Launch preparations 's rollout from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB) to be stacked for launch. Preparation for the mission began on June 3, 1983, with the assembly of the shuttle's
solid rocket boosters (SRB) on the
Mobile Launcher Platform. The boosters were stacked on June 20, 1983, and the
external tank (ET) mated to the assembly on June 23, 1983.
Challenger arrived at
Kennedy Space Center on June 29, 1983, and was transferred to the
Orbiter Processing Facility on June 30, 1983. After post-flight maintenance and preparation for the new mission, including the installation of most flight payloads, the shuttle was transferred to the
Vehicle Assembly Building on July 27, 1983, and mated to the booster/tank stack. The stack was checked out on July 29 and 30, 1983, and moved to
Launch Complex 39A on August 2, 1983. INSAT-1B was loaded into the orbiter when on the pad; the overall processing time from
Challenger arriving at KSC to being ready for launch was only sixty-two days, a record for the program at the time. The launch had originally been scheduled for on August 4, 1983, and was later rescheduled for on August 20, 1983. The requirement to conduct testing with the
Tracking and Data Relay Satellite System (TDRSS) required a delay of ten days for the system to be ready, during which the stack remained on the launch pad. During the on-pad delay,
Hurricane Barry (1983) hit the
Florida coastline, making landfall just south of the Kennedy Space Center on the morning of August 25, 1983. The storm had only been identified two days earlier, and there was no time to roll
Challenger back from the pad; the decision was made to secure the launch stack and ride out the storm.
Launch strike near the orbiter stack, some hours before launch.
Challenger finally launched at 06:32:00
UTC (02:32:00
EDT) on August 30, 1983, after a final 17-minute delay due to
thunderstorms near the launch site. The launch window extended from 06:15 to 06:49. The countdown to launch was called by Mark Hess, public information officer. The launch, which occurred in pre-dawn darkness, was the first American night launch since
Apollo 17, and was watched by several thousand spectators. The unusual launching time was due to tracking requirements for the primary payload, INSAT-1B; The crew had attempted to prepare for it by training in darkened simulators so as to keep their
night vision, but in practice it was discovered that the light of the solid-fuel rocket boosters made the immediate area around the launchpad virtually as bright as a day launch. The launch was the first to use a newly developed high-performance motor for the solid rocket boosters, which gave approximately 7% greater thrust. Post-flight analysis later showed there was nearly a burn-through of the rocket casing, a significant problem that later
doomed the 51-L mission (see "Post-flight safety analysis" section below for more). This launch was also the second-to-last to use the original standard-mass steel casings for the boosters. These had been replaced by a thinner case, saving some , on
STS-6 and
STS-7, but because of safety concerns the next two flights used the conventional cases.
Orbital operations After a successful insertion into a circular orbit at , the first experiments began; the first two samples were run through the Continuous Flow Electrophoresis System, and measurements were taken for the atmospheric luminosities study. A hydraulic circulation pump failed, but this was worked around and it proved to have no impact on operations. Other experimentation continued, though telemetry through TDRS was lost for around three hours, requiring manual intervention. A fire alarm sounded in the morning, indicating signs of a fire in the
avionics compartment, but a second alarm remained silent and it was eventually determined to be a false alarm. On the third and fourth days (September 1 and 2, 1983), work began with the
Canadarm Remote Manipulator System and the payload test article, and communications testing through TDRS continued. The former was successful, but the latter lost contact on a number of occasions, due to problems at the
White Sands ground station. As a result, the crew had to be awakened early on September 1, 1983, in order to deal with the problem. A minor cabin pressure leak on September 2, 1983, was traced to the waste management system, and quickly controlled. On the fifth day (September 3, 1983), testing of the Canadarm continued, including a number of optional "shopping list" tests, and the TDRS tests were carried out with more success. On the sixth day (September 4, 1983), experiment runs were completed and the crew prepared to deorbit. Two systems failures were recorded on this last day, the most serious of which involved a synchronization failure in one of the onboard computers.
Landing The mission plan called for a landing at
Edwards Air Force Base,
California, at 121:28
mission elapsed time (MET). On the original plan, this would have been at 07:44
UTC on September 4, 1983, before accounting for the last-minute launch delay; in the event, this was put back by one day to allow for further communications testing, and
Challenger touched down at 07:40:33 UTC (00:40:33
PDT), September 5, 1983, on Runway 22 at Edwards Air Force Base, on the morning of the seventh day of the mission. As with the launch, this was the first night landing of the program. The Shuttle orbiters had no on-board lights, due to the difficulty of designing
landing lights to survive re-entry, and so the runway was lit by high-intensity
xenon arc lamps to guide the orbiter in. There was no pressing operational requirement for a night landing, but there was a desire to prove it was possible. Footage of the landing was shown in the 1986 film
SpaceCamp. == Post-flight safety analysis ==