The primary objective for the STS-75 mission was to carry the Tethered Satellite System Reflight into orbit and deploy it spaceward on a conducting tether at a distance of more than 12 miles. The conducting tether was to generate high voltage and electrical currents as it moved through the ionosphere across the magnetic field lines of Earth. Scientists expected to learn more about the electrodynamics of a conducting tether system to deepen the understanding of physical processes in the near-Earth space environment
The mission also flew the United States Microgravity Payload (USMP-3) designed to investigate the effects of microgravity on various materials and to study condensed matter physics. The USMP-3 payload consisted of four major experiments mounted on two Mission Peculiar Experiment Support Structures and three Shuttle middeck experiments. The experiments included the Advanced Automated Directional Solidification Furnace, Materials for the Study of Interesting Phenomena of Solidification on Earth and in Orbit, Space Acceleration Measurement System, Orbital Acceleration Research Experiment, Critical Fluid Light Scattering Experiment and Isothermal Dendritic Growth Experiment.
Life sciences experiments performed during the STS-75 mission were those classified as Detailed Supplementary Objectives (DSOs). A DSO is a NASA-sponsored investigation performed by Space Shuttle crewmembers, who serve as the 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 payloads were the Commercial Protein Growth experiment, Middeck Glovebox Facility Combustion Investigations, Forced-Flow Flame Spreading Test and Comparative Soot Diagnostics experiment.
The STS-75 mission ended on March 9, 1996, with the landing of Columbia at the Kennedy Space Center.