National Aeronautics and Space Administration Orbital Debris Quarterly News Volume 15, Issue 4 October 2011 Reentry of NASA Satellite Inside... Following a highly successful atmospheric of these components were used up to four times monitoring mission lasting 14 years and an additional on UARS, the total number of surviving debris ERS-2 Maneuvered 6 years in a gradually decaying disposal orbit, was expected to be 26 and distributed along a path Into Shorter-lived NASA’s Upper Atmosphere Research Satellite 800 km long, beginning about 500 km downrange of Disposal Orbit 2 (UARS) finally fell back to Earth early on the atmospheric interface noted above. All surviving AIAA Position Paper 24 September, GMT. The 5.7-metric-ton spacecraft debris is assessed as having fallen harmlessly into the on Space Debris 2 (International Designator 1991-063B, U.S. Satellite Pacific Ocean. Number 21701) entered the dense portion of the DoD-NASA Orbital atmosphere at 0400 GMT over the middle of the Reference Debris Removal Pacific Ocean at 14.1°S, 170.2°W. 1. A summary of this assessment was presented Workshop 3 An assessment of the survivability potential for at the 34th COSPAR Scientific Assembly: Rochelle, UARS had been conducted during 2001-2002 [1]. W.C., Marichalar, J.J., and Johnson, N.L. Analysis HIMS at NASA's Only 12 of 150 evaluated components were found of Reentry Survivability of UARS Spacecraft, 2011 D-RATS 3 likely to reach the surface of the Earth. Since some PEDAS1-B1.4-0029-02 (2002). ♦ Proper Implementation of the 1998 NASA 600 Breakup Model 4 Apogee Abstracts from the 550 Operational orbit, 1991-2005 NASA Orbital Debris Perigee Program Office 6 500 Meeting Report 9 Space Missions 450 and Satellite Box Score 10 400 Altitude (km) 350 Maneuver to disposal orbit and decommissioning, December 2005 300 250 A publication of 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 the NASA Orbital Year Debris Program Office Figure 1. Orbital history of UARS. Orbital Debris Quarterly News ERS-2 Maneuvered Into Shorter-lived Disposal Orbit The European Space Agency’s (ESA) orbit with a mean altitude of approximately oldest dedicated Earth observation satellite 570 km. From this orbit, the 2.1-metric-ton completed its highly successful mission of spacecraft is expected to fall back to Earth in providing surveillance of the world’s oceans, about 15 years, well within the recommendation land, ice, and atmosphere in July 2011 of a maximum postmission orbital lifetime of after more than 16 years in space. Known 25 years. Following the depletion of all ERS-2 as ERS-2 (the second European Remote propellants, the vehicle’s other systems were Sensing satellite), the spacecraft (International also passivated to eliminate the potential for a Designator 1995-021A, U.S. Satellite Number future explosion and the inadvertent creation 23560) operated in a sun-synchronous orbit of additional orbital debris. ♦ with a mean altitude near 785 km. In accordance with ESA and international guidelines, over a period of 2 months, ERS-2 was maneuvered more than 60 times into an Figure 1. Illustration of ERS-2 in orbit. AIAA Position Paper on Space Debris: 30 Years On The American Institute of Aeronautics about 5,000 objects in orbit around the Earth; and to predict more accurately the threat of and Astronautics (AIAA) was the first body to today that number has grown to over 22,000 hazardous collisions. The paper noted that publish a comprehensive technical and policy (Figure 1). operational procedures were being modified to assessment of orbital debris issues. The 30th Not surprisingly, the majority of the reduce the probability of collision with debris anniversary of that milestone paper was marked position paper was focused on the definition and that, with sound planning decisions, the in July 2011 with many of its findings and of the orbital debris environment and the problem of space debris was to some degree recommendations remaining as valid today as potential hazards it posed to operational controllable. three decades ago. spacecraft, both manned and robotic. At the The AIAA Position Paper on Space Following a presentation by NASA’s time very little was known about the population Debris then listed five fundamental policy Donald Kessler on “Sources of Orbital Debris of debris smaller than 10 cm, the nominal and procedural questions which needed to be and the Projected Environment for Future sensitivity limit of the U.S. Space Surveillance addressed: Spacecraft” at the May 1980 AIAA International Network, but much could be inferred from the “Should a policy be adopted that Meeting and Technology Display [1], the more than 60 satellite explosions identified by requires all spacecraft to be boosted AIAA Technical Committee on Space Systems that date and studies of debris generation in out of geostationary orbit at the end of undertook a formal review of the many topics terrestrial laboratories. Already, the calculated useful life? associated with orbital debris. The resulting probabilities of damaging impacts on spacecraft concise, 7-page treatise was formally released by man-made debris far outweighed those from “Should a policy be adopted to one year later [2]. At the time, the U.S. Space natural debris (i.e., meteoroids) of the same size. regulate which objects may be left in Surveillance Network was routinely tracking Another section of the position paper long-life orbits? provided a short summary of what “If the on-orbit debris hazard was then being done becomes significant, will the use of and by whom. With collision avoidance systems relieve the the establishment problem? in 1979 of a funded “If the on-orbit debris hazard research activity at the becomes significant, will the Lyndon B. Johnson employment of impact protection Space Center, NASA (bumpers) relieve the problem? and led a small group of U.S. government “What are the implications of anti- experts and support satellite operations?” personnel with studies designed to All of these questions are still pertinent characterize more today, and most have been answered with Figure 1. Despite the efforts of many space-faring nations and organizations to curtail the growth of the satellite population, which is nearly all orbital debris, near- completely the orbital Earth space is becoming increasingly congested. debris environment continued on page 3 2 www.orbitaldebris.jsc.nasa.gov AIAA Paper continued from page 2 national and international orbital debris with the goal of forming responsible groups to the Inter-Agency Space Debris Coordination mitigation guidelines. coordinate research and to recommend policy, Committee (IADC) and the United Nations The AIAA summarized its position and concluded with a call for corrective action attest to the seriousness that the topic of space with several points, including (1) the collision “now to forestall the development of a serious debris is now given. hazard posed by space debris was real but not problem in the future.” severe, (2) space debris issues should be faced Although the magnitude of the orbital References by all space users and coordinated action debris population has grown considerably since 1. Kessler, D.J. Sources of Orbital Debris should be taken immediately, and (3) satellite 1981, the framers of the original AIAA position and the Projected Environment for Future shields and collision avoidance were useful, paper on space debris should be satisfied that Spacecraft, AIAA International Meeting and but constraining the generation of further much has been done internationally, both Technology Display, AIAA-80-0855 (1980). debris was of greater importance. The paper by national governments and commercial 2. Anom., Space Debris, A Position Paper, also underscored the need for an international entities, to curtail the generation of long-lived American Institute of Aeronautics and Astronautics dialog to be initiated on the space debris issue orbital debris. The on-going activities of (1981). ♦ DoD-NASA Orbital Debris Removal Workshop The Space Policy Office of the Under orbital debris technology synergies. approaches for active debris removal (ADR) Secretary of Defense (Policy) organized and Major General Jay Santee (USAF, and the challenges ahead. An open discussion hosted a DoD-NASA Orbital Debris Removal Principal Director, Office of the Secretary of on technical and policy issues also took place Workshop at the Pentagon on 29 August 2011. Defense – Space Policy) and Mr. John F. Hall, Jr. before the end of the meeting. This debris The objectives of the event were to coordinate (Director, Export Control & Interagency removal workshop was a follow-on to the DoD and NASA activities in support of Liaison Division, NASA/HQ) provided NASA/DoD Meeting on ADR organized by the 2010 National Space Policy direction on opening remarks at the beginning of the the NASA Orbital Debris Program Office on orbital debris removal, to identify potential meeting. A total of 10 presentations were given 2 March 2011 (ODQN, April 2011, p. 2). Both debris removal technology options across by NASA and DoD personnel and 1 private events represent a trend for NASA and DoD DoD and NASA, and to foster a collaborative company during the day-long workshop. The to initiate collaborative efforts and pave the way environment between NASA and DoD for presentations focused on various technical for further joint activities in the future. ♦ HIMS at NASA’s 2011 Desert Research and Technologies Studies The Habitat particle Impact Monitoring System (HIMS) again participated in NASA’s Desert Research and Technologies Studies (D-RATS) this year. The 2011 D-RATS activities took place at the Black Point Lava Flow, north of Flagstaff, AZ. While last year’s activities focused on concept validation and impact data collection (see “Habitat Particle Impact Monitoring System,” ODQN, October 2010, p.