For Release: March 19, 1996

Steve Roy
Office of Media Services
(205) 544-0034
steve.roy@msfc.nasa.gov

NOTE TO EDITORS: 96-18N

MARSHALL SPACE-EFFECTS EXPERIMENT AND TWO PROTEIN CRYSTAL GROWTH EXPERIMENTS TO FLY ON STS-76

An experiment to monitor the space environment and two protein crystal growth experiments are among the complement scheduled to fly to the Mir space station on Space Shuttle mission STS-76 this week.

The three experiments are managed by the Marshall Space Flight Center in Huntsville, Ala.

A "suitcase-size" container, known as the Passive Optical Sample Assembly-1, will gather data about the long-term, combined effects of contaminate particles and other constituents such as oxygen, ultraviolet radiation and heating in the environment around the Mir space station.

The experiment will be attached to the exterior handrails of the Mir docking module - one side facing the Mir and the other side facing outward- during a spacewalk on the sixth day of the mission.

The environmental sensing experiment was designed, fabricated and assembled at Marshall. It contains some 400 samples of test materials provided by five companies and a university.

The experiments will study the effects of space debris striking the Mir and the effects of the space environment on materials used in the International Space Station.

The experiment will be retrieved along with three other space environment research experiments during STS-86 in September 1997, after nearly 17 months on orbit.

During this mission, the STS-76 crew also will retrieve a closed aluminum cyclinder, called a dewar which holds hundreds of protein samples, grown aboard Mir during the past five months. The samples were placed Mir in November 1995 during STS-74. The crew will place another cylinder containing a new batch of samples aboard the Mir space station. The STS-76 dewar insert will be retrieved in August this year, during STS-79.

Upon return to Earth, the protein samples, will be studied and compared to those grown on Earth and over shorter periods during previous Shuttle missions. Evaluation of protein crystals sent aboard the first mission to the Mir space station shows that a number of uniform, high quality crystals were successfully grown.

STS-76 will also carry to the Mir a second Marshall-developed crystal growth device, called the Diffusion-Controlled Crystallation Apparatus for Microgravity (DCAM). Some 162 experiment units, mounted on six trays, will be transfered to Mir. The experiment will be retrieved in August during STS-79.

STS-76 is currently scheduled to be launched Thursday at 2:35 a.m. CST aboard the Shuttle Atlantis and to dock with Mir on the third day of the flight. Landing is scheduled to occur at the Kennedy Space Center, Fla. on Saturday, March 30, at 7:04 a.m. CST, after a nine-day flight.

During the five days of docked operations, many planned joint activities will focus on the experiments in the Middeck and SPACEHAB module.

The mission is the third of nine planned Space Shuttle-Mir Space Station link-ups between 1995 and 1998, including rendezvous, docking and crew transfers, which will pave the way for assembly of the International Space Station beginning in November 1997.