Discovery launched from Kennedy Space Center on February 3, 1995 at 12:22 AM EST and landed at Kennedy on February 11 at 6:50 AM EST. The shuttle orbited 129 times at an altitude of 213 nautical miles at an inclination of 51.6 degrees and travelled 3 million miles. The mission lasted 8 days, 6 hours, 28 minutes, and 15 seconds.
The first shuttle flight of 1995 included several historical achievements: The second flight of Russian cosmonaut on shuttle, the first approach and fly-around by the shuttle of the Russian space station Mir. Harris became the first African-American to walk in space. Eileen Collins was the first female shuttle pilot.
Beginning on flight day one, a series of thruster burns were performed to bring Discovery in line with Mir. Original plans called for orbiter to approach to no closer than 10 meters, or 32.8 feet, from Mir, and then complete fly-around of Russian space station. However, three of the 44 orbiter Reaction Control System (RCS) thrusters, small firing jets used for on-orbit maneuvering, sprang leaks prior to the rendezvous. Shortly after the main engine cut off, two leaks occurred in the aft primary thrusters, one of which was key to rendezvous.
After extensive negotiations and technical information exchanges between the U.S. and Russian space teams, the Russians concluded close approach could be safely achieved and the crew was given ‘go’ to proceed. The thruster manifold was closed and a backup thruster selected for approach. Ship-to-ship radio contact with Mir achieved well ahead of time, and Titov, who lived on Mir for more than a year, communicated excitedly with three cosmonauts aboard the space station: Mir 17 Commander Alexander Viktorenko; Flight Engineer Elena Kondakova; and Valery Polyakov, a physician who had broken Titov’s record for extended time in space. After holding at a distance of 400 feet (122 meters) from Mir and with Wetherbee manually controlling the shuttle, Discovery flew within 37 feet of Mir.
“As we are bringing our spaceships closer together, we are bringing our nations closer together,” Wetherbee said after Discovery was at the point of closest approach. “The next time we approach, we will shake your hand and together we will lead our world into the next millennium.”
“We are one. We are human,” Viktorenko responded. Wetherbee then backed away to 400 feet (122 meters) and performed a one and a quarter-loop flyaround of Mir while station was filmed and photographed. The Mir crew reported no vibrations or solar array movement as result of the approach.
The crew also worked extensively with payloads aboard Discovery. Flying in forward payload bay and activated on flight day one was SPACEHAB-3. The commercially-developed module was making its third flight on the shuttle and carried 20 experiments: 11 biotechnology experiments; three advanced materials development experiments; four technology demonstrations; and two pieces of supporting hardware measuring on-orbit accelerations.
Improvements were made to the SPACEHAB system to reduce demand on crew time. New video switches were added to lessen the need for astronaut involvement in video operations, and experiment interfaces were added to the telemetry system to allow experiment investigator to link directly via computer with onboard experiment to receive data and monitor status. Charlotte, an experimental robotic device being flown for first time, also reduced crew workload by taking over simple tasks such as changing experiment samples.
Among plant growth experiments were Astroculture, flying for the fourth time on the shuttle. The objective of Astroculture was to validate the performance of plant growth technologies in the microgravity environment of space for application to a life support system. These investigations had applications on Earth, since they covered such topics as energy-efficient lighting and the removal of pollutants from indoor air.
One of the pharmaceutical experiments, Immune, also had Earth applications. Exploiting the known tendency of spaceflight to suppress immune system, Immune tested the ability of a particular substance to prevent or reduce this suppression. Clinical applications included the treatment of individuals suffering from such immunosuppressant diseases as AIDS.
On flight day two, the crew deployed Orbital Debris Radar Calibration System-II (ODERACS-II) to help characterize the orbital debris environment for objects smaller than 10 centimeters (about four inches) in diameter. A complement of six target objects of known dimensions and with limited orbital lifespans were released into orbit and tracked by ground-based radar, allowing precise calibration of radar to more accurately track smaller pieces of space debris in low-Earth orbit.
The crew lifted SPARTAN-204 from its support structure in the payload bay. SPARTAN remained suspended on the extender arm to observe the orbiter glow phenomenon and thruster jet firings. SPARTAN-204 later was released from the arm to complete about 40 hours of free-flight, during which time its Far Ultraviolet Imaging Spectrograph instrument studied celestial targets in the interstellar medium, the gas and dust which fills the space between the stars and which is the material from which new stars and planets are formed.
SPARTAN-204 was used for extravehicular activity (EVA) near the end of the flight. Foale and Harris began EVA suspended at end of robot arm, away from payload bay, to test modifications to their spacesuits to keep spacewalkers warmer in the extreme cold of space. Two astronauts were then scheduled to practice handling approximately 2,500-pound (1,134-kilogram) SPARTAN to rehearse space station assembly techniques, but both astronauts reported they were becoming very cold — this portion of the walk was performed during a night pass. The 29th shuttle spacewalk lasted 4 hours, 38 minutes.
Discovery was crewed by Commander James D Wetherbee, Pilot Eileen M. Collins, Mission Specialists C. Michael Foale, Janice E. Voss, Bernard A. Harris, and Vladimir G. Titov (Russia).
Endeavor launched from Kennedy Space Center on March 2, 1995 at 1:38 AM EST and landed at Edwards AFB on March 18 at 1:47 PM PST. The shuttle orbited 262 times at an altitude of 187 nautical miles at an inclination of 28.45 degrees and travelled 6.9 million miles. The mission lasted 16 days, 15 hours, 8 minutes, and 48 seconds.
This was the longest shuttle mission to date, allowing sustained examination of the “hidden universe” of ultraviolet light. The primary payload, the Astro Observatory had flown once before on STS-35 in December 1990. This was the first shuttle mission connected to the Internet. Users of more than 200,000 computers from 59 countries logged on to the Astro-2 home page at Marshall Space Flight Center.
Astro-2 marked the second flight of three ultraviolet telescopes flown on Astro-1, mounted on Instrument Pointing System on the Spacelab pallet in cargo bay. The Hopkins Ultraviolet Telescope (HUT), developed at the Johns Hopkins University, performed spectroscopy in the far ultraviolet region of the spectrum to identify physical processes and chemical composition of a celestial objects.
Improvements made to HUT after Astro-1 made it three times more sensitive. The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE), built at the University of Wisconsin, measured photometry and polarization of ultraviolet radiation from astronomical objects. The Ultraviolet Imaging Telescope (UIT), sponsored by NASA’s Goddard Space Flight Center, took wide-field photographs of objects in ultraviolet light.
The crew began activating Astro-2 only hours after liftoff for around-the-clock observations. Observational sequences were planned on a daily basis in two-orbit, or three-hour blocks, with one telescope assigned priority. Astro-2 demonstrated the benefits of human interaction in on-orbit astronomy. Besides being able to position the orbiter most advantageously for observations, crew members also could manually acquire observation if desired.
HUT, considered complement to Hubble Space Telescope, completed more than 200 separate observations of more than 100 celestial objects. The telescope collected enough data to meet its primary mission objective: detecting the presence of intergalactic helium, a telltale remnant of theoretical Big Bang explosion that began universe. HUT, in conjunction with Hubble telescope, took ultraviolet measurements of Jupiter’s aurora, studied Jupiter’s moon Io, and the Venusian and Martian atmospheres.
UIT cameras imaged about two dozen large spiral galaxies for inclusion in an atlas of such galaxies, and made the first ultraviolet images of the entire moon. It studied rare, hot stars that are 100 times as hot as sun; elliptical galaxies and some of faintest galaxies in universe. Investigators were disappointed upon developing UIT film to learn that one of its two cameras had malfunctioned undetected on orbit.
WUPPE yielded a “treasure chest of data,” greatly expanding the database on ultraviolet spectropolarimetry. Targets for study included dust clouds in Milky Way and nearby galaxies. WUPPE also studied several types of stars, including Wolf-Rayet and Be stars, and capitalized on an opportunity to study three recently exploding nova stars.
Other payloads: Two Get Away Special canisters located in payload bay held the Australian-built Endeavour telescope to study the ultraviolet realm. In-cabin payloads were Commercial Materials Dispersion Apparatus Instrumentation Technology Associates Experiments-03 (CMIX-03), which featured an array of biomedical, pharmaceutical, biotechnology, cell biology, crystal growth and fluids science investigations, including one with potential for an anti-colon cancer treatment. Protein Crystal Growth experiments included two setups in middeck lockers. Also flown was Middeck Active Control Experiment (MACE) to study how disturbances caused by a payload impacting another payload attached to same support structure.
Endeavour was crewed by Commander Stephen S. Oswald, Pilot William G. Gregory, Payload Commander Tamara C. Jernigan, Mission Specialists John M. Grunsfeld, Wendy B. Lawrence, and Payload Specialists Ronald A. Parise and Samuel T. Durrance.