STS-95

The primary objectives included conducting a variety of science experiments in the pressurized Spacehab module, the deployment and retrieval of the Spartan free-flyer payload, and operations with the HST Orbital Systems Test (HOST) and the International Extreme Ultraviolet Hitchhiker (IEH) payloads carried in the payload bay.^[3]

The Spacehab module flown on STS-95 was provided by Spacehab, Inc., a private company. The Spacehab system provided additional pressurized workspace for experiments, cargo and crew activities. Spacehab modules supported various Shuttle science missions along with several of the joint Shuttle-Mir missions.

For STS-95, a single-module Spacehab flew in the forward portion of Discovery's payload bay, with the crew gaining access to the module through the airlock tunnel system. A variety of experiments sponsored by NASA, the Japanese Space Agency (NASDA) and the European Space Agency (ESA) focused on life sciences, microgravity sciences and advanced technology during the flight.

The Spartan 201-5 free-flyer was deployed and retrieved using the Shuttle's mechanical arm. It was designed to investigate physical conditions and processes of the hot outer layers of the Sun's atmosphere, or solar corona.^[3] While deployed from the Shuttle, Spartan gathered measurements of the solar corona and solar wind. NASA expected that information collected during this mission would lead to a much better understanding of the solar winds that directly influence orbiting satellites and weather conditions on Earth which in turn impact television and phone communications.^[3] This was the fifth flight for the Spartan payload; it originally flew on the STS-56 mission in April 1993.^[6] On its previous mission, STS-87 in November 1997, Spartan developed problems shortly after being deployed from the Shuttle and had to be brought back into the Shuttle's payload bay by spacewalk.^[6] These problems were due with the attitude control system for fine pointing toward solar targets, and Spartan was cleared for use again on STS-95. Its mission was to successfully perform the same experiments from the previous year.^[6]

The Hubble Space Telescope Orbital Systems Test (HOST) platform carried experiments to validate components planned for installation during the third Hubble Space Telescope servicing mission and to evaluate new technologies in an earth orbiting environment. There were four experiments on the HOST platform. The NICMOS Cooling System allowed for zero-g verification of a reverse turbocharged Brayton cycle cooler, which allowed for longer life operation than the dewar system used on Hubble at the time. The HST 486 computer allowed for the identification of any radiation-susceptible parts in the DF-224 replacement computer to be carried on the third servicing mission, and demonstrate hardware and software responses to Single Event Upsets (SEUs). A solid state recorder compared on-orbit operation of the flight-spare solid state recorder with the unit installed in Hubble. A fiber optic line test used the same 4 kbit/s data stream that was sent to the orbiter's Payload Data Interrogator (PDI) and routed to a laptop computer for post-flight comparison.^[7]

The International Extreme Ultraviolet Hitchhiker (IEH) payload involved a half dozen different experiments mounted on a support structure which was carried in Discovery's payload bay. The six experiments that made up the IEH payload were the Solar Extreme Ultraviolet Hitchhiker (SEH) payload, which obtained EUV and FUV fluxes that are required when studying the Earth's upper atmosphere; an Ultraviolet Spectrograph Telescope for Astronomical Research (UVSTAR) payload designed to measure EUV fluxes which could be used to form images of extended plasma sources (ex. Jupiter, hot stars, etc.); the STAR-LITE payload which made observations of extended and diffused astrophysical targets; the CONCAP-IV payload designed to grow thin films via physical vapor transport; the Petite Amateur Navy Satellite (PANSAT) payload which was managed by the Department of Defense Space Test Program, and involved a small deployable satellite that stored and transmitted digital communications to PANSAT ground stations; and a Getaway Special (GAS) payload.^[7]

According to the New York Times, Glenn "won his seat on the shuttle flight by lobbying NASA for two years to fly as a human guinea pig for geriatric studies", which were named as the main reasons for his participation in the STS-95 mission.^[8] This series of experiments conducted on Glenn during the mission was sponsored by NASA and the National Institute on Aging,^[9] and based on the fact that the aging process and a space flight experience share a number of similar physiological responses.^[3] The investigations were expected to gather information which may provide a model system to help scientists interested in understanding aging.^[9] Some of these similarities include bone and muscle loss, balance disorders and sleep disturbances.^[3] Shortly before the flight, researchers learned that Glenn had to be disqualified from another of the flight's two main priority human experiments (about the effects of melatonin) because he did not meet one of study's medical conditions; he still participated in two other experiments about sleep monitoring and protein use.^[8] Data provided from Glenn during this mission was compared to data obtained from Glenn's Friendship 7 orbital mission in 1962.

Glenn was the oldest person, and the third sitting member of Congress, to fly into space. He was preceded by U.S. Senator from Utah Jake Garn (STS-51-D) and U.S. Representative (later Senator) from Florida Bill Nelson (STS-61-C). At the time, Glenn was Ohio's senior or ranking Senator. Other astronauts who later entered politics include Harrison Schmitt (Apollo 17), later U.S. Senator from New Mexico, Jack Swigert (Apollo 13), who was elected to Congress in the state of Colorado but died before being sworn in, and U.S. Senator from Arizona Mark Kelly (STS-108, STS-121, STS-124, and STS-134).

In a reprise of his first space flight, while in orbit, Glenn was greeted again by the citizens of Perth and Rockingham in Australia.^[10] They left their private and municipal lights on while the Discovery passed overhead, just like they did during his Friendship 7 flight.^[10]

This is the first mission wherein a Space Shuttle orbiter (Discovery in this mission) uses NASA's meatball insignia on its markings. It replaced the worm logotype that all orbiters had. Endeavour, Atlantis, and Columbia would follow in their respective missions of STS-88, STS-101, and STS-109. Space Shuttle orbiters Enterprise and Challenger didn't have this change, for Enterprise became the property of The Smithsonian in 1985 and Challenger was destroyed in 1986.

The crew of STS-95 was awarded the Space Foundation's Douglas S. Morrow Public Outreach Award in 1999. The award is given annually to an individual or organization that has made significant contributions to public awareness of space programs.^[11]

The drag chute door detached and fell from the orbiter at main engine ignition. There was some concern that the drag chute could deploy prematurely prior to touchdown, and the decision was made not to use the chute during landing rollout. Wheel brakes and speedbrakes were sufficient to bring Discovery to a stop on Runway 33 at the Shuttle Landing Facility.^[12]

An RCS leak venting from a thruster on the left-hand OMS pod was observed in orbit. An isolation valve was used to disable the jet.^[12] Attitude control was maintained by system redundancy; there were 44 jets located around the orbiter.

The Advanced Television Systems Committee (ATSC) provided live coverage of the lift-off as the public launch of the high-definition television system in the United States.^[13] The signal was transmitted coast-to-coast, and was seen by the public in science centers, and other public theaters specially equipped to receive and display the broadcast.^[13] The Harris Corporation provided the equipment necessary for transmitting and receiving the broadcast.^[13] The coverage was hosted by former CBS News anchor Walter Cronkite, and former Gemini/Apollo-era astronaut Pete Conrad.^[14]

NASA had begun a tradition of playing music to astronauts during the Gemini program, which was first used to wake up a flight crew during Apollo 15.^[15] Each track is specially chosen and often has a particular meaning to an individual member of the crew, or it is somehow applicable to their situation.^[15]

The STS-95 mission insignia was designed by the crew, and evokes the scientific, engineering and historic elements of the flight.^[16] It depicts a stylized blue Space Shuttle with yellow, red, and blue streamers coming from its stern that represent the global benefits of the mission's science experiments and the solar science objectives of the Spartan satellite.^[16] A small Mercury space capsule is depicted orbiting the Shuttle, and the red streamer extends up towards the center of the Shuttle to form a "7". The capsule and the number seven are in reference to Glenn's historic association with the Mercury Seven astronauts and their spacecraft: all of the crewed Mercury spacecraft had "7" as part of their name.^[16] The mission payloads—microgravity material science, medical research for humans on Earth and in space, and astronomy—represent three major scientific fields and are symbolized in the insignia by rocket plumes.^[16]

• John H. Glenn Jr.
• List of human spaceflights
• List of Space Shuttle missions
• Mercury-Atlas 6
• Outline of space science

• NASA mission summary
• STS-95 Video Highlights Archived 26 May 2009 at the Wayback Machine