| 词条 | PROCYON |
| 释义 |
| name = PROCYON | image = | image_caption = | image_alt = | image_size = | mission_type = Asteroid flyby, technology demonstration | operator = University of Tokyo / JAXA | COSPAR_ID = 2014-076D | SATCAT = | website = {{url|http://www.t.u-tokyo.ac.jp/etpage/release/2014/141204_1.html|PROCYON on University of Tokyo site}} | mission_duration = | distance_travelled = | manufacturer = | launch_mass = Total: {{convert|67|kg|lb|abbr=on}} | landing_mass = | dry_mass = {{convert|64.5|kg|lb|abbr=on}} | payload_mass = | dimensions = {{convert|0.55|xx|0.55|xx|0.67|m|ft|abbr=on}} | power = 25 | launch_date = {{start-date|3 December 2014, 04:22 UTC|timezone=yes}} | launch_rocket = H-IIA 202 | launch_site = LA-Y, Tanegashima Space Center | last_contact = {{end-date|3 December 2015}} |interplanetary = |type = flyby |object = Earth |arrival_date = 3 December 2015 |distance = {{Infobox spaceflight/IP |type = flyby |object = yet undecided asteroid |orbits = |arrival_date = to be decided |departure_date = |periapsis = |apoapsis = |inclination = |apsis = apsis | landing_date = | landing_site = | programme = | previous_mission = Hodoyoshi 4 | next_mission = EQUULEUS }} PROCYON (Proximate Object Close flyby with Optical Navigation) was an asteroid flyby space probe that was launched together with Hayabusa2 on 4 December 2014 13:22:04 (JST). It was developed by University of Tokyo and JAXA. It was a small (70kg, approx. 60 cm cube), low cost ({{JPY|500 million|link=yes}}) spacecraft.[1] It was intended to flyby the asteroid {{mpl|185851|2000 DP|107}} in 2016,[2] but the plan was abandoned due to the malfunction of the ion thruster.[1] Mission overviewPROCYON was launched as secondary payload together with the Hayabusa2 asteroid landing probe. After separation from the carrier rocket, PROCYON was left on a heliocentric orbit. On February 22, 2015, the ion engine was started, with the intention of adjusting the orbit so that an Earth flyby in December 2015 would direct the probe towards asteroid {{mp|2000 DP|107}}.[3] Initial results were favourable - the engine delivered 330 µN of thrust rather than the designed 250 µN - but the engine failed on March 10 and could not be restarted; PROCYON flew past Earth on December 3, 2015, but was unable to make a controlled orbit change. Shortly after the Earth flyby, contact with the spacecraft was lost.[4] The 70 kg spacecraft had a specific impulse of 1000 seconds, for a delta-V budget of about 500 ms−1; the intention was to use 20% of the xenon propellant for the initial orbit correction, and the rest of the propellant between the Earth flyby and the asteroid flyby to ensure a controlled flyby distance of 30 km.[5] A novel subsystem tested by PROCYON involved feeding both the main ion engine and the eight cold-gas attitude control thrusters from the same tank (containing 2.5 kg of xenon at launch) Instruments
Science resultsPROCYON observed the Lyman-alpha emission of comet 67P/Churyumov–Gerasimenko to determine its overall coma structure.[7] See also{{Portal|Spaceflight}}
References1. ^1 {{cite web |url=http://mainichi.jp/select/news/20150509k0000m040022000c.html |script-title=ja:プロキオン:小惑星への接近観測断念 |website=Mainichi Shimbun |date=May 8, 2015 |accessdate=May 8, 2015 |deadurl=yes |archiveurl=https://web.archive.org/web/20150518083332/http://mainichi.jp/select/news/20150509k0000m040022000c.html |archivedate=18 May 2015 |df=dmy-all }} 2. ^{{cite web |url=http://senews.jp/satellite/2015/04/07/528 |script-title=ja:超小型探査機「PROCYON」 二重小惑星を目指して航行中 |trans-title=Very Small Probe PROCYON Cruising Toward a Binary Asteroid |work=Space Elevator News |date=April 7, 2015 |accessdate=April 7, 2015}} 3. ^{{cite web|url=http://issfd.org/2015/files/downloads/papers/072_Campagnola.pdf|title=Low-thrust trajectory design and operations of PROCYON, the first deep-space micro spacecraft}} 4. ^{{cite web|title=On the situation of ultra small deep space explorer "PROCYON (Proquion)"|url=http://www.isas.jaxa.jp/j/topics/topics/2015/1211.shtml|website=ISAS (Institute of Space and Astronautical Science)|accessdate=23 March 2018}} 5. ^{{cite web|url=http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3102&context=smallsat|title=50kg- class Deep Space Exploration Technology Demonstration Micro-spacecraft PROCYON|publisher=digitalcommons.edu|author=|date=|accessdate=}} 6. ^{{cite web |url=http://www.space.t.u-tokyo.ac.jp/nlab/PROCYON_public_jp_150115.pdf |script-title=超小型深宇宙探査機 PROCYON（プロキオン） |author=PROCYON development team |language=Japanese |accessdate=May 14, 2015}} 7. ^{{cite web |url=http://www.nao.ac.jp/en/news/science/2017/20170124-procyon.html |title=Micro spacecraft investigates cometary water mystery |publisher=National Astronomical Observatory of Japan |date=24 January 2017 |accessdate=26 January 2017}} External links
6 : Japanese space probes|Missions to near-Earth asteroids|Space probes launched in 2014|2014 in Japan|Japanese inventions|Spacecraft launched by H-II rockets |
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