halley

SPARTAN 201 is a small, Shuttle-launched and -retrieved satellite, whose mission is to study the Sun. SPARTAN 201's science payload consists of two telescopes: the Ultraviolet Coronal Spectrometer (UVCS) and the White Light Coronagraph (WLC). Destroyed on STS-51L, redeployed on STS-56, STS-64 and STS-69.

The tenth mission for Challenger, STS-51-L was scheduled to deploy the second in a series of Tracking and Data Relay Satellites, carry out the first flight of the Shuttle-Pointed Tool for Astronomy (SPARTAN-203)/Halley's Comet Experiment Deployable in order to observe Halley's Comet.

ESA mission to study Comet Halley

Giotto flew by the Earth on July 1. Closest approach was about 219,000 km at approximately 02:40 UT (10:40 p.m. EDT, 30
June). The spacecraft was moving at about 3.5 km/sec relative to Earth.