STS-5
"Columbia" landed on Runway 22 at Edwards Air Force Base on 16 November 1982, at 6:33 am PST, having traveled 2 million miles in 81 orbits during a mission that lasted 5 days, 2 hours, 14 minutes and 26 seconds. "Columbia" was returned to KSC on 22 November 1982. STS-5 was the first shuttle flight in which the crew did not wear pressure suits for the launch, reentry, and landing portions of the flight, similar to the Soviet Voskhod and Soyuz missions prior to the ill-fated Soyuz 11 mission in 1971.
The shuttle was formally declared "operational" after STS-4. However, the Columbia Accident Investigation Board (CAIB), in its report on the loss with all crew aboard of "Columbia" during STS-107 in 2003, asserted that the orbiter should never have been considered operational and that, while not intrinsically unsafe, it was in fact an experimental vehicle. The CAIB's rationale was that civilian and military aircraft that are considered operational must have been tested and proven over thousands of safe flights in their final operational configurations, whereas the shuttle had conducted under 200 flights, with continuous modification. NASA operated the Space Shuttle as an experimental vehicle for the remainder of the program.
Space Shuttle Columbia disaster
"Columbia" was scheduled to land at 9:16 a.m. EST.
In 2008, NASA released a detailed report on survivability aspects of the "Columbia" reentry. The crew would have had less than a minute between the beginning of orbiter disintegration and depressurization. The structural failure of the left wing set off alarms in the cabin, although they had no way of knowing that the wing had broken apart as the rear of the orbiter could not be seen from the cabin. All evidence indicated that the crew frantically tried to regain control of "Columbia" as it began to spin out of control, but the loss of the left wing caused the orbiter to yaw to the right, exposing its underside to extreme aerodynamic forces and causing total structural disintegration. The crew cabin separated from the rest of the orbiter and rapidly depressurized, which would have killed or incapacitated the astronauts within seconds. Afterwards, the cabin spun around at high RPM, which caused the seat restraints on their upper bodies to fail. They were thus whipped around violently and pummeled by flying and falling objects from the disintegrating cabin, along with their heads and necks being slammed against the helmets, which were not designed to provide any head protection. Even if the cabin had remained structurally intact and reached a lower altitude where air could refill it, the high altitude depressurization would have been fatal to the astronauts unless they received medical attention within five minutes, approximately the amount of time it would take between cerebral hypoxia and brain death.