TheHalley Armada was a series of space probes, five of which were successful, sent to examineHalley's Comet during its 1986 passage through the inner Solar System.^[1] The armada included one probe from theEuropean Space Agency, two probes that were joint projects between theSoviet Union andFrance and two probes from theInstitute of Space and Astronautical Science inJapan.NASA did not contribute a probe to the Halley Armada.

Without the measurements from the other space probes, Giotto's closest distance would have been 4,000 km instead of the 596 km achieved.^[2]

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 itsperihelion February 9, 1986. Its UV-spectrometer observed the water loss when Halley's Comet was difficult to observe from the Earth.^[3]
• International Cometary Explorer, which was repurposed as a cometary probe in 1982 and visitedComet Giacobini-Zinner in 1985, transited between the Sun and Halley's Comet in late March 1986 and took measurements.^[1]

TheSpace ShuttleChallenger, on its launch on January 28, 1986, was carryingSPARTAN-203 withthe mission to make observations of Halley's Comet.STS-51Lfailed to reach orbit, resulting in the total loss of crew and vehicle. That launch failure resulted in thecancellation of dozens of subsequent shuttle missions, including the next scheduled launch,STS-61-E, planned for March 6, 1986, with a payload including the ASTRO-1 observatory, which was intended to make astronomical observations of Halley's Comet.

TheInternational Comet Mission, consisting of a carrier NASA probe and a smaller European probe based on theISEE-2 design, with the intention that the American probe would release the European probe towards Halley for a close flyby, before going on to explore Comet10P/Tempel itself.^[4] The NASA probe was cancelled November 1979.^[5]

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

• Missions to Halley's Comet
• Soviet space probes
• European Space Agency space probes
• NASA space probes
• Japanese space probes

• Articles with short description
• Short description matches Wikidata