Suisei (spacecraft)

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Suisei

An artist's rendering of the Suisei spacecraft
Names	PLANET-A
Mission type	Halley flyby
Operator	ISAS
COSPAR ID	1985-073A
SATCAT no.	15967
Website	isas.ac.jp
Mission duration	5 years, 6 months and 4 days
Spacecraft properties
Launch mass	139.5 kg (308 lb)[1]
Start of mission
Launch date	August 18, 1985 23:33 UTC
Rocket	M-3SII
Launch site	Uchinoura Space Center
End of mission
Disposal	Decommissioned
Deactivated	February 22, 1991
Orbital parameters
Reference system	Heliocentric
Flyby of 1P/Halley
Closest approach	March 8, 1986
Distance	151,000 km (94,000 mi)
Flyby of Earth
Closest approach	August 20, 1992
Distance	~900,000 km (560,000 mi)
PLANET series Nozomi → Halley Armada ← Giotto

Suisei (すいせい, lit. "Comet"), originally known as Planet-A, was an uncrewed space probe developed by the Institute of Space and Astronautical Science (now part of the Japanese Aerospace Exploration Agency, or JAXA).

It constituted a part of the Halley Armada together with Sakigake, the Soviet Vega probes, the ESA Giotto and the NASA International Cometary Explorer, to explore Halley's Comet during its 1986 sojourn through the inner Solar System.