoke the presence of an asteroid belt to explain the previously reported compact millimeter source in this system.

  1. LightForce Photon-Pressure Collision Avoidance: Efficiency Assessment on an Entire Catalogue of Space Debris

    NASA Technical Reports Server (NTRS)

    Stupl, Jan Michael; Faber, Nicolas; Foster, Cyrus; Yang Yang, Fan; Levit, Creon

    2013-01-01

    The potential to perturb debris orbits using photon pressure from ground-based lasers has been confirmed by independent research teams. Two useful applications of this scheme are protecting space assets from impacts with debris and stabilizing the orbital debris environment, both relying on collision avoidance rather than de-orbiting debris. This paper presents the results of a new assessment method to analyze the efficiency of the concept for collision avoidance. Earlier research concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, can prevent a significant fraction of debris-debris collisions in low Earth orbit. That research used in-track displacement to measure efficiency and restricted itself to an analysis of a limited number of objects. As orbit prediction error is dependent on debris object properties, a static displacement threshold should be complemented with another measure to assess the efficiency of the scheme. In this paper we present the results of an approach using probability of collision. Using a least-squares fitting method, we improve the quality of the original TLE catalogue in terms of state and co-state accuracy. We then calculate collision probabilities for all the objects in the catalogue. The conjunctions with the highest risk of collision are then engaged by a simulated network of laser ground stations. After those engagements, the perturbed orbits are used to re-assess the collision probability in a 20 minute window around the original conjunction. We then use different criteria to evaluate the utility of the laser-based collision avoidance scheme and assess the number of base-line ground stations needed to mitigate a significant number of high probability conjunctions. Finally, we also give an account how a laser ground station can be used for both orbit deflection and debris tracking.

  2. Probing Terrestrial Planet Formation by Witnessing Large Collisions in Extreme Debris Disks

    NASA Astrophysics Data System (ADS)

    Su, Kate

    2015-12-01

    The Kepler results indicate that many young planetary systems build terrestrial planets. The most dramatic phases of this process are thought to be oligarchic and chaotic growth, roughly up to ages of 200 million years, when violent collisions occur between bodies of sizes up to proto-planets. Such events should be marked by the production of huge amounts of debris, including clouds of dust, as has been observed in some of the extreme debris disks (young stars with high fractional dust luminosity and prominent solid-state features in the mid-infrared). The newly discovered variable emission from extreme debris disks provides a unique opportunity to learn about asteroid-sized bodies in young exoplanetary systems and to explore planetesimal collisions and their aftermaths during the era of terrestrial- planet-building.We have a on-going Spitzer program to monitor a dozen of young, dusty debris systems to investigate the incidence, nature, and evolution of these impacts through time-domain observations. I will highlight recent results from time-series monitoring of a 35 Myr-old disk around ID8 in NGC 2547, and discuss future directions for the study of the detailed process of large impacts in the era of terrestrial planet formation using space facilities.

  3. LightForce Photon-Pressure Collision Avoidance: Efficiency Assessment on an Entire Catalogue of Space Debris

    NASA Astrophysics Data System (ADS)

    Stupl, J.; Faber, N.; Foster, C.; Yang, F.; Levit, C.

    2013-09-01

    The potential to perturb debris orbits using photon pressure from ground-based lasers has been confirmed by independent research teams. Useful applications of this scheme are protecting space assets from impacts with debris and stabilizing the orbital debris environment, both relying on collision avoidance rather than de-orbiting debris. This paper presents the results of a new assessment method to analyze the efficiency of the concept. Earlier research concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, can avoid a significant fraction of debris-debris collisions in low Earth orbit. That research used in-track displacement to measure efficiency and restricted itself to an analysis of a limited number of objects. As orbit prediction error is dependent on debris object properties, a static displacement threshold should be complemented with another measure to assess the efficiency of the scheme. In this paper we present the results of an approach using probability of collision. Using a least-squares fitting method, we improve the quality of the original TLE catalogue in terms of state and co-state accuracy. We then calculate collision probabilities for all the objects in the catalogue. The conjunctions with the highest risk of collision are then engaged by a simulated network of laser ground stations. After those engagements, the perturbed orbits are used to re-assess the collision probability in a 24h window around the original conjunction. We then use different criteria to evaluate the utility of the laser based collision avoidance scheme and assess the number of base-line ground stations needed to mitigate a significant number of high probability conjunctions. Finally, we also give an account how a laser ground station can be used for both orbit deflection and debris tracking.

  4. Satellite Collision Modeling with Physics-Based Hydrocodes: Debris Generation Predictions of the Iridium-Cosmos Collision Event and Other Impact Events

    SciTech Connect

    Springer, H K; Miller, W O; Levatin, J L; Pertica, A J; Olivier, S S

    2010-09-06

    Satellite collision debris poses risks to existing space assets and future space missions. Predictive models of debris generated from these hypervelocity collisions are critical for developing accurate space situational awareness tools and effective mitigation strategies. Hypervelocity collisions involve complex phenomenon that spans several time- and length-scales. We have developed a satellite collision debris modeling approach consisting of a Lagrangian hydrocode enriched with smooth particle hydrodynamics (SPH), advanced material failure models, detailed satellite mesh models, and massively parallel computers. These computational studies enable us to investigate the influence of satellite center-of-mass (CM) overlap and orientation, relative velocity, and material composition on the size, velocity, and material type distributions of collision debris. We have applied our debris modeling capability to the recent Iridium 33-Cosmos 2251 collision event. While the relative velocity was well understood in this event, the degree of satellite CM overlap and orientation was ill-defined. In our simulations, we varied the collision CM overlap and orientation of the satellites from nearly maximum overlap to partial overlap on the outermost extents of the satellites (i.e, solar panels and gravity boom). As expected, we found that with increased satellite overlap, the overall debris cloud mass and momentum (transfer) increases, the average debris size decreases, and the debris velocity increases. The largest predicted debris can also provide insight into which satellite components were further removed from the impact location. A significant fraction of the momentum transfer is imparted to the smallest debris (< 1-5mm, dependent on mesh resolution), especially in large CM overlap simulations. While the inclusion of the smallest debris is critical to enforcing mass and momentum conservation in hydrocode simulations, there seems to be relatively little interest in their

  5. Satellite Collision Modeling with Physics-Based Hydrocodes: Debris Generation Predictions of the Iridium-Cosmos Collision Event and Other Impact Events

    NASA Astrophysics Data System (ADS)

    Springer, H.; Miller, W.; Levatin, J.; Pertica, A.; Olivier, S.

    2010-09-01

    Satellite collision debris poses risks to existing space assets and future space missions. Predictive models of debris generated from these hypervelocity collisions are critical for developing accurate space situational awareness tools and effective mitigation strategies. Hypervelocity collisions involve complex phenomenon that spans several time and length-scales. We have developed a satellite collision debris modeling approach consisting of a Lagrangian hydrocode enriched with smooth particle hydrodynamics (SPH), advanced material failure models, detailed satellite mesh models, and massively parallel computers. These computational studies enable us to investigate the influence of satellite center-of-mass (CM) overlap and orientation, relative velocity, and material composition on the size, velocity, and material type distributions of collision debris. We have applied our debris modeling capability to the recent Iridium 33-Cosmos 2251 collision event. While the relative velocity was well understood in this event, the degree of satellite CM overlap and orientation was ill-defined. In our simulations, we varied the collision CM overlap and orientation of the satellites from nearly maximum overlap to partial overlap on the outermost extents of the satellites (i.e, solar panels and gravity boom). As expected, we found that with increased satellite overlap, the overall debris cloud mass and momentum (transfer) increases, the average debris size decreases, and the debris velocity increases. The largest predicted debris can also provide insight into which satellite components were further removed from the impact location. A significant fraction of the momentum transfer is imparted to the smallest debris (< 1-5mm, dependent on mesh resolution), especially in large CM overlap simulations. While the inclusion of the smallest debris is critical to enforcing mass and momentum conservation in hydrocode simulations, there seems to be relatively little interest in their

  6. Spectroscopic Measurements of Collision-less Coupling Between Explosive Debris Plasmas and Ambient, Magnetized Background Plasmas

    NASA Astrophysics Data System (ADS)

    Bondarenko, Anton; Schaeffer, Derek; Everson, Erik; Vincena, Stephen; van Compernolle, Bart; Constantin, Carmen; Clark, Eric; Niemann, Christoph

    2013-10-01

    Emission spectroscopy is currently being utilized in order to assess collision-less momentum and energy coupling between explosive debris plasmas and ambient, magnetized background plasmas of astrophysical relevance. In recent campaigns on the Large Plasma Device (LAPD) (nelec =1012 -1013 cm-3, Telec ~ 5 eV, B0 = 200 - 400 G) utilizing the new Raptor laser facility (1053 nm, 100 J per pulse, 25 ns FWHM), laser-ablated carbon debris plasmas were generated within ambient, magnetized helium background plasmas and prominent spectral lines of carbon and helium ions were studied in high spectral (0 . 01 nm) and temporal (50 ns) resolution. Time-resolved velocity components extracted from Doppler shift measurements of the C+4 227 . 1 nm spectral line along two perpendicular axes reveal significant deceleration as the ions stream and gyrate within the helium background plasma, indicating collision-less momentum coupling. The He+1 320 . 3 nm and 468 . 6 nm spectral lines of the helium background plasma are observed to broaden and intensify in response to the carbon debris plasma, indicative of strong electric fields (Stark broadening) and energetic electrons. The experimental results are compared to 2D hybrid code simulations.

  7. Remote Maneuver of Space Debris Using Photon Pressure for Active Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Smith, C.

    2014-09-01

    The Space Environment Research Corporation (SERC) is a consortium of companies and research institutions that have joined together to pursue research and development of technologies and capabilities that will help to preserve the orbital space environment. The consortium includes, Electro Optics Systems (Australia), Lockheed Martin Australia, Optus Satellite Systems (Australia), The Australian national University, RMIT University, National Institute of Information and Communications Technology (NICT, Japan) as well as affiliates from NASA Ames and ESA. SERC is also the recipient of and Australian Government Cooperative Research Centre grant. SERC will pursue a wide ranging research program including technologies to improve tracking capability and capacity, orbit determination and propagation algorithms, conjunction analysis and collision avoidance. All of these technologies will contribute to the flagship program to demonstrate active collision avoidance using photon pressure to provide remote maneuver of space debris. This project joins of the proposed NASA Lightforce concept with infrastructure and capabilities provided by SERC. This paper will describe the proposed research and development program to provide an on-orbit demonstration within the next five years for remote maneuver of space debris.

  8. Fomalhaut b is Probably Not a Planet: Frequent Collisions within the Fomalhaut Debris Disk

    NASA Astrophysics Data System (ADS)

    Lawler, Samantha; Greenstreet, Sarah; Gladman, Brett

    2015-12-01

    Fomalhaut hosts a beautiful debris disk ring and a directly imaged planet candidate, Fomalhaut b, which seems to continually defy expectations. Originally thought to be a Jovian-mass planet constraining the ring, its unexpected spectral properties and highly eccentric, possibly ring-crossing orbit have completely ruled out that possibility. Many theories have been proposed to explain the weird properties of Fomalhaut b, including a large circumplanetary ring, a system of irregular satellites, and a recent small body collision. We expand on the last theory, discussing our collisional probability simulations of the Fomalhaut debris disk, based on the structure of our Kuiper belt, which show the catastrophic disruption rate of d~100 km bodies in the high-eccentricity scattering component is several per decade. This model paints a picture of the Fomalhaut system as having recently (with ~10-100 Myr) experienced a dynamical instability within its planetary system, which scattered a massive number of planetesimals onto large, high-eccentricity orbits similar to that of Fom b. If Fomalhaut b is indeed a dust cloud produced by such a collision, we should soon see another appear, while Fomalhaut b will expand until it is either resolved or becomes too faint to be seen.

  9. Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Programs

    NASA Technical Reports Server (NTRS)

    2011-01-01

    Over the past 50 years, various NASA communities have contributed significantly to maturing NASA s meteoroid and orbital debris (MMOD)1 programs to their current state. As a result of these community efforts, and to NASA s credit, NASA s MMOD programs and models are now widely used and respected by the providers and users of both government and commercial satellites, nationally as well as internationally. Satellites have been redesigned to protect critical components from MMOD damage by moving critical components from exterior surfaces to deep inside a satellite s structure. Orbits are monitored and altered to minimize the risk of collision with tracked orbital debris. MMOD shielding added to the International Space Station (ISS) protects critical components and astronauts from potentially catastrophic damage that might result from smaller, untracked debris and meteoroid impacts. The space shuttle, as it orbited Earth, and whether docked to the ISS or not, was optimally oriented to protect its fragile thermal protection and thermal radiation systems from MMOD damage. In addition, astronauts inspected its thermal protection system for MMOD damage before the shuttle reentered Earth s atmosphere; Orion, NASA s capsule to carry astronauts to low Earth orbit, includes designs to mitigate the threat of MMOD damage and provide increased safety to the crew. When a handful of reasonable assumptions are used in NASA s MMOD models, scenarios are uncovered that conclude that the current orbital debris environment has already reached a "tipping point." That is, the amount of debris - in terms of the population of large debris objects, as well as overall mass of debris in orbit - currently in orbit has reached a threshold where it will continually collide with itself, further increasing the population of orbital debris. This increase will lead to corresponding increases in spacecraft failures, which will only create more feedback into the system, increasing the debris population

  10. Azimuthal asymmetries in the debris disk around HD 61005. A massive collision of planetesimals?

    NASA Astrophysics Data System (ADS)

    Olofsson, J.; Samland, M.; Avenhaus, H.; Caceres, C.; Henning, Th.; Moór, A.; Milli, J.; Canovas, H.; Quanz, S. P.; Schreiber, M. R.; Augereau, J.-C.; Bayo, A.; Bazzon, A.; Beuzit, J.-L.; Boccaletti, A.; Buenzli, E.; Casassus, S.; Chauvin, G.; Dominik, C.; Desidera, S.; Feldt, M.; Gratton, R.; Janson, M.; Lagrange, A.-M.; Langlois, M.; Lannier, J.; Maire, A.-L.; Mesa, D.; Pinte, C.; Rouan, D.; Salter, G.; Thalmann, C.; Vigan, A.

    2016-06-01

    Context. Debris disks offer valuable insights into the latest stages of circumstellar disk evolution, and can possibly help us to trace the outcomes of planetary formation processes. In the age range 10 to 100 Myr, most of the gas is expected to have been removed from the system, giant planets (if any) must have already been formed, and the formation of terrestrial planets may be on-going. Pluto-sized planetesimals, and their debris released in a collisional cascade, are under their mutual gravitational influence, which may result into non-axisymmetric structures in the debris disk. Aims: High angular resolution observations are required to investigate these effects and constrain the dynamical evolution of debris disks. Furthermore, multi-wavelength observations can provide information about the dust dynamics by probing different grain sizes. Methods: Here we present new VLT/SPHERE and ALMA observations of the debris disk around the 40 Myr-old solar-type star HD 61005. We resolve the disk at unprecedented resolution both in the near-infrared (in scattered and polarized light) and at millimeter wavelengths. We perform a detailed modeling of these observations, including the spectral energy distribution. Results: Thanks to the new observations, we propose a solution for both the radial and azimuthal distribution of the dust grains in the debris disk. We find that the disk has a moderate eccentricity (e ~ 0.1) and that the dust density is two times larger at the pericenter compared to the apocenter. Conclusions: With no giant planets detected in our observations, we investigate alternative explanations besides planet-disk interactions to interpret the inferred disk morphology. We postulate that the morphology of the disk could be the consequence of a massive collision between ~1000 km-sized bodies at ~61 au. If this interpretation holds, it would put stringent constraints on the formation of massive planetesimals at large distances from the star. Based on observations

  11. SILICATE DUST SIZE DISTRIBUTION FROM HYPERVELOCITY COLLISIONS: IMPLICATIONS FOR DUST PRODUCTION IN DEBRIS DISKS

    SciTech Connect

    Takasawa, S.; Nakamura, A. M.; Arakawa, M.; Seto, Y.; Sangen, K.; Setoh, M.; Machii, N.; Kadono, T.; Shigemori, K.; Hironaka, Y.; Fujioka, S.; Sano, T.; Watari, T.; Dohi, K.; Ohno, S.; Maeda, M.; Sakaiya, T.; Otani, K.; Takeuchi, T.

    2011-06-01

    Fragments generated by high-velocity collisions between solid planetary bodies are one of the main sources of new interplanetary dust particles. However, only limited ranges of collision velocity, ejecta size, and target materials have been studied in previous laboratory experiments, and the collision condition that enables the production of dust-sized particles remains unclear. We conducted hypervelocity impact experiments on silicate rocks at relative velocities of 9 to 61 km s{sup -1}, which is beyond the upper limit of previous laboratory studies. Sub-millimeter-diameter aluminum and gold spheres were accelerated by laser ablation and were shot into dunite and basalt targets. We analyzed the surfaces of aerogel blocks deployed near the targets using an electron probe micro analyzer and counted the number of particles that contained the target material. The size distributions of ejecta ranged from five to tens of microns in diameter. The total cross-sectional area of dust-sized ejecta monotonically increased with the projectile kinetic energy, independent of impact velocity, projectile diameter, and projectile and target material compositions. The slopes of the cumulative ejecta-size distributions ranged from -2 to -5. Most of the slopes were steeper than the -2.5 or -2.7 that is expected for a collisional equilibrium distribution in a collision cascade with mass-independent or mass-dependent catastrophic disruption thresholds, respectively. This suggests that the steep dust size-distribution proposed for the debris disk around HD172555 (an A5V star) could be due to a hypervelocity collision.

  12. Energy deposited in the high luminosity inner triplets of the LHC by collision debris

    SciTech Connect

    Wildner, E.; Broggi, F.; Cerutti, F.; Ferrari, A.; Hoa, C.; Koutchouk, J.-P.; Mokhov, N.V.; /Fermilab

    2008-06-01

    The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this contribution to the heat, that has to be transported by the cryogenic system, have been made to guarantee that the energy deposition in the superconducting magnets does not exceed limits for magnet quenching and the capacity of the cryogenic system. The models of the LHC base-line are detailed and include description of, for energy deposition, essential elements like beam-pipes and corrector magnets. The evaluations made using the Monte-Carlo code FLUKA are compared to previous studies using MARS. For the consolidation of the calculations, a dedicated comparative study of these two codes was performed for a reduced setup.

  13. An Upper Bound on Orbital Debris Collision Probability When Only One Object has Position Uncertainty Information

    NASA Technical Reports Server (NTRS)

    Frisbee, Joseph H., Jr.

    2015-01-01

    no good because the analyst defaults to no knowledge of the combined, relative position error covariance matrix. It is reasonable to think, given an assumption of no covariance information, an analyst might still attempt to determine the error covariance matrix that results in an upper bound on the P (sub c). Without some guidance on limits to the shape, size and orientation of the unknown covariance matrix, the limiting case is a degenerate ellipse lying along the relative miss vector in the collision plane. Unless the miss position is exceptionally large or the at-risk object is exceptionally small, this method results in a maximum P (sub c) too large to be of practical use. For example, assuming that the miss distance is equal to the current ISS alert volume along-track (+ or -) distance of 25 kilometers and that the at-risk area has a 70 meter radius. The maximum (degenerate ellipse) P (sub c) is about 0.00136. At 40 kilometers, the maximum P (sub c) would be 0.00085 which is still almost an order of magnitude larger than the ISS maneuver threshold of 0.0001. In fact, a miss distance of almost 340 kilometers is necessary to reduce the maximum P (sub c) associated with this degenerate ellipse to the ISS maneuver threshold value. Such a result is frequently of no practical value to the analyst. Some improvement may be made with respect to this problem by realizing that while the position error covariance matrix of one of the objects (usually the debris object) may not be known the position error covariance matrix of the other object (usually the asset) is almost always available. Making use of the position error covariance information for the one object provides an improvement in finding a maximum P (sub c) which, in some cases, may offer real utility. The equations to be used are presented and their use discussed.

  14. Capture of dusts from hypervelocity collision of planetary materials: Implication for dust size distribution in debris discs

    NASA Astrophysics Data System (ADS)

    Takasawa, Susumu; Nakamura, Akiko; Kadono, Toshihiko; Arakawa, Masahiko; Dohi, Hirotsugu; Seto, Yusuke; Maeda, Makoto; Shigemori, Keisuke; Hironaka, Yoichiro; Sakaiya, Tatsuhiro; Sano, Takayoshi; Watari, Takeshi; Fujioka, Shinsuke; Ohno, Sohsuke; Takeuchi, Taku; Sangen, Kazuyoshi

    2011-06-01

    In order to examine the size distribution of dust particles from collision of solid bodies, we conducted hypervelocity impact experiments. Sub-mm size metal spheres were accelerated to velocities from 9 to 61 km/s by laser ablation and were shot into rock targets. Dust particles were collected by aerogels and were analyzed by Electron Probe Micro Analyzer (EPMA). We derived the size distributions of ejecta ranging from five to tens of micron in diameter. The slope of cumulative ejecta size distribution was steeper than a purely collisional equilibrium distribution in a collision cascade. This suggests that a steep dust size distribution in a debris disc around an A5V star HD172555 can be due to a hypervelocity impact.

  15. LightForce photon-pressure collision avoidance: Efficiency analysis in the current debris environment and long-term simulation perspective

    NASA Astrophysics Data System (ADS)

    Yang Yang, Fan; Nelson, Bron; Aziz, Jonathan; Carlino, Roberto; Dono Perez, Andres; Faber, Nicolas; Foster, Cyrus; Frost, Chad; Henze, Chris; Karacalıoğlu, Arif Göktuğ; Levit, Creon; Marshall, William; Mason, James; O'Toole, Conor; Swenson, Jason; Worden, Simon P.; Stupl, Jan

    2016-09-01

    This work provides an efficiency analysis of the LightForce space debris collision avoidance scheme in the current debris environment and describes a simulation approach to assess its impact on the long-term evolution of the space debris environment. LightForce aims to provide just-in-time collision avoidance by utilizing photon pressure from ground-based industrial lasers. These ground stations impart minimal accelerations to increase the miss distance for a predicted conjunction between two objects. In the first part of this paper we will present research that investigates the short-term effect of a few systems consisting of 20 kW class lasers directed by 1.5 m diameter telescopes using adaptive optics. The results found such a network of ground stations to mitigate more than 85 percent of conjunctions and could lower the expected number of collisions in Low Earth Orbit (LEO) by an order of magnitude. While these are impressive numbers that indicate LightForce's utility in the short-term, the remaining 15 % of possible collisions contain (among others) conjunctions between two massive objects that would add large amount of debris if they collide. Still, conjunctions between massive objects and smaller objects can be mitigated. Hence, we choose to expand the capabilities of the simulation software to investigate the overall effect of a network of LightForce stations on the long-term debris evolution. In the second part of this paper, we will present the planned simulation approach for that effort. For the efficiency analysis of collision avoidance in the current debris environment, we utilize a simulation approach that uses the entire Two Line Element (TLE) catalog in LEO for a given day as initial input. These objects are propagated for one year and an all-on-all conjunction analysis is performed. For conjunctions that fall below a range threshold, we calculate the probability of collision and record those values. To assess efficiency, we compare a baseline

  16. Revealing Asymmetries in the HD 181327 Debris Disk: A Recent Massive Collision or Interstellar Medium Warping

    NASA Astrophysics Data System (ADS)

    Stark, Christopher C.; Schneider, Glenn; Weinberger, Alycia J.; Debes, John H.; Grady, Carol A.; Jang-Condell, Hannah; Kuchner, Marc J.

    2014-07-01

    New multi-roll coronagraphic images of the HD 181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain. We detect large scale asymmetries in the disk, consistent with either the recent catastrophic disruption of a body with mass >1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.

  17. Revealing asymmetries in the HD 181327 debris disk: A recent massive collision or interstellar medium warping

    SciTech Connect

    Stark, Christopher C.; Kuchner, Marc J.; Schneider, Glenn; Weinberger, Alycia J.; Debes, John H.; Grady, Carol A.; Jang-Condell, Hannah

    2014-07-01

    New multi-roll coronagraphic images of the HD 181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain. We detect large scale asymmetries in the disk, consistent with either the recent catastrophic disruption of a body with mass >1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.

  18. Revealing Asymmetries in the HD181327 Debris Disk: A Recent Massive Collision or Interstellar Medium Warping

    NASA Technical Reports Server (NTRS)

    Stark, Christopher C.; Schneider, Glenn; Weinberger, Alycia J.; Debes, John H.; Grady, Carol A.; Jang-Condell, Hannah; Kuchner, Marc J.

    2014-01-01

    New multi-roll coronagraphic images of the HD181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/ deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain.We detect large scale asymmetries in the disk, consistent with either the recent catastrophic disruption of a body with mass greater than 1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.

  19. Detection of Orbital Debris Collision Risks for the Automated Transfer Vehicle

    NASA Technical Reports Server (NTRS)

    Peret, L.; Legendre, P.; Delavault, S.; Martin, T.

    2007-01-01

    In this paper, we present a general collision risk assessment method, which has been applied through numerical simulations to the Automated Transfer Vehicle (ATV) case. During ATV ascent towards the International Space Station, close approaches between the ATV and objects of the USSTRACOM catalog will be monitored through collision rosk assessment. Usually, collision risk assessment relies on an exclusion volume or a probability threshold method. Probability methods are more effective than exclusion volumes but require accurate covariance data. In this work, we propose to use a criterion defined by an adaptive exclusion area. This criterion does not require any probability calculation but is more effective than exclusion volume methods as demonstrated by our numerical experiments. The results of these studies, when confirmed and finalized, will be used for the ATV operations.

  20. LightForce Photon-pressure Collision Avoidance: Efficiency Analysis in the Current Debris Environment and Long-Term Simulation Perspective

    NASA Technical Reports Server (NTRS)

    Yang, Fan Y.; Nelson, Bron; Carlino, Roberto; Perez, Andres D.; Faber, Nicolas; Henze, Chris; Karacahoglu, Arif G.; O'Toole, Conor; Swenson, Jason; Stupl, Jan

    2015-01-01

    This work provides an efficiency analysis of the LightForce space debris collision avoidance scheme in the current debris environment and describes a simulation approach to assess its impact on the long-term evolution of the space debris environment. LightForce aims to provide just-in-time collision avoidance by utilizing photon pressure from ground-based industrial lasers. These ground stations impart minimal accelerations to increase the miss distance for a predicted conjunction between two objects. In the first part of this paper we will present research that investigates the short-term effect of a few systems consisting of 10kW class lasers directed by 1.5 m diameter telescopes using adaptive optics. The results found such a network of ground stations to mitigate more than 85 percent of conjunctions and could lower the expected number of collisions in Low Earth Orbit (LEO) by an order of magnitude. While these are impressive numbers that indicate LightForce's utility in the short-term, the remaining 15 percent of possible collisions contain (among others) conjunctions between two massive objects that would add large amount of debris if they collide. Still, conjunctions between massive objects and smaller objects can be mitigated. Hence we choose to expand the capabilities of the simulation software to investigate the overall effect of a network of LightForce stations on the long-term debris evolution. In the second part of this paper, we will present the planed simulation approach for that effort.

  1. Spectroscopic Measurements of Collision-less Coupling Between Laser-Produced, Super-Alfvénic Debris Plasmas and Magnetized, Ambient Plasmas

    NASA Astrophysics Data System (ADS)

    Bondarenko, Anton; Everson, E.; Schaeffer, D.; Constantin, C.; Vincena, S.; Van Compernolle, B.; Clark, S.; Niemann, C.

    2013-06-01

    Emission spectroscopy is currently being utilized in order to assess collision-less momentum and energy coupling between super-Alfvénic debris plasmas and magnetized, ambient plasmas of astrophysical relevance. In a recent campaign on the Large Plasma Device (LAPD) utilizing the Phoenix laboratory Raptor laser (130 J, 25 ns FWHM), laser-ablated carbon debris plasmas were generated within magnetized, ambient helium plasmas (nelec ≈ 3×1012 cm-3, Telec ≈ 5.5 eV, B0 = 200 G), and prominent spectral lines of carbon and helium ions were studied in high resolution (˜ 0.01 nm). Time-resolved Doppler shift and width measurements of a C V ion spectral line reveal significant deceleration as the ions stream through the background plasma, which may indirectly indicate momentum coupling. Spectral lines of He II ions are observed to intensify by orders of magnitude and broaden, indicating energy transfer from the debris plasma to the background plasma.

  2. A Summary of the NASA ISS Space Debris Collision Avoidance Program

    NASA Technical Reports Server (NTRS)

    Frisbee, Joseph

    2002-01-01

    Creating and implementing a process for the mitigation of the impact hazards due to cornets and asteroids will prove to be a complex and involved process. The closest similar program is the collision avoidance process currently used for protection of the International Space Station (ISS). This process, in operation for over three years, has many similarities to the NEG risk problem. By reviewing the ISS program, a broader perspective on the complications of and requirements for a NEO risk mitigation program might be obtained. Specifically, any lessons learned and continuing issues of concern might prove useful in the development of a NEO risk assessment and mitigation program.

  3. Benefits of Active Debris Removal on the LEO Debris Population

    NASA Astrophysics Data System (ADS)

    Maniwa, Kazuaki; Hanada, Toshiya; Kawamoto, Satomi

    Since the launch of Sputnik, orbital debris population continues to increase due to ongoing space activities, on-orbit explosions, and accidental collisions. In the future, a great deal of fragments can be expected to be created by explosions and collisions. In spite of prevention of satellite and rocket upper stage explosions and other mitigation measures, debris population in low Earth orbit may not be stabilized. To better limit the growth of the future debris population, it is necessary to remove the existing debris actively. This paper studies about the effectiveness of active debris removal in low Earth orbit where the collision rate with and between space debris is high. This study does not consider economic problems, but investigates removing debris which may stabilize well the current debris population based on the concept of Japan Aerospace Exploration Agency.

  4. Orbital Debris Modeling

    NASA Technical Reports Server (NTRS)

    Liou, J. C.

    2012-01-01

    Presentation outlne: (1) The NASA Orbital Debris (OD) Engineering Model -- A mathematical model capable of predicting OD impact risks for the ISS and other critical space assets (2) The NASA OD Evolutionary Model -- A physical model capable of predicting future debris environment based on user-specified scenarios (3) The NASA Standard Satellite Breakup Model -- A model describing the outcome of a satellite breakup (explosion or collision)

  5. Orbital Debris: A Policy Perspective

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2007-01-01

    A viewgraph presentation describing orbital debris from a policy perspective is shown. The contents include: 1) Voyage through near-Earth Space-animation; 2) What is Orbital Debris?; 3) Orbital Debris Detectors and Damage Potential; 4) Hubble Space Telescope; 5) Mir Space Station Solar Array; 6) International Space Station; 7) Space Shuttle; 8) Satellite Explosions; 9) Satellite Collisions; 10) NASA Orbital Debris Mitigation Guidelines; 11) International Space Station Jettison Policy; 12) Controlled/Uncontrolled Satellite Reentries; 13) Return of Space Objects; 14) Orbital Debris and U.S. National Space Policy; 15) U.S Government Policy Strategy; 16) Bankruptcy of the Iridium Satellite System; 17) Inter-Agency Space Debris Coordination Committee (IADC); 18) Orbital Debris at the United Nations; 19) Chinese Anti-satellite System; 20) Future Evolution of Satellite Population; and 21) Challenge of Orbital Debris

  6. Comparing Two Different Methods to Evaluate Convariance-Matrix of Debris Orbit State in Collision Probability Estimation

    NASA Astrophysics Data System (ADS)

    Cheng, Haowen; Liu, Jing; Xu, Yang

    The evaluation of convariance-matrix is an inevitable step when estimating collision probability based on the theory. Generally, there are two different methods to compute convariance-matrix. One is so-called Tracking-Delta-Fitting method, first introduced when estimating the collision probability using TLE catalogue data, in which convariance-matrix is evaluated by fitting series of differences between propagated orbits of formal data and updated orbit data. In the second method, convariance-matrix is evaluated in the process of orbit determination. Both of the methods has there difficulties when introduced in collision probability estimation. In the first method, the value of convariance-matrix is evaluated based only on historical orbit data, ignoring information of latest orbit determination. As a result, the accuracy of the method strongly depends on the stability of convariance-matrix of latest updated orbit. In the second method, the evaluation of convariance-matrix is acceptable when the determined orbit satisfies weighted-least-square estimation, depending on the accuracy of observation error convariance, which is hard to obtain in real application, evaluated by analyzing the residuals of orbit determination in our research. In this paper we provided numerical tests to compare these two methods. A simulation of cataloguing objects in LEO, MEO and GEO regions has been carried out for a time span of 3 months. The influence of orbit maneuver has been included in GEO objects cataloguing simulation. For LEO objects cataloguing, the effect of atmospheric density variation has also been considered. At the end of the paper accuracies of evaluated convariance-matrix and estimated collision probability have been tested and compared.

  7. MEO Debris Environment Projection Study

    NASA Astrophysics Data System (ADS)

    Jenkin, Alan B.; Sorge, Marlon E.; McVey, John P.; Peterson, Glenn E.; Yoo, Bernard Y.

    2013-08-01

    The recently developed Aerospace Debris Environment Projection Tool was used to project the future debris environment in medium Earth orbit (MEO) over the next 200 years. The entire Earth orbital population was modeled to account for the possibility of cross-coupling between the MEO population and the low Earth orbit (LEO) and geosynchronous populations via objects on highly eccentric orbits that transit through MEO. It was found that a large fraction of the MEO debris originated from collisions in LEO involving satellites and rocket bodies that transit through LEO and MEO. Results showed that world-wide compliance with orbit lifetime reduction will significantly reduce the amount of debris in MEO.

  8. SPECS: Orbital debris removal

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The debris problem has reached a stage at which the risk to satellites and spacecraft has become substantial in low Earth orbit (LEO). This research discovered that small particles posed little threat to spacecraft because shielding can effectively prevent these particles from damaging the spacecraft. The research also showed that, even though collision with a large piece of debris could destroy the spacecraft, the large pieces of debris pose little danger because they can be tracked and the spacecraft can be maneuvered away from these pieces. Additionally, there are many current designs to capture and remove large debris particles from the space environment. From this analysis, it was decided to concentrate on the removal of medium-sized orbital debris, that is, those pieces ranging from 1 cm to 50 cm in size. The current design incorporates a transfer vehicle and a netting vehicle to capture the medium-sized debris. The system is based near an operational space station located at 28.5 deg inclination and 400 km altitude. The system uses ground-based tracking to determine the location of a satellite breakup or debris cloud. These data are uploaded to the transfer vehicle, which proceeds to rendezvous with the debris at a lower altitude parking orbit. Next, the netting vehicle is deployed, tracks the targeted debris, and captures it. After expending the available nets, the netting vehicle returns to the transfer vehicle for a new netting module and continues to capture more debris in the target area. Once all the netting modules are expended, the transfer vehicle returns to the space station's orbit where it is resupplied with new netting modules from a space shuttle load. The new modules are launched by the shuttle from the ground and the expended modules are taken back to Earth for removal of the captured debris, refueling, and repacking of the nets. Once the netting modules are refurbished, they are taken back into orbit for reuse. In a typical mission, the

  9. Rates inferred from the space debris catalog

    SciTech Connect

    Canavan, G.H.

    1996-08-01

    Collision and fragmentation rates are inferred from the AFSPC space debris catalog and compare with estimates from other treatments. The collision rate is evaluated without approximation. The fragmentation rate requires additional empirical assessments. The number of fragments per collision is low compared to analytic and numerical treatments, is peaked low, and falls rapidly with altitude.

  10. Recognizing Patterns in Debris Disks

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2009-01-01

    An extrasolar planet sculpts the famous debris dish around Fomalhaut; probably many other debris disks contain planets that we could locate if only we could better recognize their signatures in the dust that surrounds them. I will describe the latest 3-D models of debris dish dynamics / models that include planets, grain-grain collisions and even ISM-disk interactions. I will show why all these ingredients are needed to explain disk images--and what the images are telling us about planet formation.

  11. Uncertainties in debris growth predictions

    SciTech Connect

    McKnight, D.S. )

    1991-01-10

    The growth of artificial space debris in Earth orbit may pose a significant hazard to satellites in the future though the collision hazard to operational spacecraft is presently manageable. The stability of the environment is dependent on the growth of debris from satellite deployment, mission operations and fragmentation events. Growth trends of the trackable on-orbit population are investigated highlighting the complexities and limitations of using the data that supports this modeling. The debris produced by breakup events may be a critical aspect of the present and future environment. As a result, growth predictions produced using existing empirically-based models may have large, possibly even unacceptable, uncertainties.

  12. An Introduction to Space Debris

    NASA Astrophysics Data System (ADS)

    Wright, David

    2008-04-01

    Space debris is any human-made object in orbit that no longer serves a useful purpose, including defunct satellites, discarded equipment and rocket stages, and fragments from the breakup of satellites and rocket stages. It is a concern because--due to its very high speed in orbit--even relatively small pieces can damage or destroy satellites in a collision. Since debris at high altitudes can stay in orbit for decades or longer, it accumulates as more is produced and the risk of collisions with satellites grows. Since there is currently no effective way to remove large amounts of debris from orbit, controlling the production of debris is essential for preserving the long-term use of space. Today there are 860 active satellites in orbit, supporting a wide range of civil and military uses. The 50 years of space activity since the launch of Sputnik 1 has also resulted in well over half a million pieces of orbiting debris larger than 1 cm in size. There are two main sources of space debris: (1) routine space activity and the accidental breakup of satellites and stages placed in orbit by such activity, and (2) the testing or use of destructive anti-satellite (ASAT) weapons that physically collide with satellites at high speed. The international community is attempting to reduce the first category by developing strict guidelines to limit the debris created as a result of routine space activities. However, the destruction of a single large spy satellite by an ASAT weapon could double the total amount of large debris in low earth orbit, and there are currently no international restrictions on these systems. This talk will give an introduction to what's in space, the origins of space debris, efforts to stem its growth, the threat it poses to satellites in orbit, and the long-term evolution of the debris population.

  13. An Assessment of the Current LEO Debris Environment and the Need for Active Debris Removal

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi

    2010-01-01

    The anti-satellite test on the Fengun-1 C weather satellite in early 2007 and the collision between Iridium 33 and Cosmos 2251 in 2009 dramatically altered the landscape of the human-made orbital debris environment in the low Earth orbit (LEO). The two events generated approximately 5500 fragments large enough to be tracked by the U.S. Space Surveillance Network. Those fragments account for more than 60% increase to the debris population in LEO. However, even before the ASAT test, model analyses already indicated that the debris population (for those larger than 10 cm) in LEO had reached a point where the population would continue to increase, due to collisions among existing objects, even without any future launches. The conclusion implies that as satellites continue to be launched and unexpected breakup events continue to occur, commonly-adopted mitigation measures will not be able to stop the collision-driven population growth. To remediate the debris environment in LEO, active debris removal must be considered. This presentation will provide an updated assessment of the debris environment after the Iridium 33/Cosmos 2251 collision, an analysis of several future environment projections based on different scenarios, and a projection of collision activities in LEO in the near future. The need to use active debris removal to stabilize future debris environment will be demonstrated and the effectiveness of various active debris removal strategies will be quantified.

  14. Space Debris & its Mitigation

    NASA Astrophysics Data System (ADS)

    Kaushal, Sourabh; Arora, Nishant

    2012-07-01

    Space debris has become a growing concern in recent years, since collisions at orbital velocities can be highly damaging to functioning satellites and can also produce even more space debris in the process. Some spacecraft, like the International Space Station, are now armored to deal with this hazard but armor and mitigation measures can be prohibitively costly when trying to protect satellites or human spaceflight vehicles like the shuttle. This paper describes the current orbital debris environment, outline its main sources, and identify mitigation measures to reduce orbital debris growth by controlling these sources. We studied the literature on the topic Space Debris. We have proposed some methods to solve this problem of space debris. We have also highlighted the shortcomings of already proposed methods by space experts and we have proposed some modification in those methods. Some of them can be very effective in the process of mitigation of space debris, but some of them need some modification. Recently proposed methods by space experts are maneuver, shielding of space elevator with the foil, vaporizing or redirecting of space debris back to earth with the help of laser, use of aerogel as a protective layer, construction of large junkyards around international space station, use of electrodynamics tether & the latest method proposed is the use of nano satellites in the clearing of the space debris. Limitations of the already proposed methods are as follows: - Maneuvering can't be the final solution to our problem as it is the act of self-defence. - Shielding can't be done on the parts like solar panels and optical devices. - Vaporizing or redirecting of space debris can affect the human life on earth if it is not done in proper manner. - Aerogel has a threshold limit up to which it can bear (resist) the impact of collision. - Large junkyards can be effective only for large sized debris. In this paper we propose: A. The Use of Nano Tubes by creating a mesh

  15. Orbital Debris

    NASA Technical Reports Server (NTRS)

    Kessler, D. J. (Compiler); Su, S. Y. (Compiler)

    1985-01-01

    Earth orbital debris issues and recommended future activities are discussed. The workshop addressed the areas of environment definition, hazards to spacecraft, and space object management. It concluded that orbital debris is a potential problem for future space operations. However, before recommending any major efforts to control the environment, more data are required. The most significant required data are on the population of debris smaller than 4 cm in diameter. New damage criteria are also required. When these data are obtained, they can be combined with hypervelocity data to evaluate the hazards to future spacecraft. After these hazards are understood, then techniques to control the environment can be evaluated.

  16. Behavior of tethered debris with flexible appendages

    NASA Astrophysics Data System (ADS)

    Aslanov, Vladimir S.; Yudintsev, Vadim V.

    2014-11-01

    Active exploration of the space leads to growth of a near-Earth space pollution. The frequency of the registered collisions of space debris with functional satellites highly increased during last 10 years. As a rule a large space debris can be observed from the Earth and catalogued, then it is possible to avoid collision with the active spacecraft. However every large debris is a potential source of a numerous small debris particles. To reduce debris population in the near Earth space the large debris should be removed from working orbits. The active debris removal technique is considered that intend to use a tethered orbital transfer vehicle, or a space tug attached by a tether to the space debris. This paper focuses on the dynamics of the space debris with flexible appendages. Mathematical model of the system is derived using the Lagrange formalism. Several numerical examples are presented to illustrate the mutual influence of the oscillations of flexible appendages and the oscillations of a tether. It is shown that flexible appendages can have a significant influence on the attitude motion of the space debris and the safety of the transportation process.

  17. Reduction of CO2 and orbital debris: can CO2 emission trading principles be applied to debris reduction?

    NASA Astrophysics Data System (ADS)

    Orlando, Giovanni; Kinnersley, Mark; Starke, Juergen; Hugel, Sebastian; Hartner, Gloria; Singh, Sanjay; Loubiere, Vincent; Staebler, Dominik-Markus; O'Brien-Organ, Christopher; Schwindt, Stefan; Serreau, Francois; Sharma, Mohit

    In the past years global pollution and the specific situation of global warming changes have been strongly influencing public opinion and thus obliged politicians to initiate/ negotiate in-ternational agreements to control, avoid or at least reduce the impact of CO2 emissions e.g. The Kyoto Protocol (1997) and the International Copenhagen conference on Climate Change (2009). In the orbital debris area the collision between the Iridium33 and Cosmos 2251 satel-lites in 2009 has again pushed to the forefront the discussion of the space pollution by space debris and the increasing risk of critical and catastrophic events during the nominal life time of space objects. It is shown by simulations that for Low Earth Orbits the critical debris situation is already achieved and the existing space objects will probably produce sufficient space debris elements -big enough -to support the cascade effect (Kessler Syndrome). In anal-ogy with CO2 emissions, potential recommendations / regulations to reduce the production of Space Debris or its permanence in orbit, are likely to open new markets involving Miti-gation and Removal of Space Debris. The principle approach for the CO2 emission trading model will be investigated and the applicability for the global space debris handling will be analysed. The major differences of the two markets will be derived and the consequences in-dicated. Potential alternative solutions will be proposed and discussed. For the example of the CO2 emission trading principles within EU and worldwide legal conditions for space debris (national / international laws and recommendations) will be considered as well as the commer-cial approach from the controlled situation of dedicated orders to a free / competitive market in steps. It is of interest to consider forms of potential industrial organisations and interna-tional co-operations to react on a similar architecture for the debris removal trading including incentives and penalties for the different

  18. Reading the Signatures of Extrasolar Planets in Debris Disks

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc J.

    2009-01-01

    An extrasolar planet sculpts the famous debris dish around Fomalhaut; probably ma ny other debris disks contain planets that we could locate if only we could better recognize their signatures in the dust that surrounds them. But the interaction between planets and debris disks involves both orbital resonances and collisions among grains and rocks in the disks --- difficult processes to model simultanemus]y. I will describe new 3-D models of debris disk dynamics that incorporate both collisions and resonant trapping of dust for the first time, allowing us to decode debris disk images and read the signatures of the planets they contain.

  19. Space Debris Environment Remediation Concepts

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.; Klinkrad, Heiner

    2009-01-01

    Long-term projections of the space debris environment indicate that even drastic measures, such as an immediate, complete halt of launch and release activities, will not result in a stable environment of man-made space objects. Collision events between already existing space hardware will within a few decades start to dominate the debris population, and result in a net increase of the space debris population, also in size regimes which may cause further catastrophic collisions. Such a collisional cascading will ultimately lead to a run-away situation ("Kessler syndrome"), with no further possibility of human intervention. The International Academy of Astronautics (IAA) has been investigating the status and the stability of the space debris environment in several studies by first looking into space traffic management possibilities and then investigating means of mitigating the creation of space debris. In an ongoing activity, an IAA study group looks at ways of active space debris environment remediation. In contrast to the former mitigation study, the current activity concentrates on the active removal of small and large objects, such as defunct spacecraft, orbital stages, and mission-related objects, which serve as a latent mass reservoir that fuels initial catastrophic collisions and later collisional cascading. The paper will outline different mass removal concepts, e.g. based on directed energy, tethers (momentum exchange or electrodynamic), aerodynamic drag augmentation, solar sails, auxiliary propulsion units, retarding surfaces, or on-orbit capture. Apart from physical principles of the proposed concepts, their applicability to different orbital regimes, and their effectiveness concerning mass removal efficiency will be analyzed. The IAA activity on space debris environment remediation is a truly international project which involves more than 23 contributing authors from 9 different nations.

  20. NASA Orbital Debris Baseline Populations

    NASA Technical Reports Server (NTRS)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  1. Nuclear-powered space debris sweeper

    NASA Technical Reports Server (NTRS)

    Metzger, John D.; Leclaire, Rene J., Jr.; Howe, Steven D.; Burgin, Karen C.

    1989-01-01

    Future spacecraft design will be affected by collisions with man-made debris orbiting the earth. Most of this orbital space debris comes from spent rocket stages. It is projected that the source of future debris will be the result of fragmentation of large objects through hypervelocity collisions. Orbiting spacecraft will have to be protected from hypervelocity debris in orbit. The options are to armor the spacecraft, resulting in increased mass, or actively removing the debris from orbit. An active space debris sweeper is described which will utilize momentum transfer to the debris through laser-induced ablation to alter its orbital parameters to reduce orbital lifetime with eventual entry into the earth's atmosphere where it will burn. The paper describes the concept, estimates the amount of velocity change (Delta V) that can be imparted to an object through laser-induced ablation, and investigates the use of a neutral particle beam for the momentum transfer. The space sweeper concept could also be extended to provide a collision avoidance system for the space station and satellites, or could be used for collision protection during interplanetary travel.

  2. Orbital debris from upper-stage breakup

    NASA Technical Reports Server (NTRS)

    Loftus, Joseph P., Jr. (Editor)

    1989-01-01

    The present conference on the effects of launch vehicle upper-stage breakup on the orbital debris scenario discusses an analysis of the SPOT 1 Ariane third stage, the explosive fragmentation of orbiting propellant tanks, albedo estimates for debris, Ariane-related debris in deep-space orbit, and the relationship of hypervelocity impacts to upper-stage breakups. Also discussed are the prospects for and the economics of the future removal of orbital debris, collision probabilities in GEO, current operational practices for Delta second stage breakup prevention, breakup-precluding modifications to the Ariane third stage, and the safing of the H-1 second stage after spacecraft separation.

  3. Orbiting Debris: a Space Environmental Problem. Background Paper

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Artificial debris, deposited in a multitude of orbits about the Earth as the result of the exploration and use of the space environment, poses a growing hazard to future space operations. Unless nations sharply reduce the amount of orbital debris they produce, future space activites could suffer loss of capability, loss of income, and even loss of life as a result of collisions between spacecraft and debris. This background paper discusses the sources of debris and how they can be greatly reduced.

  4. The Orbital Debris Problem and the Challenges for Environment Remediation

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.

    2013-01-01

    Orbital debris scientists from major international space agencies, including JAXA and NASA, have worked together to predict the trend of the future environment. A summary presentation was given to the United Nations in February 2013. The orbital debris population in LEO will continue to increase. Catastrophic collisions will continue to occur every 5 to 9 years center dot To limit the growth of the future debris population and to better protect future spacecraft, active debris removal, should be considered.

  5. Space Debris Environent Remediation Concepts

    NASA Astrophysics Data System (ADS)

    Klinkrad, H.; Johnson, N. L.

    2009-03-01

    Long-term projections of the space debris environment indicate that even drastic measures, such as an immediate, complete halt of launch and release activities, will not result in a stable environment of man-made space objects. Collision events between already existing space hardware will within a few decades start to dominate the debris population, and result in a net increase of the space debris population, also at sizes which may cause further catastrophic collisions. A collisional cascading may ultimately lead to a run-away situation ("Kessler syndrome"), with no further possibility of human intervention.The International Academy of Astronautics (IAA) has been investigating the status and the stability of the space debris environment in several studies by first looking into space traffic management possibilities, and then investigating means of mitigating the creation of space debris. In an on-going activity, an IAA study group looks into methods of active space debris environment remediation. In contrast to the former mitigation study, the current activity concentrates on the active removal of large objects, such as defunct spacecraft, orbital stages, and mission-related objects, which serve as a latent mass reservoir that fuels initial castastrophic collisions and later collisional cascading. The paper will outline different mass removal concepts, e.g. based on directed energy, tethers (momentum exchange or electro-dynamic), aerodynamic drag augmentation, solar sails, auxiliary propulsion units, retarding surfaces, or on-orbit capture. Apart from physical principles of the proposed concepts, their applicability to different orbital regimes, and their effectiveness concerning mass removal efficiency will be discussed.

  6. Orbital debris: Technical issues and future directions

    NASA Technical Reports Server (NTRS)

    Potter, Andrew (Editor)

    1992-01-01

    An international conference on orbital debris sponsored jointly by the American Institute of Aeronautics and Astronautics, NASA, and the Department of Defense, was held in Baltimore, Maryland, 16-19 Apr. 1990. Thirty-three papers were presented. The papers were grouped into the areas of measurements, modeling, and implications of orbital debris for space flight. New radar and optical measurements of orbital debris were presented that showed the existence of a large population of small debris. Modeling of potential future environments showed that runaway growth of the debris population from random collisions was a real possibility. New techniques for shielding against orbital debris and methods for removal of satellites from orbit were discussed.

  7. Space debris executive summary

    SciTech Connect

    Canavan, G.H.; Judd, O.; Naka, R.F.

    1996-09-01

    Spacecraft, boosters, and fragments are potential hazards to space vehicles, and it is argued that collisions between them could produce a cascade that could preclude activity in LEO in 25 to 50 years. That has generated pressure for constraints on military space operations, so the AF SAB performed a study of technical aspects of the debris problem. The Study was independent of the efforts of the Air Force Space Command (AFSPC) as well as those of and NASA Johnson Space Center (JSC), which is the principal advocate for cascades and constraints. Most work on space debris has been performed by AFSPC and JSC, so the Study was in part an assessment of their efforts, in which both have been cooperative. The Study identified the main disagreements and quantified their impacts. It resolved some issues and provided bounds for the rest. It treated radar and optical observations; launch, explosion, and decay rates; and the number and distribution of fragments from explosions and collisions. That made it possible to address hazard to manned spacecraft at low altitudes and the possibility of cascading at higher altitudes, both of which now appear less likely.

  8. The physics of debris flows

    USGS Publications Warehouse

    Iverson, R.M.

    1997-01-01

    Recent advances in theory and experimentation motivate a thorough reassessment of the physics of debris flows. Analyses of flows of dry, granular solids and solid-fluid mixtures provide a foundation for a comprehensive debris flow theory, and experiments provide data that reveal the strengths and limitations of theoretical models. Both debris flow materials and dry granular materials can sustain shear stresses while remaining static; both can deform in a slow, tranquil mode characterized by enduring, frictional grain contacts; and both can flow in a more rapid, agitated mode characterized by brief, inelastic grain collisions. In debris flows, however, pore fluid that is highly viscous and nearly incompressible, composed of water with suspended silt and clay, can strongly mediate intergranular friction and collisions. Grain friction, grain collisions, and viscous fluid flow may transfer significant momentum simultaneously. Both the vibrational kinetic energy of solid grains (measured by a quantity termed the granular temperature) and the pressure of the intervening pore fluid facilitate motion of grains past one another, thereby enhancing debris flow mobility. Granular temperature arises from conversion of flow translational energy to grain vibrational energy, a process that depends on shear rates, grain properties, boundary conditions, and the ambient fluid viscosity and pressure. Pore fluid pressures that exceed static equilibrium pressures result from local or global debris contraction. Like larger, natural debris flows, experimental debris flows of ???10 m3 of poorly sorted, water-saturated sediment invariably move as an unsteady surge or series of surges. Measurements at the base of experimental flows show that coarse-grained surge fronts have little or no pore fluid pressure. In contrast, finer-grained, thoroughly saturated debris behind surge fronts is nearly liquefied by high pore pressure, which persists owing to the great compressibility and moderate

  9. NASA's Long-term Debris Environment and Active Debris Removal Modeling Activities

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.

    2009-01-01

    This slide presentation reviews the modeling activities for modeling of the long-term debris environment, the updated assessments of the environment, and the necessity to model the effectiveness of the technologies aimed at the removal of orbital debris. The model being used is named a LEO to GEO environment debris (LEGEND). It is a high fidelity three dimensional numerical simulation model with the capability to treat objects individually. It uses a Monte Carlo approach and a collision probability evaluation algorithm to simulate future satellite breakups and the growth of the debris populations.

  10. JSC Orbital Debris Website Description

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2006-01-01

    required. These data also help in the analysis and interpretation of impact features on returned spacecraft surfaces. 4) Mitigation - Controlling the growth of the orbital debris population is a high priority for NASA, the United States, and the major space-faring nations of the world to preserve near-Earth space for future generations. Mitigation measures can take the form of curtailing or preventing the creation of new debris, designing satellites to withstand impacts by small debris, and implementing operational procedures ranging from utilizing orbital regimes with less debris, adopting specific spacecraft attitudes, and even maneuvering to avoid collisions with debris. Downloadable items include several documents in PDF format and executable software.and 5) Reentry - Because of the increasing number of objects in space, NASA has adopted guidelines and assessment procedures to reduce the number of non-operational spacecraft and spent rocket upper stages orbiting the Earth. One method of postmission disposal is to allow reentry of these spacecraft, either from orbital decay (uncontrolled entry) or with a controlled entry. Orbital decay may be achieved by firing engines to lower the perigee altitude so that atmospheric drag will eventually cause the spacecraft to enter. However, the surviving debris impact footprint cannot be guaranteed to avoid inhabited landmasses. Controlled entry normally occurs by using a larger amount of propellant with a larger propulsion system to drive the spacecraft to enter the atmosphere at a steeper flight path angle. It will then enter at a more precise latitude, longitude, and footprint in a nearly uninhabited impact region, generally located in the ocean.

  11. Comparison of space debris estimates

    SciTech Connect

    Canavan, G.H.; Judd, O.P.; Naka, R.F.

    1996-10-01

    Debris is thought to be a hazard to space systems through impact and cascading. The current environment is assessed as not threatening to defense systems. Projected reductions in launch rates to LEO should delay concerns for centuries. There is agreement between AFSPC and NASA analyses on catalogs and collision rates, but not on fragmentation rates. Experiments in the laboratory, field, and space are consistent with AFSPC estimates of the number of fragments per collision. A more careful treatment of growth rates greatly reduces long-term stability issues. Space debris has not been shown to be an issue in coming centuries; thus, it does not appear necessary for the Air Force to take additional steps to mitigate it.

  12. Orbital Debris and NASA's Measurement Program

    NASA Astrophysics Data System (ADS)

    Africano, J. L.; Stansbery, E. G.

    2002-05-01

    Since the launch of Sputnik in 1957, the number of manmade objects in orbit around the Earth has dramatically increased. The United States Space Surveillance Network (SSN) tracks and maintains orbits on over nine thousand objects down to a limiting diameter of about ten centimeters. Unfortunately, active spacecraft are only a small percentage ( ~ 7%) of this population. The rest of the population is orbital debris or ``space junk" consisting of expended rocket bodies, dead payloads, bits and pieces from satellite launches, and fragments from satellite breakups. The number of these smaller orbital debris objects increases rapidly with decreasing size. It is estimated that there are at least 130,000 orbital debris objects between one and ten centimeters in diameter. Most objects smaller than 10 centimeters go untracked! As the orbital debris population grows, the risk to other orbiting objects, most importantly manned space vehicles, of a collision with a piece of debris also grows. The kinetic energy of a solid 1 cm aluminum sphere traveling at an orbital velocity of 10 km/sec is equivalent to a 400 lb. safe traveling at 60 mph. Fortunately, the volume of space in which the orbiting population resides is large, collisions are infrequent, but they do occur. The Space Shuttle often returns to earth with its windshield pocked with small pits or craters caused by collisions with very small, sub-millimeter-size pieces of debris (paint flakes, particles from solid rocket exhaust, etc.), and micrometeoroids. To get a more complete picture of the orbital-debris environment, NASA has been using both radar and optical techniques to monitor the orbital debris environment. This paper gives an overview of the orbital debris environment and NASA's measurement program.

  13. Orbital Debris: Quarterly News, Volume 14, Issue 2

    NASA Technical Reports Server (NTRS)

    Liou, J. C. (Editor); Shoots, Debi (Editor)

    2010-01-01

    This bulletin contains articles from the Orbital Debris Program office. This issue's articles are: "Orbital Debris Success Story --A Decade in the Making", "Old and New Satellite Breakups Identified," "Update on Three Major Debris Clouds," and "MMOD Inspection of the HST Bay 5 Multi-Layer Insulation Panel" about micrometeoroid and orbital debris (MMOD) inspection of the Hubble Space Telescope (HST) insulation panel. A project review is also included (i.e., "Small Debris Observations from the Iridium 33/Cosmos 2251 Collision.") There are also abstra cts of conference papers from the staff of the program office.

  14. Orbital Debris Quarterly News, Vol. 13, No. 2

    NASA Technical Reports Server (NTRS)

    Liou, J.-C. (Editor); Shoots, Debi (Editor)

    2009-01-01

    Topics include: debris clouds left by satellite collision; debris flyby near the International Space Station; and break-up of an ullage motor from a Russian Proton launch vehicle. Findings from the analysis of the STS-126 Shuttle Endeavour window impact damage are provided. Abstracts from the NASA Orbital Debris program office are presented and address a variety of topics including: Reflectance Spectra Comparison of Orbital Debris, Intact Spacecraft, and Intact Rocket Bodies in the GEO Regime; Shape Distribution of Fragments From Microsatellite Impact Tests; Micrometeoroid and Orbital Debris Threat Mitigation Techniques for the Space Shuttle Orbiter; Space Debris Environment Remediation Concepts; and, In Situ Measurement Activities at the NASA Orbital Debris Program Office. Additionally, a Meeting Report is provided for the 12 meeting of the NASA/DoD Orbital Debris Working Group.

  15. Orbital debris removal and meteoroid deflection

    NASA Astrophysics Data System (ADS)

    Campbell, Jonathan W.; Taylor, Charles R.; Smalley, Larry L.; Dickerson, Thomas

    1998-11-01

    Orbital debris in low-Earth orbit in the size range from 1 to 10 cm in diameter can be detected but not tracked reliably enough to be avoided by spacecraft. It can cause catastrophic damage even to a shielded spacecraft. With adaptive optics, a ground-based pulsed laser ablating the debris surface can produce enough propulsion in several hundred pulses to cause such debris to reenter the atmosphere. A single laser station could remove all of the 1 - 10 cm debris in three years or less. A technology demonstration of laser space propulsion is proposed which would pave the way for the implementation of such a debris removal system. The cost of the proposed demonstration is comparable with the estimated annual cost of spacecraft operations in the present orbital debris environment. Orbital debris is not the only space junk that is deleterious to the Earth's environment. Collisions with asteroids have caused major havoc to the Earth's biosphere many times in the ancient past. Since the possibility still exists for major impacts of asteroids with the Earth, it shown that it is possible to scale up the systems to prevent these catastrophic collisions providing sufficient early warning is available from new generation space telescopes plus deep space radar tracking.

  16. Orbital Debris: the Growing Threat to Space Operations

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2010-01-01

    For nearly 50 years the amount of man-made debris in Earth orbit steadily grew, accounting for about 95% of all cataloged space objects over the past few decades. The Chinese anti-satellite test in January 2007 and the accidental collision of two spacecraft in February 2009 created more than 4000 new cataloged debris, representing an increase of 40% of the official U.S. Satellite Catalog. The frequency of collision avoidance maneuvers for both human space flight and robotic operations is increasing along with the orbital debris population. However, the principal threat to space operations is driven by the smaller and much more numerous uncataloged debris. Although the U.S. and the international aerospace communities have made significant progress in recognizing the hazards of orbital debris and in reducing or eliminating the potential for the creation of new debris, the future environment is expected to worsen without additional corrective measures.

  17. Orbital Debris Quarterly News, Volume 13, Issue 4

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi (Editor); Shoots, Debi (Editor)

    2009-01-01

    Although NASA has conducted research on orbital debris since the 1960s, the NASA Orbital Debris Program Office is now considered to have been established in October 1979, following the recognition by senior NASA officials of orbital debris as a space environmental issue and the allocation by NASA Headquarters Advanced Programs Office to the Lyndon B. Johnson Space Center (JSC) of funds specifically dedicated for orbital debris investigations. In the 30 years since, the NASA Orbital Debris Program Office has pioneered the characterization of the orbital debris environment and its potential effects on current and future space systems, has developed comprehensive orbital debris mitigation measures, and has led efforts by the international aerospace community in addressing the challenges posed by orbital debris. In 1967 the Flight Analysis Branch at the Manned Spacecraft Center (renamed the Lyndon B. Johnson Space Center in 1973) evaluated the risks of collisions between an Apollo spacecraft and orbital debris. Three years later the same group calculated collision risks for the forthcoming Skylab space station, which was launched in 1973. By 1976, the nucleus of NASA s yet-to-be-formed orbital debris research efforts, including Andrew Potter, Burton Cour-Palais, and Donald Kessler, was found in JSC s Environmental Effects Office, examining the potential threat of orbital debris to large space platforms, in particular the proposed Solar Power Satellites (SPS).

  18. Collector/Compactor for Waste or Debris

    NASA Technical Reports Server (NTRS)

    Mangialiardi, John K.

    1987-01-01

    Device collects and compacts debris by sweeping through volume with net. Consists of movable vane, fixed vane, and elastic net connected to both vanes. Movable vane is metal strip curved to follow general contour of container with clearance to prevent interference with other parts on inside wall of container. One end of movable vane mounted in bearing and other end connected to driveshaft equipped with handle. User rotates movable vane, net stretched and swept through container. Captures most of debris coarser than mesh as it moves, compressing debris as it arrives at fixed vane. Applications include cleaning swimming pools and tanks.

  19. Orbital evolution of space debris due to aerodynamic forces

    NASA Astrophysics Data System (ADS)

    Crowther, R.

    1993-08-01

    The concepts used in the AUDIT (Assessment Using Debris Impact Theory) debris modelling suite are introduced. A sensitivity analysis is carried out to determine the dominant parameters in the modelling process. A test case simulating the explosion of a satellite suggest that at the parent altitude there is a greater probability of collision with more massive fragments.

  20. Orbital Dynamics of Space Debris around operational artificial satellites

    NASA Astrophysics Data System (ADS)

    Sampaio, Jarbas

    2016-07-01

    The increasing number of space debris, orbiting the Earth justifies and requires more efforts to observe and track them to avoid collisions among them and the earth's satellites. In this way, several studies are important to preserve the operability of the artificial satellites. In this work, the orbital dynamics of space debris are studied in the neighborhood of operational artificial satellites. The results show that the collision risks between these objects is high and solutions to avoid these events are necessary.

  1. Tethers and debris mitigation

    NASA Astrophysics Data System (ADS)

    van der Heide, Erik Jan; Kruijff, Michiel

    2001-03-01

    In recent years, the use of tethers has been proposed for reduction of space debris either through momentum transfer or use of electrodynamic effects. Tethers have been shown to at least theoretically allow for quick, elegant and cost-effective deorbit of defunct satellites or spent stages. On the other hand, the large risk that tethers themselves may pose to other satellites in orbit has been recognized as well. The large collision area of tethers, combined with operational hazards and meteoroid risk may result in a large orbital exposure. For example, in 1997, the ESA/Dutch 35-km tether deployment of YES from TEAMSAT was inhibited after an analysis of the collision risk for the case the tether operation would fail. The question rises how these two points of view compare to eachother. This paper intends to highlight a representative selection of the proposed tether applications while taking into account the added risks caused by the tethers themselves. Typical applications from recent literature will be briefly described, such as an Ariane 502 spent stage re-entry from GTO and the concept of deboost of defunct satellites by interaction of a conductive tether with the Earth magnetic field. Mass savings of the tethered sytems versus conventional equivalents will be evaluated. Based on a crude risk analysis, involving elements such as mission complexity, dynamic stability, meteoroid risk and orbital life time, a general outline of limiting factors can be given for the various applications. Special attention is reserved for implementation of mechanisms that help reduce this tether risk, such as the DUtether (Tether Degradable by Ultraviolet), utilization of airdrag and solar pressure, the effect of residual current in bare tethers, tether retrieval etc. It is proposed how a net tether-induced mitigation can be compared to that of conventional alternatives, i.e. deboost by rocket engine or a completely passive approach. This comparison is put in the perspective of an

  2. The fast debris evolution model

    NASA Astrophysics Data System (ADS)

    Lewis, H. G.; Swinerd, G. G.; Newland, R. J.; Saunders, A.

    2009-09-01

    The 'particles-in-a-box' (PIB) model introduced by Talent [Talent, D.L. Analytic model for orbital debris environmental management. J. Spacecraft Rocket, 29 (4), 508-513, 1992.] removed the need for computer-intensive Monte Carlo simulation to predict the gross characteristics of an evolving debris environment. The PIB model was described using a differential equation that allows the stability of the low Earth orbit (LEO) environment to be tested by a straightforward analysis of the equation's coefficients. As part of an ongoing research effort to investigate more efficient approaches to evolutionary modelling and to develop a suite of educational tools, a new PIB model has been developed. The model, entitled Fast Debris Evolution (FADE), employs a first-order differential equation to describe the rate at which new objects ⩾10 cm are added and removed from the environment. Whilst Talent [Talent, D.L. Analytic model for orbital debris environmental management. J. Spacecraft Rocket, 29 (4), 508-513, 1992.] based the collision theory for the PIB approach on collisions between gas particles and adopted specific values for the parameters of the model from a number of references, the form and coefficients of the FADE model equations can be inferred from the outputs of future projections produced by high-fidelity models, such as the DAMAGE model. The FADE model has been implemented as a client-side, web-based service using JavaScript embedded within a HTML document. Due to the simple nature of the algorithm, FADE can deliver the results of future projections immediately in a graphical format, with complete user-control over key simulation parameters. Historical and future projections for the ⩾10 cm LEO debris environment under a variety of different scenarios are possible, including business as usual, no future launches, post-mission disposal and remediation. A selection of results is presented with comparisons with predictions made using the DAMAGE environment model

  3. Engineering Challenges for Active Debris Removal

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi

    2011-01-01

    Recent modeling studies on the instability of the debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have underlined the need for active debris removal. A 2009 analysis by the NASA Orbital Debris Program Office shows that, in order to maintain the LEO debris population at a constant level for the next 200 years, an active debris removal of about five objects per year is needed. The targets identified for removal are those with the highest mass and collision probability products in the environment. Many of these objects are spent upper stages with masses ranging from 1 to more than 8 metric tons, residing in several altitude regions and concentrated in about 10 inclination bands. To remove five of those objects on a yearly basis, in a cost-effective manner, represents many challenges in engineering, technology development, and operations. This paper outlines a conceptual end-to-end debris removal operation, including launch, precision tracking, rendezvous, stabilization (of the tumbling targets), capture, and deorbit of the targets; and highlights major challenges associated with the operations. Pros and cons of several proposed removal techniques are also evaluated.

  4. Space Debris and Space Safety - Looking Forward

    NASA Astrophysics Data System (ADS)

    Ailor, W.; Krag, H.

    Man's activities in space are creating a shell of space debris around planet Earth which provides a growing risk of collision with operating satellites and manned systems. Including both the larger tracked objects and the small, untracked debris, more than 98% of the estimated 600,000 objects larger than 1 cm currently in orbit are “space junk”--dead satellites, expended rocket stages, debris from normal operations, fragments from explosions and collisions, and other material. Recognizing the problem, space faring nations have joined together to develop three basic principles for minimizing the growth of the debris population: prevent on-orbit breakups, remove spacecraft and orbital stages that have reached the end of their mission operations from the useful densely populated orbit regions, and limit the objects released during normal operations. This paper provides an overview of what is being done to support these three principles and describes proposals that an active space traffic control service to warn satellite operators of pending collisions with large objects combined with a program to actively remove large objects may reduce the rate of future collisions. The paper notes that cost and cost effectiveness are important considerations that will affect the evolution of such systems.

  5. Instability of the Current Space Debris Population in Low Earth Orbit

    NASA Astrophysics Data System (ADS)

    Maniwa, Kazuaki; Hanada, Toshiya; Kawamoto, Satomi

    Since the launch of Sputnik, orbital debris population continues to increase due to ongoing space activities, on-orbit explosions, and accidental collisions. In the future, it is expected that a great deal of fragments will be created by explosions and collisions. Thus, the number of space debris may increase exponentially (Kessler Syndrome). This paper analyzes the Kessler Syndrome using the Low Earth Orbital Debris Environmental Evolutionary Model (LEODEEM) developed at Kyushu University with collaboration from JAXA. The purpose of the study aims at understanding the issues related to space environment conservation. The results provide effective conditions of Active Debris Removal which is one of the space debris mitigation procedures.

  6. Small Orbital Debris Mitigation Mission Architecture

    NASA Technical Reports Server (NTRS)

    Wiegmann, Bruce M.

    2011-01-01

    Small orbital debris in LEO (1-10 cm in size) presents a clear and present danger to operational LEO spacecraft. This debris field has dramatically increased (nearly doubled) in recent years following the Chinese ASAT Test in 2007 and the Iridium/Cosmos collision in 2009. Estimates of the number of small debris have grown to 500,000 objects after these two events; previously the population was 300,000 objects. These small, untracked debris objects (appproximately 500,000) outnumber the larger and tracked objects (appproximately 20,000) by a factor 25 to 1. Therefore, the risk of the small untracked debris objects to operational spacecraft is much greater than the risk posed by the larger and tracked LEO debris objects. A recent study by The Aerospace Corporation found that the debris environment will increase the costs of maintaining a constellation of government satellites by 5%, a constellation of large commercial satellites by 11%, and a constellation of factory built satellites by 26% from $7.6 billion to $9.57 billion. Based upon these facts, the NASA Marshall Space Flight Center (MSFC) Advanced Concepts Office (ACO) performed an architecture study on Small Orbital Debris Active Removal (SODAR) using a space-based nonweapons- class laser satellite for LEO debris removal. The goal of the SODAR study was to determine the ability of a space-based laser system to remove the most pieces of debris (1 cm to 10 cm, locations unknown), in the shortest amount of time, with the fewest number of spacecraft. The ESA developed MASTER2005 orbital debris model was used to probabilistically classify the future debris environment including impact velocity, magnitude, and directionality. The study ground rules and assumptions placed the spacecraft into a high inclination Low Earth Orbit at 800 km as an initial reference point. The architecture study results found that a spacecraft with an integrated forward-firing laser is capable of reducing the small orbital debris flux within

  7. Expanding capabilities of the debris analysis workstation

    NASA Astrophysics Data System (ADS)

    Spencer, David B.; Sorge, Marlon E.; Mains, Deanna L.; Shubert, Ann J.; Gerhart, Charlotte M.; Yates, Ken W.; Leake, Michael

    1996-10-01

    Determining the hazards from debris-generating events is a design and safety consideration for a number of space systems, both currently operating and planned. To meet these and other requirements, the United States Air Force (USAF) Phillips Laboratory (PL) Space Debris Research Program has developed a simulation software package called the Debris Analysis Workstation (DAW). This software provides an analysis capability for assessing a wide variety of debris hazards. DAW integrates several component debris analysis models and data visualization tools into a single analysis platform that meets the needs for Department of Defense space debris analysis, and is both user friendly and modular. This allows for studies to be performed expeditiously by analysts who are not debris experts. The current version of DAW includes models for spacecraft breakup, debris orbital lifetime, collision hazard risk assessment, and collision dispersion, as well as a satellite catalog database manager, a drag inclusive propagator, a graphical user interface, and data visualization routines. Together they provide capabilities to conduct several types of analyses, ranging from range safety assessments to satellite constellation risk assessment. Work is progressing to add new capabilities with the incorporation of additional models and improved designs. The existing tools are in their initial integrated form, but the 'glue' that will ultimately bring them together into an integrated system is an object oriented language layer scheduled to be added soon. Other candidate component models under consideration for incorporation include additional orbital propagators, error estimation routines, other dispersion models, and other breakup models. At present, DAW resides on a SUNR workstation, although future versions could be tailored for other platforms, depending on the need.

  8. Orbital Debris Quarterly News, Volume 13, No. 3

    NASA Technical Reports Server (NTRS)

    Liou, J.-C. (Editor); Shoots, Debi (Editor)

    2009-01-01

    This issue of the Orbital Debris Quarterly contains articles on the congressional hearing that was held on orbital debris and space traffic; the update received by the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) on the collision of the Iridium 33 and Cosmos 2251 satellites; the micrometeoroid and orbital debris (MMOD) inspection of the Hubble Space Telescope Wide Field Planetary Camera; an analysis of the reentry survivability of the Global Precipitation Measurement (GPM) spacecraft; an update on recent major breakup fragments; and a graph showing the current debris environment in low Earth orbit.

  9. Present Research and Standardization Activities on Small Space Debris at Space Environment Prevention

    NASA Astrophysics Data System (ADS)

    Kitazawa, Yukihito; Hanada, Toshiya; Matsumoto, Haruhisa; Akahoshi, Yasuhiro; Higashide, Masumi; Okudaira, Osamu; Kamiya, Koki; Nitta, Kumi

    2016-07-01

    The micro-debris of the size from 100 μm to several mm is expected to cause a spacecraft critical failures and troubles. However, the collision probability of the micro-debris and its effect on space equipment are hardly predicted due to lack knowledge regarding the debris distribution and experimental/numerical investigation on material and components. This paper introduce research and standardization activities related on micro-debris for space environmental prevention

  10. Segregation dynamics in debris flows

    NASA Astrophysics Data System (ADS)

    Hill, K. M.; Fei, M.

    2014-12-01

    Debris flows are massive flows consisting of mixtures of particles of different sizes and interstitial fluids such as water and mud. In sheared mixtures of different-sized (same density) particles, it is well known that larger particles tend to go up (toward the free surface), and the smaller particles, down, commonly referred to as the "Brazil-nut problem" or "kinetic sieving". When kinetic sieving fluxes are combined with advection in flows, they can give rise to a spectacular range of segregation patterns. These segregation / advection dynamics are recognized as playing a role in the coarsening of a debris flow front (its "snout") and the coarsening of the self-formed channel sides or levees. Since particle size distribution influences the flow dynamics including entrainment of bed materials, modeling segregation dynamics in debris flows is important for modeling the debris flows themselves. In sparser systems, the Brazil-nut segregation is well-modeled using kinetic theory applied to dissipative systems, where an underlying assumption involves random, uncorrelated collisions. In denser systems, where kinetic theory breaks down we have recently developed a new mixture model that demonstrates the segregation fluxes are driven by two effects associated with the kinetic stress or granular temperature (the kinetic energy associated with velocity fluctuations): (1) the difference between the partitioning of kinetic and contact stresses among the species in the mixture and (2) a kinetic stress gradient. Both model frameworks involve the temperature gradient as a driving force for segregation, but kinetic theory sends larger particles toward lower temperatures, and our mixture model sends larger particles away from lower temperatures. Which framework works under what conditions appears to depend on correlations in the flow such as those manifested in clusters and force chains. We discuss the application of each theoretical framework to representing segregation dynamics

  11. Prize of the best thesis 2015: Study of debris discs through state-of-the-art numerical modelling

    NASA Astrophysics Data System (ADS)

    Kral, Q.; Thébault, P.

    2015-12-01

    This proceeding summarises the thesis entitled ``Study of debris discs with a new generation numerical model'' by Quentin Kral, for which he obtained the prize of the best thesis in 2015. The thesis brought major contributions to the field of debris disc modelling. The main achievement is to have created, almost ex-nihilo, the first truly self-consistent numerical model able to simultaneously follow the coupled collisional and dynamical evolutions of debris discs. Such a code has been thought as being the ``Holy Grail'' of disc modellers for the past decade, and while several codes with partial dynamics/collisions coupling have been presented, the code developed in this thesis, called ``LIDT-DD'' is the first to achieve a full coupling. The LIDT-DD model, which is the first of a new-generation of fully self-consistent debris disc models is able to handle both planetesimals and dust and create new fragments after each collision. The main idea of LIDT-DD development was to merge into one code two approaches that were so far used separately in disc modelling, that is, an N-body algorithm to investigate the dynamics, and a statistical scheme to explore the collisional evolution. This complex scheme is not straightforward to develop as there are major difficulties to overcome: 1) collisions in debris discs are highly destructive and produce clouds of small fragments after each single impact, 2) the smallest (and most numerous) of these fragments have a strongly size-dependent dynamics because of the radiation pressure, and 3) the dust usually observed in discs is precisely these smallest grains. These extreme constraints had so far prevented all previous attempts at developing self-consistent disc models to succeed. The thesis contains many examples of the use of LIDT-DD that are not yet published but the case of the collision between two asteroid-like bodies is studied in detail. In particular, LIDT-DD is able to predict the different stages that should be observed

  12. DIAGNOSING CIRCUMSTELLAR DEBRIS DISKS

    SciTech Connect

    Hahn, Joseph M.

    2010-08-20

    A numerical model of a circumstellar debris disk is developed and applied to observations of the circumstellar dust orbiting {beta} Pictoris. The model accounts for the rates at which dust is produced by collisions among unseen planetesimals, and the rate at which dust grains are destroyed due to collisions. The model also accounts for the effects of radiation pressure, which is the dominant perturbation on the disk's smaller but abundant dust grains. Solving the resulting system of rate equations then provides the dust abundances versus grain size and dust abundances over time. Those solutions also provide the dust grains' collisional lifetime versus grain size, and the debris disk's optical depth and surface brightness versus distance from the star. Comparison to observations then yields estimates of the unseen planetesimal disk's radius, and the rate at which the disk sheds mass due to planetesimal grinding. The model can also be used to measure or else constrain the dust grain's physical and optical properties, such as the dust grains' strength, their light-scattering asymmetry parameter, and the grains' efficiency of light scattering Q{sub s}. The model is then applied to optical observations of the edge-on dust disk orbiting {beta} Pictoris, and good agreement is achieved when the unseen planetesimal disk is broad, with 75 {approx}< r {approx}< 150 AU. If it is assumed that the dust grains are bright like Saturn's icy rings (Q{sub s} = 0.7), then the cross section of dust in the disk is A{sub d} {approx_equal} 2 x 10{sup 20} km{sup 2} and its mass is M{sub d} {approx_equal} 11 lunar masses. In this case, the planetesimal disk's dust-production rate is quite heavy, M-dot {sub d{approx}}9 M {sub +} Myr{sup -1}, implying that there is or was a substantial amount of planetesimal mass there, at least 110 Earth masses. If the dust grains are darker than assumed, then the planetesimal disk's mass-loss rate and its total mass are heavier. In fact, the apparent dearth

  13. Orbital Debris: A Chronology

    NASA Technical Reports Server (NTRS)

    Portree, Davis S. F. (Editor); Loftus, Joseph P., Jr. (Editor)

    1999-01-01

    This chronology covers the 37-year history of orbital debris concerns. It tracks orbital debris hazard creation, research, observation, experimentation, management, mitigation, protection, and policy. Included are debris-producing, events; U.N. orbital debris treaties, Space Shuttle and space station orbital debris issues; ASAT tests; milestones in theory and modeling; uncontrolled reentries; detection system development; shielding development; geosynchronous debris issues, including reboost policies: returned surfaces studies, seminar papers reports, conferences, and studies; the increasing effect of space activities on astronomy; and growing international awareness of the near-Earth environment.

  14. Handling Difficult Towers in the Calibration of the PHENIX Muon Piston Calorimeter (MPC) for Analysis of RHIC Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Lallow, Emran; Phenix Collaboration

    2015-10-01

    The PHENIX Muon Piston Calorimeter (MPC) is an electromagnetic detector with a kinematic coverage of (3 . 1 < | η | < 3 . 9). This allows for measurements at high forward and backward pseudorapidity and will be used to measure transverse energy in √{SNN} = 200, 62.4, 39, and 7.7 GeV RHIC Au+Au collisions in this kinematic region. The towers will be calibrated by using an iterative procedure in which neutral pions are reconstructed from their decay photons. To augment the iterative process, rough calibrations of individual towers can be obtained by direct examination of ADC distributions. These rough calibrations serve as input to the more rigorous neutral pion reconstruction method and will be described in this poster. This material is based upon work supported by the National Science Foundation under Grant No. 1507841.

  15. LEGEND, a LEO-to-GEO Environment Debris Model

    NASA Technical Reports Server (NTRS)

    Liou, Jer Chyi; Hall, Doyle T.

    2013-01-01

    LEGEND (LEO-to-GEO Environment Debris model) is a three-dimensional orbital debris evolutionary model that is capable of simulating the historical and future debris populations in the near-Earth environment. The historical component in LEGEND adopts a deterministic approach to mimic the known historical populations. Launched rocket bodies, spacecraft, and mission-related debris (rings, bolts, etc.) are added to the simulated environment. Known historical breakup events are reproduced, and fragments down to 1 mm in size are created. The LEGEND future projection component adopts a Monte Carlo approach and uses an innovative pair-wise collision probability evaluation algorithm to simulate the future breakups and the growth of the debris populations. This algorithm is based on a new "random sampling in time" approach that preserves characteristics of the traditional approach and captures the rapidly changing nature of the orbital debris environment. LEGEND is a Fortran 90-based numerical simulation program. It operates in a UNIX/Linux environment.

  16. Report on orbital debris

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The success of space endeavors depends upon a space environment sufficiently free of debris to enable the safe and dependable operation of spacecraft. An environment overly cluttered with debris would threaten the ability to utilize space for a wide variety of scientific, technological, military, and commercial purposes. Man made space debris (orbital debris) differs from natural meteoroids because it remains in earth orbit during its lifetime and is not transient through the space around the Earth. The orbital debris environment is considered. The space environment is described along with sources of orbital debris. The current national space policy is examined, along with ways to minimize debris generation and ways to survive the debris environment. International efforts, legal issues and commercial regulations are also examined.

  17. POST Earthquake Debris Management - AN Overview

    NASA Astrophysics Data System (ADS)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  18. Debris exhaust system

    DOEpatents

    McBride, D.D.; Bua, D.; Domankevitz, Y.; Nishioka, N.

    1998-06-23

    A debris removal system removes debris from a work site by flowing fluid away from the work site toward the periphery of a structure. The fluid flow can be kept constant around the periphery so that debris is removed evenly. The structure can have a reduced cross section between the fluid inlet and the work site so that the resulting increased fluid velocity works to prevent debris from escaping. 9 figs.

  19. Debris exhaust system

    DOEpatents

    McBride, Donald D.; Bua, Dominic; Domankevitz, Yacov; Nishioka, Norman

    1998-01-01

    A debris removal system removes debris from a work site by flowing fluid away from the work site toward the periphery of a structure. The fluid flow can be kept constant around the periphery so that debris is removed evenly. The structure can have a reduced cross section between the fluid inlet and the work site so that the resulting increased fluid velocity works to prevent debris from escaping.

  20. Lightcurves of Extreme Debris Disks

    NASA Astrophysics Data System (ADS)

    Rieke, George; Meng, Huan; Su, Kate

    2012-12-01

    We have recently discovered that some planetary debris disks with extreme fractional luminosities are variable on the timescale of a few years. This behavior opens a new possibility to understand planet building. Two of the known variable disks are around solar-like stars in the age range of 30 to 100+ Myr, which is the expected era of the final stages of terrestrial planet building. Such variability can be attributed to violent collisions (up to ones on the scale of the Moon-forming event between the proto-Earth and another proto-planet). The collisional cascades that are the aftermaths of these events can produce large clouds of tiny dust grains, possibly even condensed from silica vapor. A Spitzer pilot program has obtained the lightcurve of such a debris disk and caught two minor outbursts. Here we propose to continue the lightcurve monitoring with higher sampling rates and to expand it to more disks. The proposed time domain observations are a new dimension of debris disk studies that can bring unique insight to their evolution, providing important constraints on the collisional and dynamical models of terrestrial planet formation.

  1. Impact Forces from Tsunami-Driven Debris

    NASA Astrophysics Data System (ADS)

    Ko, H.; Cox, D. T.; Riggs, H.; Naito, C. J.; Kobayashi, M. H.; Piran Aghl, P.

    2012-12-01

    Debris driven by tsunami inundation flow has been known to be a significant threat to structures, yet we lack the constitutive equations necessary to predict debris impact force. The objective of this research project is to improve our understanding of, and predictive capabilities for, tsunami-driven debris impact forces on structures. Of special interest are shipping containers, which are virtually everywhere and which will float even when fully loaded. The forces from such debris hitting structures, for example evacuation shelters and critical port facilities such as fuel storage tanks, are currently not known. This research project focuses on the impact by flexible shipping containers on rigid columns and investigated using large-scale laboratory testing. Full-scale in-air collision experiments were conducted at Lehigh University with 20 ft shipping containers to experimentally quantify the nonlinear behavior of full scale shipping containers as they collide into structural elements. The results from the full scale experiments were used to calibrate computer models and used to design a series of simpler, 1:5 scale wave flume experiments at Oregon State University. Scaled in-air collision tests were conducted using 1:5 scale idealized containers to mimic the container behavior observed in the full scale tests and to provide a direct comparison to the hydraulic model tests. Two specimens were constructed using different materials (aluminum, acrylic) to vary the stiffness. The collision tests showed that at higher speeds, the collision became inelastic as the slope of maximum impact force/velocity decreased with increasing velocity. Hydraulic model tests were conducted using the 1:5 scaled shipping containers to measure the impact load by the containers on a rigid column. The column was instrumented with a load cell to measure impact forces, strain gages to measure the column deflection, and a video camera was used to provide the debris orientation and speed. The

  2. The Fast Debris Evolution Model

    NASA Astrophysics Data System (ADS)

    Lewis, Hugh G.; Swinerd, Graham; Newland, Rebecca; Saunders, Arrun

    The ‘Particles-in-a-box' (PIB) model introduced by Talent (1992) removed the need for computerintensive Monte Carlo simulation to predict the gross characteristics of an evolving debris environment. The PIB model was described using a differential equation that allows the stability of the low Earth orbit (LEO) environment to be tested by a straightforward analysis of the equation's coefficients. As part of an ongoing research effort to investigate more efficient approaches to evolutionary modelling and to develop a suite of educational tools, a new PIB model has been developed. The model, entitled Fast Debris Evolution (FaDE), employs a first-order differential equation to describe the rate at which new objects (˜ 10 cm) are added and removed from the environment. Whilst Talent (1992) based the collision theory for the PIB approach on collisions between gas particles and adopted specific values for the parameters of the model from a number of references, the form and coefficients of the FaDE model equations can be inferred from the outputs of future projections produced by high-fidelity models, such as the DAMAGE model. The FaDE model has been implemented as a client-side, web-based service using Javascript embedded within a HTML document. Due to the simple nature of the algorithm, FaDE can deliver the results of future projections immediately in a graphical format, with complete user-control over key simulation parameters. Historical and future projections for the ˜ 10 cm low Earth orbit (LEO) debris environment under a variety of different scenarios are possible, including business as usual, no future launches, post-mission disposal and remediation. A selection of results is presented with comparisons with predictions made using the DAMAGE environment model. The results demonstrate that the FaDE model is able to capture comparable time-series of collisions and number of objects as predicted by DAMAGE in several scenarios. Further, and perhaps more importantly

  3. Measurement of Satellite Impact Test Fragments for Modeling Orbital Debris

    NASA Technical Reports Server (NTRS)

    Hill, Nicole M.

    2009-01-01

    There are over 13,000 pieces of catalogued objects 10cm and larger in orbit around Earth [ODQN, January 2009, p12]. More than 6000 of these objects are fragments from explosions and collisions. As the earth-orbiting object count increases, debris-generating collisions in the future become a statistical inevitability. To aid in understanding this collision risk, the NASA Orbital Debris Program Office has developed computer models that calculate quantity and orbits of debris both currently in orbit and in future epochs. In order to create a reasonable computer model of the orbital debris environment, it is important to understand the mechanics of creation of debris as a result of a collision. The measurement of the physical characteristics of debris resulting from ground-based, hypervelocity impact testing aids in understanding the sizes and shapes of debris produced from potential impacts in orbit. To advance the accuracy of fragment shape/size determination, the NASA Orbital Debris Program Office recently implemented a computerized measurement system. The goal of this system is to improve knowledge and understanding of the relation between commonly used dimensions and overall shape. The technique developed involves scanning a single fragment with a hand-held laser device, measuring its size properties using a sophisticated software tool, and creating a three-dimensional computer model to demonstrate how the object might appear in orbit. This information is used to aid optical techniques in shape determination. This more automated and repeatable method provides higher accuracy in the size and shape determination of debris.

  4. Conceptual design of an orbital debris collector

    NASA Technical Reports Server (NTRS)

    Odonoghue, Peter (Editor); Brenton, Brian; Chambers, Ernest; Schwind, Thomas; Swanhart, Christopher; Williams, Thomas

    1991-01-01

    The current Lower Earth Orbit (LEO) environment has become overly crowded with space debris. An evaluation of types of debris is presented in order to determine which debris poses the greatest threat to operation in space, and would therefore provide a feasible target for removal. A target meeting these functional requirements was found in the Cosmos C-1B Rocket Body. These launchers are spent space transporters which constitute a very grave risk of collision and fragmentation in LEO. The motion and physical characteristics of these rocket bodies have determined the most feasible method of removal. The proposed Orbital Debris Collector (ODC) device is designed to attach to the Orbital Maneuvering Vehicle (OMV), which provides all propulsion, tracking, and power systems. The OMV/ODC combination, the Rocket Body Retrieval Vehicle (RBRV), will match orbits with the rocket body, use a spin table to match the rotational motion of the debris, capture it, despin it, and remove it from orbit by allowing it to fall into the Earth's atmosphere. A disposal analysis is presented to show how the debris will be deorbited into the Earth's atmosphere. The conceptual means of operation of a sample mission is described.

  5. Effect of thermospheric contraction on remediation of the near-Earth space debris environment

    NASA Astrophysics Data System (ADS)

    Lewis, Hugh G.; Saunders, Arrun; Swinerd, Graham; Newland, Rebecca J.

    2011-08-01

    Historically, computer simulations of the near-Earth space debris environment have provided a basis for international debris mitigation guidelines and, today, continue to influence international debate on debris environment remediation and active debris removal. Approximately 22,500 objects larger than 10 cm are known to exist in Earth orbit, and less than 5% of these are operational payloads, with the remaining population classed as space debris. These objects represent a significant risk to satellite operations because of the possibility of damaging or catastrophic collisions, as demonstrated by the collision between Iridium 33 and Cosmos 2251 in February 2009. Indeed, recent computer simulations have suggested that the current population in low Earth orbit (LEO) has reached a sufficient density at some altitudes for collision activity there to continue even in the absence of new launches. Even with the widespread adoption of debris mitigation guidelines, the growth of the LEO population, in particular, is expected to result in eight or nine collisions among cataloged objects in the next 40 years. With a new study using the University of Southampton's space debris model, entitled DAMAGE, we show that the effectiveness of debris mitigation and removal strategies to constrain the growth of the LEO debris population could be more than halved because of a long-term future decline in global thermospheric density. However, increasing debris remediation efforts can reverse the impact of this negative density trend.

  6. Active Debris Removal and the Challenges for Environment Remediation

    NASA Technical Reports Server (NTRS)

    Liou, J. C.

    2012-01-01

    Recent modeling studies on the instability of the debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have underlined the need for active debris removal. A 2009 analysis by the NASA Orbital Debris Program Office shows that, in order to maintain the LEO debris population at a constant level for the next 200 years, an active debris removal of about five objects per year is needed. The targets identified for removal are those with the highest mass and collision probability products in the environment. Many of these objects are spent upper stages with masses ranging from 1 to more than 8 metric tons, residing in several altitude regions and concentrated in about 7 inclination bands. To remove five of those objects on a yearly basis, in a cost-effective manner, represents many challenges in technology development, engineering, and operations. This paper outlines the fundamental rationale for considering active debris removal and addresses the two possible objectives of the operations -- removing large debris to stabilize the environment and removing small debris to reduce the threat to operational spacecraft. Technological and engineering challenges associated with the two different objectives are also discussed.

  7. Dimensional analysis of natural debris flows

    NASA Astrophysics Data System (ADS)

    Zhou, Gordon; Ouyang, Chaojun

    2015-04-01

    Debris flows occur when masses of poorly sorted sediment, agitated and saturated with water, surge down slopes in response to gravitational attraction. They are of great concern because they often cause catastrophic disasters due to the long run-out distance and large impact forc-es. Different from rock avalanches and sediment-laden water floods, both solid and fluid phases affected by multiple parameters can influence the motion of debris flows and govern their rheological properties. A dimensional analysis for a systematic study of the governing parameters is presented in this manuscript. Multiple dimensionless numbers with clear physical meanings are critically reviewed. Field data on natural debris flows are available here based on the fifty years' observation and measurement in the Jiangjia Gully, which is located in the Dongchuan City, Yunnan Province of China. The applications of field data with the dimensional analysis for studying natural debris flows are demonstrated. Specific values of dimensionless numbers (e.g., modified Savage Number, Reynolds number, Friction number) for classifying flowing regimes of natural debris flows on the large scales are obtained. Compared to previous physical model tests conducted mostly on small scales, this study shows that the contact friction between particles dominates in natural debris flows. In addition, the solid inertial stress due to particle collisions and the pore fluid viscous shear stress play key roles in governing the dynamic properties of debris flows and the total normal stress acting on the slope surfaces. The channel width as a confinement to the flows can affect the solids discharge per unit width significantly. Furthermore, a dimensionless number related to pore fluid pressure dissipation is found for distinguishing surge flows and continuous flows in field satisfactorily. It indicates that for surge debris flows, the high pore fluid pressures generated in granular body dissipate quite slowly and may

  8. Drag-o-llision Models of Extrasolar Planets in Debris Disks

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2009-01-01

    An extrasolar planet sculpts the famous debris disk around Fomalhaut; probably many other debris disks contain planets that we could locate if only we could better recognize their signatures in the dust that surrounds them. But the interaction between planets and debris disks involves both orbital resonances and collisions among grains and rocks in the disks---difficult processes to model simultaneously. The author describes new 3-D models of debris disk dynamics, Drag-o-llision models, that incorporate both collisions and resonant trapping of dust for the first time. The author also discusses the implications of these models for coronagraphic imaging with Gemini and other telescopes.

  9. Development of in-situ micro-debris measurement system

    NASA Astrophysics Data System (ADS)

    Nakamura, Maki; Kitazawa, Yukihito; Matsumoto, Haruhisa; Okudaira, Osamu; Hanada, Toshiya; Sakurai, Akira; Funakoshi, Kunihiro; Yasaka, Tetsuo; Hasegawa, Sunao; Kobayashi, Masanori

    2015-08-01

    The in-situ debris environment awareness system has been developed. The objective of the system is to measure small debris (between 100 μm and several cm) in orbit. The orbital distribution and the size distribution of the debris are not well understood. The size distribution is difficult to measure from the ground, although the size distribution is very important for the risk evaluation of the impact of debris on spacecraft. The in-situ measurement of the size distribution is useful for: (1) verification of meteoroid and debris environment models, (2) verification of meteoroid and debris environment evolution models, (3) real time detection of unexpected events, such as explosions and/or collisions on an orbit. This paper reports the development study of the in-situ debris measurement system and shows demonstration experiments and their results to describe the performance of the micro-debris sensor system. The sensor system for monitoring micro-debris with sizes ranging from 100 μm to a few mm must have a large detection area, while the constraints of space deployment require that these systems be low in mass, low in power, robust and have low telemetry requirements. For this reason, we have been developing a simple trans-film sensor. Thin and conductive stripes (copper) are formed with fine pitch (100 μm) on a thin film of nonconductive material (12.5-μm thick polyimide). A hypervelocity micro-particle impact is detected when one or more stripes are severed by perforation of the film. We designed a debris detector specialized for measuring the micro-debris size and collision rate. We then manufactured and calibrated the detector.

  10. Space Debris in the neighborhood of the ISS

    NASA Astrophysics Data System (ADS)

    Sampaio, Jarbas; Vilhena de Moraes, Rodolpho; Celestino, Claudia C.; Fiorilo de Melo, Cristiano

    2016-07-01

    The International Space Station (ISS) is a great opportunity to use a research platform in space. An international partnership of space agencies provides the operation of the ISS since 2000. The ISS is in Low Earth Orbits, in the same region of most of the space debris orbiting the planet. In this way, several studies are important to preserve the operability of the space station and operational artificial satellites, considering the increasing number of distinct objects in the space environment offering collision risks. In this work, the orbital dynamics of space debris are studied in the neighborhood of the ISS - International Space Station. The results show that the collision risk of space debris with the ISS is high and purposes to avoid these events are necessary. Solutions for the space debris mitigation are considered.

  11. Relative motion in a debris cloud

    NASA Astrophysics Data System (ADS)

    Kebe, Fatoumata

    2016-07-01

    After an explosion or collision in space, a hundred or thousands of debris are generated. To be able to study a debris cloud it's necessary to develop new analysis tools. In that sense, we have studied several representations of the relative motion with the parent body's orbit as the reference. Thus, in the case of an explosion the original spacecraft has a circular orbit which will be the reference one in the relative motion's equations while, in the case of a collision, we will take one of the spacecraft's orbit as the reference. We mainly focus on the relative motion method that used the differential elements instead of the Cartesian coordinates as it allows to take into account the main perturbation.

  12. Development of orbital debris spacecraft breakup models

    NASA Astrophysics Data System (ADS)

    Tedeschi, William J.; Connell, John C.; McKnight, Darren S.

    1991-08-01

    The Defense Nuclear Agency has initiated an Orbital Debris Spacecraft Breakup Modeling Program to improve the accuracy and usefulness of satellite breakup models with an emphasis on collision-induced events. Empirical, semianalytic, and complex approaches are used in the modeling. Current results from the modeling effort are presented and discussed along with data from associated hypervelocity impact test programs. It is shown that major improvements in modeling have been made but that milestones must be achieved before the models will routinely provide accurate predictions for a wide range of collision scenarios.

  13. Grain size segregation in debris discs

    NASA Astrophysics Data System (ADS)

    Thebault, P.; Kral, Q.; Augereau, J.-C.

    2014-01-01

    Context. In most debris discs, dust grain dynamics is strongly affected by stellar radiation pressure. Because this mechanism is size-dependent, we expect dust grains to be spatially segregated according to their sizes. However, because of the complex interplay between radiation pressure, grain processing by collisions, and dynamical perturbations, this spatial segregation of the particle size distribution (PSD) has proven difficult to investigate and quantify with numerical models. Aims: We propose to thoroughly investigate this problem by using a new-generation code that can handle some of the complex coupling between dynamical and collisional effects. We intend to explore how PSDs behave in both unperturbed discs at rest and in discs pertubed by planetary objects. Methods: We used the DyCoSS code to investigate the coupled effect of collisions, radiation pressure, and dynamical perturbations in systems that have reached a steady-state. We considered two setups: a narrow ring perturbed by an exterior planet, and an extended disc into which a planet is embedded. For both setups we considered an additional unperturbed case without a planet. We also investigated the effect of possible spatial size segregation on disc images at different wavelengths. Results: We find that PSDs are always spatially segregated. The only case for which the PSD follows a standard dn ∝ s-3.5ds law is for an unperturbed narrow ring, but only within the parent-body ring itself. For all other configurations, the size distributions can strongly depart from such power laws and have steep spatial gradients. As an example, the geometrical cross-section of the disc is very rarely dominated by the smallest grains on bound orbits, as it is expected to be in standard PSDs in sq with q ≤ -3. Although the exact profiles and spatial variations of PSDs are a complex function of the set-up that is considered, we are still able to derive some reliable results that will be useful for image or SED

  14. Engineering and Technology Challenges for Active Debris Removal

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi

    2011-01-01

    After more than fifty years of space activities, the near-Earth environment is polluted with man-made orbital debris. The collision between Cosmos 2251 and the operational Iridium 33 in 2009 signaled a potential collision cascade effect, also known as the "Kessler Syndrome", in the environment. Various modelling studies have suggested that the commonly-adopted mitigation measures will not be sufficient to stabilize the future debris population. Active debris removal must be considered to remediate the environment. This paper summarizes the key issues associated with debris removal and describes the technology and engineering challenges to move forward. Fifty-four years after the launch of Sputnik 1, satellites have become an integral part of human society. Unfortunately, the ongoing space activities have left behind an undesirable byproduct orbital debris. This environment problem is threatening the current and future space activities. On average, two Shuttle window panels are replaced after every mission due to damage by micrometeoroid or orbital debris impacts. More than 100 collision avoidance maneuvers were conducted by satellite operators in 2010 to reduce the impact risks of their satellites with respect to objects in the U.S. Space Surveillance Network (SSN) catalog. Of the four known accident collisions between objects in the SSN catalog, the last one, collision between Cosmos 2251 and the operational Iridium 33 in 2009, was the most significant. It was the first ever accidental catastrophic destruction of an operational satellite by another satellite. It also signaled the potential collision cascade effect in the environment, commonly known as the "Kessler Syndrome," predicted by Kessler and Cour-Palais in 1978 [1]. Figure 1 shows the historical increase of objects in the SSN catalog. The majority of the catalog objects are 10 cm and larger. As of April 2011, the total objects tracked by the SSN sensors were more than 22,000. However, approximately 6000 of

  15. Observations of Human-Made Debris in Earth Orbit

    NASA Technical Reports Server (NTRS)

    Cowardia, Heather

    2011-01-01

    Orbital debris is defined as any human-made object in orbit about the Earth that no longer serves a useful purpose. Beginning in 1957 with the launch of Sputnik 1, there have been more than 4,700 launches, with each launch increasing the potential for impacts from orbital debris. Almost 55 years later there are over 16,000 catalogued objects in orbit over 10 cm in size. Agencies world-wide have realized this is a growing issue for all users of the space environment. To address the orbital debris issue, the Inter-Agency Space Debris Coordination Committee (IADC) was established to collaborate on monitoring, characterizing, and modeling orbital debris, as well as formulating policies and procedures to help control the risk of collisions and population growth. One area of fundamental interest is measurements of the space debris environment. NASA has been utilizing radar and optical measurements to survey the different orbital regimes of space debris for over 25 years, as well as using returned surfaces to aid in determining the flux and size of debris that are too small to detect with ground-based sensors. This paper will concentrate on the optical techniques used by NASA to observe the space debris environment, specifically in the Geosynchronous earth Orbit (GEO) region where radar capability is severely limited.

  16. NASA Safety Standard: Guidelines and Assessment Procedures for Limiting Orbital Debris

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Collision with orbital debris is a hazard of growing concern as historically accepted practices and procedures have allowed man-made objects to accumulate in orbit. To limit future debris generation, NASA Management Instruction (NMI) 1700.8, 'Policy to Limit Orbital Debris Generation,' was issued in April of 1993. The NMI requires each program to conduct a formal assessment of the potential to generate orbital debris. This document serves as a companion to NMI 1700.08 and provides each NASA program with specific guidelines and assessment methods to assure compliance with the NMI. Each main debris assessment issue (e.g., Post Mission Disposal) is developed in a separate chapter.

  17. Electrostatic Tractor Analysis for GEO Debris Remediation

    NASA Astrophysics Data System (ADS)

    Hogan, Erik A.

    The high value of operating in the geostationary ring, coupled with increasing numbers of orbital debris, highlights the need for GEO debris remediation techniques. One recent proposed technique for GEO debris mitigation is the electrostatic tractor. Here, a tug vehicle approaches a target debris object and emits a focused electron beam onto it. This results in a negative charge on the debris, and a positive charge on the tug vehicle. Due to the near proximity of the highly charged objects (20 meters or less) an attractive electrostatic force on the order of milliNewtons results. This electrostatic force is used in conjunction with low thrusting by the tug vehicle to tow the debris object into a disposal orbit 200-300 kilometers above the GEO belt. During the tugging period, the charged relative motion between tug and deputy is stabilized through a feedback control law. This is accomplished using a novel relative motion description that isolates separation distance from the relative orientation. The equations of motion for the relative motion description are derived from the Clohessy-Wiltshire equations, assuming the debris object is in a nearly circular orbit. Lyapunov stability theory is used to derive an asymptotically stable control law for the tug thrusters during the towing period. The control law requires an estimate of the electrostatic force magnitude, and the impacts of improperly modeled charging on control response are determined. If the electrostatic force is under-predicted too severely, a collision may result. A bound on the control gains is determined to prevent such a collision. Expected reorbiting performance levels achievable with the electrostatic tractor are computed. An open-loop analytical performance study is performed where variational equations are used to predict how much general orbital elements may be changed using the electrostatic tractor over one orbital period for a towed object at geosynchronous altitude. In contrast to earlier

  18. Space debris clearing with lasers: Myth and reality

    NASA Astrophysics Data System (ADS)

    Bohn, Willy L.

    2012-07-01

    Since the Chinese anti-missile test in 2007 the problem of space debris and their threat to all space assets has become known to a larger community. Today, advances in laser sources and large mirrors including adaptive optics have matured and are in principle available. The paper first addresses the current situation of accumulated space debris and future predictions of collisions in space. Second, different solutions to mitigate the debris problem will be reviewed with emphasis on the use of high power pulsed lasers as derived from fundamental relations governing the momentum imparted to the debris by the laser pulse and causing their re-entry into the atmosphere with subsequent burn up. Unfortunately the required laser specifications lead to a demand of laser sources which cannot be satisfied with currently available devices. Therefore, two novel laser architectures will be presented. Finally, operational concepts and safety aspects will be addressed in order to evaluate the prospects of laser debris removal.

  19. VARIABILITY OF THE INFRARED EXCESS OF EXTREME DEBRIS DISKS

    SciTech Connect

    Meng, Huan Y. A.; Rieke, George H.; Su, Kate Y. L.; Rujopakarn, Wiphu; Ivanov, Valentin D.; Vanzi, Leonardo

    2012-05-20

    Debris disks with extremely large infrared excesses (fractional luminosities >10{sup -2}) are rare. Those with ages between 30 and 130 Myr are of interest because their evolution has progressed well beyond that of protoplanetary disks (which dissipate with a timescale of order 3 Myr), yet they represent a period when dynamical models suggest that terrestrial planet building may still be progressing through large, violent collisions that could yield large amounts of debris and large infrared excesses. For example, our Moon was formed through a violent collision of two large protoplanets during this age range. We report two disks around the solar-like stars ID8 and HD 23514 in this age range where the 24 {mu}m infrared excesses vary on timescales of a few years, even though the stars are not variable in the optical. Variations this rapid are difficult to understand if the debris is produced by collisional cascades, as it is for most debris disks. It is possible that the debris in these two systems arises in part from condensates from silicate-rich vapor produced in a series of violent collisions among relatively large bodies. If their evolution is rapid, the rate of detection of extreme excesses would indicate that major collisions may be relatively common in this age range.

  20. Space debris detection and mitigation

    SciTech Connect

    Allahdadi, F.

    1993-01-01

    Space debris is defined as all useless man-made objects in space. This conference covers the following areas: debris detection, tracking, and surveillance; orbital debris analytical modeling; debris environment and safety issues; and orbital debris mitigation. Separate abstracts were prepared for 26 papers in this conference.

  1. Debris analysis workstation: from concept to reality

    NASA Astrophysics Data System (ADS)

    Spencer, David B.; Maethner, Scott R.; Shubert, Ann J.; Yates, Ken W.

    1995-06-01

    Determining the hazards from debris generating events is a design and safety consideration for a number of space systems, both currently operating and planned. To meet these and other requirements, the US Air Force Phillips Laboratory Space Debris Research Program is developing a simulation platform called the Debris Analysis Workstation (DAW) which provides an analysis capability for assessing a wide variety of debris studies. DAW integrates several component debris analysis models and data visualization tools into a single analysis platform that meets the needs for DoD space debris analysis, and is both user friendly and modular. This allows for studies to be performed expeditiously by analysts that are not debris experts. DAW has gone from concept to reality with the recent deliveries of Versions 0.1 to 0.4 to a number of customers. The current version of DAW incorporates a spacecraft break-up model, drag inclusive propagator, a collision dispersion model, a graphical user interface, and data visualization routines, which together provide capabilities to conduct missile intercept range safety analyses. Work is progressing to add new capabilities with the incorporation of additional models and improved designs. The existing tools are in their initial integrated form, but the 'glue' that will ultimately bring them together into an integrated, user-friendly system, is an object oriented language layer that is scheduled to be added in 1995. Other candidate component models that are under consideration for incorporation include additional orbital propagators, error estimation routines, dispersion models, and other breakup models. At present, DAW resides on a SUN workstation, although future versions could be tailored for other platforms, depending on the need.

  2. Orbital Debris Engineering Model (ORDEM) v.3

    NASA Technical Reports Server (NTRS)

    Matney, Mark; Krisko, Paula; Xu, Yu-Lin; Horstman, Matthew

    2013-01-01

    A model of the manmade orbital debris environment is required by spacecraft designers, mission planners, and others in order to understand and mitigate the effects of the environment on their spacecraft or systems. A manmade environment is dynamic, and can be altered significantly by intent (e.g., the Chinese anti-satellite weapon test of January 2007) or accident (e.g., the collision of Iridium 33 and Cosmos 2251 spacecraft in February 2009). Engineering models are used to portray the manmade debris environment in Earth orbit. The availability of new sensor and in situ data, the re-analysis of older data, and the development of new analytical and statistical techniques has enabled the construction of this more comprehensive and sophisticated model. The primary output of this model is the flux [#debris/area/time] as a function of debris size and year. ORDEM may be operated in spacecraft mode or telescope mode. In the former case, an analyst defines an orbit for a spacecraft and "flies" the spacecraft through the orbital debris environment. In the latter case, an analyst defines a ground-based sensor (telescope or radar) in terms of latitude, azimuth, and elevation, and the model provides the number of orbital debris traversing the sensor's field of view. An upgraded graphical user interface (GUI) is integrated with the software. This upgraded GUI uses project-oriented organization and provides the user with graphical representations of numerous output data products. These range from the conventional flux as a function of debris size for chosen analysis orbits (or views), for example, to the more complex color-contoured two-dimensional (2D) directional flux diagrams in local spacecraft elevation and azimuth.

  3. Adaptive optics for space debris tracking

    NASA Astrophysics Data System (ADS)

    Bennet, Francis; D'Orgeville, Celine; Gao, Yue; Gardhouse, William; Paulin, Nicolas; Price, Ian; Rigaut, Francois; Ritchie, Ian T.; Smith, Craig H.; Uhlendorf, Kristina; Wang, Yanjie

    2014-07-01

    Space debris in Low Earth Orbit (LEO) is becoming an increasing threat to satellite and spacecraft. A reliable and cost effective method for detecting possible collisions between orbiting objects is required to prevent an exponential growth in the number of debris. Current RADAR survey technologies used to monitor the orbits of thousands of space debris objects are relied upon to manoeuvre operational satellites to prevent possible collisions. A complimentary technique, ground-based laser LIDAR (Light Detection and Ranging) have been used to track much smaller objects with higher accuracy than RADAR, giving greater prediction of possible collisions and avoiding unnecessary manoeuvring. Adaptive optics will play a key role in any ground based LIDAR tracking system as a cost effective way of utilising smaller ground stations or less powerful lasers. The use of high power and high energy lasers for the orbital modification of debris objects will also require an adaptive optic system to achieve the high photon intensity on the target required for photon momentum transfer and laser ablation. EOS Space Systems have pioneered the development of automated laser space debris tracking for objects in low Earth orbit. The Australian National University have been developing an adaptive optics system to improve this space debris tracking capability at the EOS Space Systems Mount Stromlo facility in Canberra, Australia. The system is integrated with the telescope and commissioned as an NGS AO system before moving on to LGS AO and tracking operations. A pulsed laser propagated through the telescope is used to range the target using time of flight data. Adaptive optics is used to increase the maximum range and number or targets available to the LIDAR system, by correcting the uplink laser beam. Such a system presents some unique challenges for adaptive optics: high power lasers reflecting off deformable mirrors, high slew rate tracking, and variable off-axis tracking correction. A

  4. Tidal Debris Around Merger Remnants.

    NASA Astrophysics Data System (ADS)

    McQullan, Maria

    2015-01-01

    We present images of the interacting pair NGC 3310. These images were taken using the HDI camera on the 0.9m at Kitt Peak in Arizona. NGC 3310 is a starburst galaxy which recently underwent a collision with a much smaller mass galaxy. It has been postulated that this galaxy was then scattered in the orbit of NGC 3310 creating multiple tidal loops around the galaxy. In order to observe and study these loops, the data must be clear of noise within 1% error. We present our method of correcting to this precision level and an analysis of the tidal loop system. We will also discuss the implications of this stellar debris on the evolutionary history of this galaxy.

  5. Operational Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Guit, Bill

    2015-01-01

    This presentation will describe the early days of the EOS Aqua and Aura operational collision avoidance process. It will highlight EOS debris avoidance maneuvers, EOS high interest event statistic and A-Train systematic conjunctions and conclude with future challenges. This is related to earlier e-DAA (tracking number 21692) that an abstract was submitted to a different conference. Eric Moyer, ESMO Deputy Project Manager has reviewed and approved this presentation on May 6, 2015

  6. Orbital Debris Mitigation

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Jarkey, D. R.; Stansbery, G.

    2014-01-01

    Policies on limiting orbital debris are found throughout the US Government, many foreign space agencies, and as adopted guidelines in the United Nations. The underlying purpose of these policies is to ensure the environment remains safe for the operation of robotic and human spacecraft in near- Earth orbit. For this reason, it is important to consider orbital debris mitigation during the design of all space vehicles. Documenting compliance with the debris mitigation guidelines occurs after the vehicle has already been designed and fabricated for many CubeSats, whereas larger satellites are evaluated throughout the design process. This paper will provide a brief explanation of the US Government Orbital Debris Mitigation Standard Practices, a discussion of international guidelines, as well as NASA's process for compliance evaluation. In addition, it will discuss the educational value of considering orbital debris mitigation requirements as a part of student built satellite design.

  7. Laser Remediation of Threats Posed by Small Orbital Debris

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Rogers, Jan R.; Hovater, Mary A.

    2012-01-01

    The continually increasing amount of orbital debris in near Earth space poses an increasing challenge to space situational awareness. Recent collisions of spacecraft caused abrupt increases in the density of both large and small debris in near Earth space. An especially challenging class of threats is that due to the increasing density of small (1 mm to 10 cm dimension) orbital debris. This small debris poses a serious threat since: (1) The high velocity enables even millimeter dimension debris to cause serious damage to vulnerable areas of space assets, e.g., detector windows; (2) The small size and large number of debris elements prevent adequate detection and cataloguing. We have identified solutions to this threat in the form of novel laser systems and novel ways of using these laser systems. While implementation of the solutions we identify is challenging we find approaches offering threat mitigation within time frames and at costs of practical interest. We base our analysis on the unique combination of coherent light specifically structured in both space and time and applied in novel ways entirely within the vacuum of space to deorbiting small debris. We compare and contrast laser based small debris removal strategies using ground based laser systems with strategies using space based laser systems. We find laser systems located and used entirely within space offer essential and decisive advantages over groundbased laser systems.

  8. A Parametric Study on Using Active Debris Removal to Stabilize the Future LEO Debris Environment

    NASA Technical Reports Server (NTRS)

    Liou, J.C.

    2010-01-01

    Recent analyses of the instability of the orbital debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have reignited the interest in using active debris removal (ADR) to remediate the environment. There are; however, monumental technical, resources, operational, legal, and political challenges in making economically viable ADR a reality. Before a consensus on the need for ADR can be reached, a careful analysis of the effectiveness of ADR must be conducted. The goal is to demonstrate the feasibility of using ADR to preserve the future environment and to guide its implementation to maximize the benefit-cost ratio. This paper describes a comprehensive sensitivity study on using ADR to stabilize the future LEO debris environment. The NASA long-term, orbital debris evolutionary model, LEGEND, is used to quantify the effects of many key parameters. These parameters include (1) the starting epoch of ADR implementation, (2) various target selection criteria, (3) the benefits of collision avoidance maneuvers, (4) the consequence of targeting specific inclination or altitude regimes, (5) the consequence of targeting specific classes of vehicles, and (6) the timescale of removal. Additional analyses on the importance of postmission disposal and how future launches might affect the requirements to stabilize the environment are also included.

  9. Modeling debris-covered glaciers: response to steady debris deposition

    NASA Astrophysics Data System (ADS)

    Anderson, Leif S.; Anderson, Robert S.

    2016-05-01

    Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedbacks in the debris-glacier-climate system, we developed a 2-D long-valley numerical glacier model that includes englacial and supraglacial debris advection. We ran 120 simulations on a linear bed profile in which a hypothetical steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier terminus. Our model and parameter selections can produce 2-fold increases in glacier length. Debris flux onto the glacier and the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibrium-line altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Debris deposited near the equilibrium-line altitude re-emerges high in the ablation zone and therefore impacts melt rate over a greater fraction of the glacier surface. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to initial debris-free glaciers. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). Our simulations reproduce the "general trends" between debris cover, AARs, and glacier surface velocity patterns from modern debris-covered glaciers. We provide a quantitative, theoretical foundation to interpret the effect of debris cover on the moraine record, and to assess the effects of climate change on debris-covered glaciers.

  10. Circumstellar Debris Disks: Diagnosing the Unseen Perturber

    NASA Astrophysics Data System (ADS)

    Nesvold, Erika R.; Naoz, Smadar; Vican, Laura; Farr, Will M.

    2016-07-01

    The first indication of the presence of a circumstellar debris disk is usually the detection of excess infrared emission from the population of small dust grains orbiting the star. This dust is short-lived, requiring continual replenishment, and indicating that the disk must be excited by an unseen perturber. Previous theoretical studies have demonstrated that an eccentric planet orbiting interior to the disk will stir the larger bodies in the belt and produce dust via interparticle collisions. However, motivated by recent observations, we explore another possible mechanism for heating a debris disk: a stellar-mass perturber orbiting exterior to and inclined to the disk and exciting the disk particles’ eccentricities and inclinations via the Kozai–Lidov mechanism. We explore the consequences of an exterior perturber on the evolution of a debris disk using secular analysis and collisional N-body simulations. We demonstrate that a Kozai–Lidov excited disk can generate a dust disk via collisions and we compare the results of the Kozai–Lidov excited disk with a simulated disk perturbed by an interior eccentric planet. Finally, we propose two observational tests of a dust disk that can distinguish whether the dust was produced by an exterior brown dwarf or stellar companion or an interior eccentric planet.

  11. Development of high precision laser measurement to Space Debris and Applications in SHAO

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongping; Chen, Juping; Xiong, Yaoheng; Han, Xingwei

    2016-07-01

    Artificial space debris has become the focus during the space exploration because of producing the damage for the future active spacecrafts and high precision measurement for space debris are required for debris surveillance and collision avoidance. Laser ranging technology is inherently high accurate and will play an important role in precise orbit determination, accurate catalog of space debris. Shanghai Astronomical Observatory (SHAO) of CAS, has been developing the technology of laser measurement to space debris for several years. According to characteristics of laser echoes from space debris and the experiences of relevant activities, high repetition rate, high power laser system and low dark noise APD detector with high quantum efficiency and high transmissivity of narrow bandwidth spectral filter are applied to laser measurement to space debris in SHAO. With these configurations, great achievements of laser measurement to space debris are made with hundreds of passes of laser data from space debris in the distance between 500km and 2500km with Radar Cross Section (RCS) of more than 10 m^{2} to less than 0.5m^{2} at the measuring precision of less than 1m (RMS). For better application of laser ranging technology, Chinese Space Debris Observation network, consisting of Shanghai, Changchun and Kunming station, has been preliminary developed and the coordinated observation has been performed to increase the measuring efficiency for space debris. It is referred from data that laser ranging technology can be as the essential high accuracy measurement technology in the study of space debris.

  12. Controlling the Growth of Future LEO Debris Populations with Active Debris Removal

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.; Johnson, N. L.; Hill, N. M.

    2008-01-01

    Active debris removal (ADR) was suggested as a potential means to remediate the low Earth orbit (LEO) debris environment as early as the 1980s. The reasons ADR has not become practical are due to its technical difficulties and the high cost associated with the approach. However, as the LEO debris populations continue to increase, ADR may be the only option to preserve the near-Earth environment for future generations. An initial study was completed in 2007 to demonstrate that a simple ADR target selection criterion could be developed to reduce the future debris population growth. The present paper summarizes a comprehensive study based on more realistic simulation scenarios, including fragments generated from the 2007 Fengyun-1C event, mitigation measures, and other target selection options. The simulations were based on the NASA long-term orbital debris projection model, LEGEND. A scenario, where at the end of mission lifetimes, spacecraft and upper stages were moved to 25-year decay orbits, was adopted as the baseline environment for comparison. Different annual removal rates and different ADR target selection criteria were tested, and the resulting 200-year future environment projections were compared with the baseline scenario. Results of this parametric study indicate that (1) an effective removal strategy can be developed based on the mass and collision probability of each object as the selection criterion, and (2) the LEO environment can be stabilized in the next 200 years with an ADR removal rate of five objects per year.

  13. Collisions in the Oort Cloud

    SciTech Connect

    Stern, S.A.

    1988-03-01

    The present assessment of the consequentiality of physical collisions between Oort Cloud objects by a first-generation model indicates that natural power-law population structures produce significant numbers of collisions between each comet and smaller objects over the age of the solar system. These collisions are held to constitute a feedback mechanism for small debris production. The impacts yield extensive comet surface evolution in the cloud, in conditions where the number of small orbiting objects conforms to the standard power-law populations. 16 references.

  14. Orbital debris: A technical assessment

    NASA Technical Reports Server (NTRS)

    Gleghorn, George; Asay, James; Atkinson, Dale; Flury, Walter; Johnson, Nicholas; Kessler, Donald; Knowles, Stephen; Rex, Dietrich; Toda, Susumu; Veniaminov, Stanislav

    1995-01-01

    To acquire an unbiased technical assessment of (1) the research needed to better understand the debris environment, (2) the necessity and means of protecting spacecraft against the debris environment, and (3) potential methods of reducing the future debris hazard, NASA asked the National Research Council to form an international committee to examine the orbital debris issue. The committee was asked to draw upon available data and analyses to: characterize the current debris environment, project how this environment might change in the absence of new measures to alleviate debris proliferation, examine ongoing alleviation activities, explore measures to address the problem, and develop recommendations on technical methods to address the problems of debris proliferation.

  15. GENERALIZED VISCOPLASTIC MODELING OF DEBRIS FLOW.

    USGS Publications Warehouse

    Chen, Cheng-lung

    1988-01-01

    The earliest model developed by R. A. Bagnold was based on the concept of the 'dispersive' pressure generated by grain collisions. Some efforts have recently been made by theoreticians in non-Newtonian fluid mechanics to modify or improve Bagnold's concept or model. A viable rheological model should consist both of a rate-independent part and a rate-dependent part. A generalized viscoplastic fluid (GVF) model that has both parts as well as two major rheological properties (i. e. , the normal stress effect and soil yield criterion) is shown to be sufficiently accurate, yet practical for general use in debris-flow modeling. In fact, Bagnold's model is found to be only a particular case of the GVF model. analytical solutions for (steady) uniform debris flows in wide channels are obtained from the GVF model based on Bagnold's simplified assumption of constant grain concentration.

  16. Space debris hazard to defense systems

    SciTech Connect

    Canavan, G.H.

    1996-05-01

    Natural and man-made debris are argued to present hazards to space systems, but recent data indicate that at low altitudes, the impact rates from small particles may have been overestimated by an order of magnitude. At high altitudes, small particles only present an impact hazard to large satellites; they would not support a cascade. Large particles would apparently produce a cascade only on time scales of centuries or millennia. Radar and optical data should be capable of resolving these uncertainties, but their observations are, as yet, inconsistent. While independent analytic and numerical estimates of collision and cascade rates agree, given consistent inputs, different groups produced significantly different estimates of debris growth rates. This note examines the basis for these discrepancies.

  17. Orbital Debris: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Stansbery, Gene; Johnson, Nicholas

    2013-01-01

    In the early days of spaceflight, the gBig Sky h theory was the near universally accepted paradigm for dealing with collisions of orbiting objects. This theory was also used during the early years of the aviation industry. Just as it did in aviation, the gBig Sky h theory breaks down as more and more objects accumulate in the environment. Fortunately, by the late 1970 fs some visionaries in NASA and the US Department of Defense (DoD) realized that trends in the orbital environment would inevitably lead to increased risks to operational spacecraft from collisions with other orbiting objects. The NASA Orbital Debris Program was established at and has been conducted at Johnson Space Center since 1979. At the start of 1979, fewer than 5000 objects were being tracked by the US Space Surveillance Network and very few attempts had been made to sample the environment for smaller sizes. Today, the number of tracked objects has quadrupled. Ground ]based and in situ measurements have statistically sampled the LEO environment over most sizes and mitigation guidelines and requirements are common among most space faring nations. NASA has been a leader, not only in defining the debris environment, but in promoting awareness of the issues in the US and internationally, and in providing leadership in developing policies to address the issue. This paper will discuss in broad terms the evolution of the NASA debris program from its beginnings to its present broad range of debris related research. The paper will discuss in some detail current research topics and will attempt to predict future research trends.

  18. Comprehensive Census and Analysis of Nearby Debris Disk Stars

    NASA Astrophysics Data System (ADS)

    Cotten, Tara H.

    2016-01-01

    Debris disks are intimately linked to planetary system evolution since the rocky material surrounding the star is believed to originate in collisions between planetesimals, asteroids and comets. With the conclusion of all major space infrared missions and lack of future large-scale infrared excess survey missions, it is time to make a complete list of all debris disk systems and search for trends in the population. A thorough search of the literature for infrared excess stars has been combined with a large-scale survey for excess stars in the Tycho-2 catalog that makes use of all available infrared photometry. The result is a list of ~580 unique high fidelity debris disk stars. This project seeks a comprehensive analysis of debris disk stars not yet completed on this large scale. A summary of the creation of the high fidelity debris disk census and the multi-facility endeavor to obtain various stellar and disk parameters for each debris disk will be presented. I will offer an exploration into the relationships between host stars and their debris disks through properties such as metallicity, age, and rotation.

  19. ON THE RELATIONSHIP BETWEEN DEBRIS DISKS AND PLANETS

    SciTech Connect

    Kospal, Agnes; Ardila, David R.; Moor, Attila; Abraham, Peter

    2009-08-01

    Dust in debris disks is generated by collisions among planetesimals. The existence of these planetesimals is a consequence of the planet formation process, but the relationship between debris disks and planets has not been clearly established. Here we analyze Spitzer/MIPS 24 and 70 {mu}m data for 150 planet-bearing stars, and compare the incidence of debris disks around these stars with a sample of 118 stars around which planets have been searched for, but not found. Together they comprise the largest sample ever assembled to deal with this question. The use of survival analysis techniques allows us to account for the large number of nondetections at 70 {mu}m. We discovered 10 new debris disks around stars with planets and one around a star without known planets. We found that the incidence of debris disks is marginally higher among stars with planets, than among those without, and that the brightness of the average debris disk is not significantly different in the two samples. We conclude that the presence of a planet that has been detected via current radial velocity techniques is not a good predictor of the presence of a debris disk detected at infrared wavelengths.

  20. Characterization of Debris from the DebriSat Hypervelocity Test

    NASA Technical Reports Server (NTRS)

    Rivero, M.; Kleespies, J.; Patankar, K.; Fitz-Coy, N.; Liou, J.-C.; Sorge, M.; Huynh, T.; Opiela, J.; Krisko, P.; Cowardin, H.

    2015-01-01

    The DebriSat project is an effort by NASA and the DoD to update the standard break-up model for objects in orbit. The DebriSat object, a 56 kg representative LEO satellite, was subjected to a hypervelocity impact in April 2014. For the hypervelocity test, the representative satellite was suspended within a "soft-catch" arena formed by polyurethane foam panels to minimize the interactions between the debris generated from the hypervelocity impact and the metallic walls of the test chamber. After the impact, the foam panels and debris not caught by the panels were collected and shipped to the University of Florida where the project has now advanced to the debris characterization stage. The characterization effort has been divided into debris collection, measurement, and cataloguing. Debris collection and cataloguing involves the retrieval of debris from the foam panels and cataloguing the debris in a database. Debris collection is a three-step process: removal of loose debris fragments from the surface of the foam panels; X-ray imaging to identify/locate debris fragments embedded within the foam panel; extraction of the embedded debris fragments identified during the X-ray imaging process. As debris fragments are collected, they are catalogued into a database specifically designed for this project. Measurement involves determination of size, mass, shape, material, and other physical properties and well as images of the fragment. Cataloguing involves a assigning a unique identifier for each fragment along with the characterization information.

  1. The Top 10 Questions for Active Debris Removal

    NASA Technical Reports Server (NTRS)

    Liou, J. -C.

    2010-01-01

    This slide presentation reviews the requirement and issues around removal of debris from the earth orbital environment. The 10 questions discussed are: 1. Which region (LEO/MEO/GEO) has the fastest projected growth rate and the highest collision activities? 2. Can the commonly-adopted mitigation measures stabilize the future environment? 3. What are the objectives of active debris removal (ADR)? 4. How can effective ADR target selection criteria to stabilize the future LEO environment be defined? 5. What are the keys to remediate the future LEO environment? 6. What is the timeframe for ADR implementation? 7. What is the effect of practical/operational constraints? 8. What are the collision probabilities and masses of the current objects? 9. What are the benefits of collision avoidance maneuvers? 10. What is the next step?

  2. Investigation of Orbital Debris: Mitigation, Removal, and Modeling the Debris Population

    NASA Astrophysics Data System (ADS)

    Slotten, Joel

    The population of objects in orbit around Earth has grown since the late 1950s. Today there are over 21,000 objects over 10 cm in length in orbit, and an estimated 500,000 more between 1 and 10 cm. Only a small fraction of these objects are operational satellites. The rest are debris: old derelict spacecraft or rocket bodies, fragments created as the result of explosions or collisions, discarded objects, slag from solid rockets, or even flaked off paint. Traveling at up to 7 km/s, a collision with even a 1 cm piece of debris could severely damage or destroy a satellite. This dissertation examines three aspects of orbital debris. First, the concept of a self-consuming satellite is explored. This nanosatellite would use its own external structure as propellant to execute a deorbit maneuver at the end of its operational life, thus allowing it to meet current debris mitigation standards. Results from lab experiments examining potential materials for this concept have shown favorable results. Second, Particle in Cell techniques are modified and used to model the plasma plume from a micro-cathode arc thruster. This model is then applied to the concept of an ion beam shepherd satellite. This satellite would use its plasma plume to deorbit another derelict satellite. Results from these simulations indicate the micro-cathode arc thruster could potentially deorbit a derelict CubeSat in a matter of a few weeks. Finally, the orbital debris population at geosynchronous orbit is examined, focusing on variations in the density of the population as a function of longitude. New insights are revealed demonstrating that the variation in population density is slightly less than previously reported.

  3. Effect of impactor area on collision rate estimates

    SciTech Connect

    Canavan, G.H.

    1996-08-01

    Analytic and numercial estimates provide an assessment of the effect of impactor area on space debris collision rates, which is sufficiently small and insensitive to parameters of inerest that it could be neglected or corrected.

  4. Space Debris Symposium (A6.) Measurements and Space Surveillance (1.): Measurements of the Small Particle Debris Cloud from the 11 January, 2007 Chinese Anti-satellite Test

    NASA Technical Reports Server (NTRS)

    Matney, Mark J.; Stansbery, Eugene; J.-C Liou; Stokely, Christopher; Horstman, Matthew; Whitlock, David

    2008-01-01

    On January 11, 2007, the Chinese military conducted a test of an anti-satellite (ASAT) system, destroying their own Fengyun-1C spacecraft with an interceptor missile. The resulting hypervelocity collision created an unprecedented number of tracked debris - more than 2500 objects. These objects represent only those large enough for the US Space Surveillance Network (SSN) to track - typically objects larger than about 5-10 cm in diameter. There are expected to be even more debris objects at sizes too small to be seen and tracked by the SSN. Because of the altitude of the target satellite (865 x 845 km orbit), many of the debris are expected to have long orbital lifetimes and contribute to the orbital debris environment for decades to come. In the days and weeks following the ASAT test, NASA was able to use Lincoln Laboratory s Haystack radar on several occasions to observe portions of the ASAT debris cloud. Haystack has the capability of detecting objects down to less than one centimeter in diameter, and a large number of centimeter-sized particles corresponding to the ASAT cloud were clearly seen in the data. While Haystack cannot track these objects, the statistical sampling procedures NASA uses can give an accurate statistical picture of the characteristics of the debris from a breakup event. For years computer models based on data from ground hypervelocity collision tests (e.g., the SOCIT test) and orbital collision experiments (e.g., the P-78 and Delta-180 on-orbit collisions) have been used to predict the extent and characteristics of such hypervelocity collision debris clouds, but until now there have not been good ways to verify these models in the centimeter size regime. It is believed that unplanned collisions of objects in space similar to ASAT tests will drive the long-term future evolution of the debris environment in near-Earth space. Therefore, the Chinese ASAT test provides an excellent opportunity to test the models used to predict the future debris

  5. Impact of high-risk conjunctions on Active Debris Removal target selection

    NASA Astrophysics Data System (ADS)

    Lidtke, Aleksander A.; Lewis, Hugh G.; Armellin, Roberto

    2015-10-01

    Space debris simulations show that if current space launches continue unchanged, spacecraft operations might become difficult in the congested space environment. It has been suggested that Active Debris Removal (ADR) might be necessary in order to prevent such a situation. Selection of objects to be targeted by ADR is considered important because removal of non-relevant objects will unnecessarily increase the cost of ADR. One of the factors to be used in this ADR target selection is the collision probability accumulated by every object. This paper shows the impact of high-probability conjunctions on the collision probability accumulated by individual objects as well as the probability of any collision occurring in orbit. Such conjunctions cannot be predicted far in advance and, consequently, not all the objects that will be involved in such dangerous conjunctions can be removed through ADR. Therefore, a debris remediation method that would address such events at short notice, and thus help prevent likely collisions, is suggested.

  6. The Orbital Debris Problem and the Challenges for Environment Remediation

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.

    2014-01-01

    LEO debris population will continue to increase even with a good implementation of the commonly-adopted mitigation measures. The root-cause of the increase is catastrophic collisions involving large/massive intact objects (rocket bodies or spacecraft). The major mission-ending risks for most operational spacecraft, however, come from impacts with debris just above the threshold of the protection shields (5-mm to 1-cm). A solution-driven approach is to seek: Concepts for removal of massive intacts with high P(collision); Concepts capable of preventing collisions involving intacts; Concepts for removal of 5-mm to 1-cm debris; Enhanced impact protection shields for valuable space assets. Key questions for remediation consideration of orbital debris: What is the acceptable threat level? What are the mission objectives? What is the appropriate roadmap/timeframe for remediation? Support advanced technology development when an economically viable approach is identified. Address non-technical issues, such as policy, coordination, ownership, legal, and liability at the national and international levels.

  7. Space debris detection

    NASA Astrophysics Data System (ADS)

    Eather, Robert H.

    1992-12-01

    A feasibility study on the possibility of detecting less than or = 10 cm space debris using a large-aperture ground-based telescope (with an intensified CCD detector) was completed, showing that detection should be possible. A detector system was designed and built, and installed on the 2.54 m WRDC telescope at Wright Patterson AFB. Bad seeing conditions in the Dayton area prevented the expected debris detection. Subsequently, a small 40 cm telescope was built and operated from the Haystack Observatory (Groton, MA). Known objects were used to test pointing and acquisition procedures, and the system was then shipped to Rattlesnake Observatory (Richland, WA) for participation in the ODERAC's debris calibration experiment from the Space Shuttle. This experiment failed, and our instrument has been stored at Rattlesnake in anticipation of a new ODERAC's flight in late 1993.

  8. Material Density Distribution of Small Debris in Earth Orbit

    NASA Technical Reports Server (NTRS)

    Krisko, P. H.; Xu, Y.-l.; Opiela, J. N.; Hill, N. M.; Matney, M. J.

    2008-01-01

    Over 200 spacecraft and rocket body breakups in Earth orbit have populated that regime with debris fragments in the sub-micron through meter size range. Though the largest debris fragments can cause significant collisional damage to active (operational) spacecraft, these are few and trackable by radar. Fragments on the order of a millimeter to a centimeter in size are as yet untrackable. But this smaller debris can result in damage to critical spacecraft systems and, under the worst conditions, fragmenting collision events. Ongoing research at the NASA Orbital Debris Program Office on the sources of these small fragments has focused on the material components of spacecraft and rocket bodies and on breakup event morphology. This has led to fragment material density estimates, and also the beginnings of shape categorizations. To date the NASA Standard Breakup Model has not considered specific material density distinctions of small debris. The basis of small debris in that model is the fourth hypervelocity impact event of the Satellite Orbital Debris Characterization Impact Test (SOCIT) series. This test targeted a flight-ready, U.S. Transit navigation satellite with a solid aluminum sphere impactor. Results in this event yield characteristic length (size) and area-to-mass distributions of fragments smaller than 10 cm in the NASA model. Recent re-analysis of the SOCIT4 small fragment dataset highlighted the material-specific characteristics of metals and non-metals. Concurrent analysis of Space Shuttle in-situ impact data showed a high percentage of aluminum debris in shuttle orbit regions. Both analyses led to the definition of three main on-orbit debris material density categories -low density (< 2 g/cc), medium density (2 to 6 g/cc), and high density (> 6 g/cc). This report considers the above studies in an explicit extension of the NASA Standard Breakup Model where separate material densities for debris are generated and these debris fragments are propagated in

  9. Debris-flow deposition: Effects of pore-fluid pressure and friction concentrated at flow margins

    USGS Publications Warehouse

    Major, J.J.; Iverson, R.M.

    1999-01-01

    Measurements of pore-fluid pressure and total bed-normal stress at the base of several ???10 m3 experimental debris flows provide new insight into the process of debris-flow deposition. Pore-fluid pressures nearly sufficient to cause liquefaction were developed and maintained during flow mobilization and acceleration, persisted in debris-flow interiors during flow deceleration and deposition, and dissipated significantly only during postdepositional sediment consolidation. In contrast, leading edges of debris flows exhibited little or no positive pore-fluid pressure. Deposition therefore resulted from grain-contact friction and bed friction concentrated at flow margins. This finding contradicts models that invoke widespread decay of excess pore-fluid pressure, uniform viscoplastic yield strength, or pervasive grain-collision stresses to explain debris-flow deposition. Furthermore, the finding demonstrates that deposit thickness cannot be used to infer the strength of flowing debris.

  10. Meteoroid/Debris Shielding

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L.

    2003-01-01

    This report provides innovative, low-weight shielding solutions for spacecraft and the ballistic limit equations that define the shield's performance in the meteoroid/debris environment. Analyses and hypervelocity impact testing results are described that have been used in developing the shields and equations. Spacecraft shielding design and operational practices described in this report are used to provide effective spacecraft protection from meteoroid and debris impacts. Specific shield applications for the International Space Station (ISS), Space Shuttle Orbiter and the CONTOUR (Comet Nucleus Tour) space probe are provided. Whipple, Multi-Shock and Stuffed Whipple shield applications are described.

  11. A methodology for selective removal of orbital debris

    NASA Technical Reports Server (NTRS)

    Ash, R. L.; Odonoghue, P. J.; Chambers, E. J.; Raney, J. P.

    1992-01-01

    Earth-orbiting objects, large enough to be tracked, were surveyed for possible systematic debris removal. Based upon the statistical collision studies of others, it was determined that objects in orbits approximately 1000 km above the Earth's surface are at greatest collisional risk. Russian C-1B boosters were identified as the most important target of opportunity for debris removal. Currently, more than 100 in tact boosters are orbiting the Earth with apogees between 950 km and 1050 km. Using data provided by Energia USA, specific information on the C-1B booster, in terms of rendezvous and capture strategies, was discussed.

  12. Current and Future Impact Risks from Small Debris to Operational Satellites

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Kessler, Don

    2011-01-01

    The collision between Iridium 33 and Cosmos 2251 in 2009 signaled the potential onset of the collision cascade effect, commonly known as the "Kessler Syndrome", in the low Earth orbit (LEO) region. Recent numerical simulations have shown that the 10 cm and larger debris population in LEO will continue to increase even with a good implementation of the commonly-adopted mitigation measures. This increase is driven by collisions involving large and massive intacts, i.e., rocket bodies and spacecraft. Therefore, active debris removal (ADR) of large and massive intacts with high collision probabilities has been argued as a direct and effective means to remediate the environment in LEO. The major risk for operational satellites in the environment, however, comes from impacts with debris just above the threshold of the protection shields. In general, these are debris in the millimeter to centimeter size regime. Although impacts by these objects are insufficient to lead to catastrophic breakup of the entire vehicle, the damage is certainly severe enough to cause critical failure of the key instruments or the entire payload. The focus of this paper is to estimate the impact risks from 5 mm and 1 cm debris to active payloads in LEO (1) in the current environment and (2) in the future environment based on different projection scenarios, including ADR. The goal of the study is to quantify the benefits of ADR in reducing debris impact risks to operational satellites.

  13. Space debris removal system using a small satellite

    NASA Astrophysics Data System (ADS)

    Nishida, Shin-Ichiro; Kawamoto, Satomi; Okawa, Yasushi; Terui, Fuyuto; Kitamura, Shoji

    2009-07-01

    Since the number of satellites in Earth orbit is steadily increasing, space debris will eventually pose a serious problem to near-Earth space activities if left unchecked, and so effective measures to mitigate it are becoming urgent. Equipping new satellites with an end-of-life de-orbit or orbital lifetime reduction capability could be an effective means of reducing the amount of debris by reducing the probability of the collisions between objects. On the other hand, the active removal of space debris and the retrieval of failed satellites by spacecraft are other possible measures. The Institute of Aerospace Technology, Japan Aerospace Exploration Agency (JAXA), is studying a micro-satellite system for active space debris removal, and is examining the applicability of electro-dynamic tether (EDT) technology as its high efficiency orbital transfer system. A small EDT package provides a possible means for lowering the orbits of objects without the need for propellant. Capture is indispensable for the retrieval of large space debris objects, and we propose a flexible robot arm for this purpose. This paper discusses a space debris removal satellite system and describes the development status of prototypes of the EDT package and a new robot arm for capturing non-cooperative targets.

  14. Space Debris Mitigation Guidelines

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2011-01-01

    The purpose of national and international space debris mitigation guides is to promote the preservation of near-Earth space for applications and exploration missions far into the future. To accomplish this objective, the accumulation of objects, particularly in long-lived orbits, must be eliminated or curtailed.

  15. Insights into Planet Formation from Debris Disks - II. Giant Impacts in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Wyatt, Mark C.; Jackson, Alan P.

    2016-03-01

    Giant impacts refer to collisions between two objects each of which is massive enough to be considered at least a planetary embryo. The putative collision suffered by the proto-Earth that created the Moon is a prime example, though most Solar System bodies bear signatures of such collisions. Current planet formation models predict that an epoch of giant impacts may be inevitable, and observations of debris around other stars are providing mounting evidence that giant impacts feature in the evolution of many planetary systems. This chapter reviews giant impacts, focussing on what we can learn about planet formation by studying debris around other stars. Giant impact debris evolves through mutual collisions and dynamical interactions with planets. General aspects of this evolution are outlined, noting the importance of the collision-point geometry. The detectability of the debris is discussed using the example of the Moon-forming impact. Such debris could be detectable around another star up to 10 Myr post-impact, but model uncertainties could reduce detectability to a few 100 yr window. Nevertheless the 3 % of young stars with debris at levels expected during terrestrial planet formation provide valuable constraints on formation models; implications for super-Earth formation are also discussed. Variability recently observed in some bright disks promises to illuminate the evolution during the earliest phases when vapour condensates may be optically thick and acutely affected by the collision-point geometry. The outer reaches of planetary systems may also exhibit signatures of giant impacts, such as the clumpy debris structures seen around some stars.

  16. A Laser Optical System to Remove Low Earth Orbit Space Debris

    NASA Astrophysics Data System (ADS)

    Phipps, Claude R.; Baker, Kevin L.; Libby, Stephen B.; Liedahl, Duane A.; Olivier, Scot S.; Pleasance, Lyn D.; Rubenchik, Alexander; Nikolaev, Sergey; Trebes, James E.; George, Victor E.; Marrcovici, Bogdan; Valley, Michael T.

    2013-08-01

    Collisions between existing Low Earth Orbit (LEO) debris are now a main source of new debris, threatening future use of LEO space. As solutions, flying up and interacting with each object is inefficient due to the energy cost of orbit plane changes, while debris removal systems using blocks of aerogel or gas-filled balloons are prohibitively expensive. Furthermore, these solutions to the debris problem address only large debris, but it is also imperative to remove 10-cm-class debris. In Laser-Orbital-Debris-Removal (LODR), a ground-based pulsed laser makes plasma jets on LEO debris objects, slowing them slightly, and causing them to re-enter the atmosphere and burn up. LODR takes advantage of recent advances in pulsed lasers, large mirrors, nonlinear optics and acquisition systems. LODR is the only solution that can address both large and small debris. International cooperation is essential for building and operating such a system. We also briefly discuss the orbiting laser debris removal alternative.

  17. Electrochemical behavior of simulated debris from a severe accident using a molten salt system

    SciTech Connect

    Takahashi, Yuya; Nakamura, Hitoshi; Yamada, Akira; Mizuguchi, Koji; Fujita, Reiko

    2013-07-01

    In a severe nuclear accident, the fuel in the reactor may melt, forming debris, which contains a UO{sub 2}-ZrO{sub 2} stable oxide mixture and parts of the reactor, such as Zircaloy and iron components. Proper handling of the debris is a critically important issue. The debris does not have the same composition as spent fuel, and so it is impossible to apply conventional reprocessing technology directly. In this study, we successfully separated Zr and Fe from simulated debris using NaCl-KCl molten salt electrolysis, and we selectively recovered the Zr and Fe. The simulated debris was made from Zr, Fe, and CeO{sub 2}. The CeO{sub 2} was used for simulating stable UO{sub 2}-ZrO{sub 2}. With this approach, it should be possible to reduce the volume of the debris by recovering metals, which can then be treated as low level radioactive wastes.

  18. An efficient algorithm for orbital evolution of space debris

    NASA Astrophysics Data System (ADS)

    Abdel-Aziz, Y.; Abd El-Salam, F.

    More than four decades of space exploration have led to accumulation of significant quantities of debris around the Earth. These objects range in size from a tiny piece of junk to a large inoperable satellite, although these objects that have small size they have high are-to-mass ratios, and consequently their orbits are strongly influenced by solar radiation pressure and atmospheric drag. So the increasing population of space debris object in the LEO, MEO and GEO present growing with time, serious hazard for the survival of operating spacecrafts, particularly satellites and astronomical observatories. Since the average collision velocity between any spacecraft orbiting in the LOE and debris objects is about 10 km/s and about 3 km/s in the GEO. Space debris may significantly disturb any satellite operations or cause catastrophic damage to a spacecraft itself. Applying different shielding techniques spacecraft my be protected against impacts of space debris with diameters smaller than 1 cm. For larger debris objects, only one effective method to avoid catastrophic consequence of collision is a manoeuvre that will change the spacecraft orbit. The necessary conditions in this case is to evaluate and predict future positions of the spacecraft and space debris with sufficient accuray. Numerical integration of equations of motion are used until now. Existing analytical methods can solve this problem only with low accuracy. Difficulties are caused mainly by the lack of satisfying analytical solution of the resonance problem for geosynchronous orbit as well as from the lack of efficient analytical theory combining luni-solar perturbation and solar radiation pressure with geopotential attraction. Numerical integration is time consuming in some cases, and then for qualitative analysis of the satellite's and debris's motion it is necessary to apply analytical solution. This is the reason for searching for an accurate model to evaluate the orbital position of the operating

  19. GEO Debris Observation of PMO

    NASA Astrophysics Data System (ADS)

    Ping, Yiding; Zhao, Changyin; Zhao, Haibin

    2009-03-01

    This paper summarizes observations and results obtained by Purple Mountain Observatory in March 2007 of space debris at geosynchronous orbit (GEO) in support of WG1 Action Item 23.4, International 2007 Optical Debris Campaign in Higher Earth Orbit, organized by the Inter-Agency Space Debris Coordination Committee (IADC). The main goal of Pmo's work is to develop the observational techniques of Higher Earth Orbit Space debris for the future work. A new telescope designed for debris observation is also described here.

  20. Evolution of gas in debris discs

    NASA Astrophysics Data System (ADS)

    Kral, Quentin; Wyatt, Mark; Pringle, Jim

    2015-12-01

    A non negligible quantity of gas has been discovered in an increasing number of debris disc systems. ALMA high sensitivity and high resolution is changing our perception of the gaseous component of debris discs as CO is discovered in systems where it should be rapidly photodissociated. It implies that there is a replenishment mechanism and that the observed gas is secondary. Past missions such as Herschel probed the atomic part of the gas through O I and C II emission lines. Gas science in debris discs is still in its infancy, and these new observations raise a handful of questions concerning the mechanisms to create the gas and about its evolution in the planetary system when it is released. The latter question will be addressed in this talk as a self-consistent gas evolution scenario is proposed and is compared to observations for the peculiar case of β Pictoris.Our model proposes that carbon and oxygen within debris discs are created due to photodissociation of CO which is itself created from the debris disc dust (due to grain-grain collisions or photodesorption). The evolution of the carbon atoms is modelled as viscous spreading, with viscosity parameterised using an α model. The temperature, ionisation fraction and population levels of carbon are followed with a PDR model called Cloudy, which is coupled to the dynamical viscous α model. Only carbon gets ionised due to its lower ionisation potential than oxygen. The carbon gas disc can end up with a high ionisation fraction due to strong FUV radiation field. A high ionisation fraction means that the magnetorotational instability (MRI) is very active, so that α is very high. Gas density profiles can be worked out for different input parameters such as the α value, the CO input rate, the location of the input and the incoming radiation field. Observability predictions can be made for future observations, and our model is tested on β Pictoris observations. This new gas evolution model fits the carbon and CO

  1. Earth Satellite Population Instability: Underscoring the Need for Debris Mitigation

    NASA Technical Reports Server (NTRS)

    Liou, Jer-chyi; Johnson, N. L.

    2006-01-01

    A recent study by NASA indicates that the implementation of international orbital debris mitigation measures alone will not prevent a significant increase in the artificial Earth satellite population, beginning in the second half of this century. Whereas the focus of the aerospace community for the past 25 years has been on the curtailment of the generation of long-lived orbital debris, active remediation of the current orbital debris population should now be reconsidered to help preserve near-Earth space for future generations. In particular, we show in this paper that even if launch operations were to cease today, the population of space debris would continue to grow. Further, proposed remediation techniques do not appear to offer a viable solution. We therefore recommend that, while the aerospace community maintains the current debris-limiting mission regulations and postmission disposal procedures, future emphasis should be placed on finding new remediation technologies for solving this growing problem. Since the launch of Sputnik 1, space activities have created an orbital debris environment that poses increasing impact risks to existing space systems, including human space flight and robotic missions (1, 2). Currently, more than 9,000 Earth orbiting man-made objects (including many breakup fragments), with a combined mass exceeding 5 million kilograms, are tracked by the US Space Surveillance Network and maintained in the US satellite catalog (3-5). Three accidental collisions between cataloged satellites during the period from late 1991 to early 2005 have already been documented (6), although fortunately none resulted in the creation of large, trackable debris clouds. Several studies conducted during 1991-2001 demonstrated, with assumed future launch rates, the unintended growth potential of the Earth satellite population, resulting from random, accidental collisions among resident space objects (7-13). In some low Earth orbit (LEO) altitude regimes where

  2. LightForce: An Update on Orbital Collision Avoidance Using Photon Pressure

    NASA Technical Reports Server (NTRS)

    Stupl, Jan; Mason, James; De Vries, Willem; Smith, Craig; Levit, Creon; Marshall, William; Salas, Alberto Guillen; Pertica, Alexander; Olivier, Scot; Ting, Wang

    2012-01-01

    We present an update on our research on collision avoidance using photon-pressure induced by ground-based lasers. In the past, we have shown the general feasibility of employing small orbit perturbations, induced by photon pressure from ground-based laser illumination, for collision avoidance in space. Possible applications would be protecting space assets from impacts with debris and stabilizing the orbital debris environment. Focusing on collision avoidance rather than de-orbit, the scheme avoids some of the security and liability implications of active debris removal, and requires less sophisticated hardware than laser ablation. In earlier research we concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, could avoid a significant fraction of debris-debris collisions in low Earth orbit. This paper describes our recent efforts, which include refining our original analysis, employing higher fidelity simulations and performing experimental tracking tests. We investigate the efficacy of one or more laser ground stations for debris-debris collision avoidance and satellite protection using simulations to investigate multiple case studies. The approach includes modeling of laser beam propagation through the atmosphere, the debris environment (including actual trajectories and physical parameters), laser facility operations, and simulations of the resulting photon pressure. We also present the results of experimental laser debris tracking tests. These tests track potential targets of a first technical demonstration and quantify the achievable tracking performance.

  3. MODELING COLLISIONAL CASCADES IN DEBRIS DISKS: THE NUMERICAL METHOD

    SciTech Connect

    Gaspar, Andras; Psaltis, Dimitrios; Oezel, Feryal; Rieke, George H.; Cooney, Alan E-mail: dpsaltis@as.arizona.edu E-mail: grieke@as.arizona.edu

    2012-04-10

    We develop a new numerical algorithm to model collisional cascades in debris disks. Because of the large dynamical range in particle masses, we solve the integro-differential equations describing erosive and catastrophic collisions in a particle-in-a-box approach, while treating the orbital dynamics of the particles in an approximate fashion. We employ a new scheme for describing erosive (cratering) collisions that yields a continuous set of outcomes as a function of colliding masses. We demonstrate the stability and convergence characteristics of our algorithm and compare it with other treatments. We show that incorporating the effects of erosive collisions results in a decay of the particle distribution that is significantly faster than with purely catastrophic collisions.

  4. Debris disks: seeing dust, thinking of planetesimals and planets

    NASA Astrophysics Data System (ADS)

    Krivov, Alexander V.

    2010-05-01

    Debris disks are optically thin, almost gas-free dusty disks observed around a significant fraction of main-sequence stars older than about 10 Myr. Since the circumstellar dust is short-lived, the very existence of these disks is considered as evidence that dust-producing planetesimals are still present in mature systems, in which planets have formed - or failed to form - a long time ago. It is inferred that these planetesimals orbit their host stars at asteroid to Kuiper-belt distances and continually supply fresh dust through mutual collisions. This review outlines observational techniques and results on debris disks, summarizes their essential physics and theoretical models, and then places them into the general context of planetary systems, uncovering interrelations between the disks, dust parent bodies, and planets. It is shown that debris disks can serve as tracers of planetesimals and planets and shed light on the planetesimal and planet formation processes that operated in these systems in the past.

  5. Tethers as Debris: Hydrocode Simulation of Impacts of Polymer Tether Fragments on Aluminum Plates

    NASA Technical Reports Server (NTRS)

    Evans, Steven W.

    2003-01-01

    Tethers promise to find use in a variety of space applications. Despite being narrow objects, their great lengths result in them having large total areas. Consequently, tethers are very susceptible to being severed by orbital debris. Extensive work has been done designing tethers that resist severs by small debris objects, in order to lengthen their working lives. It is from this perspective that most recent work has considered the tether - debris question. The potential of intact tethers, or severed tether fragments, as debris, to pose a significant collision risk to other spacecraft has been less well studied. Understanding the consequences of such collisions is important in assessing the risks tethers pose to other spacecraft. This paper discusses the damage that polymer tethers may produce on aluminum plates, as revealed by hypervelocity impact simulations using the SPHC hydrodynamic code.

  6. Erosive Hit-and-Run Impact Events: Debris Unbound

    NASA Astrophysics Data System (ADS)

    Sarid, Gal; Stewart, Sarah T.; Leinhardt, Zoë M.

    2016-01-01

    Erosive collisions among planetary embryos in the inner solar system can lead to multiple remnant bodies, varied in mass, composition and residual velocity. Some of the smaller, unbound debris may become available to seed the main asteroid belt. The makeup of these collisionally produced bodies is different from the canonical chondritic composition, in terms of rock/iron ratio and may contain further shock-processed material. Having some of the material in the asteroid belt owe its origin from collisions of larger planetary bodies may help in explaining some of the diversity and oddities in composition of different asteroid groups.

  7. Orbital debris measurements

    NASA Technical Reports Server (NTRS)

    Kessler, D. J.

    1986-01-01

    What is currently known about the orbital debris flux is from a combination of ground based and in-space measurements. These measurements have revealed an increasing population with decreasing size. A summary of measurements is presented for the following sources: the North American Aerospace Defense Command Catalog, the Perimeter Acquisition and Attack Characterization System Radar, ground based optical telescopes, the Explorer 46 Meteoroid Bumper Experiment, spacecraft windows, and Solar Max surfaces.

  8. Coronagraphic Imaging of Debris Disks from a High-Altitude Balloon Platform

    NASA Technical Reports Server (NTRS)

    Unwin, Stephen C.; Traub, Wesley A.; Trauger, John T.; Bryden, Geoffrey; Krist, John; Stuchlik, David W.; Lillie, Charles F.

    2012-01-01

    Debris disks are rings of micron-size dust orbiting in the outer regions of planetary systems. Asteroid and comet collisions are the probable sources of the dust. Radiation pressure and Poynting-Robertson drag. Planets shepherd and sculpt the dust into a ring. The dust ring is bright enough to be imaged, brighter than the planets themselves. So debris disk images are our connection to as-yet unseen planets, comets, and asteroids.

  9. Molecular Gas Clumps from the Destruction of Icy Bodies in the beta Pictoris Debris Disk

    NASA Technical Reports Server (NTRS)

    Dent, W. R. F.; Wyatt, M. C.; Roberge, A.; Augereau, J. -C.; Casassus, S.; Corder, S.; Greaves, J. S.; DeGregorio-Monsalvo, I.; Hales, A.; Jackson, A. P.; Hughes, A. Meredith; Lagrange, A. -M.; Matthews, B.; Wilner, D.

    2014-01-01

    Many stars are surrounded by disks of dusty debris formed in the collisions of asteroids, comets and dwarf planets. But is gas also released in such events? Observations at sub-mm wavelengths of the archetypal debris disk around ß Pictoris show that 0.3% of a Moon mass of carbon monoxide orbits in its debris belt. The gas distribution is highly asymmetric, with 30% found in a single clump 85 AU from the star, in a plane closely aligned with the orbit of the inner planet, beta Pic b. This gas clump delineates a region of enhanced collisions, either from a mean motion resonance with an unseen giant planet, or from the remnants of a collision of Mars-mass planets.

  10. Molecular gas clumps from the destruction of icy bodies in the β Pictoris debris disk.

    PubMed

    Dent, W R F; Wyatt, M C; Roberge, A; Augereau, J-C; Casassus, S; Corder, S; Greaves, J S; de Gregorio-Monsalvo, I; Hales, A; Jackson, A P; Hughes, A Meredith; Lagrange, A-M; Matthews, B; Wilner, D

    2014-03-28

    Many stars are surrounded by disks of dusty debris formed in the collisions of asteroids, comets, and dwarf planets, but is gas also released in such events? Observations at submillimeter wavelengths of the archetypal debris disk around β Pictoris show that 0.3% of a Moon mass of carbon monoxide orbits in its debris belt. The gas distribution is highly asymmetric, with 30% found in a single clump 85 astronomical units from the star, in a plane closely aligned with the orbit of the inner planet, β Pictoris b. This gas clump delineates a region of enhanced collisions, either from a mean motion resonance with an unseen giant planet or from the remnants of a collision of Mars-mass planets. PMID:24603151

  11. Space Debris Modeling at NASA

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2001-01-01

    Since the Second European Conference on Space Debris in 1997, the Orbital Debris Program Office at the NASA Johnson Space Center has undertaken a major effort to update and improve the principal software tools employed to model the space debris environment and to evaluate mission risks. NASA's orbital debris engineering model, ORDEM, represents the current and near-term Earth orbital debris population from the largest spacecraft to the smallest debris in a manner which permits spacecraft engineers and experimenters to estimate the frequency and velocity with which a satellite may be struck by debris of different sizes. Using expanded databases and a new program design, ORDEM2000 provides a more accurate environment definition combined with a much broader array of output products in comparison with its predecessor, ORDEM96. Studies of the potential long-term space debris environment are now conducted with EVOLVE 4.0, which incorporates significant advances in debris characterization and breakup modeling. An adjunct to EVOLVE 4.0, GEO EVOLVE has been created to examine debris issues near the geosynchronous orbital regime. In support of NASA Safety Standard 1740.14, which establishes debris mitigation guidelines for all NASA space programs, a set of evaluation tools called the Debris Assessment Software (DAS) is specifically designed for program offices to determine whether they are in compliance with NASA debris mitigation guidelines. DAS 1.5 has recently been released with improved WINDOWS compatibility and graphics functions. DAS 2.0 will incorporate guideline changes in a forthcoming revision to NASA Safety Standard 1740.14. Whereas DAS contains a simplified model to calculate possible risks associated with satellite reentries, NASA's higher fidelity Object Reentry Survival Analysis Tool (ORSAT) has been upgraded to Version 5.0. With the growing awareness of the potential risks posed by uncontrolled satellite reentries to people and property on Earth, the

  12. The Collision of Iridium 33 and Cosmos 2251: The Shape of Things to Come

    NASA Technical Reports Server (NTRS)

    Nicholas, Johnson

    2009-01-01

    The collision of Iridium 33 and Cosmos 2251 was the most severe accidental fragmentation on record. More than 1800 debris approx. 10 cm and larger were produced. If solar activity returns to normal, half of the tracked debris will reenter within five years. Less than 60 cataloged debris had reentered by 1 October 2009. Some debris from both satellites will remain in orbit through the end of the century. The collision rate of one every five years will increase without future removal of large derelict spacecraft and launch vehicle orbital stages.

  13. LightForce: Photon Pressure Induced Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Levit, C.; Smith, C.; Stupl, J.; Mason, J.; Marshall, M.

    2012-09-01

    We investigate the feasibility of using a medium-powered (5 kW) ground-based laser combined with a ground-based telescope to prevent collisions between debris objects in low-Earth orbit (LEO), for which there is no current, effective mitigation strategy. The scheme utilizes photon pressure alone as a means to perturb the orbit of a debris object. Applied over multiple engagements, this alters the debris orbit succinctly to reduce the risk of an upcoming conjunction. We employ standard assumptions for atmospheric conditions and the resulting beam propagation. Using case studies designed to represent the properties (e.g. area and mass) of the current debris population, we show that one could significantly reduce the risk of more than half of all debris-debris collisions using only one such laser/telescope facility. We speculate on whether this could mitigate the debris fragmentation rate such that it falls below the natural debris re-entry rate due to atmospheric drag, and thus whether continuous long-term operation could entirely mitigate the Kessler syndrome in LEO, without need for relatively expensive active debris removal.

  14. A Numerical Approach to Estimate the Ballistic Coefficient of Space Debris from TLE Orbital Data

    NASA Technical Reports Server (NTRS)

    Narkeliunas, Jonas

    2016-01-01

    Low Earth Orbit (LEO) is full of space debris, which consist of spent rocket stages, old satellites and fragments from explosions and collisions. As of 2009, more than 21,000 orbital debris larger than 10 cm are known to exist], and while it is hard to track anything smaller than that, the estimated population of particles between 1 and 10 cm in diameter is approximately 500,000, whereas small as 1 cm exceeds 100 million. These objects orbit Earth with huge kinetic energies speeds usually exceed 7 kms. The shape of their orbit varies from almost circular to highly elliptical and covers all LEO, a region in space between 160 and 2,000 km above sea level. Unfortunately, LEO is also the place where most of our active satellites are situated, as well as, International Space Station (ISS) and Hubble Space Telescope, whose orbits are around 400 and 550 km above sea level, respectively.This poses a real threat as debris can collide with satellites and deal substantial damage or even destroy them.Collisions between two or more debris create clouds of smaller debris, which are harder to track and increase overall object density and collision probability. At some point, the debris density couldthen reach a critical value, which would start a chain reaction and the number of space debris would grow exponentially. This phenomenon was first described by Kessler in 1978 and he concluded that it would lead to creation of debris belt, which would vastly complicate satellite operations in LEO. The debris density is already relatively high, as seen from several necessary debris avoidance maneuvers done by Shuttle, before it was discontinued, and ISS. But not all satellites have a propulsion system to avoid collision, hence different methods need to be applied. One of the proposed collision avoidance concepts is called LightForce and it suggests using photon pressure to induce small orbital corrections to deflect debris from colliding. This method is very efficient as seen from

  15. Man-made space debris - Does it restrict free access to space

    NASA Technical Reports Server (NTRS)

    Wolfe, M.; Chobotov, V.; Kessler, D.; Reynolds, R.

    1981-01-01

    Consideration is given to the hazards posed by existing and future man-made space debris to spacecraft operations. The components of the hazard are identified as those fragments resulting from spacecraft explosions and spent stages which can be tracked, those fragments which are too small to be tracked at their present distances, and future debris, which, if present trends in spacecraft design and operation continue, may lead to an unacceptably high probability of collision with operational spacecraft within a decade. It is argued that a coordinated effort must be undertaken by all space users to evaluate means of space debris control in order to allow for the future unrestricted use of near-earth space. A plan for immediate action to forestall the space debris problem by activities in the areas of education, debris monitoring and collection technology, space vehicle design, space operational procedures and practices and space policies and treaties is proposed.

  16. ORDEM 3.0 and the Risk of High-Density Debris

    NASA Technical Reports Server (NTRS)

    Matney, Mark; Anz-Meador, Philip

    2014-01-01

    NASA’s Orbital Debris Engineering Model was designed to calculate orbital debris fluxes on spacecraft in order to assess collision risk. The newest of these models, ORDEM 3.0, has a number of features not present in previous models. One of the most important is that the populations and fluxes are now broken out into material density groups. Previous models concentrated on debris size alone, but a particle’s mass and density also determine the amount of damage it can cause. ORDEM 3.0 includes a high-density component, primarily consisting of iron/steel particles that drive much of the risk to spacecraft. This paper will outline the methods that were used to separate and identify the different densities of debris, and how these new densities affect the overall debris flux and risk.

  17. Active Debris Removal - A Grand Engineering Challenge for the Twenty-First Century

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.

    2011-01-01

    The collision between Iridium 33 and Cosmos 2251 in 2009 has reignited interest in using active debris removal to remediate the near-Earth orbital debris environment. A recent NASA study shows that, in order to stabilize the environment in the low Earth orbit (LEO) region for the next 200 years, active debris removal of about five large and massive (1 to more than 8 metric tons) objects per year is needed. To develop the capability to remove five of those objects per year in a cost-effective manner truly represents a grand challenge in engineering and technology development.

  18. Approaches and selection to space debris mitigation for small satellite

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Zhang, B.; Zheng, Y.; Meng, B.; Xu, X.; Liu, Y.; Wu, Z.; Hao, Y.; Dong, Y.

    Aiming at space debris mitigation for small satellite after the end of mission, several approaches are analyzed and compared, and implementations are suggested in this paper. In recent years more and more small satellites have been developed and launched into orbit. Most of them run on Low Earth Orbit (LEO) with height less than 2000km. On the one hand, the small satellites increase the density of space debris and the risk of collision; on the other hand, some of them have orbit lifetime over 25 years if only depending natural attenuation beyond the guideline of Inter-agency Space Debris Coordination Committee (IADC). In this paper several approaches are analyzed and compared for space debris mitigation after the end of mission, including the utilizations of air drag, solar radiation pressure, rocket propulsion, and others. The cost will be required for small satellite to mitigate space debris. For lower orbit small satellites and their constellation, the functions and performances perhaps are degraded. For higher orbit satellites, lifetime of spacecraft always is more than 25 years. Then some supererogatory equipments should be appended to shorten orbit lifetime, such as air chamber, sail, even thruster, usually they are not necessary for small satellites. Based on the analysis of effect and cost for these approaches, implementations are suggested for small satellite with different functions (whether or not provide capability of orbit control) and different mass: 50kg, 100kg, 150kg and 300kg. This research is supported by China National Space Administration (CNSA).

  19. Laser/space material uncooperative propulsion for orbital debris removal and asteroid, meteoroid, and comet deflection

    NASA Astrophysics Data System (ADS)

    Campbell, Jonathan W.; Taylor, Charles R.; Smalley, Larry L.; Dickerson, Thomas

    1999-01-01

    Orbital debris in low-Earth orbit in the size range from 1 to 10 cm in diameter can be detected but not tracked reliably enough to be avoided by spacecraft. It can cause catastrophic damage even to a shielded spacecraft. With adaptive optics, a ground-based pulsed laser ablating the debris surface can produce enough propulsion in several hundred pulses to cause such debris to reenter the atmosphere. A single laser station could remove all of the 1-10 cm debris in three years or less. A technology demonstration of laser space propulsion is proposed which would pave the way for the implementation of such a debris removal system. The cost of the proposed demonstration is comparable with the estimated annual cost of spacecraft operations in the present orbital debris environment. Orbital debris is not the only space junk that is deleterious to the Earth's environment. Collisions with asteroids have caused major havoc to the Earth's biosphere many times in the ancient past. Since the possibility still exists for major impacts, it is shown that it is possible to scale up the systems to prevent these catastrophic collisions given sufficient early warning.

  20. Current Issues in Orbital Debris

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2011-01-01

    During the past two decades, great strides have been made in the international community regarding orbital debris mitigation. The majority of space-faring nations have reached a consensus on an initial set of orbital debris mitigation measures. Implementation of and compliance with the IADC and UN space debris mitigation guidelines should remain a high priority. Improvements of the IADC and UN space debris mitigation guidelines should continue as technical consensus permits. The remediation of the near-Earth space environment will require a significant and long-term undertaking.

  1. Characterizing Longitude-Dependent Orbital Debris Congestion in the Geosynchronous Orbit Regime

    NASA Astrophysics Data System (ADS)

    Anderson, Paul V.

    The geosynchronous orbit (GEO) is a unique commodity of the satellite industry that is becoming increasingly contaminated with orbital debris, but is heavily populated with high-value assets from the civil, commercial, and defense sectors. The GEO arena is home to hundreds of communications, data transmission, and intelligence satellites collectively insured for an estimated 18.3 billion USD. As the lack of natural cleansing mechanisms at the GEO altitude renders the lifetimes of GEO debris essentially infinite, conjunction and risk assessment must be performed to safeguard operational assets from debris collisions. In this thesis, longitude-dependent debris congestion is characterized by predicting the number of near-miss events per day for every longitude slot at GEO, using custom debris propagation tools and a torus intersection metric. Near-miss events with the present-day debris population are assigned risk levels based on GEO-relative position and speed, and this risk information is used to prioritize the population for debris removal target selection. Long-term projections of debris growth under nominal launch traffic, mitigation practices, and fragmentation events are also discussed, and latitudinal synchronization of the GEO debris population is explained via node variations arising from luni-solar gravity. In addition to characterizing localized debris congestion in the GEO ring, this thesis further investigates the conjunction risk to operational satellites or debris removal systems applying low-thrust propulsion to raise orbit altitude at end-of-life to a super-synchronous disposal orbit. Conjunction risks as a function of thrust level, miss distance, longitude, and semi-major axis are evaluated, and a guidance method for evading conjuncting debris with continuous thrust by means of a thrust heading change via single-shooting is developed.

  2. Space Debris Hazard Evaluation

    NASA Technical Reports Server (NTRS)

    Davison, Elmer H.; Winslow, Paul C., Jr.

    1961-01-01

    The hazard to space vehicles from natural space debris has been explored. A survey of the available information pertinent to this problem is presented. The hope is that this presentation gives a coherent picture of the knowledge to date in terms of the topic covered. The conclusion reached is that a definite hazard exists but that it can only be poorly assessed on the basis of present information. The need for direct measurement of this hazard is obvious, and some of the problems involved in making these direct measurements have been explored.

  3. Removal of orbital debris

    NASA Technical Reports Server (NTRS)

    Petro, Andrew J.; Talent, David L.

    1989-01-01

    The several methods presently identified for the reduction of orbital debris populations are broadly classifiable as either preventive or remedial, and fall within distinctive operational regimes. For all particles, (1) in the 250-2000-km altitude band, intelligent sweepers may be used; (2) for large objects, in the 80-250-km altitude band, orbital decay renders removal impractical; (3) for the 250-750-km altitude band, deorbit devices should be used; (4) for 750-2500-km altitude, OMV rendezvous for propulsive deorbit package attachment is foreseeable; and beyond 2500 km, (5) propulsive escape from earth orbit is required.

  4. Microplastic debris in sandhoppers

    NASA Astrophysics Data System (ADS)

    Ugolini, A.; Ungherese, G.; Ciofini, M.; Lapucci, A.; Camaiti, M.

    2013-09-01

    Adults of the sandhopper Talitrus saltator were fed with dry fish food mixed with polyethylene microspheres (diameter 10-45 μm). Observations of homogenized guts revealed the presence of microspheres independently of their dimensions. The gut resident time (GRT) was recorded and most of the microspheres are expelled in 24 h. Microspheres are totally expelled in one week. Preliminary investigations did not show any consequence of microsphere ingestion on the survival capacity in the laboratory. FT-IR analyses carried out on faeces of freshly collected individuals revealed the presence of polyethylene and polypropylene. This confirms that microplastic debris could be swallowed by T. saltator in natural conditions.

  5. A reorbiter for large GEO debris objects using ion beam irradiation

    NASA Astrophysics Data System (ADS)

    Kitamura, Shoji; Hayakawa, Yukio; Kawamoto, Satomi

    2014-02-01

    In recent years, space debris problems have become very serious. The worst case occurs in the low Earth orbit (LEO) region, where debris-to-debris collisions generate new debris. The situation in the geostationary orbit (GEO) region is not as bad as that in the LEO. The debris problem in the GEO region, however, should not be left as it is because the GEO is unique and has few debris-cleansing modes. Thus, we proposed a concept for a reorbiter to reorbit large GEO debris objects such as satellites and rocket upper stages left in orbit after the ends of their missions. This concept is based on the idea of thrusting a debris object by irradiating it with an ion beam. The reorbiter, equipped with two ion engines, approaches a debris object, and the ion beam exhausted from one of the ion engines irradiates and thrusts it to change its orbit. The other engine on the opposite side is operated so that the reorbiter follows the debris object. Their orbits are raised in a spiral to a disposal orbit approximately 300 km higher. After that, the reorbiter returns to GEO to approach another debris object. This system can operate without catching debris objects; thus, it can be applied to a wide range of debris objects without regard to their shapes or rotations. A mission scenario was made to conduct efficient maneuvers. In the GEO region, a number of debris objects are distributed on orbit planes close to each other, and they can be reorbited one after another using a single reorbiter. For a typical model mission, the mission time and the total impulse of the ion engines were calculated. The results show that six debris objects can be reorbited in 170 days. The reorbiter has a targeted launch mass of 2500 kg and 6.9 kW of total power. The ion beam convergence, the effects of ion beam irradiation, and non-cooperative rendezvous were recognized as the critical issues of this system. A highly converged beam is required to make efficient debris irradiation. Numerical calculations

  6. Feature test report for the Small Debris Collection and Packaging System

    SciTech Connect

    Brisbin, S.A.

    1995-03-17

    The Spent Nuclear Fuel Equipment Engineering group performed feature testing of the Small Debris Collection and Packaging System (SDCPS) in the 305 Cold Test Facility from January 30, 1995, to February 1, 1995. Feature testing of the Small Debris Collection and Packaging System (SDCPS) was performed for the following reasons: To assess the feasibility of using ``drop-out`` vessels to collect small debris (<2.5 cm) in MK-II fuel canisters while transferring sludge to the Weasel Pit. To evaluate system performance under conditions similar to those in the K-Basins (e.g. submerged under 4.9 meters of water and operated with long handled tools) while using a surrogate sludge mixed with debris. To determine if canister weight could be used to predict the volume of sludge and/or debris contained within the canisters during system operation.

  7. Active Debris Removal of Multiple Priority Targets

    NASA Astrophysics Data System (ADS)

    Braun, Vitali; Flegel, Sven Kevin; Vörsmann, Peter; Wiedemann, Carsten; Gelhaus, Johannes; Moeckel, Marek; Kebschull, Christopher

    2012-07-01

    Today's space debris environment shows major concentrations of objects within distinct orbital regions for nearly all size regimes. The most critical region is found at orbital altitudes near 800 kilometers with high declinations. Within this region many satellites are operated in so called sun-synchronous orbits (SSO). Among those, there are Earth observation, communication and weather satellites. Due to the orbital geometry, head-on encounters with relative velocities of about 15 km/s are most probable and would thus result in highly energetic collisions, which are often referred to as catastrophic collisions, leading to the complete fragmentation of the participating objects. So called feedback collisions can then be triggered by the newly generated fragments, thus leading to a further population increase in the affected orbital region. This effect is known as the Kessler syndrome. Current studies show that catastrophic collisions are not a major problem today, but will become the main process for debris generation within the SSO region in the near future, even without any future launches. In order to avoid this effect, objects with a major impact on collisional cascading have to be actively removed from the critical region after their end of life. Not having the capability to perform an end-of-life maneuver in order to transfer to a graveyard orbit or to de-orbit, many satellites and rocket bodies would have to be de-orbited within a dedicated mission. In such a mission, a service satellite would perform a de-orbit maneuver, after having docked to a specific target. In this paper several systems, e.g. chemical and electrical engines are analysed with the main focus on removing multiple targets within one single mission. The service satellite has to undock from the previously de-orbited target in order to start the rendezvous and docking phase for a subsequent target. The targets are chosen from a previously defined priority list in order to enhance the mission

  8. Active debris removal of multiple priority targets

    NASA Astrophysics Data System (ADS)

    Braun, Vitali; Lüpken, A.; Flegel, S.; Gelhaus, J.; Möckel, M.; Kebschull, C.; Wiedemann, C.; Vörsmann, P.

    2013-05-01

    Today's space debris environment shows major concentrations of objects within distinct orbital regions for nearly all size regimes. The most critical region is found at orbital altitudes near 800 km with high declinations. Within this region many satellites are operated in so called sun-synchronous orbits (SSO). Among those, there are Earth observation, communication and weather satellites. Due to the orbital geometry in SSO, head-on encounters with relative velocities of about 15 km/s are most probable and would thus result in highly energetic collisions, which are often referred to as catastrophic collisions, leading to the complete fragmentation of the participating objects. So called feedback collisions can then be triggered by the newly generated fragments, thus leading to a further population increase in the affected orbital region. This effect is known as the Kessler syndrome.Current studies show that catastrophic collisions are not a major problem today, but will become the main process for debris generation within the SSO region in the near future, even without any further launches. In order to avoid this effect, objects with a major impact on collisional cascading have to be actively removed from the critical region after their end of life. Not having the capability to perform an end-of-life maneuver in order to transfer to a graveyard orbit or to de-orbit, many satellites and rocket bodies would have to be de-orbited within a dedicated mission. In such a mission, a service satellite would perform a de-orbit maneuver, after having docked to a specific target.In this paper, chemical and electric propulsion systems were analysed with the main focus on removing multiple targets within one single mission. The targets were chosen from a previously defined priority list in order to enhance the mission efficiency. Total mission time, ΔV and system mass were identified as key parameters to allow for an evaluation of the different concepts. It was shown that it

  9. Space debris modeling at NASA

    NASA Astrophysics Data System (ADS)

    Johnson, Nicholas L.

    2001-10-01

    Since the Second European Conference on Space Debris in 1997, the Orbital Debris Program Office at the NASA Johnson Space Center has undertaken a major effort to update and improve the principal software tools employed to model the space debris environment and to evaluate mission risks. NASA's orbital debris engineering model, ORDEM, represents the current and near-term Earth orbital debris population from the largest spacecraft to the smallest debris in a manner which permits spacecraft engineers and experimenters to estimate the frequency and velocity with which a satellite may be struck by debris of different sizes. Using expanded databases and a new program design, ORDEM2000 provides a more accurate environment definition combined with a much broader array of output products in comparison with its predecessor, ORDEM96. Studies of the potential long-term space debris environment are now conducted with EVOVLE 4.0, which incorporates significant advances in debris characterization and breakup modeling. An adjunct to EVOLVE 4.0, GEO EVOLVE has been created to examine debris issues near the geosynchronous orbital regime. In support of NASA Safety Standard (NSS) 1740.14, which establishes debris mitigation guidelines for all NASA space programs, a set of evaluation tools called the Debris Assessment Software (DAS) is specifically designed for program offices to determine whether they are in compliance with NASA debris mitigation guidelines. DAS 1.5 has recently been completed with improved WINDOWS compatibility and graphics functions. DAS 2.0 will incorporate guideline changes in a forthcoming revision to NSS 1740.14. Whereas DAS contains a simplified model to calculate possible risks associated with satellite reentries, NASA's higher fidelity Object Reentry Survival Analysis Tool (ORSAT) has been upgraded to Version 5.0. With the growing awareness of the potential risks posed by uncontrolled satellite reentries to people and property on Earth, the application of

  10. The Challenge of Orbital Debris

    NASA Technical Reports Server (NTRS)

    Matney, Mark

    2012-01-01

    Since the dawn of the Space Age more than 50 years ago, humans have been launching objects into the space environment faster than they have been removed by active means or natural decay. This has led to a proliferation of debris -- derelict satellites, discarded rocket upper stages, and pieces from satellite breakups -- in Earth orbit, especially in well-used orbital regimes. This talk will summarize the current knowledge of the debris environment and describe plans to address the challenges orbital debris raises for the future usability of near-Earth space. The talk will be structured around 4 categories: Measurements, Modeling, Shielding, and Mitigation. This will include discussions of the long-term prognosis of debris growth (i.e., the "Kessler Syndrome") as well as plans for active debris removal.

  11. Orbital Debris Research at NASA

    NASA Technical Reports Server (NTRS)

    Stansbery, Eugene G.

    2009-01-01

    The United States has one of the most active programs of research of the orbital debris environment in the world. Much of the research is conducted by NASA s Orbital Debris Program Office at the Johnson Space Center. Past work by NASA has led to the development of national space policy which seeks to limit the growth of the debris population and limit the risk to spacecraft and humans in space and on the Earth from debris. NASA has also been instrumental in developing consistent international policies and standards. Much of NASA's efforts have been to measure and characterize the orbital debris population. The U.S. Department of Defense tracks and catalogs spacecraft and large debris with it's Space Surveillance Network while NASA concentrates on research on smaller debris. In low Earth orbit, NASA has utilized short wavelength radars such as Haystack, HAX, and Goldstone to statistically characterize the population in number, size, altitude, and inclination. For higher orbits, optical telescopes have been used. Much effort has gone into the understanding and removal of observational biases from both types of measurements. NASA is also striving to understand the material composition and shape characteristics of debris to assess these effects on the risk to operational spacecraft. All of these measurements along with data from ground tests provide the basis for near- and long-term modeling of the environment. NASA also develops tools used by spacecraft builders and operators to evaluate spacecraft and mission designs to assess compliance with debris standards and policies which limit the growth of the debris environment.

  12. Recent Measurements of the Orbital Debris Environment at NASA Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Stansbery, E. G.; Settecerri, T. J.; Africano, J. L.

    1999-01-01

    Space debris presents many challenges to current space operations. Although, the probability of collision between an operational spacecraft and a piece of space debris is quite small, the potential losses can be quite high. Prior to 1990, characterization of the orbital debris environment was divided into two categories. Objects larger than 10 cm are monitored by the United States Space Surveillance Network (SSN) and documented in the U.S. Space Command (USSPACECOM) catalog. Knowledge of debris smaller than 0.1 cm has come from the analyses of returned surfaces. The lack of information about the debris environment in the size range from 0.1 to 1 0 cm led to a joint NASA-DOD effort for orbital debris measurements using the Haystack radar and the unbuilt Haystack Auxiliary (HAX) radars. The data from these radars have been critical to the design of shielding for the International Space Station and have been extensively used in the creation of recent models describing the orbital debris environment. Recent debris campaigns have been conducted to verify and validate through comparative measurements, the results and conclusions drawn from the Haystack/HAX measurements. The Haystack/HAX measurements and results will be described as well as the results of the recent measurement campaigns.

  13. SPACeMAN -a Satellite to Actively Reduce Sub-Centimeter Debris

    NASA Astrophysics Data System (ADS)

    Knirsch, Uli

    In-orbit fragmentation events, whether accidental or intentional, are bound to increase the population of space debris. "Critical debris" ranging between 1 and 10mm are numerous and can be lethal to both satellites and inhabited structures. This in turn creates further debris, potentially leading to a chain reaction ("Kessler syndrome"). In first approximation, collecting sub-centimeter debris appears impractical since rendezvous maneuvers are prohibitively expensive in terms of delta v and hardware complexity. One possible solution is to fly a spacecraft with a small constant vertical thrust. As a result, it will move somewhat faster than other, passive objects in its orbit -such as space debris. This "non-Keplerian orbit" thus creates a small chance of accidental collision. The sPACeMAN is designed to withstand impacts, capturing the debris. Since the probability of capture is low, some active control, particularly of the vertical thrust, can be instituted. The sPACeMAN concept was developed to reduce the population of NaK droplets in critical orbits. However, it can be extended to other debris as well. Since its effectiveness is greatest in areas of relatively high population densities of space debris, it would be best suited for quick responses, such as after a fragmentation event.

  14. Treatability Variance for Containerised Liquids in Mixed Debris Waste - 12101

    SciTech Connect

    Alstatt, Catherine M.

    2012-07-01

    The TRU Waste Processing Center (TWPC) is a Department of Energy facility whose mission is to receive and process for appropriate disposal legacy Contact Handled (CH) and Remote Handled (RH) waste, including debris waste stored at various DOE Oak Ridge facilities. Acceptable Knowledge (AK) prepared for the waste characterizes the waste as mixed waste, meaning it is both radioactive and regulated under the Resource Conservation and Recovery Act (RCRA). The AK also indicates that a number of the debris waste packages contain small amounts of containerised liquids. The documentation indicates liquid wastes generated in routine lab operations were typically collected for potential recovery of valuable isotopes. However, during activities associated with decontamination and decommissioning (D and D), some containers with small amounts of liquids were placed into the waste containers with debris waste. Many of these containers now hold from 2.5 milliliters (ml) to 237 ml of liquid; a few contain larger volumes. At least some of these containers were likely empty at the time of generation, but documentation of this condition is lacking. Since WIPP compliant AK is developed on a waste stream basis, rather than an individual container basis, and includes every potential RCRA hazardous constituent within the waste stream, it is insufficient for the purpose of characterizing individual containers of liquid. Debris waste is defined in 40 CFR 268.2(g) as 'solid material exceeding a 60 mm particle size that is intended for disposal and that is: a manufactured object; or plant or animal matter; or natural geologic material'. The definition further states that intact containers of hazardous waste that are not ruptured and that retain at least 75% of their original volume are not debris. The prescribed treatment is removal of intact containers from the debris waste, and treatment of their contents to meet specific Land Disposal Restrictions (LDR) standards. This is true for

  15. Autonomous space processor for orbital debris

    NASA Technical Reports Server (NTRS)

    Ramohalli, Kumar; Campbell, David; Brockman, Jeff P.; Carter, Bruce; Donelson, Leslie; John, Lawrence E.; Marine, Micky C.; Rodina, Dan D.

    1989-01-01

    This work continues to develop advanced designs toward the ultimate goal of a GETAWAY SPECIAL to demonstrate economical removal of orbital debris utilizing local resources in orbit. The fundamental technical feasibility was demonstrated last year through theoretical calculations, quantitative computer animation, a solar focal point cutter, a robotic arm design and a subscale model. During this reporting period, several improvements are made in the solar cutter, such as auto track capabilities, better quality reflectors and a more versatile framework. The major advance has been in the design, fabrication and working demonstration of a ROBOTIC ARM that has several degrees of freedom. The functions were specifically tailored for the orbital debris handling. These advances are discussed here. Also a small fraction of the resources were allocated towards research in flame augmentation in SCRAMJETS for the NASP. Here, the fundamental advance was the attainment of Mach numbers up to 0.6 in the flame zone and a vastly improved injection system; the current work is expected to achieve supersonic combustion in the laboratory and an advanced monitoring system.

  16. Review of uncertainty sources affecting the long-term predictions of space debris evolutionary models

    NASA Astrophysics Data System (ADS)

    Dolado-Perez, J. C.; Pardini, Carmen; Anselmo, Luciano

    2015-08-01

    Since the launch of Sputnik-I in 1957, the amount of space debris in Earth's orbit has increased continuously. Historically, besides abandoned intact objects (spacecraft and orbital stages), the primary sources of space debris in Earth's orbit were (i) accidental and intentional break-ups which produced long-lasting debris and (ii) debris released intentionally during the operation of launch vehicle orbital stages and spacecraft. In the future, fragments generated by collisions are expected to become a significant source as well. In this context, and from a purely mathematical point of view, the orbital debris population in Low Earth Orbit (LEO) should be intrinsically unstable, due to the physics of mutual collisions and the relative ineffectiveness of natural sink mechanisms above~700 km. Therefore, the real question should not be "if", but "when" the exponential growth of the space debris population is supposed to start. From a practical point of view, and in order to answer the previous question, since the end of the 1980's several sophisticated long-term debris evolutionary models have been developed. Unfortunately, the predictions performed with such models, in particular beyond a few decades, are affected by considerable uncertainty. Such uncertainty comes from a relative important number of variables that being either under the partial control or completely out of the control of modellers, introduce a variability on the long-term simulation of the space debris population which cannot be captured with standard Monte Carlo statistics. The objective of this paper is to present and discuss many of the uncertainty sources affecting the long-term predictions done with evolutionary models, in order to serve as a roadmap for the uncertainty and the statistical robustness analysis of the long-term evolution of the space debris population.

  17. Space Station: Delays in dealing with space debris may reduce safety and increase costs

    NASA Astrophysics Data System (ADS)

    1992-06-01

    The majority of NASA's current designs for protecting the space station and crew from debris are outdated and its overall debris protection strategy is insufficient. NASA's contractors have designed the station using a 1984 model of the space environment that is obsolete, significantly underestimating the increasing amount of debris that the station will encounter during its 30-year lifetime. In February 1992, NASA directed its space centers to incorporate an updated 1991 model into their designs. However, the agency has not yet made critical decisions on how to implement this change. Preliminary evaluations show that incorporating the 1991 model using currently established safety criteria could entail a major redesign of some components, with significant cost impact and schedule delays. NASA's overall protection strategy for space debris is insufficient. While NASA has concentrated its protection on shielding the space station from small debris and plans to augment this initial shielding in orbit, it has not yet developed designs or studied the cost and operational impact of augmenting its protection with additional shielding. Further, current designs do not provide the capability of warning or protecting the crew from imminent collision with mid-size debris. Finally, although some capabilities exist for maneuvering the station away from large debris, the agency lacks collision-avoidance plans and debris-tracking equipment. In developing a comprehensive strategy to protect the station from the more severe debris environment, NASA cannot avoid some difficult decisions. These decisions involve tradeoffs between how much the agency is willing to pay to protect the station, the schedule delays it may incur, and the risk to station safety it is willing to accept. It is important that these decisions be made before NASA completes its critical design reviews in early 1993. At that time key designs will be made final and manufacturing will begin. Without a comprehensive

  18. Charging of space debris in the LEO and GEO regions

    NASA Astrophysics Data System (ADS)

    Sen, Abhijit; Tiwari, Sanat Kumar

    The near exponential rise of space debris at the satellite orbital altitudes (particularly in the low earth orbit (LEO) region) and the risk they pose for space assets is a source of major concern for all nations engaged in space activities. Considerable efforts are therefore being expended into accurate modeling and tracking of these objects and various ideas for the safe removal of these debris are being explored. The debris objects are likely to acquire a large amount of charge since they are typically found in a plasma environment - such as the earth’s ionospheric plasma in the LEO region (100 kms to 1000 kms) and the radiation belts in the geosynchronous orbit (GEO) region. The consequent flow of electron and ion currents on them lead to the accumulation of a large amount of surface charge and the development of a surface potential on these objects. The influence of the plasma environment on the dynamics and charging of the debris is a relatively unexplored area of Space Situational Awareness (SSA) and Space Debris (SD) research and can be potentially important for the accurate prediction of the long-term evolution of debris orbits and their collision probabilities with other space objects. In this paper we will report on the charging of space debris under a variety of orbital conditions in the LEO and GEO regions using both analytic and particle-in-cell (PIC) modeling. The analytic estimates are obtained using refined Orbit Motion Limited (OML) modeling while the simulation studies are carried out using the SPIS code [1]. In the GEO region account is taken of charging due to photoemission processes as well as energetic beam charging. The PIC approach enables us to study charging of irregularly shaped debris objects as well as differential charging on objects that are composed of patches of conducting and insulated regions. The dynamical consequences of the debris charging on their orbital trajectories and rotational characteristics will be discussed. [1] J

  19. Implementation of the hazardous debris rule

    SciTech Connect

    Sailer, J.E.

    1993-01-05

    Hazardous debris includes objects contaminated with hazardous waste. Examples of debris include tree stumps, timbers, boulders, tanks, piping, crushed drums, personal protective clothing, etc. Most of the hazardous debris encountered comes from Superfund sites and other facility remediation, although generators and treaters of hazardous waste also generate hazardous debris. Major problems associated with disposal of debris includes: Inappropriateness of many waste treatments to debris; Difficulties in obtaining representative samples; Costs associated with applying waste specific treatments to debris; Subtitle C landfill space was being used for many low hazard debris types. These factors brought about the need for debris treatment technologies and regulations that addressed these issues. The goal of such regulation was to provide treatment to destroy or remove the contamination if possible and, if this is achieved, to dispose of the cleaned debris as a nonhazardous waste. EPA has accomplished this goal through promulgation of the Hazardous Debris Rule, August 18, 1992.

  20. A model for the evolution of on-orbit manmade debris environment

    NASA Technical Reports Server (NTRS)

    Reynolds, R. C.; Fischer, N. H.; Edgecombe, D. S.

    1985-01-01

    Man-made debris in low-Earth orbit (LEO) and the conduct of operations/procedures which leave debris in orbit are discussed. With continued deposition and larger vehicles and longer times on orbit for LEO operations, the probability of collisions between such vehicles and some member of the debris population becomes large. Because the collisions will occur at very large relative speeds, a small object which would not normally be considered a hazard might pose a lethal threat to an operating spacecraft. Future debris states must be deduced from an evaluation of many models using a Monte Carlo method for future deposition events. A model for the population evolution is presented and results of model calculations are discussed. Contributions to the population which may be expected to arise from on-orbit collisions and explosions are examined. Results are presented as models for future space usage as an extrapolation of usage in the past, for an era of enhanced space usage, and for an era in which antisatellite tests provide a debris contribution.

  1. A novel data association scheme for LEO space debris surveillance based on a double fence radar system

    NASA Astrophysics Data System (ADS)

    Huang, Jian; Hu, Weidong; Xin, Qin; Guo, Weiwei

    2012-12-01

    The increasing amount of space debris threatens to seriously deteriorate and damage space-based instruments in Low Earth Orbit (LEO) environments. Therefore, LEO space debris surveillance systems must be developed to provide situational awareness in space and issue warnings of collisions with LEO space debris. In this paper, a double fence radar system is proposed as an emerging paradigm for LEO space debris surveillance. This system exhibits several unique and promising characteristics compared with existing surveillance systems. In this paper, we also investigate the data association scheme for LEO space debris surveillance based on a double fence radar system. We also perform a theoretical analysis of the performance of our proposed scheme. The superiority and the effectiveness of our novel data association scheme is demonstrated by experimental results. The data used in our experiments is the LEO space debris catalog produced by the North American Air Defense Command (NORAD) up to 2009, especially for scenarios with high densities of LEO space debris, which were primarily produced by the collisions between Iridium 33 and Cosmos 2251. We hope that our work will stimulate and benefit future work on LEO space debris surveillance approaches and enable construction of the double fence radar system.

  2. Implications of Prolonged Solar Minimum Conditions for the Space Debris Population

    NASA Astrophysics Data System (ADS)

    Lewis, Hugh G.; Horbury, Timothy

    2013-08-01

    Observations of the current solar cycle show the likely continuation of a long-term decline in solar activity that began during the 1980s. This decline could lead to conditions similar to the Maunder minimum within 40 years [1], which would have consequences for the space debris environment. Solar activity is a key driver of atmospheric mass density and, subsequently, drag on orbiting spacecraft and debris. Whilst several studies have investigated potential effects on the global climate, no assessment has been made of the impact of a Maunder-like minimum on the space debris population in Low Earth Orbit (LEO). Consequently, we present a new study of the future debris environment under Maunder minimum conditions and provide an assessment of the possible consequences to the LEO space debris population and space operations. The University of Southampton's Debris Analysis and Monitoring Architecture to the Geosynchronous Environment (DAMAGE) has been used to analyse the consequences of a Maunder minimum of approximately 50 years duration and to quantify the impact on the effectiveness of debris mitigation measures. Results from these studies suggest an increase in collision activity and a corresponding, rapid growth of the debris population during a Maunder minimum period, in spite of on-going mitigation efforts. In the best case, the DAMAGE results suggest that the population of debris > 10 cm could double in number by the end of Maunder minimum conditions. However, the rapid growth in the population is followed by a strong recovery period on exit from a Maunder minimum. The recovery is characterised by a decrease in the debris population, which can be to a level similar to that seen before the onset of the Maunder minimum, if mitigation efforts are sustained. As such, prolonged solar minimum conditions may have relatively benign implications for the long-term evolution of the debris environment. However, the risks to spacecraft from collisions with debris during a

  3. The long-term implications of operating satellite constellations in the low earth orbit debris environment

    NASA Astrophysics Data System (ADS)

    Walker, R.; Crowther, R.; Swinerd, G. G.

    1997-05-01

    DRA's Integrated Debris Evolution Suite (IDES) model is used in this study to predict the future evolution of the orbital debris environment for two distinct scenarios. For the first case, a pre-generated background debris population for 1995 and `business as usual' future launch/explosion rates are used as input to the model. IDES then employs its collision event prediction algorithm to simulate evolution from 1996 to 2020 as a baseline. The second scenario uses the same initial conditions and future trends, but in addition, a large constellation is introduced into the simulation process from year 1998 onwards. The additional contribution of the constellation to the temporal variation of key environment/population parameters is presented; including enhancement from any long-term collision coupling effects.

  4. Detection Of Exocomets Within Edge-on Debris Disks

    NASA Astrophysics Data System (ADS)

    Montgomery, Sharon Lynn; Welsh, B.

    2011-01-01

    The youngest circumstellar debris disks in orbit around main sequence stars are thought to represent the last stage in the formation of a planetary system. Dust and gas continues to be replenished in these systems when planetesimals reach sizes of around 2000 km. Dynamical instabilities can "stir" the population of smaller planetesimals such that they undergo violent dust-generating collisions with each other. The same instabilities may send comets on highly eccentric orbits toward the star in these debris disk systems. Four stars, including the protypical debris disk star Beta Pic, have already been shown to exhibit short-term (i.e., night-to-night) variability in Ca II, which is widely believed to be due to infalling evaporating bodies (FEBs or exocomets). We have collected moderately high-resolution spectra of ten young, A-type, rapidly-rotating stars with excess infrared continuum emission using the Cassegrain-Echelle spectrograph of the 2.1m Otto Struve Telescope. Here, we report the detection of two new gas disk systems with short-term variability in CaII: 5 Vul and 49 Cet. While the circumstellar disks of both stars have been previously described in the literature, this is the first report of night-to-night variability within the debris disk gas. Velocity arguments have allowed us to place some constraints on the dynamics of the absorbing gas.

  5. Comprehensive Census and Complete Characterization of Nearby Debris Disk Stars

    NASA Astrophysics Data System (ADS)

    Cotten, Tara H.; Song, Inseok

    2016-01-01

    Debris disks are intimately linked to planetary system evolution since the rocky material surrounding the host stars is believed to be due to secondary generation from the collisions of planetesimals. With the conclusion and lack of future large scale infrared excess survey missions, it is time to summarize the history of using excess emission in the infrared as a tracer of debris and exploit all available data as well as provide a comprehensive study of the parameters of these important objects. We have compiled a catalog of infrared excess stars from peer-reviewed articles and performed an extensive search for new debris disks by cross-correlating the Tycho-2 and AllWISE catalogs. This study will conclude following the thorough examination of each debris disk star's parameters obtained through high-resolution spectroscopy at various facilities which is currently ongoing. We will maintain a webpage (www.debrisdisks.org) devoted to these infrared excess sources and provide various resources related to our catalog creation, SED fitting, and data reduction.

  6. Brute Force Modeling of the Orbital Debris Evolution

    NASA Astrophysics Data System (ADS)

    Nikolaev, S.; Phillion, D.; Horsley, M.; Johnson, N.

    2012-09-01

    The Kessler Syndrome (runaway increase in the number of orbiting debris fragments through cascading collisions) presents a serious danger to future space missions. To understand its implications and study the effectiveness of various proposed debris mitigation strategies, long-term evolutionary models for near-Earth space environment (e.g. NASA's LEGEND, ESA's MASTER-2009) are used. Because of the long timescales involved, existing models represent the orbiting population by some average spatial density functions, resulting in a limited spatial and temporal resolution of such models. Here, we present the brute force approach to evolutionary debris modeling, by propagating and monitoring every object in orbit for the length of the simulation (100+ years). The approach involved designing a custom, efficient orbital propagator, coupled with a fast conjunction analysis module. The resulting highly parallel simulation code was run on LLNL's supercomputers, due to the extremely demanding computing power requirements. Here we present some of the results of these high-fidelity simulations. This approach allows unprecedented, high-resolution view of the evolution of orbiting populations, and establishes new state of the art in evolutionary debris modeling.

  7. 14 CFR 417.211 - Debris analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Debris analysis. 417.211 Section 417.211... TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight safety analysis must include a debris analysis. For an orbital or suborbital launch, a debris...

  8. 14 CFR 417.211 - Debris analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Debris analysis. 417.211 Section 417.211... TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight safety analysis must include a debris analysis. For an orbital or suborbital launch, a debris...

  9. 44 CFR 206.224 - Debris removal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Debris removal. 206.224... Debris removal. (a) Public interest. Upon determination that debris removal is in the public interest, the Regional Administrator may provide assistance for the removal of debris and wreckage from...

  10. Orbital Envelope for Debris Generated by a Satellite Breakup: A stochastic Study

    NASA Astrophysics Data System (ADS)

    Vieira Neto, Ernesto; Winter, Othon

    2012-07-01

    The collision between the Russian satellite Kosmos-2251 and the American satellite Iridium 33 in February 2009 leads to several questions about the debris resulted in that collision. For example, we could ask how much of the debris stay in orbit, or how much of these debris decay to Earth. This are the kind of simple questions that we try to answer in this study. The fragmentation process occurs in a large branch of natural phenomena and thus it is a very important field of interest. We can find in the literature numerous theories about fragmentation, but none is complete and much of these theories could be used only for particular cases. Objects which breakup due a collision can generate fragments of various size. The size distribution generated by the destruction depends on many factors, as the physical properties of the object, the way the object was broken, the geometry of the impact, and the energy of the projectile used to break it. After we solve the problem of find a size distribution of the fragments, the next problem is to know the velocity distribution of these fragments, which is also a difficult problem to be modeled. Our method is to make a stochastic simulations of a satellite breakup using random walk, and thus we study the spread of the debris when we distribute random impulses to the fragments. With this process we obtain the velocity distribution of the particles to use it in the orbital evolution of the debris. Thus, We had split our problem into three steps: in the first step we fragment the satellite do produce a size distribution for the debris; in the second step we give linear momenta to the fragments to obtain the velocity distribution; finally, in the third step we use this velocity distribution to study the orbital envelope generated by the debris. Peculiarities of this model and the results we have achieved will be shown in the presentation.

  11. Lightweight Shield Against Space Debris

    NASA Technical Reports Server (NTRS)

    Redmon, John W., Jr.; Lawson, Bobby E.; Miller, Andre E.; Cobb, W. E.

    1992-01-01

    Report presents concept for lightweight, deployable shield protecting orbiting spacecraft against meteoroids and debris, and functions as barrier to conductive and radiative losses of heat. Shield made in four segments providing 360 degree coverage of cylindrical space-station module.

  12. Collision tectonics

    SciTech Connect

    Coward, M.P.; Ries, A.C.

    1985-01-01

    The motions of lithospheric plates have produced most existing mountain ranges, but structures produced as a result of, and following the collision of continental plates need to be distinguished from those produced before by subduction. If subduction is normally only stopped when collision occurs, then most geologically ancient fold belts must be collisional, so it is essential to recognize and understand the effects of the collision process. This book consists of papers that review collision tectonics, covering tectonics, structure, geochemistry, paleomagnetism, metamorphism, and magmatism.

  13. Gap Clearing by Planets in a Collisional Debris Disk

    NASA Astrophysics Data System (ADS)

    Nesvold, Erika R.; Kuchner, Marc J.

    2015-01-01

    We apply our 3D debris disk model, SMACK, to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (α = 2/7). We find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index α of the power law depends on the age of the system t relative to the collisional timescale t coll of the disk by α = 0.32(t/t coll)-0.04, with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion resonances near the chaotic zone. We investigate the effects of the initial eccentricity distribution of the disk particles and find a negligible effect on the gap size at Jovian planet masses, since collisions tend to erase memory of the initial particle eccentricity distributions. Finally, we find that the presence of Trojan analogs is a potentially powerful diagnostic of planets in the mass range ~1-10 M Jup. We apply our model to place new upper limits on planets around Fomalhaut, HR 4796 A, HD 202628, HD 181327, and β Pictoris.

  14. GAP CLEARING BY PLANETS IN A COLLISIONAL DEBRIS DISK

    SciTech Connect

    Nesvold, Erika R.; Kuchner, Marc J. E-mail: Marc.Kuchner@nasa.gov

    2015-01-10

    We apply our 3D debris disk model, SMACK, to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (α = 2/7). We find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index α of the power law depends on the age of the system t relative to the collisional timescale t {sub coll} of the disk by α = 0.32(t/t {sub coll}){sup –0.04}, with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion resonances near the chaotic zone. We investigate the effects of the initial eccentricity distribution of the disk particles and find a negligible effect on the gap size at Jovian planet masses, since collisions tend to erase memory of the initial particle eccentricity distributions. Finally, we find that the presence of Trojan analogs is a potentially powerful diagnostic of planets in the mass range ∼1-10 M {sub Jup}. We apply our model to place new upper limits on planets around Fomalhaut, HR 4796 A, HD 202628, HD 181327, and β Pictoris.

  15. Effective Echo Detection and Accurate Orbit Estimation Algorithms for Space Debris Radar

    NASA Astrophysics Data System (ADS)

    Isoda, Kentaro; Sakamoto, Takuya; Sato, Toru

    Orbit estimation of space debris, objects of no inherent value orbiting the earth, is a task that is important for avoiding collisions with spacecraft. The Kamisaibara Spaceguard Center radar system was built in 2004 as the first radar facility in Japan devoted to the observation of space debris. In order to detect the smaller debris, coherent integration is effective in improving SNR (Signal-to-Noise Ratio). However, it is difficult to apply coherent integration to real data because the motions of the targets are unknown. An effective algorithm is proposed for echo detection and orbit estimation of the faint echoes from space debris. The characteristics of the evaluation function are utilized by the algorithm. Experiments show the proposed algorithm improves SNR by 8.32dB and enables estimation of orbital parameters accurately to allow for re-tracking with a single radar.

  16. Grain Handling and Storage.

    ERIC Educational Resources Information Center

    Harris, Troy G.; Minor, John

    This text for a secondary- or postecondary-level course in grain handling and storage contains ten chapters. Chapter titles are (1) Introduction to Grain Handling and Storage, (2) Elevator Safety, (3) Grain Grading and Seed Identification, (4) Moisture Control, (5) Insect and Rodent Control, (6) Grain Inventory Control, (7) Elevator Maintenance,…

  17. Is the Sky Really Falling? An Overview of Orbital Debris

    NASA Technical Reports Server (NTRS)

    Hull, Scott M.

    2015-01-01

    Orbital debris has been a prominent topic for a while, even before the movie Gravity came out. An anti-satellite test and a collision with an operational satellite both produced large highly-publicized debris clouds within recent years. While large objects like abandoned satellites and rocket bodies may be the most recognizable and identifiable concerns, a majority of the daily threat comes from the much more numerous smaller particles. In fact, small particle penetration continues to rank among the leading risks for manned space missions to the International Space Station and beyond. How much 'stuff' is up there, where did it come from, what harm can it do, and what is being done about it? These questions and more will be discussed.

  18. Conjunction challenges of low-thrust geosynchronous debris removal maneuvers

    NASA Astrophysics Data System (ADS)

    Anderson, Paul V.; Schaub, Hanspeter

    2016-06-01

    The conjunction challenges of low-thrust engines for continuous thrust re-orbiting of geosynchronous (GEO) objects to super-synchronous disposal orbits are investigated, with applications to end-of-life mitigation and active debris removal (ADR) technologies. In particular, the low maneuverability of low-thrust systems renders collision avoidance a challenging task. This study investigates the number of conjunction events a low-thrust system could encounter with the current GEO debris population during a typical re-orbit to 300 km above the GEO ring. Sensitivities to thrust level and initial longitude and inclination are evaluated, and the impact of delaying the start time for a re-orbiting maneuver is assessed. Results demonstrate that the mean number of conjunctions increases hyperbolically as thrust level decreases, but timing the start of the maneuver appropriately can reduce the average conjunction rate when lower thrust levels are applied.

  19. Laser-reactive protection of spacecraft from fine debris

    SciTech Connect

    Kuznetsov, L I; Savichev, V Yu; Tikhonov, N N

    1998-04-30

    An analysis is made of the optimal conditions for laser irradiation and of typical paths of man-made debris in laser-reactive protection of spacecraft. Protection is provided by the recoil momentum resulting from laser evaporation of the surface layers of a debris particle, which can change its path, thus avoiding an collision with a spacecraft. Estimates are obtained of changes in the paths of particles with a characteristic size 1 cm when they are irradiated by radiation from a laser located on the protected spacecraft moving along one of the circular orbits at altitudes of 200, 400, or 700 km above the Earth's surface. (laser applications and other topics in quantum electronics)

  20. Debris flows: Experiments and modelling

    NASA Astrophysics Data System (ADS)

    Turnbull, Barbara; Bowman, Elisabeth T.; McElwaine, Jim N.

    2015-01-01

    Debris flows and debris avalanches are complex, gravity-driven currents of rock, water and sediments that can be highly mobile. This combination of component materials leads to a rich morphology and unusual dynamics, exhibiting features of both granular materials and viscous gravity currents. Although extreme events such as those at Kolka Karmadon in North Ossetia (2002) [1] and Huascarán (1970) [2] strongly motivate us to understand how such high levels of mobility can occur, smaller events are ubiquitous and capable of endangering infrastructure and life, requiring mitigation. Recent progress in modelling debris flows has seen the development of multiphase models that can start to provide clues of the origins of the unique phenomenology of debris flows. However, the spatial and temporal variations that debris flows exhibit make this task challenging and laboratory experiments, where boundary and initial conditions can be controlled and reproduced, are crucial both to validate models and to inspire new modelling approaches. This paper discusses recent laboratory experiments on debris flows and the state of the art in numerical models.

  1. Methodology of design and analysis of external walls of space station for hypervelocity impacts by meteoroids and space debris

    NASA Technical Reports Server (NTRS)

    Batla, F. A.

    1986-01-01

    The development of criteria and methodology for the design and analysis of Space Station wall elements for collisions with meteoroids and space debris at hypervelocities is discussed. These collisions will occur at velocities of 10 km/s or more and can be damaging to the external wall elements of the Space Station. The wall elements need to be designed to protect the pressurized modules of the Space Station from functional or structural failure due to these collisions at hypervelocities for a given environment and population of meteoroids and space debris. The design and analysis approach and the associated computer program presented is to achieve this objective, including the optimization of the design for a required overall probability of no penetration. The approach is based on the presently available experimental and actual data on meteoroids and space debris flux and damage assessments and the empirical relationships resulting from the hypervelocity impact studies in laboratories.

  2. Active Debris Removal System Based on Polyurethane Foam

    NASA Astrophysics Data System (ADS)

    Rizzitelli, Federico; Valdatta, Marcelo; Bellini, Niccolo; Candini Gian, Paolo; Rastelli, Davide; Romei, Fedrico; Locarini, Alfredo; Spadanuda, Antonio; Bagassi, Sara

    2013-08-01

    Space debris is an increasing problem. The exponential increase of satellite launches in the last 50 years has determined the problem of space debris especially in LEO. The remains of past missions are dangerous for both operative satellites and human activity in space. But not only: it has been shown that uncontrolled impacts between space objects can lead to a potentially dangerous situation for civil people on Earth. It is possible to reach a situation of instability where the big amount of debris could cause a cascade of collisions, the so called Kessler syndrome, resulting in the infeasibility of new space missions for many generations. Currently new technologies for the mitigation of space debris are under study: for what concerning the removal of debris the use of laser to give a little impulse to the object and push it in a graveyard orbit or to be destroyed in the atmosphere. Another solution is the use of a satellite to rendezvous with the space junk and then use a net to capture it and destroy it in the reentry phase. In a parallel way the research is addressed to the study of deorbiting solutions to prevent the formation of new space junk. The project presented in this paper faces the problem of how to deorbit an existing debris, applying the studies about the use of polyurethane foam developed by Space Robotic Group of University of Bologna. The research is started with the Redemption experiment part of last ESA Rexus program. The foam is composed by two liquid components that, once properly mixed, trig an expansive reaction leading to an increase of volume whose entity depends on the chemical composition of the two starting components. It is possible to perform two kind of mission: 1) Not controlled removal: the two components are designed to react producing a low density, high expanded, spongy foam that incorporates the debris. The A/m ratio of the debris is increased and in this way also the ballistic parameter. As a consequence, the effect of

  3. A Collisional Algorithm for Modeling Circumstellar Debris Disks

    NASA Technical Reports Server (NTRS)

    Nesvold, Erika; Kuchner, Marc

    2011-01-01

    Many planetary systems harbor circumstellar disks of dust and planetesimals thought to be debris left over from planet formation. These debris disks exhibit a range of morphological features which can arise from the gravitational perturbations of planets. Accurate models of these features, accounting for the interactions of the particles in a disk with each other and with whatever planets they contain, can act as signposts for planets in debris disks that otherwise could not be detected. Such models can also constrain the planet's mass and orbital parameters. Current models for many disks consider the gravitational and radiative effects of the star and planets on the disk, but neglect the morphological consequences of collisional interactions between the planetesimals. Many observed disk features are not satisfactorily explained by the current generation of models. I am developing a new kind of debris disk model that considers both the gravitational shaping of the disk by planets and the inelastic collisions between particles. I will use a hybrid N-body integrator to numerically solve the equations of motion for the particles and planets in the disk. To include the collisional effects, I begin with an algorithm that tests for collisions at each step of the orbit integration and readjusts the velocities of colliding particles. I am adapting this algorithm to the problem at hand by allowing each particle to represent a "swarm" of planetesimals with a range of masses. When the algorithm detects an encounter between swarms, two or three swarms are produced to approximate the range of possible trajectories of the daughter planetesimals. Here I present preliminary results from my collisional algorithm.

  4. The New NASA Orbital Debris Engineering Model ORDEM 3.0

    NASA Technical Reports Server (NTRS)

    Krisko, P. H.

    2014-01-01

    The NASA Orbital Debris Program Office (ODPO) has released its latest Orbital Debris Engineering Model, ORDEM 3.0. It supersedes ORDEM 2.0. This newer model encompasses the Earth satellite and debris flux environment from altitudes of low Earth orbit (LEO) through geosynchronous orbit (GEO). Debris sizes of 10 microns through 1 m in non-GEO and 10 cm through 1 m in GEO are modeled. The inclusive years are 2010 through 2035. The ORDEM model series has always been data driven. ORDEM 3.0 has the benefit of many more hours from existing data sources and from new sources that weren't available to past versions. Returned surfaces, ground tests, and remote sensors all contribute data. The returned surface and ground test data reveal material characteristics of small particles. Densities of fragmentation debris particles smaller than 10 cm are grouped in ORDEM 3.0 in terms of high-, medium-, and lowdensities, along with RORSAT sodium-potassium droplets. Supporting models have advanced significantly. The LEO-to-GEO ENvironment Debris model (LEGEND) includes an historical and a future projection component with yearly populations that include launched and maneuvered intacts, mission related debris (MRD), and explosion and collision fragments. LEGEND propagates objects with ephemerides and physical characteristics down to 1 mm in size. The full LEGEND yearly population acts as an a priori condition for a Bayesian statistical model. Specific, well defined populations are added like the Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium (NaK) droplets, recent major accidental and deliberate collision fragments, and known anomalous debris event fragments. For microdebris of sizes 10 microns to 1 mm the ODPO uses an in-house Degradation/Ejecta model in which a MLE technique is used with returned surface data to estimate populations. This paper elaborates on the upgrades of this model over previous versions highlighting the material density splits and consequences of

  5. NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0

    NASA Technical Reports Server (NTRS)

    Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.

    2013-01-01

    The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.

  6. A laser-optical system to re-enter or lower low Earth orbit space debris

    NASA Astrophysics Data System (ADS)

    Phipps, Claude R.

    2014-01-01

    Collisions among existing Low Earth Orbit (LEO) debris are now a main source of new debris, threatening future use of LEO space. Due to their greater number, small (1-10 cm) debris are the main threat, while large (>10 cm) objects are the main source of new debris. Flying up and interacting with each large object is inefficient due to the energy cost of orbit plane changes, and quite expensive per object removed. Strategically, it is imperative to remove both small and large debris. Laser-Orbital-Debris-Removal (LODR), is the only solution that can address both large and small debris. In this paper, we briefly review ground-based LODR, and discuss how a polar location can dramatically increase its effectiveness for the important class of sun-synchronous orbit (SSO) objects. With 20% clear weather, a laser-optical system at either pole could lower the 8-ton ENVISAT by 40 km in about 8 weeks, reducing the hazard it represents by a factor of four. We also discuss the advantages and disadvantages of a space-based LODR system. We estimate cost per object removed for these systems. International cooperation is essential for designing, building and operating any such system.

  7. Linear Collisions

    ERIC Educational Resources Information Center

    Walkiewicz, T. A.; Newby, N. D., Jr.

    1972-01-01

    A discussion of linear collisions between two or three objects is related to a junior-level course in analytical mechanics. The theoretical discussion uses a geometrical approach that treats elastic and inelastic collisions from a unified point of view. Experiments with a linear air track are described. (Author/TS)

  8. Changes of Space Debris Orbits After LDR Operation

    NASA Astrophysics Data System (ADS)

    Wnuk, E.; Golebiewska, J.; Jacquelard, C.; Haag, H.

    2013-09-01

    A lot of technical studies are currently developing concepts of active removal of space debris to protect space assets from on orbit collision. For small objects, such concepts include the use of ground-based lasers to remove or reduce the momentum of the objects thereby lowering their orbit in order to facilitate their decay by re-entry into the Earth's atmosphere. The concept of the Laser Debris Removal (LDR) system is the main subject of the CLEANSPACE project. One of the CLEANSPACE objectives is to define a global architecture (including surveillance, identification and tracking) for an innovative ground-based laser solution, which can remove hazardous medium debris around selected space assets. The CLEANSPACE project is realized by a European consortium in the frame of the European Commission Seventh Framework Programme (FP7), Space topic. The use of sequence of laser operations to remove space debris, needs very precise predictions of future space debris orbital positions, on a level even better than 1 meter. Orbit determination, tracking (radar, optical and laser) and orbit prediction have to be performed with accuracy much better than so far. For that, the applied prediction tools have to take into account all perturbation factors that influence object orbit. The expected object's trajectory after the LDR operation is a lowering of its perigee. To prevent the debris with this new trajectory to collide with another object, a precise trajectory prediction after the LDR sequence is therefore the main task allowing also to estimate re-entry parameters. The LDR laser pulses change the debris object velocity v. The future orbit and re-entry parameters of the space debris after the LDR engagement can be calculated if the resulting ?v vector is known with the sufficient accuracy. The value of the ?v may be estimated from the parameters of the LDR station and from the characteristics of the orbital debris. However, usually due to the poor knowledge of the debris

  9. Omnidirectional Actuator Handle

    NASA Technical Reports Server (NTRS)

    Moetteli, John B.

    1995-01-01

    Proposed actuator handle comprises two normally concentric rings, cables, and pulleys arranged such that relative displacement of rings from concentricity results in pulling of cable and consequent actuation of associated mechanism. Unlike conventional actuator handles like levers on farm implements, actuated from one or two directions only, proposed handle reached from almost any direction and actuated by pulling or pushing inner ring in any direction with respect to outer ring. Flanges installed on inner ring to cover gap between inner ring and housing to prevent clothing from being caught.

  10. Debris about asteroids: Where and how much?

    NASA Technical Reports Server (NTRS)

    Burns, Joseph A.; Hamilton, Douglas P.

    1992-01-01

    We summarize several recent findings on the size and shape of the region within which material can stably orbit an asteroid. If the asteroid (with assumed density 2.38 g/cu cm) circles the Sun at 2.55 AU, co-planar prograde material will remain trapped whenever started on unperturbed circular orbits at less than about 220 R(sub A) (asteroid radii); co-planar retrograde particles are stable out twice as far. Our 3-D stability surface, which encloses several hundred numerically calculated orbits that start with various inclinations, is shaped like a sphere with its top and bottom sliced off; its dimensions scale like the Hill radius =(mu/3)(exp 1/3)R, where mu is the asteroid-to-solar mass ratio and R is the asteroid's orbital radius. If the asteroid moves along an elliptical orbit, a fairly reliable indicator of the dimensions of the hazard zone is the size of its Hill sphere at the orbit's pericenter. Grains with radii less than a few mm will be lost through the action of radiation forces which can induce escape or cause collisions with the asteroid on times scales of a few years; interplanetary micrometeoroids produce collisional break-up of these particles in approximately 10(exp 4) yrs. The effects of Jupiter and of asteroids that pass close to the target asteroid allow particles to diffuse from the system, again shrinking the hazard zone. None of the considered sources-primordial formation, debris spalled off the asteroid during micrometeoroid impact, captured interplanetary particles, feeder satellites, etc., seem capable of densely populating distant orbits from the asteroid. No certain detections of debris clouds or of binary asteroids have been made. Thus, it seems highly unlikely that a spacecraft fly-by targeted at 100 R(sub A) from the asteroid over its orbital pole would encounter any material.

  11. Optical Observations of Space Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Abercromby, Kira; Rodriquez, Heather; Barker, Edwin S.; Kelecy, Thomas

    2008-01-01

    This viewgraph presentation reviews the use of optical telescopes to observe space debris. .It will present a brief review of how the survey is conducted, and what some of the significant results encompass. The goal is to characterize the population of debris objects at GEO, with emphasis on the faint object population. Because the survey observations extend over a very short arc (5 minutes), a full six parameter orbit can not be determined. Recently we have begun to use a second telescope, the 0.9-m at CTIO, as a chase telescope to do follow-up observations of potential GEO debris candidates found by MODEST. With a long enough sequence of observations, a full six-parameter orbit including eccentricity can be determined. The project has used STK since inception for planning observing sessions based on the distribution of bright cataloged objects and the anti-solar point (to avoid eclipse). Recently, AGI's Orbit Determination Tool Kit (ODTK) has been used to determine orbits, including the effects of solar radiation pressure. Since an unknown fraction of the faint debris at GEO has a high area-to-mass ratio (A/M), the orbits are perturbed significantly by solar radiation. The ODTK analysis results indicate that temporal variations in the solar perturbations, possibly due to debris orientation dynamics, can be estimated in the OD process. Additionally, the best results appear to be achieved when solar forces orthogonal to the object-Sun line are considered. Determining the A/M of individual objects and the distribution of A/M values of a large sample of debris is important to understanding the total population of debris at GEO

  12. LIDT-DD: A new self-consistent debris disc model that includes radiation pressure and couples dynamical and collisional evolution

    NASA Astrophysics Data System (ADS)

    Kral, Q.; Thébault, P.; Charnoz, S.

    2013-10-01

    Context. In most current debris disc models, the dynamical and the collisional evolutions are studied separately with N-body and statistical codes, respectively, because of stringent computational constraints. In particular, incorporating collisional effects (especially destructive collisions) into an N-body scheme has proven a very arduous task because of the exponential increase of particles it would imply. Aims: We present here LIDT-DD, the first code able to mix both approaches in a fully self-consistent way. Our aim is for it to be generic enough to be applied to any astrophysical case where we expect dynamics and collisions to be deeply interlocked with one another: planets in discs, violent massive breakups, destabilized planetesimal belts, bright exozodiacal discs, etc. Methods: The code takes its basic architecture from the LIDT3D algorithm for protoplanetary discs, but has been strongly modified and updated to handle the very constraining specificities of debris disc physics: high-velocity fragmenting collisions, radiation-pressure affected orbits, absence of gas that never relaxes initial conditions, etc. It has a 3D Lagrangian-Eulerian structure, where grains of a given size at a given location in a disc are grouped into super-particles or tracers whose orbits are evolved with an N-body code and whose mutual collisions are individually tracked and treated using a particle-in-a-box prescription designed to handle fragmenting impacts. To cope with the wide range of possible dynamics for same-sized particles at any given location in the disc, and in order not to lose important dynamical information, tracers are sorted and regrouped into dynamical families depending on their orbits. A complex reassignment routine that searches for redundant tracers in each family and reassignes them where they are needed, prevents the number of tracers from diverging. Results: The LIDT-DD code has been successfully tested on simplified cases for which robust results have

  13. Determining the effects of space debris impacts on spacecraft structures

    NASA Astrophysics Data System (ADS)

    Tedeschi, William J.; Connell, John C.; McKnight, Darren S.; Allahdadi, Firooz; Reinhardt, Al; Hunt, Ronald D.; Hogg, David M.

    1992-07-01

    A Spacecraft Breakup Modeling Program initiated by the Defense Nuclear Agency (DNA) in support of the DoD/NASA/DOT Orbital Debris Research Plan is discussed. The program is aimed at improving the accuracy and usefulness of satellite breakup models, with an emphasis on collision-induced events. The program encompasses hypervelocity impact tests, developing predictive models based on the analysis of test result, transferring appropriate technology to avoid duplication of effort, and continually interacting with DNA customers to identify and refine their specific technology needs.

  14. Real-time ground-based optical detection system for space debris

    NASA Astrophysics Data System (ADS)

    Marchant, Jonathan; Green, Simon; Dick, James

    1996-10-01

    There are many advantages to supplementing ground based radar debris detection systems with optical systems. For example: objects with a low radar signature can still be optically bright (and vice versa); in the field of space debris optical detection is less sensitive to range; the minimum detectable debris size for a given range is less than that for radar. Destructive debris can be as small as 1 cm, so any improvement in detection sensitivity towards this standard is important. To improve the accuracy of debris orbital elements, a real-time detection system might be preferable in contrast to one in which images are stored for post-observation ('daytime') analysis. This is because more than one telescope is needed to lengthen the observing baseline and so increase the detected fraction of the debris orbit. Therefore, any software based at one telescope that recognizes debris in its field of view, produces a first approximation of its orbit elements and alerts extra telescopes along track, must process its data quickly, and preferably during the same pass. A prototype of such a software system under development for use with a CCD camera at the Royal Greenwich Observatory's satellite laser ranger at Herstmonceux, East Sussex, England, is outlined. The methods which the detection algorithm employs to handle data from the camera system are described, along with the limitations that the hardware and processing time impose on the physical nature of the problem.

  15. Handling Pyrophoric Reagents

    SciTech Connect

    Alnajjar, Mikhail S.; Haynie, Todd O.

    2009-08-14

    Pyrophoric reagents are extremely hazardous. Special handling techniques are required to prevent contact with air and the resulting fire. This document provides several methods for working with pyrophoric reagents outside of an inert atmosphere.

  16. Helicopter Handling Qualities

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Helicopters are used by the military and civilian communities for a variety of tasks and must be capable of operating in poor weather conditions and at night. Accompanying extended helicopter operations is a significant increase in pilot workload and a need for better handling qualities. An overview of the status and problems in the development and specification of helicopter handling-qualities criteria is presented. Topics for future research efforts by government and industry are highlighted.

  17. Biological response to prosthetic debris

    PubMed Central

    Bitar, Diana; Parvizi, Javad

    2015-01-01

    Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic host response to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics (size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression. PMID:25793158

  18. Biological response to prosthetic debris.

    PubMed

    Bitar, Diana; Parvizi, Javad

    2015-03-18

    Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic host response to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics (size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression. PMID:25793158

  19. A Comparison of Catastrophic On-Orbit Collisions

    NASA Astrophysics Data System (ADS)

    Stansbery, G.; Matney, M.; Liou, J.; Whitlock, D.

    Orbital debris environment models, such as NASA's LEGEND model, show that accidental collisions between satellites will begin to be the dominant cause for future debris population growth within the foreseeable future. The collisional breakup models employed are obviously a critical component of the environment models. The Chinese Anti-Satellite (ASAT) test which destroyed the Fengyun-1C weather satellite provided a rare, but not unique, chance to compare the breakup models against an actual on-orbit collision. Measurements from the U.S. Space Surveillance Network (SSN), for debris larger than 10-cm, and from Haystack, for debris larger than 1-cm, show that the number of fragments created from Fengyun significantly exceeds model predictions using the NASA Standard Collision Breakup Model. However, it may not be appropriate to alter the model to match this one, individual case. At least three other on-orbit collisions have occurred which have produced significant numbers of debris fragments. In September 1985, the U.S. conducted an ASAT test against the Solwind P-78 spacecraft at an altitude of approximately 525 km. A year later, in September 1986, the Delta 180 payload was struck by its Delta II rocket body in a planned collision at 220 km altitude. And, in February 2008, the USA-193 satellite was destroyed by a ship launched missile in order to eliminate risk to humans on the ground from an on-board tank of frozen hydrazine. Although no Haystack data was available in 1985-6 and very few debris pieces were cataloged from Delta 180 due to its low altitude, measurements were collected sensors in the days after each test. This paper will examine the available data from each test and compare and contrast the results with model predictions and with the results from the more recent Fengyun ASAT test.

  20. The Near-Earth Orbital Debris Problem and the Challenges for Environment Remediation

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi

    2012-01-01

    The near-Earth space environment has been gradually polluted with orbital debris (OD) since the beginning of space activities 55 years ago. Although this problem has been known to the research community for decades, the public was, in general, unaware of the issue until the anti-satellite test conducted by China in 2007 and the collision between Cosmos 2251 and the operational Iridium 33 in 2009. The latter also underlined the potential of an ongoing collision cascade effect (the "Kessler Syndrome") in the low Earth orbit (LEO, the region below 2000 km altitude). Recent modeling results have indicated that mitigation measures commonly adopted by the international space community will be insufficient to stabilize the LEO debris population. To better limit the OD population increase, more aggressive actions must be considered. There are three options for OD environment remediation-removal of large/massive intact objects to address the root cause of the OD population growth problem, removal of 5-mm-to-1 cm debris to mitigate the main mission-ending threats for the majority of operational spacecraft, and prevention of major debris-generating collisions as a temporary means to slow down the OD population increase. The technology, engineering, and cost challenges to carry out any of these three options are monumental. It will require innovative ideas, game-changing technologies, and major collaborations at the international level to address the OD problem and preserve the near-Earth environment for future generations.

  1. A Deterministic Approach to Active Debris Removal Target Selection

    NASA Astrophysics Data System (ADS)

    Lidtke, A.; Lewis, H.; Armellin, R.

    2014-09-01

    Many decisions, with widespread economic, political and legal consequences, are being considered based on space debris simulations that show that Active Debris Removal (ADR) may be necessary as the concerns about the sustainability of spaceflight are increasing. The debris environment predictions are based on low-accuracy ephemerides and propagators. This raises doubts about the accuracy of those prognoses themselves but also the potential ADR target-lists that are produced. Target selection is considered highly important as removal of many objects will increase the overall mission cost. Selecting the most-likely candidates as soon as possible would be desirable as it would enable accurate mission design and allow thorough evaluation of in-orbit validations, which are likely to occur in the near-future, before any large investments are made and implementations realized. One of the primary factors that should be used in ADR target selection is the accumulated collision probability of every object. A conjunction detection algorithm, based on the smart sieve method, has been developed. Another algorithm is then applied to the found conjunctions to compute the maximum and true probabilities of collisions taking place. The entire framework has been verified against the Conjunction Analysis Tools in AGIs Systems Toolkit and relative probability error smaller than 1.5% has been achieved in the final maximum collision probability. Two target-lists are produced based on the ranking of the objects according to the probability they will take part in any collision over the simulated time window. These probabilities are computed using the maximum probability approach, that is time-invariant, and estimates of the true collision probability that were computed with covariance information. The top-priority targets are compared, and the impacts of the data accuracy and its decay are highlighted. General conclusions regarding the importance of Space Surveillance and Tracking for the

  2. Active Space Debris Removal using European Modified Launch Vehicle Upper Stages Equipped with Electrodynamic Tethers

    NASA Astrophysics Data System (ADS)

    Nasseri, Ali S.; Emanuelli, Matteo; Raval, Siddharth; Turconi, Andrea; Becker, Cristoph

    2013-08-01

    During the past few years, several research programs have assessed the current state and future evolution of the Low Earth Orbit region. These studies indicate that space debris density could reach a critical level such that there will be a continuous increase in the number of debris objects, primarily driven by debris-debris collision activity known as the Kessler effect. This cascade effect can be even more significant when intact objects as dismissed rocket bodies are involved in the collision. The majority of the studies until now have highlighted the urgency for active debris removal in the next years. An Active Debris Removal System (ADRS) is a system capable of approaching the debris object through a close-range rendezvous, establishing physical connection, stabilizing its attitude and finally de-orbiting the debris object using a type of propulsion system in a controlled manoeuvre. In its previous work, this group showed that a modified Fregat (Soyuz FG's 4th stage) or Breeze-M upper stage (Proton-M) launched from Plesetsk (Russian Federation) and equipped with an electro-dynamic tether (EDT) system can be used, after an opportune inclination's change, to de-orbit a Kosmos-3M second stage rocket body while also delivering an acceptable payload to orbit. In this paper, we continue our work on the aforementioned concept, presented at the 2012 Beijing Space Sustainability Conference, by comparing its performance to ADR missions using only chemical propulsion from the upper stage for the far approach and the de-orbiting phase. We will also update the EDT model used in our previous work and highlight some of the methods for creating physical contact with the object. Moreover, we will assess this concept also with European launch vehicles (Vega and Soyuz 2-1A) to remove space debris from space. In addition, the paper will cover some economic aspects, like the cost for the launches' operator in term of payload mass' loss at the launch. The entire debris removal

  3. Debris Flows and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Ancey, C.

    Torrential floods are a major natural hazard, claiming thousands of lives and millions of dollars in lost property each year in almost all mountain areas on the Earth. After a catastrophic eruption of Mount St. Helen in the USA in May 1980, water from melting snow, torrential rains from the eruption cloud, and water displaced from Spirit Lake mixed with deposited ash and debris to produce very large debris flows and cause extensive damage and loss of life [1]. During the 1985 eruption of Nevado del Ruiz in Colombia, more than 20,000 people perished when a large debris flow triggered by the rapid melting of snow and ice at the volcano summit, swept through the town of Armero [2]. In 1991, the eruption of Pinatubo volcano in the Philippines disperses more than 5 cubic kilometres of volcanic ash into surrounding valleys. Much of that sediment has subsequently been mobilised as debris flows by typhoon rains and has devastated more than 300 square kilometres of agricultural land. Even, in Eur opean countries, recent events that torrential floods may have very destructive effects (Sarno and Quindici in southern Italy in May 1998, where approximately 200 people were killed). The catastrophic character of these floods in mountainous watersheds is a consequence of significant transport of materials associated with water flows. Two limiting flow regimes can be distinguished. Bed load and suspension refer to dilute transport of sediments within water. This means that water is the main agent in the flow dynamics and that the particle concentration does not exceed a few percent. Such flows are typically two-phase flows. In contrast, debris flows are mas s movements of concentrated slurries of water, fine solids, rocks and boulders. As a first approximation, debris flows can be treated as one-phase flows and their flow properties can be studied using classical rheological methods. The study of debris flows is a very exciting albeit immature science, made up of disparate elements

  4. Acoustophoretic contactless transport and handling of matter

    NASA Astrophysics Data System (ADS)

    Foresti, Daniele; Nabavi, Majid; Klingauf, Mirko; Ferrari, Aldo; Poulikakos, Dimos

    2013-11-01

    Levitation and controlled motion of matter in air, has a wealth of potential applications ranging from materials processing to biochemistry and pharmaceuticals. We present a novel acoustophoretic concept, for the contactless transport and handling of matter in air. Spatiotemporal modulation of the levitation acoustic field allows continuous planar transport and processing of multiple objects (volume 0.1-10 μl) . The independence of the handling principle from special material properties (magnetic, optical or electrical) is illustrated with a wide palette of application experiments, such as contactless droplet coalescence and mixing, solid-liquid encapsulation, absorption, dissolution, and DNA transfection. The dynamics of droplets and particles collision is studied numerically and experimentally. The findings show that the secondary acoustic force gives a significant contribution to the samples impact velocity. We thank the Swiss National Science Foundation (Grant 144397) for financial support.

  5. A Sensitivity Study on the Effectiveness of Active Debris Removal in LEO

    NASA Technical Reports Server (NTRS)

    Liou, J. C.; Johnson, Nicholas L.

    2007-01-01

    The near-Earth orbital debris population will continue to increase in the future due to ongoing space activities, on-orbit explosions, and accidental collisions among resident space objects. Commonly adopted mitigation measures, such as limiting postmission orbital lifetimes of satellites to less than 25 years, will slow down the population growth, but may be insufficient to stabilize the environment. The nature of the growth, in the low Earth orbit (LEO) region, is further demonstrated by a recent study where no future space launches were conducted in the environment projection simulations. The results indicate that, even with no new launches, the LEO debris population would remain relatively constant for only the next 50 years. Beyond that, the debris population would begin to increase noticeably, due to the production of collisional debris. Therefore, to better limit the growth of future debris population to protect the environment, remediation option, i.e., removing existing large and massive objects from orbit, needs to be considered. This paper does not intend to address the technical or economical issues for active debris removal. Rather, the objective is to provide a sensitivity study to quantify the effectiveness of various remediation options. A removal criterion based upon mass and collision probability is developed to rank objects at the beginning of each projection year. This study includes simulations with removal rates ranging from 2 to 20 objects per year, starting in the year 2020. The outcome of each simulation is analyzed, and compared with others. The summary of the study serves as a general guideline for future debris removal consideration.

  6. The New NASA Orbital Debris Engineering Model ORDEM 3.0

    NASA Technical Reports Server (NTRS)

    Krisko, P. H.

    2014-01-01

    The NASA Orbital Debris Program Office (ODPO) has released its latest Orbital Debris Engineering Model, ORDEM 3.0. It supersedes ORDEM 2000, now referred to as ORDEM 2.0. This newer model encompasses the Earth satellite and debris flux environment from altitudes of low Earth orbit (LEO) through geosynchronous orbit (GEO). Debris sizes of 10 micron through larger than 1 m in non-GEO and 10 cm through larger than 1 m in GEO are available. The inclusive years are 2010 through 2035. The ORDEM model series has always been data driven. ORDEM 3.0 has the benefit of many more hours of data from existing sources and from new sources than past ORDEM versions. The object data range in size from 10 µm to larger than 1 m, and include in situ and remote measurements. The in situ data reveals material characteristics of small particles. Mass densities are grouped in ORDEM 3.0 in terms of 'high-density', represented by 7.9 g/cc, 'medium-density' represented by 2.8 g/cc and 'low-density' represented by 1.4 g/cc. Supporting models have also advanced significantly. The LEO-to-GEO ENvironment Debris model (LEGEND) includes an historical and a future projection component with yearly populations that include launched and maneuvered intact spacecraft and rocket bodies, mission related debris, and explosion and collision event fragments. LEGEND propagates objects with ephemerides and physical characteristics down to 1 mm in size. The full LEGEND yearly population acts as an a priori condition for a Bayesian statistical model. Specific populations are added from sodium potassium droplet releases, recent major accidental and deliberate collisions, and known anomalous debris events. This paper elaborates on the upgrades of this model over previous versions. Sample validation results with remote and in situ measurements are shown, and the consequences of including material density are discussed as it relates to heightened risks to crewed and robotic spacecraft

  7. DebriSat Project Update and Planning

    NASA Technical Reports Server (NTRS)

    Sorge, M.; Krisko, P. H.

    2016-01-01

    DebriSat Reporting Topics: DebriSat Fragment Analysis Calendar; Near-term Fragment Extraction Strategy; Fragment Characterization and Database; HVI (High-Velocity Impact) Considerations; Requirements Document.

  8. 14 CFR 417.211 - Debris analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... activation; (2) Launch vehicle explosion; (3) Aerodynamic loads; (4) Inertial loads; (5) Atmospheric reentry heating; and (6) Impact of intact vehicle. (c) Debris fragment lists. A debris analysis must produce...

  9. 14 CFR 417.211 - Debris analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... activation; (2) Launch vehicle explosion; (3) Aerodynamic loads; (4) Inertial loads; (5) Atmospheric reentry heating; and (6) Impact of intact vehicle. (c) Debris fragment lists. A debris analysis must produce...

  10. NASA Orbital Debris Requirements and Best Practices

    NASA Technical Reports Server (NTRS)

    Hull, Scott

    2014-01-01

    Limitation of orbital debris accumulation is an international and national concern, reflectedin NASA debris limitation requirements. These requirements will be reviewed, along with some practices that can be employed to achieve the requirements.