Sakigake

Sakigake

Sakigake spacecraft
Mission type	Comet flyby
Operator	ISAS
COSPAR ID	1985-001A
SATCAT №	15464
Spacecraft properties
Launch mass	138.1 kilograms (304 lb)
Start of mission
Launch date	January 7, 1985, 19:27 UTC
Rocket	Mu-3S-II
Launch site	Kagoshima
End of mission
Last contact	Data: November 15, 1995 Beacon: January 8, 1999
Orbital parameters
Reference system	Heliocentric
Perihelion	0.92 astronomical units
Apohelion	1.15 astronomical units
Inclination	0.07 degrees
Period	382.8 days
Flyby of 1P/Halley
Closest approach	March 11, 1986, 04:18 UTC
Distance	6,990,000 kilometres (4,340,000 mi)

Sakigake (さきがけ lit. "pioneer" or "pathfinder"), known before launch as MS-T5, was Japan's first interplanetary spacecraft, and the first deep space probe to be launched by any country other than the USA or the Soviet Union. It aimed to demonstrate the performance of the new launch vehicle, test the schemes of the first escape from the Earth gravitation for Japan on engineering basis, and observe space plasma and magnetic field in interplanetary space. Sakigake was also supposed to get references for scientists. Early measurements would be used to improve the mission of the Suisei probe several months later.

Sakigake was developed by the Institute of Space and Astronautical Science for the National Space Development Agency (both of which are now part of the Japanese Aerospace Exploration Agency, or JAXA). It became a part of the Halley Armada together with Suisei, the Soviet/French 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.

Design

Unlike its twin Suisei, it carried no imaging instruments in its instrument payload.

Launch

Sakigake was launched January 7, 1985 from Kagoshima Space Center by M-3SII-1 launch vehicle.

Halley encounter

It carried out a flyby of Halley's Comet on March 11, 1986 at a distance of 6.99 million km.

Giacobini-Zinner encounter

There were plans for the spacecraft to go on to an encounter with 21P/Giacobini-Zinner in 1998 but they had to be abandoned due to lack of propellant.

End of mission

Telemetry contact was lost on 15 November 1995, though a beacon signal continued to be received until 7 January 1999.^[1][2]

References

1. "Sakigake - Japan ISAS Halley's Comet Mission Sakigake". Space.about.com. Retrieved 2010-02-01.
2. "Sakigake – NASA Master Catalog". Nssdc.gsfc.nasa.gov. Retrieved 2010-02-01.

External links

• SAKIGAKE
• Sakigake Mission Profile by NASA's Solar System Exploration
• Halley's Comet Flyby