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Jer-Chyi Liou

Bio: Jer-Chyi Liou is an academic researcher. The author has contributed to research in topics: Space debris & Debris. The author has an hindex of 16, co-authored 59 publications receiving 2069 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors compare the new breakup model to the old breakup model in detail, including the size distributions for explosions and collisions, the area-to-mass and impact velocity assignments and distributions, and the delta-velocity distributions.

337 citations

Journal ArticleDOI
20 Jan 2006-Science
TL;DR: The LEGEND (LEO-to-GEO Environment Debris model) is a high-fidelity three-dimensional physical model developed by the U.S. National Aeronautics and Space Administration (NASA) that is capable of simulating the historical environment and the evolution of future debris populations as discussed by the authors.
Abstract: 340 C R E D IT : (T O P ) N A S A S ince the launch of Sputnik I, 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 9000 Earth-orbiting man-made objects (including many breakup fragments), with a combined mass exceeding 5 million kg, are tracked by the U.S. Space Surveillance Network and maintained in the U.S. satellite catalog (3–5). Three accidental collisions between catalogued objects 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. The most recent (January 2005) was between a 31-year-old U.S. rocket body and a fragment from the third stage of a Chinese CZ-4 launch vehicle that had exploded in March 2000. Several studies conducted during 1991–2001 demonstrated, with assumed future launch rates, the potential increase in the Earth satellite population, resulting from random, accidental collisions among resident space objects (7–13). In some low Earth orbit (LEO) altitude regimes, where the number density of objects is above a critical spatial density, the production rate of new debris due to collisions exceeds the loss of objects due to orbital decay. LEGEND (LEO-to-GEO Environment Debris model), is a highfidelity three-dimensional physical model developed by the U.S. National Aeronautics and Space Administration (NASA) that is capable of simulating the historical environment, as well as the evolution of future debris populations (14, 15). The LEGEND future projection adopts a Monte Carlo approach to simulate future onorbit explosions and collisions (16). A total of 50 (17), 200-year future projection Monte Carlo simulations were executed and evaluated, under the assumptions that no rocket bodies and spacecraft were launched after December 2004 and that no future disposal maneuvers were allowed for existing spacecraft (few of which currently have such a capability) (18). The simulated 10-cm and larger debris populations in LEO (defined as the region between altitudes of 200 and 2000 km) between 1957 and the end of a 200-year future projection period

324 citations

Journal ArticleDOI
TL;DR: A new sensitivity study on using ADR to stabilize the future LEO debris environment is described, using the NASA long-term orbital debris evolutionary model, LEGEND, to quantify the effects of several key parameters, including target selection criteria/constraints and the starting epoch of ADR implementation.

320 citations

Journal ArticleDOI
TL;DR: In this article, a removal criterion based upon mass and collision probability is developed to rank objects at the beginning of each projection year, with removal rates ranging from 2 to 20 objects per year, starting in the year 2020.

205 citations

Journal ArticleDOI
TL;DR: In this article, a new study has been conducted in the Orbital Debris Program Office at the NASA Lyndon B. Johnson Space Center, using higher fidelity models to evaluate the current debris environment.

193 citations


Cited by
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Journal ArticleDOI
TL;DR: This paper provides review and comparison of the existing technologies on active space debris capturing and removal, and reviews research areas worth investigating under each capture and removal method.

527 citations

Journal ArticleDOI
20 Jan 2006-Science
TL;DR: The LEGEND (LEO-to-GEO Environment Debris model) is a high-fidelity three-dimensional physical model developed by the U.S. National Aeronautics and Space Administration (NASA) that is capable of simulating the historical environment and the evolution of future debris populations as discussed by the authors.
Abstract: 340 C R E D IT : (T O P ) N A S A S ince the launch of Sputnik I, 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 9000 Earth-orbiting man-made objects (including many breakup fragments), with a combined mass exceeding 5 million kg, are tracked by the U.S. Space Surveillance Network and maintained in the U.S. satellite catalog (3–5). Three accidental collisions between catalogued objects 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. The most recent (January 2005) was between a 31-year-old U.S. rocket body and a fragment from the third stage of a Chinese CZ-4 launch vehicle that had exploded in March 2000. Several studies conducted during 1991–2001 demonstrated, with assumed future launch rates, the potential increase in the Earth satellite population, resulting from random, accidental collisions among resident space objects (7–13). In some low Earth orbit (LEO) altitude regimes, where the number density of objects is above a critical spatial density, the production rate of new debris due to collisions exceeds the loss of objects due to orbital decay. LEGEND (LEO-to-GEO Environment Debris model), is a highfidelity three-dimensional physical model developed by the U.S. National Aeronautics and Space Administration (NASA) that is capable of simulating the historical environment, as well as the evolution of future debris populations (14, 15). The LEGEND future projection adopts a Monte Carlo approach to simulate future onorbit explosions and collisions (16). A total of 50 (17), 200-year future projection Monte Carlo simulations were executed and evaluated, under the assumptions that no rocket bodies and spacecraft were launched after December 2004 and that no future disposal maneuvers were allowed for existing spacecraft (few of which currently have such a capability) (18). The simulated 10-cm and larger debris populations in LEO (defined as the region between altitudes of 200 and 2000 km) between 1957 and the end of a 200-year future projection period

324 citations

Journal ArticleDOI
TL;DR: A new sensitivity study on using ADR to stabilize the future LEO debris environment is described, using the NASA long-term orbital debris evolutionary model, LEGEND, to quantify the effects of several key parameters, including target selection criteria/constraints and the starting epoch of ADR implementation.

320 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented 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.

258 citations

Journal ArticleDOI
TL;DR: In this article, a removal criterion based upon mass and collision probability is developed to rank objects at the beginning of each projection year, with removal rates ranging from 2 to 20 objects per year, starting in the year 2020.

205 citations