The Space Shuttle "Challenger", on its launch on January 28th, 1986, was carrying SPARTAN-203 with the mission to make observations of Halley's Comet. STS-51L failed to reach orbit, resulting in the total loss of crew and vehicle. That launch failure resulted in the cancellation 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.