, 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 A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and sys ...

, test its ability to escape from

Earth gravity The gravity of Earth, denoted by , is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation). It is a vector quantity ...

, and observe the interplanetary medium and

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

. ''Sakigake'' was also supposed to act as a frame of reference for data received from probes that flew closer to

Halley's Comet Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the on ...

. Early measurements would be used to improve the mission of the Suisei probe launched 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

Vega Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, a ...

probes, the ESA

Giotto Giotto di Bondone (; – January 8, 1337), known mononymously as Giotto ( , ) and Latinised as Giottus, was an Italian painter and architect from Florence during the Late Middle Ages. He worked during the Gothic/ Proto-Renaissance period. G ...

and the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

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 The Mu, also known as M, was a series of Japanese solid-fueled carrier rockets, which were launched from Uchinoura between 1966 and 2006. Originally developed by Japan's Institute of Space and Astronautical Science, Mu rockets were later operate ...

launch vehicle on M-3SII-1 mission.

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 A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, ...

to go on to an encounter with 21P/Giacobini-Zinner in 1998 but the flyby had to be abandoned due to lack of

propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the ...

End of mission

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

References

External links

''Sakigake''

''Sakigake'' Mission Profile
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NASA's Solar System Exploration

''Sakigake'' Mission Comet Halley Data Archive
at the NASA Planetary Data System, Small Bodies Node {{Orbital launches in 1985 Japanese space probes Missions to Halley's Comet Satellites orbiting the Sun 1985 in spaceflight Derelict space probes Spacecraft launched in 1985 Japanese inventions