National Aeronautics and Space Administration
USA Space Debris Environment, Operations, and Measurement Updates
J.-C. Liou, PhD Chief Scientist for Orbital Debris NASA Orbital Debris Program Office
52 nd Session of the Scientific and Technical Subcommittee Committee on the Peaceful Uses of Outer Space, United Nations 2-13 February 2015 National Aeronautics and Space Administration Presentation Outline
• Earth Satellite Population
• Space Missions in 2014
• Spacecraft Disposals
• Satellite Fragmentations
• Collision Avoidance Maneuvers
• Satellite Reentries
• DebriSat, MCAT, and DRAGONS
2 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 decreased slightly in 2014, driven by the decay of light weight fragmentation debris during high solar activities. 18000
16000 Collision of Cosmos 2251 and Iridium 33
Total Objects 14000 Fragmentation Debris Destruction of Fengyun-1C 12000 Spacecraft Mission-related Debris 10000 Rocket Bodies
8000
6000 Number of Objects of Number
4000
2000
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 3 National Aeronautics and Space Administration Mass in Near-Earth Space Continued to Increase
• The material mass in Earth orbit continued to increase and reached a total of 6700 metric tons in 2014.
7
Total Objects 6 Spacecraft
Rocket Bodies 5 Fragmentation Debris
Mission-related Debris 4
3
2 Mass Orbit in (millions of kg) 1
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
4 National Aeronautics and Space Administration World-Wide Space Activity in 2014
• A total of 90 space launches placed more than 180 spacecraft into Earth orbits during 2014. 140
120
100
80
60
40
20 Launches World-Wide to Reach Earth Orbit orBeyond Earth Reach to Launches World-Wide
0 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 201 5
5 National Aeronautics and Space Administration Disposal of USA Spacecraft in GEO
• Five USA civil spacecraft completed operations in the geosynchronous Earth orbit (GEO) in 2014.
• All were moved to disposal orbits above GEO in compliance with UN COPUOS Space Debris Mitigation Guidelines to protect the GEO region.
International Minimum Height Maximum Height Spacecraft Designator above GEO above GEO
Intelsat 706 1995-023A 334 km 364 km
AMC-5 1998-063B 241 km 292 km
Galaxy 26 1999-005A 331 km 392 km
DIRECTV 1R 1999-056A 355 km 390 km
XM-2 2001-012A 335 km 341 km
6 National Aeronautics and Space Administration Satellite Fragmentations During 2014
• Twelve minor satellite fragmentations were detected by the U.S. Space Surveillance Network during 2014. 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 Cosmos 1867 1987-060A 775 800 6 Unknown
Delta II 2 nd Stage 1999-008D 635 840 6 Unknown
Cosmos 2428 2007-029A 845 860 17 Unknown
SOZ Ullage Motor 1994-076G 420 18,990 15 Propulsion
SOZ Ullage Motor 2008-046H 865 18,720 7 Propulsion
Cosmos 862 Deb 1976-105F 110 14,990 3 Aerodynamic
Titan 3C Transtage 1969-013B 35,970 37,130 5 Unknown
Iridium 47 1997-082C 776 779 10 Unknown
Haiyang 2A 2011-043A 965 965 4 Unknown
SOZ Ullage Motor 2010-007G 770 18,750 16 Propulsion
SOZ Ullage Motor 2007-052F 730 18,790 70 Propulsion Iridium 91 2002-005A 776 779 4 Unknown
7 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 2014 NASA executed or assisted in the execution of 21 collision avoidance maneuvers by robotic spacecraft.
– 2 maneuvers were needed to avoid debris from Fengyun-1C
– 4 maneuvers were needed to avoid debris from the collision of Cosmos 2251 and Iridium 33
8 National Aeronautics and Space Administration ISS Collision Avoidance Maneuvers
• The International Space Station (ISS) has conducted 21 debris collision avoidance maneuvers since 1999.
• During 2014, a record five debris avoidance maneuvers were executed.
5
4
3
2
1
0 ISS Collision Avoidance Maneuvers ISS CollisionAvoidance 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
9 National Aeronautics and Space Administration Satellite Reentries in 2014
• More than 600 reentries of spacecraft, launch vehicle upper stages, and other debris were recorded by the U.S. Space Surveillance Network during 2014. – Spacecraft: 86; upper stages: 49; debris: 467 (including 243 reentries of the Fengyun 1C, Iridium 33, and Cosmos 2251 fragmentation debris). – The high reentry rate was due to the peak of solar maximum in 2014. TIROS-2 – The oldest spacecraft that reentered was NASA’s weather satellite TIROS-2, which was launched into a 619 km × 732 km orbit for a one-year mission in 1960.
• The total mass of the 2014 reentries was more than 100 metric tons.
• No accounts of personal injury or significant property damage were reported.
10 National Aeronautics and Space Administration Laboratory-Based Satellite Impact Experiments
• The “DebriSat” project is a collaboration among NASA, the U.S. Air Force, The Aerospace Corporation, and the University of Florida for laboratory- based hypervelocity impact experiments on a representative, modern LEO satellite and an upper stage mockup.
• The objective is to characterize the physical properties of impact fragments to improve satellite breakup models and space situational awareness.
30 cm Multi-Layer Insulation
Al alloy tank Sun Sensor 50 cm Stainless steel fuel lines
Al alloy strap- Optical Imager on tanks (one on each side) Spectrometer Divert Thruster Delta-II Ti roll control thruster assembly S-band Antenna Deployable Solar Panels X-band Antenna UHF/VHF Antenna Composite Body Panels 11 National Aeronautics and Space Administration Hypervelocity Impact Sequences
• Hypervelocity impacts of the two targets were successfully carried out at the Arnold Engineering Development Complex in April 2014.
• Fragment processing and measurements are currently underway.
598 g projectile @ 6.9 km/sec
570 g projectile @ 6.8 km/sec
12 National Aeronautics and Space Administration Meter Class Autonomous Telescope (MCAT)
• NASA, the U.S. Air Force, and the Air Force Research Laboratory are building a new 1.3-m debris telescope to be deployed on Ascension Island. – Groundbreaking for the observatory occurred in October 2014. – Operations will start in late 2015. – The telescope will be operated remotely from NASA JSC.
• The low latitude of the site will permit observations of low inclination debris at all altitudes. – Debris as small as 10 cm in GEO Ascension should be detectable. Island
13 National Aeronautics and Space Administration In-Situ Measurements of Small Debris
• NASA, the U.S. Naval Academy, the U.S. Naval Research Laboratory, Virginia Tech, and the University of Kent (Great Britain) are developing new technologies for in-situ measurements of small debris from space.
• A new system, Debris Resistive/Acoustic Grid Orbital Navy-NASA Sensor (DRAGONS), has been approved by the International Space Station (ISS) Program for a 2017 deployment on the ISS.
• DRAGONS combines several particle impact detection principles to measure time, location, speed, direction, energy, and the size of each impacting particle to improve the environment definition for the millimeter and smaller debris population.
Planned location for DRAGONS
14