National Aeronautics and Space Administration Orbital Debris and Future Environment Remediation J.-C. Liou, PhD NASA Orbital Debris Program Office Johnson Space Center, Houston, Texas Presentations at the Korea Aerospace Research Institute (KARI) Daejon, Korea, 21-22 November 2011 National Aeronautics and Space Administration Outline • Part 1 (Nov 21st): The Near-Earth Orbital Debris Environment – Overview of the orbital debris populations – Optical, radar, and in-situ measurements – Orbital debris modeling • Part 2 (Nov 22nd): Environment Remediation and Active Debris Removal – Projected growth of the future debris population – The need for active debris removal (ADR) – Adhllfth21A grand challenge for the 21st century – The forward path 2/72 JCL National Aeronautics and Space Administration Part 1: The Near-Earth Orbital Debris Environment 3/72 JCL National Aeronautics and Space Administration Overview of the Orbital Debris Environment 4/72 JCL National Aeronautics and Space Administration The Near -Earth Environment (1957 -2010) • Only objects in the US Space Surveillance Network (SSN) catalog are shown • Sizes of the dots are not to scale 5/72 JCL National Aeronautics and Space Administration What Is Orbital Debris? • Orbital debris is any man-made object in orbit about the Earth that no longer serves a useful purpose • Examples – Intacts: Spent rocket bodies (R/Bs, i.e., upper stages) and retired spp(acecraft (S/C, i.e., ppyayloads) – Breakup fragments (via explosions or collisions) – Mission-related debris: objects released during normal mission operations (eng ine covers, yo-yo didespinweihtights, etc.) – Solid rocket motor effluents (Al2O3 slag and dust particles) – NaK droplets (coolant leaked from Russian nuclear reactors) – Surface degradation debris (paint flakes, etc.) 6/72 JCL National Aeronautics and Space Administration The Orbital Debris Family Objects in the Near-Earth Environment R/Bs, S/C Breakuppg Fragments Mission-related Debris l Debris NaK Orbita Al2O3 Al2O3 (slag) Paint Flakes MLI Pieces MtMeteoro ids 10 μm 100 μm 1 mm 1 cm 10 cm 1 m 10 m Size (diameter) 7/72 JCL National Aeronautics and Space Administration How Much Junk Is Currently Up There? SfSoftball size or larger (≥10 cm): ~22,000 (tracked by the Space Surveillance Network) Marble size or larger (≥1 cm): ~500,000 Dot or larger (≥1 mm): ~100, 000, 000 (a grain of salt) • Total mass: ~6300 tons LEO-to-GEO (~2700 tons in LEO) • Debris as small as 0 .2 mm pose a realistic threat to Human Space Flight (EVA suit penetration, Shuttle window replacement) 8/72 JCL National Aeronautics and Space Administration The Environment 1.0E+6 LRIR flux, 350-600 km 1.0E+5 HAX Flux 450-600 km 1.0E+4 LDEF IDE, 300-400 km SMM impacts 1.0E+3 LDEF craters (Humes) Larger Larger 1.0E+2 HST Impacts (Drolshagen), 500 km 1.0E+1 Space Flyer Unit, 480 km Size and Size 1.0E+0 Goldstone radar, 300-600 km r] nn YY - SMM holes 2 1.0E-1 SMM craters, 500-570 km 1.0E-2 LDEF craters (Horz) x of a Give of x mber/m 10E1.0E-3 uu Impact Kinetic Energy: EuReCa Impacts (Drolshagen), 500 km [Nu 1.0E-4 golf ball @ 10 km/sec ≈ 99165 TLEs, 450-600 km 1.0E-5 midsize sedan @ 120 mile/hr Mir (Mandeville, 2000) ctional Fl ee 1.0E-6 1.0E-7 Threat Regime Cross-s 1.0E-8 0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000 Diameter [cm] 9/72 JCL National Aeronautics and Space Administration An Example – Shuttle Vulnerabilities Potential Shuttle Damage 6.5 Window Replacement EVA Suit Penetration 5.5 Radiator Penetration RCC Penetration 4.5 • Shuttle Loss of Crew andTPS Vehicl Tile Penetratione (LOCV) risks from MMOD impact dithfdamage are in the range of 1Cabin in 250Penetrationto 1 in 300 per miiission 3.5 ¾ The risks vary with altitude, missionCargo duration, Bay Damage and attitude ¾ OD to MM is about 2:1 at ISS altitude 2.5 1.5 0.5 0.001 0.01 0.1 1 10 100 1000 Debris Diameter in Centimeters 10/72 JCL Number of Objects and National Aeronautics Space Administration Growth of the Historical 10000 12000 13000 14000 15000 16000 11000 1000 2000 3000 4000 5000 6000 7000 8000 9000 0 1956 1958 1960 of 1962 Rocket Bodies Mission-related Debris Spacecraft Fragmentation Debris Objects Total 1964 the 1966 NumberofObject Monthly 1968 Historical 1970 1972 1974 1976 1978 Year 11/72 s in Earth Orbit by Object Type (SSN Catalog) s inEarthOrbitby Object Type 1980 Catalog 1982 1984 1986 1988 1990 Populations 1992 FY - Iridium-Cosmos 1994 1C ASAT Test 1996 ASAT 1998 2000 Test 2002 2004 2006 operational 2008 ~1000 are JCL 2010 2012 National Aeronautics and Space Administration Sources of the Catalog Populations • ~4700 launches conducted worldwide since 1957 • 208 known breakups – Major events: • Titan Transtage (473, 1965) Source Breakdown • Agena D stage (373, 1970) anom. debris, • Ariane 1 stagg(e (489, 1986) 1.9% • Pegasus HAPS (709, 1996) payloads, • Long March 4 stage (316, 2000) 25.2% • PSLV (326 , 2001) • Fengyun 1C (~3200, 2007) breakup • Briz-M (>1000a, 2007) debris, 47.7% rocket bodies, • Cosmos 2421 (509, 2008) 12.9% • Iridium 33 (>700, 2009) mission‐ • Cosmos 2251 (>1500, 2009) related dbidebris, 12. 3% ainitial report 12/72 JCL National Aeronautics and Space Administration Accidental On-Orbit Collisions • Four accidental collisions between cataloged objects have been identified – 1991: Russian Sat (launched in 1988) ↔ Russian fragment – 1996: French Sat (launched in 1995) ↔ French fragment – 2005: US R/B (launched in 1974) ↔ PRC fragment – 2009: Iridium 33 (launched in 1997) ↔ Cosmos 2251 (launched in 1993) Iridium33 Cosmos 2251 (560 kg) (900 kg ) CERISE (1996) 13/72 JCL National Aeronautics and Space Administration Optical, Radar, and In-Situ Measurements 14/72 JCL National Aeronautics and Space Administration Current NASA Debris Data (1/2) 36,000 MODEST telescope 10,000 Goldstone radars (>32. 2º) Haystack radar (>30º) 2000 1000 HST-WFPC2 (580x610 km, 93-09) U.S. Space Surveillance Network STS (300x400 km, 95-11) HAX radar (>42.6º) 100 10 μm 100 μm 1mm1 mm 1cm1 cm 10 cm 1m1 m 10 m (*Boundaries are notional.) Particle Diameter 15/72 JCL National Aeronautics and Space Administration Current NASA Debris Data (2/2) Goldstone radars 36,000Haystack (30-m dish, X-band) MODEST telescope HAX (12.2-m dish, 10,000 Ku-band) Goldstone radars (>32. 2º) Haystack radar (>30º) 2000 DSS-14 (70-m dish, X-band) DSS-15 (34-m dish receiver) 1000 HST-WFPC2MODEST (580x610 (0.6-m, km, Cerro 93-09) Tololo) U.S. Space Surveillance Network STS (300x400 km, 95-11) HAX radar (>42.6º) 100 Impact crater 10 μm 100 μm 1mm1 mm 1cm1 cmHST WFPC10- 2radiator2 cm radiator 1m1 m 10 m (*Boundaries are notional.) Particle Diameter 16/72 JCL National Aeronautics and Space Administration NASA RADAR Observations • Signal processing • Object detection/correlation • Debris size estimation • Orbit determination • Environment definition Goldstone Haystack and HAX 17/72 JCL National Aeronautics and Space Administration NASA Optical Observations • Photometric and spectral measurements • Object detection and correlation • Optical Measurement Center (OMC) • SfSurface ma tilidtifititerial identification • Orbit determination • Environment definition MODEST MCAT OMC 18/72 JCL National Aeronautics and Space Administration In-Situ Data from Returned Surfaces WFPC2 radiator 19/72 JCL National Aeronautics and Space Administration Inspection of the HST WFPC2 Radiator • 685 impact features (≥300 µm) were identified – Recorded each impact feature’s shape, size, depth, and volume 1 mm 300 µm 20/72 JCL National Aeronautics and Space Administration Critical Data Gaps 36,000 MODEST Gap 2 telescope 10,000 Goldstone radars (>32. 2º) Haystack radar (>30º) 2000 1000 HST-WFPC2 (580x610 km, 93-09) U.S. Space Gap 1 Surveillance Network STS (300x400 km, 95-11) HAX radar (>42.6º) 100 10 μm 100 μm 1mm1 mm 1cm1 cm 10 cm 1m1 m 10 m (*Boundaries are notional.) Particle Diameter 21/72 JCL National Aeronautics and Space Administration Future NASA Debris Telescope • NASA Meter Class Autonomous Telescope (MCAT) – 1.3 m aperture, 0.96° field of view, f/4 – Located at Kwajalein Atoll (9°N, 168°E) – Target detection limits • GEO ~10 cm diameter (20.5 V-mag) – Primary objectives • GEO debris down to ~10 cm • LEO debris with low inclinations and high eccentricities • Simu ltaneous ra dar-optica l ob servati ons – Expected operations ~2012 22/72 JCL National Aeronautics and Space Administration A New Particle Impact Detection Technology • Debris Resistive/Acoustic Grid Orbital Navy Sensor (DRAGONS) – Objective: A low-cost/mass/power experiment to detect and characterize 0. 1 to 1 mm MMOD particles at 800-1000 km altitude – Components: (1) a large surface (≥1 m2) coated with thin resistive grids, (2) acoustic sensors attached to the backside of the board/film – Team: USNA, NASA/ODPO , Ken t (UK), NRL, VT – Status: Presented to the annual DoD Space Experiment Review Board (SERB) since 2007, no firm flight opportunity identified by STP Hypervelocity Impact Tests • Resistive grid width: 75 μm •Projectile: 0.3 mm stainless steel • Impact speed: 5.06 km/sec • Impact angle: normal • Two PVDF acoustic sensors attached to the board 23/72 JCL National Aeronautics and Space Administration Modeling 24/72 JCL National Aeronautics and Space Administration General Orbital Debris Modeling (1/2) • Evolutionary model – Is a physical model (such as LEGEND) capable of predicting future debris environment – StthdltSupports the development ofUS/NASAdf US/NASA de bibris mitiga tion guidelines and safety standards • Engineering model – Is a mathematical model (such as ORDEM) capable of predicting OD impact risks for the