The primary objective of STS-69 was the deployment and retrieval of the Wake Shield Facility (WSF). The WSF is a 12 foot diameter, saucer shaped, stainless steel satellite that flew free of the Shuttle for several days. While the WSF flew free of the Shuttle, it generated an "ultra-vacuum" environment in space. Inside the vacuum, thin semiconductor films for next-generation advanced electronics were developed. The commercial applications for these new semiconductors include digital cellular telephones, high-speed transistors and processors, fiber optics, opto-electronics and high definition television (HDTV).
A second objective was the deployment and retrieval of the Spartan 201 astronomy satellite. The Spartan 201 mission was a scientific research effort aimed at investigating the interactions between the Sun and its outflowing wind of charged particles. Spartan's goal was to study the outer atmosphere of the Sun and its transition into the solar wind that constantly flows past the Earth. This flight was intended to coincide with the passage of the Ulysses spacecraft over the sun's northern polar region. Ulysses was a cooperative deep space mission between the European Space Agency (ESA) and NASA, which was launched from the Space Shuttle in 1990 (STS-41) with the goal of studying the Sun at high heliographic latitudes.
Life sciences payloads aboard STS-69 included the National Institutes of Health Cells (NIH-C4) and the Biological Research in Canister (BRIC-6). NIH-C4 was the fourth in a series of eight collaborative missions between NASA and the National Institutes of Health. The two experiments in NIH.C4 were designed to study the effects of microgravity on bone cells. One experiment studied whether space flight caused changes in osteoblasts consistent with a reduction in bone formation and an increase in bone resorption. The second experiment was designed to study the effect of space flight on bone cell formation and loss. Two established bone-cell lines, one rat and one human, were used in each of the experiments. The cells for each experiment were loaded into cartridges and placed into the Space Tissue Loss-A (STL-A) module, which fits inside a Shuttle middeck locker. The automated STL-A collected and stored cell fractions during flight for analysis upon return to Earth.
STS-69 was the sixth flight of a BRIC payload. BRIC payloads consist of passive experiments contained within a metal canister placed in a middeck locker with foam padding used to dampen vibrations. The BRIC-06 payload was specifically designed to study the gravity-sensing mechanism within mammalian cells. BRIC experiment specimens were exposed to the temperatures, carbon dioxide, oxygen, atmospheric pressure and humidity conditions of the middeck.
Other life sciences experiments performed during the STS-69 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.
Additional payloads flying aboard Endeavour were the combined Capillary Pumped Loop-2/Gas Bridge Assembly, the International Extreme Ultraviolet Hitchhiker and the Electrolysis Performance Improvement Concept Study. Several Get Away Special (GAS) payloads also flew on STS-69. Get Away Special (GAS) payloads are payloads in canisters mounted to the side wall of the Shuttle payload bay or on a cross bay truss structure. These payloads are operated by the Shuttle's crew and provide their own battery power. These experiments investigated areas such as the interaction of spacecraft attitude and orbit control systems with spacecraft structures, fluid-filled beams as structural dampers in space and the effects of smoldering combustion in a long-term microgravity environment.
On the tenth flight day, Mission Specialists Jim Newman and Mike Gernhardt performed a 6-hour spacewalk to evaluate and verify specific assembly and maintenance techniques for the International Space Station. In addition, the spacewalk evaluated spacesuit design modifications that will protect astronauts from the extremely cold environment of space.
STS-69 landed on September 18, 1995, at Kennedy Space Center in Florida.