Asteroid and Comet Mission Targets Observed by Radar


Last update: 2024 March 26

                                           Date of      
Spacecraft       Space                     Spacecraft        Dates of Radar  
Mission          Agency    Target          Encounter         Observations  
----------       ------    ------          -----------       --------------
Giotto           ESA        1P/Halley        1986             1985           
Vega 1, 2        Soviet Union, Hungary, France, East Germany, West Germany, Poland, Bulgaria, Czechoslovakia, Austria, United States
                            1P/Halley        1986             
Suisei           JAXA       1P/Halley        1986             
Sakigake         JAXA       1P/Halley        1986             
ICE              NASA       1P/Halley        1986             

Giotto           ESA       26P/Grigg-
                               Skjellerup    1992             1982 

Clementine       SDI      1620 Geographos    1994             1983, 1994       Flyby did not occur due to a mission failure

NEAR-Shoemaker   NASA      253 Mathilde      1997             2001          
                           433 Eros          1998,2000-2001   1975, 1988       1998 flyby, 2000-2001 rendezvous
                          4660 Nereus        Didn't happen    2002             Original target for the mission; subsequently changed to Eros

CONTOUR          NASA       2P/Encke         Didn't happen    1980, 2003       2003 flyby mission did not occur due to failure in 2002

Hayabusa         JAXA    25143 Itokawa       2005-2006        2001, 2004       2010 sample return
                          4660 Nereus        Didn't happen    2002             Original target; subsequently changed to 25143 Itokawa

CONTOUR          NASA      73P/Schwassmann-
                               Wachmann 3    Didn't happen    2006             2006 flyby mission did not occur due to failure in 2002

Rosetta          ESA        21 Lutetia       2010             1985, 2004     

EPOXI            NASA     103P/Hartley 2     2010             2010 

Dawn             NASA         4 Vesta        2011-2012        1979, 1981, 1988, 1992, 2001, 2003

Chang'e 2        CNSA      4179 Toutatis     2012             1992, 1996, 2000, 2004, 2008, 2012, 2016

Dawn             NASA         1 Ceres        2015-2016        1977, 1984, 1986, 1990, 1995, 2000, 2004

PROCYON          JAXA    185851 2000 DP107   Didn't happen    2000, 2008        2016 flyby did not occur due to an engine failure in 2015

Deep Impact      NASA    163249 2002 GT      2020 flyby       2013              Spacecraft ceased operating in 2013.  

Rosetta          ESA       46P/Wirtanen      Didn't happen    2018              Original target for Rosetta; changed due to launch delay

Hayabusa2        JAXA    162173 Ryugu        2018             2020              Rendezvous in 2018.  Observed at Goldstone in 2020.  

OSIRIS-REx       NASA    101955 Bennu        2018             1999, 2005, 2011  Rendezvous and 2023 sample return.

NEA Scout        NASA    2018 PK21 or 2013 WA44               2020 (2018 PK21)  Target changed due to launch delay. 2013 WA44: no radar.

DART             NASA     65803 Didymos      2022 impact      2003, 2022        PDCO directed mission
LICIA Cube       ASI      65803 Didymos      2022 flyby       2003, 2022        Companion with the DART spacecraft

NEA Scout        NASA           2020 GE      2023             Radar opportunity in 2024.  Launched in Nov. 2022.  Mission lost.

Hayabusa2        JAXA     98943 2001 CC21    2027             No radar          Target changed.  
                                                                                Would have been observable at Arecibo in 2023, 2024, 2025.
Hayabusa2        JAXA           2001 AV43    2029             2001, 2013    Previous extended mission target; no longer under consideration.


Future Encounters, missions launched: OSIRIS-APEX NASA 99942 Apophis 2029 rendezvous 2005,2006,2012,2013,2021 Extension of the OSIRIS-REx mission. 2029 radar target. Hayabusa2 JAXA 1998 KY26 2031 1998 Extended mission target. Psyche NASA 16 Psyche Aug. 2029 1980,1985,2005,2017 Launched in 2023. Discovery program.
Missions selected and/or under construction, but not yet launched: Hera ESA 65803 Didymos Dec. 2026 2003, 2022 Launch in 2024 DESTINY+ JAXA 3200 Phaethon 2028 2007, 2017 Launch in 2025 Tianwen-2 CNSA 469219 Kamo'oalewa 2025-2027 No radar Launch in 2025 AKA 2016 HO3 (Earth co-orbital) Tianwen-2 CNSA 311P/Pan-STARRS mid 2030s No radar Launch in 2025 Chinese Asteroid Defense Mission 2019 VL5 2025 No radar Launch in 2025 Mission built but not launched: Janus NASA 99942 Apophis 2029 2005,2005,2012,2013,2021 Possible target but not selected. Janus NASA 175706 1996 FG3 2026? 2011, 2022 Original target. Janus NASA 35107 1991 VH 2026? 2008, 2025 Original target.
Proposed missions not selected for launch: For the SmallSat study proposals below, it appears that this program morphed into the SIMPLEX program in 2018. Athena NASA 2 Pallas Selected for further development Planetary Science Deep Space SmallSat Study 2017 APEX NASA 99942 Apophis Selected for further development Planetary Science Deep Space SmallSat Study 2017 2005, 2006, 2012-2013 CAESAR NASA Targets not announced Selected for further development Planetary Science Deep Space SmallSat Study 2017 CAESAR NASA Comet 67P/C-G Not selected Observable in 2021 Finalist in New Frontiers competition AI3 ESA 99942 Apophis Not selected 2005, 2006, 2012-2013 Finalist in ESA Cosmic Visions F-class programme Heavy Metal ESA 16 Psyche Not selected M5 Cosmic Visions Programme DART NASA 3361 Orpheus flyby cancelled 2017 original flyby target; no longer under consideration DART NASA 138971 2001 CB21 flyby cancelled 2006 DART flyby in Mar. 2022; cancelled DART NASA 385186 1994 AW1 flyby cancelled 2015 DART flyby in Jul. 2022; cancelled AIM ESA 65803 Didymos Cancelled in 2017 Morphed into Hera in 2018 ARM NASA 341843 2008 EV5 Cancelled in 2017 Other asteroids were under consideration; e.g., 2003 SD220 BASiX NASA 175706 1996 FG3 Not selected 2011 Discovery Program 2015. DARe NASA Targets not announced Not selected Discovery Program 2015. MANTIS NASA Targets not announced Not selected Discovery Program 2015 CHagall NASA 103P/Hartley 2 Not selected 2010 Discovery Program 2015 PriME NASA 103P/Hartley 2 Not selected 2010 Discovery Program 2015 ISIS NASA 101955 Bennu Not selected 1999, 2005, 2011 Concept was under study; not selected Apophis-2029 CNES 99942 Apophis 2029 2005,2006,2012,2013 Mission concept under study Marco Polo-R ESA 341843 2008 EV5 Not selected 2008 ESA's 2010 Cosmic Visions M-class programme 175706 1996 FG3 Not selected 2011 Original target for Marco Polo-R; changed to 2008 EV5 in Nov. 2012 Comet Hopper NASA 46P/Wirtanen Not selected Planned in 2018 Discovery program 2010 BASiX NASA 65803 Didymos Not selected 2003 Discovery program 2010 Amor NASA 153591 2001 SN263 Not selected 2008 Discovery program 2010 MAX NASA 99942 Apophis Not selected 2005, 2005, 2006 Discovery program 2010 Galahad NASA 175706 1996 FG3 Not selected 2011 New Frontiers program 2009 Don Quijote ESA 99942 Apophis Not selected 2005, 2005, 2006 Marco Polo ESA 101955 Bennu Not selected 1999, 2005, 2011 Cosmic Visions M-class Program 2007 Deep Interior NASA 3908 Nyx Not selected 1988, 2004 Discovery program 2003
Radar observations have also been conducted for >100 NEAs observed by NASA's WISE mission and 90+ objects observed by NASA's Spitzer Space Telescope.
Small Body Mission Targets NOT observed by radar: ICE NASA 21P/Giacobini- Zinner 1985 Radar observations are planned in 2018 Galileo NASA 951 Gaspra 1991 Galileo NASA 243 Ida 1993 Deep Space 1 NASA 9969 Braille 1999 Deep Space 1 NASA 19P/Borrelly 2001 Stardust NASA 5535 Annefrank 2002 Stardust NASA 81P/Wild 2 2004 Deep Impact NASA 9P/Tempel 1 2005 Rosetta ESA 2867 Steins 2008 CONTOUR NASA 6P/D'Arrest 2008 Spacecraft failed in 2002; flyby never occurred Stardust NASA 9P/Tempel 1 2011 Rosetta ESA 67P/Churyumov- Gerasimenko 2014 Weak Arecibo radar target in 2021 Hayabusa 2 JAXA 162173 Ryugu 2018-2019 Radar observations in Oct. 2011 were unsuccessful. Observable in 2020. Hayabusa JAXA 10302 1989 ML Didn't happen Original target for Hayabusa; later changed to 25143 Itokawa due to launch delays http://echo.jpl.nasa.gov/~lance/radar.small.body.mission.targets.html