Space Debris & Debris Mitigation

1. Space Debris & Debris Mitigation Marlon Sorge The Aerospace Corporation AIAA Improving Space Operations Workshop 5 April 2011

2. Overview Why is debris a problem? Current environment Future environment Inter-Agency Space Debris Coordination Committee Components of mitigation US mitigation

3. The Space Debris Issue Space debris spans large size range High speeds make small debris lethal >160 events, resulting in hundreds of thousands of fragments Debris above atmosphere have long lifetimes Debris > 10 cm can be tracked but not immediately 1 - 10 cm debris is lethal but untrackable 10 cm 400 lbs 500 miles/hr 1 cm 400 lbs 20 miles/hr

4. Space Debris Risks to Satellites Short-term risk • Event driven (explosions and collisions) • Potentially significant increase in risk • “Localized“ high risk • Risk dissipates into background in weeks-months Long-term risk • Due to existing background debris environment • Risk is relatively constant for many orbits • Satellites are constantly exposed • Tracked risk can be mitigate with collision avoidance Debris Objects Not to Scale

5. Distribution of Trackable Objects in Orbit Flux of objects in LEO is significantly higher than MEO or GEO Peak in LEO 750 – 900 km LEO Distribution by Altitude Distribution of Objects in Orbit

6. Numbers of Objects in LEO Effects of individual breakups is noticeable Significant recent increase in debris Number of Tracked Objects in LEO

7. Distribution of Satellites in LEO Most satellites are Russian US represents about 30% (US + Iridium/Globalstar /Orbcomm) Iridium/Globalstar /Orbcomm Data from June 2009

8. Distribution of Rocket Bodies in LEO Most rocket bodies are Russian (SL) • Similar proportion to satellites US contributed about 1/3 of population Data from June 2009

9. Distribution of Debris in LEO Fragments from explosions and collisions Debris divided about equally between US, Russia, China • US; mostly explosions • Russia: divided between satellite and upper stage explosions • China: primarily from ASAT test Data from June 2009

10. Geosynchronous Orbit Environment R. Jehn, el. al. , “Reorbiting of Satellites in High Altitudes,” 5th European Conference on Space Debris, 30 March -2 April 2009 GEO belt distribution is not uniform

11. Future Debris Environment 100-Year Projection LEO, no new launches Trackable debris environment is expected to grow even with no additional launches Collisions between existing objects (currently tracked) will drive growth Debris from Currently Tracked vs Currently Tracked Currently Tracked LEO Debris Environment Projection

12. Inter-Agency Space Debris Coordination Committee (IADC) Primary international space debris organization International government forum for worldwide coordination of activities related to the issues of man-made and natural space debris Reports to United Nations Committee on the Peaceful Uses of Outer Space (UN-COPUOS) Produces “IADC Space Debris Mitigation Guidelines” • Agreed to practices for mitigating space debris • Provides technical justification for mitigation approaches UN General Assembly adopted resolution containing space debris (RES/62/217, 10 Jan, 2008) • Adopts IADC Mitigation Guidelines • Emphasizes importance of space debris issues IADC web site http://www.iadc-online.org

13. IADC Mitigation Guidelines Basis for many international mitigation standards Limit debris released during normal operations • Long term risk from any planned released should be assessed • Tethered systems should consider intact and severed risks Minimize the potential for on-orbit break-ups • Minimize risk of post-mission break-up from stored energy • Minimize potential for break-ups during operational phases • Avoid intentional destruction and other harmful activities • Intentional break-ups, if necessary, should be conducted at low altitudes

14. IADC Mitigation Guidelines Continued Post mission disposal • GEO disposal • Remain outside 200 km protected region around GEO • LEO disposal • “25-year rule” • Disposal by reentry should not pose undo hazard on ground Prevention of on-orbit collisions • Limit effect of small debris on satellite and disposal systems • Perform collision avoidance when needed IADC Mitigation Handbook provides additional details LEO Disposal GEO Disposal GPS Disposal

15. International Debris Mitigation Documents Space debris recognized as an international problem European Code of Conduct (ECoC) for Space Debris Mitigation • Consistent with IADC guidelines Requirements on Space Mitigation for Agency Projects (ESA) • Based on ECoC ESA Space Debris Mitigation Handbook • In depth information on mitigation practices National Guidelines (all consistent with IADC guidelines) • National Regulations or Mitigation Principles (France, Germany) • Based on ECoC • Japanese National Guidelines • Chinese National Guidelines • National Standard of the Russian Federation for Space Debris Mitigation (Russia) (2009)

16. US National Space Policy Released 28 June 2010 Significantly expanded emphasis on space debris • Includes entire section “Preserving the space environment and the responsible use of space” on debris issues • Requires compliance with US Standard Practices for Orbital Debris Mitigation “Strengthen stability in space through: domestic and international measures to promote safe and responsible operations in space; improved information collection and sharing for space object collision avoidance; … and strengthening measures to mitigate orbital debris.” National Space Policy: Goals

17. Guidance for Space Debris Management Changing as we speak… National Space Policy cites need to comply with U.S. Government Orbital Debris Mitigation Standard Practices (USDM) • USDM being revised to incorporate latest guidance from IADC on GEO disposal DoDD 3100.10, Space Policy, in revision DoDI 3100.12, Space Support, in revision; held for DoDD 3100.10 AFI 91-201, The USAF Mishap Prevention Program, its AFSPC Sup 1, and AFMAN 91-701, Launch Safety Program Policy, will require revision upon release of USDM, DoDD 3100.10 and DoDI 3100.12 AFI 91-217, Space Safety and Mishap Prevention Program, in revision NASA-STD-8719.14, NASA Safety Standard

18. Guidance for Space Debris Management (cont.) Some good news Available documents: • Inter-Agency Space Debris Coordination Committee Mitigation (IADC) Guidelines and Support Document to the IADC Mitigation Guidelines • NASA STD 8719.14 (with Change 4), Process for Limiting Orbital Debris • NASA-Handbook 8719.14, Handbook for Limiting Orbital Debris • Strategic Command Instructions • Space and Missile systems Center (SMC) Instructions • Space and Missile systems Center (SMC) Standards

19. ISO Standards for Space Debris Mitigation Standards development Non-governmental federation of national standards bodies of 149 countries Develops standards in partnership with potential users Orbital Debris Coordination Working Group established in 2003 Several debris related standards projects established • Mitigating space debris • Disposal of satellites operating at geosynchronous altitude • Prevention of break-up of unmanned spacecraft Provide guidance for manufacturers and operators on best practices that lead to compliance with debris mitigation goals Provide satellite owner with assurance that satellites comply with national and international regulations and requirements Release of international standards expected over next several years

20. Summary Space debris is a growing problem Low-earth orbit generally has the greatest risk Debris environment is expected to worsen even with no additional launches Debris mitigation is an international issue Many nations are addressing problem IADC acts as main international forum for international debris cooperation US practices are evolving Overall mitigation is more effective the earlier it is implemented All trademarks, service marks, and trade names are the property of their respective owners

21. Space Debris & Debris Mitigation Marlon SorgeThe Aerospace Corporation AIAA Improving Space Operations Workshop 5 April 2011