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"s flight data recorder was found near Hemphill, Texas, on March 19, 2003. Unlike commercial jet aircraft, the space shuttles did not have flight data recorders intended for after-crash analysis. Instead, the vehicle data were transmitted in real time to the ground via telemetry. Since "Columbia" was the first shuttle, it had a special flight data OEX (Orbiter EXperiments) recorder, designed to help engineers better understand vehicle performance during the first test flights. After the initial Shuttle test-flights were completed, the recorder was never removed from "Columbia", and it was still functioning on the crashed flight. It recorded many hundreds of parameters, and contained very extensive logs of structural and other data, which allowed the CAIB to reconstruct many of the events during the process leading to breakup. Investigators could often use the loss of signals from sensors on the wing to track how the damage progressed. This was correlated with forensic debris analysis conducted at Lehigh University and other tests to obtain a final conclusion about the probable course of events.