National Aeronautics and Space Administration
USA Space Debris Environment, Operations, and Research Updates
J.-C. Liou, PhD Chief Scientist for Orbital Debris National Aeronautics and Space Administration U.S.A.
54th Session of the Scientific and Technical Subcommittee Committee on the Peaceful Uses of Outer Space, United Nations 30 January – 10 February 2017, Vienna National Aeronautics and Space Administration Presentation Outline
• Earth Satellite Population
• Space Missions in 2016
• Satellite Fragmentations
• Collision Avoidance Maneuvers
• Satellite Reentries
• NASA CubeSat Study and SDS Development
2/14 National Aeronautics and Space Administration Evolution of the Cataloged Satellite Population
• According to the U.S. Satellite Catalog, the number of 10 cm and larger objects in Earth orbit increased slightly in 2016.
18,000 17,000 Collision of Cosmos 2251 and Iridium 33 16,000 Total Objects 15,000 Fragmentation Debris 14,000 13,000 Spacecraft Destruction of Fengyun-1C 12,000 Rocket Bodies 11,000 Mission-related Debris 10,000 9,000 8,000 7,000 ~1400 are operational 6,000
Numberof Objects 5,000 4,000 3,000 2,000 1,000 0 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Year 3/14 National Aeronautics and Space Administration Mass in Near-Earth Space Continued to Increase
• The material mass in Earth orbit continued to increase and exceeded 7400 metric tons in 2016. 8,000
7,000 Total Objects
Spacecraft 6,000 Rocket Bodies 5,000 Fragmentation Debris
4,000 Mission-related Debris
3,000
2,000 Massin Orbit (metric tons)
1,000
0 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Year 4/14 National Aeronautics and Space Administration Distribution of the Cataloged Objects, LEO-to-GEO
• The low Earth orbit (LEO, the region below 2000 km altitude) has the highest concentration of the cataloged objects. LEO to GEO (1 January 2017) 1.E-07
1.E-08 ) 3 Global Navigation Satellite Systems
1.E-09
1.E-10
1.E-11 LEO Spatial Density Density Spatial (no/km 1.E-12 Geosynchronous Earth Orbit (GEO) 1.E-13 0 10000 20000 30000 40000 Altitude (km)
5/14 National Aeronautics and Space Administration Distribution of the Cataloged Objects in LEO
• The LEO population is still heavily influenced by fragments from Fengyun-1C (FY-1C), Iridium 33, and Cosmos 2251. 1 January 2017 Catalog 5.0E-08
4.5E-08 All objects 4.0E-08 FY-1C + Iridium 33 + Cosmos 2251 fragments ) 3 3.5E-08 FY-1C fragments Iridium 33 + Cosmos 2251 Fragments 3.0E-08 Fragments Fragments 2.5E-08 Cataloged Left 2.0E-08 FY-1C 3438 2863
1.5E-08 Iridium 628 348
Spatial Density (no/km Cosmos 1668 1106 1.0E-08
5.0E-09
0.0E+00 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 Altitude (km)
6/14 National Aeronautics and Space Administration Mass Distribution in LEO
• Mass distribution is dominated by rocket bodies and spacecraft. The proposed mega-constellations, consisting of thousands of ~150-kg class spacecraft, will dramatically change the landscape in LEO. Mass Distribution in LEO (1 January 2017) 350
300 All Rocket Bodies (46% of All) 250 Spacecraft (48% of All)
200 Others
150
100
50
Mass (metric tons) per 50 km Altitude Bin Altitude (metricMassper 50km tons) 0 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
ISS not included Altitude (km) 7/14 National Aeronautics and Space Administration Worldwide Space Activity in 2016
• A total of 83 space launches placed more than 150 spacecraft into Earth orbits during 2016, following the trend of increase over the past decade. 140
120
100
80
60
40 WideLaunches (Earth Orbit or Beyond) - 20 World 0 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
8/14 National Aeronautics and Space Administration Satellite Fragmentations During 2016
• Twelve minor satellite fragmentations were detected by the U.S. Space Surveillance Network during 2016. None of them contributed large numbers of long-lived debris to the near-Earth environment. Common International Perigee Apogee Detected Cause Name Designator Altitude (km) Altitude (km) Debris Breeze-M R/B 2015-075B 33,484 35,730 6 Unknown
Astro-H (Hitomi) 2016-012A 566 580 10 Unknown
SOZ Ullage Motor 2008-067G 679 18,845 21 Propulsion
Molniya 1-93 2004-005A 77 2,145 13 Aerodynamic
SOZ Ullage Motor 2008-067H 728 18,801 30+ Propulsion
Beidou G2 2009-018A 35,384 36,137 2 Unknown
Worldview 2 2009-055A 765 767 9 Unknown
SOZ Ullage Motor 2006-062G 458 19,067 8 Propulsion
Sentinel-1A 2014-016A 695 697 7 Small debris impact
RISAT-1 2012-017A 535 544 16 Unknown
FY-1C fragment 1999-025KF 809 902 8 Unknown
DMSP 5D-2/F12 1994-057A 833 849 1 Unknown
9/14 National Aeronautics and Space Administration Robotic Spacecraft Collision Avoidance Maneuvers
• Since 2007 NASA has required frequent satellite conjunction assessments for all of its maneuverable spacecraft in LEO and GEO to avoid accidental collisions with objects tracked by the U.S. Space Surveillance Network.
• NASA also assists other U.S. government and foreign spacecraft owners with conjunction assessments and subsequent maneuvers.
• During 2016 NASA executed or assisted in the execution of 20 collision avoidance maneuvers by robotic spacecraft. – Four maneuvers were conducted to avoid debris from Fengyun-1C. – Four maneuvers were conducted to avoid debris from the collision of Cosmos 2251 and Iridium 33.
10/14 National Aeronautics and Space Administration Satellite Reentries in 2016
• More than 250 reentries of spacecraft, launch vehicle upper stages, and other cataloged debris were recorded by the U.S. Space Surveillance Network during 2016.
– Due to the low solar activity, the number of reentries was lower than previous years.
– Spacecraft: 68; upper stages: 39; other debris: 146 (including 58 reentries of the Fengyun 1C, Iridium 33, and Cosmos 2251 fragmentation debris).
– One of the reentered fragments appears to be the largest fragment from the disintegration of PAGEOS-1 Test inflation of PAGEOS (Passive Geodetic Earth Orbiting Satellite), a 30.5-meter diameter inflatable balloon initially deployed to 4200 km altitude in 1966. • The total mass of the 2016 reentries was more than 50 metric tons.
• No accounts of personal injury or significant property damage were reported.
11/14 National Aeronautics and Space Administration Disposal of USA Spacecraft in GEO
• Four USA civil and commercial spacecraft ended operations in GEO in 2016.
• Three of them, Intelsat 7, XM-1, and GOES-3, were launched years to decades before the establishment of the UN COPUOS Space Debris Mitigation Guidelines in 2007, but still conducted postmission disposal maneuvers to move away from the GEO region.
• For Intelsat 8, a major failure forced the mission to end early but the operator still took emergency actions to vent the fuel and raise the spacecraft’s orbit above GEO.
International Minimum Height Maximum Height Spacecraft Designator above GEO above GEO Intelsat 7 1998-052A 577 km 599 km
XM-1 2001-018A 360 km 364 km
Intelsat 8 1998-065A 165 km 3043 km
GOES-3 1978-062A 245 km 267 km
12/14 National Aeronautics and Space Administration NASA CubeSat Study
• The NASA Orbital Debris Program Office recently completed a study to quantify the potential negative effects to the future LEO environment from large deployments of CubeSats. – Two benchmark cases with different 25-year decay compliance levels, but with no CubeSats deployed in the future, were established as baseline. – Comparison cases included adding various CubeSat future deployment scenarios to the nominal background. – The NASA orbital debris evolutionary model, LEGEND, was used for the simulations. Each scenario was carried out for a 200-year projection and repeated with 100 Monte Carlo runs. – Based on the study scenario comparisons, (1) CubeSats contribute very little to the future mass increase in LEO and (2) a good compliance of the 25-year decay rule appears to be an effective means to mitigate the effects from CubeSats to the environment.
13/14 National Aeronautics and Space Administration Measurements of Small Debris From the ISS
• NASA has led the development of innovative small debris in-situ measurement technologies since 2002. – Integration and pre-flight testing of the Space Debris Sensor (SDS) have been completed. SDS is ready for deployment on the International Space Station (ISS) in late 2017 or early 2018. – The mission will collect sub-millimeter debris data near the ISS and mature the technologies for future mission opportunities to collect millimeter-sized debris data at high LEO altitudes.
SDS ready for launch Planned SDS location SDS flight unit at NASA KSC 14/14