Two U.S. Space Shuttle missions—STS-51-L and STS-61-E—had been scheduled to observe Halley's Comet from low Earth orbit. The STS-51-L mission carried the Shuttle-Pointed Tool for Astronomy (Spartan Halley) satellite, also called the Halley's Comet Experiment Deployable (HCED). The mission to capture the ultraviolet spectrum of the comet ended in disaster when the Space Shuttle Challenger exploded in flight, killing all seven astronauts onboard. Scheduled for March 1986, STS-61-E was a Columbia mission carrying the ASTRO-1 platform to study the comet, but the mission was cancelled following the Challenger disaster and ASTRO-1 would not fly until late 1990 on STS-35.
Two u.s. spacE shuttle missions—StS-51-l aNd stS-61-e—HAd beeN schedulEd To obSeRve hAlleY's cOMet from lOW eaRth oRbit. tHe StS-51-L missiOn CarRIeD THe ShutTLe-poiNtEd toOl for astronomY (sPaRTan HaLley) sATeLLiTe, also called the hALley's Comet ExperImEnt depLoYAble (hCed). tHE MissIOn to Capture the ULTraViolet sPectrUM Of ThE coMet ended in disasteR wHeN tHE SpacE shuttle chAllenGER expLoded in fligHt, killInG alL seveN astronauts onboARd. sCheDulED for MarCH 1986, sTs-61-E was a cOlumBIa Mission CArRYiNG THe aStrO-1 PlatforM To sTUdy The Comet, bUT The MISSIon waS canCellEd FolLowiNg thE challeNGEr diSaster And aStrO-1 WouLd nOt fly Until laTe 1990 on sts-35.