| STS-91 | Crew | Payload | Mission |
STS-91
Space Shuttle Discovery
Launched:
June 2, 1998, 6:06 p.m. EDT
Kennedy Space Center, Pad 39-A
Orbit:
173 nautical milesInclination:
51.6 degreesLanded:
June 12, 1998, 2:00 p.m. EDT
Kennedy Space CenterMission:
9 days, 19 hours, 54 minutes
STS-91
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| STS-91 | Crew | Payload | Mission |
STS-91 Crew
Commander Charles J. Precourt, Jr.
Fourth Shuttle flight and third visit to MirPilot Dominic L. Gorie
First Shuttle flightPayload Commander Franklin Chang-Díaz, Ph.D.
Sixth Shuttle flightMission Specialist Wendy B. Lawrence
Third Shuttle flight and second visit to MirMission Specialist Janet L. Kavandi, Ph.D.
First Shuttle flightCosmonaut Valery V. Ryumin
Russian Space Agency
First Shuttle flight and fourth space missionMission Specialist Andrew S. W. Thomas, Ph.D.
Third Shuttle flight; returning from Mir
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| STS-91 | Crew | Payload | Mission |
Payload
Orbiter Docking System
Space Habitation (Double) Module
Alpha Magnetic Spectrometer Investigation
Space Experiment Module
"Get Away Specials"
Protein Crystal Growth
Solid Surface Combustion
Spektr Gas Release
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| STS-91 | Crew | Payload | Mission |
Mission: June 2 - 12, 1998
When Commander Charlie Precourt and Pilot Dom Gorie landed Discovery at precisely 2 p.m. EDT on June 12, 1998, they ended the operational phase of the Shuttle-Mir Program and delivered Andy Thomas back to Earth after his 41⁄2 months onboard Mir. The landing culminated 975 days spent in orbit by the seven U.S. Mir astronauts, including 907 days spent as Mir crewmembers and an 812-day continuous U.S. presence in space. NASA now had firsthand experience of staging and running a multiyear space station program, as well as a new pool of long-duration spaceflight veterans to turn to for guidance and advice.
The landing also marked the end of the beginning of the International Space Station Program. For the next several years, most of NASAÆs Shuttle flights would be in support of the International Space Station. RussiaÆs venerable and aging Mir space station would see its last regular crew leave the outpost on August 28, 1999, while discussions continued about whenùand whetherùto deorbit the space station Mir.
One STS-91 crewmember, who understood both the significance and the nostalgia of this last Phase 1 mission, was 58-year-old Mission Specialist Valery Ryumin, the Russian Director of Shuttle-Mir. In 1957, Ryumin was a trainee at the SovietÆs Bureau of Experimental Machine Building when its top-secret project, Sputnik, became the worldÆs first artificial satellite. He went on to help develop all Soviet orbital stations, beginning with Salyut-1. A veteran of three spaceflights, Ryumin passed his one-year cumulative time in orbit mark during STS-91, which was his first space mission in 18 years. He was able to learn Shuttle operations and to examine the conditions onboard Mir.
After launch and before rendezvous, the STS-91 crew opened DiscoveryÆs payload doors, activated the SPACEHAB module and the Alpha Magnetic Spectrometer payload, filled water bags for transfer to Mir, and examined the docking system. The crew also watched for the Russian space station.
A happy Andy Thomas first saw Discovery "as a point of light out on the horizon, like a bright star. Then you just make out that it was not a star, that it actually was the Shuttle. Then, of course, it came closer and you could see it clearly. It just got closer and closer, and then at one point you feel the whole station shudder, and you know that theyÆve made contact and have latched on. It was a great moment." Hatch openings and a ceremony followed with the now-traditional shared meal. With all the preparations for docking, neither crew had eaten a meal in over 12 hours.
Once onboard, Ryumin was shocked by MirÆs onboard clutter. He told Commander Precourt, "Charlie, this place is in bad shape." Mir was "awful à worse than I imagined à unbelievable à unsafe." But, as Precourt recounted, after a few days the former Soviet Army tank commander had reacclimatized to what Mike Foale had called MirÆs "frat house" conditions. Ryumin said, "Well, you know, I think I could get used to staying up hereà. Maybe I'll just stay." As others had, Ryumin warmed to MirÆs peculiar charm.
On the other hand, Precourt had been to Mir three times and had seen it grow with the additions of the Priroda, Spektr, and docking modules. He said that, other than the fact that Spektr was sealed off, "the condition of the inside of the space station was better than it was on my previous two visits. The air was cleaner, it was a better controlled temperature, it was drier, [and] the walls of the surfaces of the structure everywhere were nice and dry."
The Shuttle crew delivered more than 1,100 pounds of water and almost 4,700 pounds of cargo, experiments, and supplies to Mir. They also conducted science investigations, including the Alpha Magnetic Spectrometer, whose Principal Investigator was Nobel Laureate Samuel Ting. This 31⁄2-ton particle detector was designed to look for antimatter left over after the creation of the universe, according to the Big Bang theory, and signs of "dark matter," theorized to constitute most of the universe.
On Flight Day 5, the crew released a fluorescent tracer gas into the depressurized Spektr module, hoping to locate the breach in SpektrÆs hull that resulted from the collision with a Progress resupply ship in 1997. If lighting conditions were right, the gas would appear as a dull green cloud. The crew could not detect any leaks at this time or when the experiment was repeated after undocking. However, the procedure may prove useful in the future on the International Space Station.
Before the undocking on Flight Day 7, Mir Commander Talgat Musabayev presented Precourt with a two-foot wrench. "Charlie, take this wrench," Musabayev said. "ItÆs sort of a relay stick from an old lady, station Mir, to the International Space Station." Precourt responded, "WeÆre going to need this for all the work that we have ahead of us."
Discovery landed at Kennedy Space Center on June 12, 1998, bringing the operational aspect of the Shuttle-Mir Program to an end. On the whole, the Shuttle-Mir rendezvous and dockings had been so flawless that their difficulty and significance went unnoticed by many.