The STS-3 mission was the third in a series of four Shuttle missions that constituted the Orbital Flight Test program, in which the Space Shuttle systems were tested for operational flight qualification. The primary objective of the Orbital Flight Test program was to assess the performance of the orbiter and its flight systems. Because of this, the experiments objectives in the other payloads were secondary to, and constrained by, the flight test operations. The remote manipulator system and thermal response measurements of the orbiter in various attitudes to the Sun were also tested.
Spacelab pallet-mounted experiments for NASA's Office of Space Sciences-1 (OSS-1) payload were carried in the Shuttle's payload bay. OSS-1 was designed to obtain data on the near-Earth space environment, including contamination (gases, dust, etc.) introduced into space by the orbiter itself.
Nine experiments were included in the OSS-1 payload. Besides observations of the orbiter's environment, studies were conducted in space life sciences, astronomy and space plasma physics. The experiments used the many unique capabilities of the Shuttle, such as the ability to carry large instruments into orbit, to operate them in space under crew supervision, and to return them to Earth. In many respects, OSS-1 was instrumental in preparing the way for more sophisticated payloads on later Shuttle missions. The OSS-1 space life sciences plant growth experiment was carried on the Shuttle middeck. All other experiments were mounted on a Spacelab pallet in the orbiter's cargo bay.
The plant growth experiment's objectives were to test the ability of the Plant Growth Unit (PGU) to support plant growth in space, to determine the effect of microgravity on lignin synthesis and to observe the overall development of young seedlings exposed to the conditions of space flight.
Additional life sciences experiments performed during the STS-3 mission were those classified as Detailed Supplementary Objectives (DSOs). A DSO is a NASA-sponsored investigation performed by Space Shuttle crewmembers, who also serve as test subjects. These studies are designed to require minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body's biochemistry.
Other experiments included the Monodisperse Latex Reactor (MLR), the Electrophoresis Equipment Verification Test (EEVT), the Heflex Bioengineering Test (HBT) and the first Shuttle Student Involvement Program (SSIP) experiment. Problems encountered during the STS-3 mission included space sickness by the crew, a malfunctioning toilet, thermostat difficulty and unexplained static that interfered with crew sleep.
After rains flooded the dry lakebed at the primary landing site in California, the Space Shuttle landing was diverted to White Sands, New Mexico. The Shuttle's landing was also delayed by one day because of high winds at the White Sands landing site. Touchdown finally occurred at White Sands after a 194-hour mission.