Sakigake

Sakigake (さきがけ; lit. 'pioneer', '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 US or the Soviet Union. Its main goals were to show how well a new launch vehicle could work, test if it could leave Earth gravity, and study the space between planets and magnetic field.

Sakigake also helped scientists by giving information about Halley's Comet. This information was used to make the Suisei probe — launched a few months later — even better.

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 from different countries in what is called the Halley Armada. This big group of probes studied Halley's Comet when it came close to the Sun in 1986. These 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, from the Kagoshima Space Center using an M-3SII launch vehicle 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 had plans to meet a comet called 21P/Giacobini-Zinner in 1998. However, 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.