National Aeronautics and Space Administration Orbital Debris Past

National Aeronautics and Space Administration Orbital Debris: Past, Present, and Future • • AIAA: Annual Technical Symposium May 9, 2008 Presenter: Heather Rodriguez 1, 2 1 ESCG, 2 University of Houston Special Acknowledgement to The Orbital Debris Program Office at NASA/JSC For more information: http: //orbitaldebris. jsc. nasa. gov/index. html

National Aeronautics and Space Administration Orbital Debris Time Machine Prepare to travel back to 1957 and watch the space environment change right before your eyes 2

National Aeronautics and Space Administration Orbital Debris Growth Before 1957 = 0 objects Cataloged objects (>10 cm diameter) represented by white dots (not to scale) 3

National Aeronautics and Space Administration Orbital Debris Growth 1960 = 10+ objects Cataloged objects >10 cm diameter 4

National Aeronautics and Space Administration Orbital Debris Growth 1970 = 1400+ objects LEO GEO ring , Molniya, Polar orbit, GTO Cataloged objects >10 cm diameter 5

National Aeronautics and Space Administration Orbital Debris Growth 1980 = 3700+ objects LEO GEO ring , Molniya, Polar orbit, GTO Cataloged objects >10 cm diameter 6

National Aeronautics and Space Administration Orbital Debris Growth 1990 = 6000+ objects LEO GEO ring , Molniya, Polar orbit, GTO Cataloged objects >10 cm diameter 7

National Aeronautics and Space Administration Orbital Debris Growth 2000 = 8900+ objects LEO GEO ring , Molniya, Polar orbit, GTO Cataloged objects >10 cm diameter 8

National Aeronautics and Space Administration Growth of the Earth Satellite Population April 2008 = 12, 000+ objects LEO GEO ring , Molniya, Polar orbit, GTO Cataloged objects >10 cm diameter 9

National Aeronautics and Space Administration Orbital Debris Background • Orbital Debris = all space objects non-functional and human-made – First launch in 1957 started growth of the orbital debris population (R/B from Sputnik Launch = SSN 1) – First satellite break-up in 1961 – Low Earth Orbit (LEO) debris can travel at speeds of ~7 km/s and ~3 km/s in Geosynchronous Earth Orbit (GEO) • Space Surveillance Network (SSN) routinely tracks targets >10 cm – Catalogued objects: objects with multiple detections, orbits established (~12, 500) – Tracked objects: detected at least once, may not be included in catalogue ( ~17, 000) 10

National Aeronautics and Space Administration Other Ground-Based Sensors • Ground-based remote systems able to detect objects as small as 2 mm in LEO and 10 cm in the GEO regime Haystack and HAX radars located in Tyngsboro, MA ESA 1 m telescope Goldstone- 70 m dish located in Barstow, CA MODEST ( 0. 6 Schmidt) located near La Serena, Chile at the Cerro Tololo Inter-American Observatory 3. 67 m Advance Electro-Optical System (AEOS) telescope, Maui, Hawaii Cobra Dane radar located on Shemya Island, AK 11

National Aeronautics and Space Administration Orbital Debris Seen From LMT 12

National Aeronautics and Space Administration Orbital Debris Population Breakdown NF S/Cs, R/Bs Breakup Fragments Mission-related Debris Na. K Al 2 O 3 (slag) Al 2 O 3 Paint Flakes Meteoroids 10 m 100 m 1 mm 1 cm 10 cm Size (diameter) 13 1 m 10 m

National Aeronautics and Space Administration Sample of Mission-Related Orbital Debris Astronaut Ed White on the first EVA during the Gemini 4 mission in 1965 14

National Aeronautics and Space Administration Sources of the Catalogued Population • • Approximately 4500 launches conducted worldwide since 1957 Known breakups = 197 – Major events: (number of catalogued fragments, YYYY) • • • Titan Transtage (473, 1965) – U. S. Agena D stage (373, 1970) – U. S. COSMOS 1275 (309, 1981) – Russia Ariane 1 stage (489, 1986) – Europe Pegasus HAPS (709, 1996) – US Long March 4 stage (316, 2000) – China PSLV (326, 2001) – India Fengyun 1 C (>2500 a, 2007) – China Briz-M (>1000 b, 2007) – Russia aon-going; binitial report 15

National Aeronautics and Space Administration 1996 Major Break-Up 16

National Aeronautics and Space Administration Principal Orbital Debris Data Sources Potential Shuttle Damage 17

National Aeronautics and Space Administration Cumulative Catalogued Population Breakdown 18

National Aeronautics and Space Administration On-Orbit Collisions • Three accidental collisions between cataloged objects have been identified – 1991: Russian Sat (launched in 1988) Russian fragment – 1996: French Sat (launched in 1995) French fragment (1986 explosion) – 2005: U. S. R/B (launched in 1974) PRC fragment (2000 explosion) DMSP R/B CZ-4 Debris 775 km by 885 km 700 km by 895 km 99. 1 deg inclination 98. 2 deg inclination Collision Altitude: 885 km Geometry of the 2005 on-orbit collision CERISE (1996) 19

National Aeronautics and Space Administration The Environment in LEO Regime Threat Regime 20

National Aeronautics and Space Administration Hazards/Risks? • Crewed Missions – – • Satellites – – – • On average, two shuttle windows are replaced per mission Seven ISS collision avoidance maneuvers conducted since 1999 Small debris particles could pose a danger to EVAs Window pit from orbital Possibility of impact to debris on STS-007. sensitive areas on crewed missions An impact that completely penetrated the antenna dish of the Hubble Space Telescope. Avoidance maneuvers Possible loss of mission As debris flux increases, need for more effective shielding Need more, improved measurements and modeling for cost-effective mitigation measures and shielding designs 1 mm Orbital debris damage seen during Hubble Space Telescope repairs. 21

National Aeronautics and Space Administration Hazards/Risks? • Prior to the most recent break-ups, explosions were the biggest concern; future worries focus on collisions. • Debris left in orbits > 600 km normally fall back to Earth within several years. At altitudes of 800 km, the time for orbital decay is often measured in decades. Above 1, 000 km, orbital debris will normally continue circling the Earth for a century or more. • The smaller the particle, the higher the potential for collision. – • Smaller particles outweigh the largest particles in population. Kinetic Energy relation. – A 1 kg object in LEO involved in a collision with an object traveling at 10 km/s will have the same impact energy as a fully loaded 35, 000 kg truck traveling at 190 km/h. 22

National Aeronautics and Space Administration Assessing the Problem: Involvement The orbital debris issue is being addressed at national and international levels Ø U. S. : • U. S. Government Orbital Debris Mitigation Standard Practices • NASA Procedural Requirements (NPR) and NASA Technical Standard (NS) on Orbital Debris Ø IADC: • • • ASI (Agenzia Spaziale Italiana) BNSC (British National Space Centre) CNES (Centre National d'Etudes Spatiales) CNSA (China National Space Administration) DLR (German Aerospace Center) ESA (European Space Agency) NSAU (National Space Agency of Ukraine) ISRO (Indian Space Research Organisation) JAXA (Japan Aerospace Exploration Agency) NASA (National Aeronautics and Space Administration) ROSCOSMOS (Russian Federal Space Agency) Ø COPUOS: United Nations Committee on Peaceful Uses of Outer Space • Started in 1959, currently has 69 member states worldwide • Albania, Algeria, Argentina, Australia, Austria, Belgium, Benin, Bolivia, Brazil, Bulgaria, Burkina Faso, Cameroon, Canada, Chad, Chile, China, Colombia, Cuba, Czech Republic, Ecuador, Egypt, France, Hungary, Germany, Greece, India, Indonesia, Iran, Iraq, Italy, Japan, Kazakhstan, Kenya, Lebanon, Libyan Arab Jamahiriya, Malaysia, Mexico, Mongolia, Morocco, Netherlands, Nicaragua, Nigeria, Pakistan, Peru, Philippines, Poland, Portugal, Republic of Korea, Romania, the Russian Federation, Saudi Arabia, Senegal, Sierra Leone, Slovakia, South Africa, Spain, Sudan, Sweden, Switzerland, Syrian Arab Republic, Thailand, Turkey, the United Kingdom of Great Britain and Northern Ireland, the United States of America, Ukraine, Uruguay, Venezuela & Viet Nam Ø ISO: The International Standards Organization Technical Committee "Aircraft And Space Vehicles" Sub-Committee "Space Systems And Operations" (known as ISO TC 20/SC 14) • Development of standards to address implementation of measures associated with debris mitigation 23

National Aeronautics and Space Administration How Does NASA Work to Control and Identify Orbital Debris? • Measurements – Radar Data Processing and Analysis Hax and Haystack – Optical Data Collection, Processing, and Analysis – In Situ Measurements and Analysis – Object detection/correlation – Debris size estimation • Radar Cross Section=Projected cross section x Reflectivity x Directivity MODEST and 0. 9 m • Optical reflected solar brightness – Orbit determination – Radar range-rate info – Photometric and spectral measurements LDEF – Surface material identification – Chemical composition of impactor (In-situ impacts ) 24

National Aeronautics and Space Administration How Does NASA Work to Control and Identify Orbital Debris? • Modeling – Long-Term Environment Modeling – Engineering Modeling • Predicting impacts risks for ISS, STS, and other S/C – Based on measurements and helps better define environment Ground based break-up experiment – Debris characteristics as functions of time, altitude, and orbital parameters – Number, type, size distribution, material, spatial density distribution, velocity distribution, flux, etc. ) – Fragment characterization based on break-up experiments 25

National Aeronautics and Space Administration How Does NASA Work to Control and Identify Orbital Debris? • Reentry Analysis – Object Reentry Survival Analysis and Risk Assessment • Safety Standards and Policies – Mission compliance with NASA Safety Standards • HITF: Hypervelocity Impact Technology Facility – Conduct hyper-velocity impact tests, provide damage assessments for ISS/STS, and help design effective shielding for spacecraft 26 January 1997, Georgetown, TX January 2001, Saudi Arabia

National Aeronautics and Space Administration The Question How Bad Is It? • Has the current LEO debris population reached the point where the environment is unstable and population growth may be inevitable? Pre-1957 2008 27 2208

National Aeronautics and Space Administration The Growth of LEO Populations (“No Future Launches” Scenario) SCIENCE 20 January 2006 • Starting in 2020 • Collision fragments replace other decaying debris through the next 50 years, keeping the total population approximately constant • Beyond 2055, the rate of decaying debris decreases, leading to a net increase in the overall satellite population due to collisions 28

National Aeronautics and Space Administration Viable Solutions? • In reality, the situation will be worse than this “no future launches” scenario – Satellites continue to be launched into space – Major break-ups continue to occur (e. g. Fengyun-1 c, Briz-M) • • Postmission mitigation measures (such as passivation and LEO 25 -year decay rule) will help, but may not be enough to prevent the self-generating phenomenon from happening To better limit the growth of future debris population, active removal of existing objects from orbit must be considered 29

National Aeronautics and Space Administration Active Debris Removal – The Next Step in LEO Debris Mitigation • PMD scenario predicts the LEO populations would increase by ~75% in 200 years • The population growth could be reduced by half with a removal rate of 2 obj/year • LEO environment could be stabilized with a removal rate of 5 obj/year 30

National Aeronautics and Space Administration Conclusions • In order to continue space exploration, the space community must not only be aware but help remediate the orbital debris environment • Through ground and in-situ measurements and modeling we can gain knowledge of the population, physical characteristics, and risks of orbital debris • The space environment is not owned or used by any one nation; therefore, we all have to work together to preserve the near-Earth space for future generations 31

National Aeronautics and Space Administration Thank you ! 32