Sakigake

Sakigake

Sakigake (さきがけ; lit. 'pioneer', 'pathfinder'), known before launch as MS-T5, was Japan's first interplanetary spacecraft. It was also the first deep space probe launched by any country except the US or the Soviet Union.

Its main goals were to test a new launch vehicle, see if it could leave Earth gravity, and study space between planets and magnetic field.

Sakigake also gave scientists important information about Halley's Comet. This helped improve the Suisei probe that was launched later.

The spacecraft was built by the Institute of Space and Astronautical Science for the National Space Development Agency. These groups are now part of the Japanese Aerospace Exploration Agency, or JAXA.

Sakigake joined many other space missions in something called the Halley Armada. This group of probes studied Halley's Comet when it came close to the Sun in 1986. The group included the Soviet Vega probes, the ESA Giotto, and the NASA International Cometary Explorer.

Design

Unlike its twin Suisei, Sakigake did not carry any cameras in its instrument set.

Launch

Sakigake was launched on January 7, 1985. It lifted off from the Kagoshima Space Center using an M-3SII launch vehicle. This happened during the M-3SII-1 mission.

Halley encounter

Sakigake flew past Halley's Comet on March 11, 1986. It passed the comet at a distance of 6.99 million kilometers.

Giacobini-Zinner encounter

The spacecraft planned to meet a comet called 21P/Giacobini-Zinner in 1998. This plan was stopped because there was not enough propellant to make the journey.

End of mission

The spacecraft stopped sending detailed information on November 15, 1995. It kept sending a simple signal until January 7, 1999.