Shuttle Challenger Accident Part 4


AvStop Magazine Online

Events Leading up to the Challenger Mission

Preparations for the launch of mission 51-L were not unusual, though they were complicated by changes in the launch schedule. The sequence of complex, interrelated steps involved in producing the detailed schedule and supporting logistics necessary for a successful mission always requires intense effort and close coordination. Flight 51-L of the Challenger was originally scheduled for July, 1985, but by the time the crew was assigned in January, 1985, launch had been postponed to late November to accommodate changes in payloads. The launch was subsequently delayed further and finally rescheduled for late January, 1986.

After a series of payload changes, the Challenger cargo included two satellites in the cargo bay and equipment in the crew compartment for experiments that would be carried out during the mission. The payloads flown on mission 51-L are listed in this table:

  • Mission 51-L Payloads

  • Tracking and Data Relay Satellite-B

  • Spartan-Halley Satellite

  • Comet Halley Active Monitoring Program

  • Fluid Dynamics Experiment

  • Phase Partitioning Experiment

  • Teacher in Space Project

  • Shuttle Student Involvement Program

  • Radiation Monitoring Experiment

The primary payloads were the Tracking and Data Relay Satellite (a NASA communications satellite0 and the Spartan satellite that would be deployed into orbit carrying special instruments for the observation of Halley's Comet. The NASA communications satellite was to have been placed in a geosynchronous orbit with the aid of a booster called the Inertial Upper Stage. The satellite would have supported communications with the Space Shuttle and up to 23 other spacecraft. The Spartan satellite was to have been deployed into low Earth orbit using the remote manipulator system. The Spartan instruments would have watched Halley's Comet when it was too close to the Sun for other observatories to do so. Subsequently, the satellite would have been retrieved and returned to Earth in the Shuttle payload bay.