Halley Armada

The Halley Armada is the generally accepted and popularly used name of five space probes sent to examine Halley's Comet during its 1986 sojourn through the inner Solar System,^[1] connected with apparition "1P/1982 U1". The armada consisted of one probe from the European Space Agency, two probes that were joint projects between the Soviet Union and France and two probes from the Institute of Space and Astronautical Science of Japan.

Main space probes

Probes involved (in order of closest approach):

• Giotto, the first space probe to get close-up color images of the nucleus of a comet. (ESA)
• Vega 1, which dropped a balloon probe and lander on Venus before going on to Halley. (USSR/France Intercosmos)
• Vega 2, which dropped a balloon probe and lander on Venus before going on to Halley. (USSR/France Intercosmos)
• Suisei, also known as PLANET-A. Data from Sakigake was used to improve upon Suisei for its dedicated mission to study Halley. (ISAS)
• Sakigake, Japan's first probe to leave the Earth system, mainly a test of interplanetary mission technology. (ISAS)

Without the measurements from the other space probes, Giotto's closest distance would have been 4,000 km instead of the 596 km achieved.

Other space probes

Other space probes had their instruments examining Halley's Comet:

• Pioneer 7 was launched on August 17, 1966. It was put into heliocentric orbit with a mean distance of 1.1 AU to study the solar magnetic field, the solar wind, and cosmic rays at widely separated points in solar orbit. On 20 March 1986, the spacecraft flew within 12.3 million kilometers of Halley's Comet and monitored the interaction between the cometary hydrogen tail and the solar wind.^[1]
• Pioneer Venus Orbiter in orbit of Venus, was positioned perfectly to take measurements of Halley's Comet during its perihelion February 9, 1986. Its UV-spectrometer observed the water loss when Halley's Comet was difficult to observe from the Earth.^[2]
• International Cometary Explorer, which was repurposed as a cometary probe in 1982 and visited Comet Giacobini-Zinner in 1985, transited between the Sun and Halley's Comet in late March 1986 and took measurements.^[1]

Presumed observations from space

• Any observations of Halley's Comet made by the crew of Soyuz T-15, which made the first trip to the Mir space station and the last to Salyut 7 in March 1986, are unknown.

References

1. "Halley Comet Missions" (PDF).
2. "Pioneer Venus Observations during Comet Halley's Inferior Conjunction" (PDF). University of California, Los Angeles. Retrieved 2009-02-10.

External links

• Image of Halley in 1986 by Giotto spacecraft (ESA Giotto. Archive.org, 27 Sep 2011)