|
As of 2016, the United States, Japan, the European Space Agency and the People's Republic of China have conducted missions to minor planets. Most missions to date that have reached their targets have been to asteroids, however the Dawn and New Horizons spacecraft have visited the dwarf planets Ceres and Pluto respectively, and the former is currently in orbit there. Spacecraft visits to minor planets have mostly been flybys, and have ranged from dedicated missions to incidental flybys and targets of opportunity for spacecraft that have already completed their missions. The first spacecraft to visit an asteroid was Galileo, which flew past 951 Gaspra in October 1991; an incidental encounter while the probe was en route to Jupiter. The first dedicated mission was NEAR Shoemaker, which was launched in February 1996, and entered orbit around 433 Eros in February 2000, having first flown past 253 Mathilde. NEAR was also the first spacecraft to land on an asteroid, surviving what was intended to be an impact with Eros at 20:01 on 12 February 2001 at the planned end of its mission. As a result of its unexpected survival, the spacecraft's mission was extended until 1 March to allow data to be collected from the surface. New Horizons, which flew by Pluto in July 2015, is currently on it's way to KBO which, if funded, it will encounter on New Year's day, 2019. } | Attitude control failure; failed to leave geocentric orbit after first phase of mission exploring the Moon. Flyby had been planned for August 1994〔(【引用サイトリンク】title=Solar System Exploration - Clementine )〕 | Titan II(23)G |- | rowspan=2| (Discovery 2) | rowspan=2| | | Flyby | | Closest approach at 12:56 UTC on 27 June 1997〔(【引用サイトリンク】title=Solar System Exploration - NEAR Shoemaker )〕 | rowspan=2| Delta II 7925 |- | | Orbiter | }} | Aborted burn three days before arrival at Eros resulted in failure to enter orbit, instead flew past at at 18:41:23 on 23 December 1998. Insertion reattempted successfully on 14 February 2000. Impacted asteroid at 20:01 on 12 February 2001 at end of mission, but survived impact and continued to operate on surface until 1 March.〔 |- style="background-color:#cccccc;" | | 〔 | | Flyby | | Distant incidental flyby en route to Saturn; closest approach 1.5 million kilometres (0.9 million miles) at 09:58 UTC on 23 January 2000〔(【引用サイトリンク】title=Solar System Exploration - Cassini )〕 | Titan IV(401)B Centaur-T |- | rowspan=2| Deep Space 1 | rowspan=2| | 〔Wilson–Harrington is catalogued as both a comet and an asteroid〕 | Flyby | | Spacecraft was unable to reach the asteroid due to ion engine operation being suspended while a problem with the probe's star tracker was investigated〔(【引用サイトリンク】title=Solar System Exploration - Deep Space 1 )〕 | rowspan=2| Delta II 7326 |- | | Flyby | | Closest approach at 04:46 UTC〔 on 29 July 1999. Intended to pass within but this was not achieved due to a computer failure, poor-quality images returned as a result. Flyby added to mission following loss of ability to reach Wilson–Harrington |- | Stardust (Discovery 4) | | | Flyby | | Closest approach of at 04:50:20 UTC on 2 November 2002 | Delta II 7426 |- | Hayabusa (MUSES-C) | rowspan=2 | | | Orbiter/lander Sample return | | Reached Itokawa on 12 September 2005, landed briefly on 19 and 25 November but sampler failed to operate, missed return window due to communications outage, finally returned to Earth on 13 June 2010 | rowspan=2 | M-V |- | Minerva | | Lander | | Deployed from Hayabusa on 12 November 2005; Accidentally released while Hayabusa was moving away from Itokawa; reached escape velocity and drifted off into heliocentric orbit |- | rowspan=2| Rosetta | rowspan=2| | | Flyby | | Closest approach on 5 September 2008 | rowspan=2| Ariane 5G+ |- | | Flyby | | Closest approach on 10 July 2010 |- | Deep Impact (Discovery 7) | | | Flyby | | Extended mission (EPOXI), flyby was expected in 2020, but communication with the spacecraft was lost in August 2013 | Delta II 7925 |- | rowspan=3| New Horizons (New Frontiers 1) | rowspan=3| | style="background-color:#cccccc;" | | style="background-color:#cccccc;" | Flyby | | style="background-color:#cccccc;" | Incidental flyby en route to Pluto, closest approach at 04:05 UTC on 13 June 2006 | rowspan=3| Atlas V 551 |- | and it's five moons. | Flyby | | Flyby occurred on 14 July 2015 |- | | Flyby | | Flyby expected in January 2019 |- | rowspan=2| Dawn (Discovery 9) | rowspan=2| | | Orbiter | | Orbited Vesta from 16 July 2011 to 5 September 2012, before departing for Ceres | rowspan=2| Delta II 7925H |- | | Orbiter | | Arrived in 2015 |- | Chang'e-2 | | | Flyby | | Flyby on 13 December 2012, closest approach | Chang Zheng 3C |- | Hayabusa 2 | rowspan=8| | rowspan=7| | Orbiter/lander Sample return | | | rowspan=8| H-IIA 202 |- | Minerva II-1A | Lander | | To be deployed from Hayabusa 2 |- | Minerva II-1B | Lander | | To be deployed from Hayabusa 2 |- | Minerva II-2 | Lander | | To be deployed from Hayabusa 2 |- | MASCOT | Lander | | To be deployed from Hayabusa 2 |- | SCI | Impactor | | To be deployed from Hayabusa 2 |- | DCAM-3 | Orbiter | | To be deployed from Hayabusa 2, will be used to observe SCI impact |- | PROCYON | | Flyby | | Flyby planned for 2016 |} ==See also== * List of minor planets and comets visited by spacecraft 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「List of missions to minor planets」の詳細全文を読む スポンサード リンク
|