, known before launch as MS-T5, was Japan's first

interplanetary spacecraft Interplanetary spaceflight or interplanetary travel is spaceflight ( crewed or uncrewed) between bodies within a single planetary system. Spaceflights become interplanetary by accelerating spacecrafts beyond orbital speed, reaching escape velocit ...

and the first deep space probe to be launched by any country other than the US or the Soviet Union. It aimed to demonstrate the performance of the new

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

, 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 quantit ...

, and observe the

interplanetary medium The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planet A dwarf planet is a small planetary ...

and

magnetic field A magnetic field (sometimes called B-field) is a physical 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 ...

. ''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 is the only known List of periodic comets, short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30) occurring after ...

. 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 , or ISAS, is a Japanese national research organization of astrophysics using rockets, astronomical satellites and interplanetary probes which played a major role in Japan's space development. Established as part of the University of Tokyo ...

for the

National Space Development Agency The , or NASDA, was a Japanese national space agency established on October 1, 1969 under the National Space Development Agency Law only for peaceful purposes. Based on the Space Development Program enacted by the Minister of Education, Culture, ...

(both of which are now part of the

Japanese Aerospace Exploration Agency The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into or ...

, or JAXA). It became a part of the

Halley Armada The Halley Armada is the name of a series of space probes, five of which were successful, sent to examine Halley's Comet during its 1986 sojourn through the inner Solar System, connected with apparition "1P/1982 U1". The armada included one prob ...

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, and ...

probes, the ESA

Giotto Giotto di Bondone (; – January 8, 1337), known mononymously as Giotto, was an List of Italian painters, Italian painter and architect from Florence during the Late Middle Ages. He worked during the International Gothic, Gothic and Italian Ren ...

and the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

International Cometary Explorer The International Cometary Explorer (ICE) spacecraft, designed and launched as the International Sun-Earth Explorer-3 (ISEE-3) satellite, was launched on 12 August 1978 into a heliocentric orbit. It was one of three spacecraft, along with the m ...

, 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 The is a space launch facility in the Japanese town of Kimotsuki, Kagoshima, Kimotsuki, Kagoshima Prefecture. Before the establishment of the Japan Aerospace Exploration Agency, JAXA space agency in 2003, it was simply called the (KSC). All o ...

M-3SII The Mu, also known as M, was a series of Japanese Solid-fuel rocket, solid-fueled carrier rockets, which were launched from Uchinoura Space Center, Uchinoura between 1966 and 2006. Originally developed by Japan's Institute of Space and Astronauti ...

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 that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

to go on to an encounter with 21P/Giacobini-Zinner in 1998, but the flyby had to be abandoned because of a 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 another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicle ...

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
b
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