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.
STS-2
STS-2 was the second Space Shuttle mission conducted by NASA, and the second flight of the orbiter "Columbia". The mission launched on 12 November 1981 and landed two days later on 14 November. STS-2 marked the first time in history that a manned, reusable orbital vehicle returned to space for a second time. This mission tested the Shuttle Imaging Radar as part of the OSTA-1 payload, along with a wide range of other experiments including the Shuttle robotic arm, commonly known as Canadarm. Other experiments or tests included Shuttle Multispectral Infrared Radiometer, Feature Identification and Location Experiment, Measurement of Air Pollution from Satellites, Ocean Color Experiment, Night/Day optical Survey of Lightning, Heflex Bioengineering Test, and Aerodynamic Coefficient Identification Package (ACIP). One of the feats accomplished was various tests on the OMS including starting and restarting the rocket engines while in orbit and various adjustments to its orbit. The OMS tests also help adjust the Shuttle's orbit for use of the radar. During the mission, President Reagan called the crew of STS-2 from Mission Control in Houston, Texas while they were in orbit.