STS -91 (English Space Transportation System) is the designation for a flight mission of the U.S. Space Shuttle Discovery ( OV- 103), NASA. The launch took place on 2 June 1998. It was the 91st Space Shuttle mission, the 24th flight of the Space Shuttle Discovery, the eleventh and last flight as part of the Shuttle -Mir program, and the ninth and final coupling of a U.S. space Shuttle to the Mir space station.


  • Charles Precourt ( 4 Space ), Commander
  • Dominic Gorie ( first space flight), Pilot
  • Wendy Lawrence ( third space flight ), Mission Specialist
  • Franklin Chang- Diaz (6th space flight), Mission Specialist
  • Janet Kavandi ( first space flight ), Mission Specialist
  • Valeri Rjumin (4th space flight), Mission Specialist ( Roscosmos / Russia)

Mir Crew Return

  • Andrew Thomas ( second space flight )

(after a flight time of 140 days, 15 hours and 12 minutes returned to Earth; way with STS -89 )

Mission Description

The last flight of a U.S. shuttles to the Russian space station Mir material transport was again to the fore. It was also Andrew Thomas, the seventh astronaut who lived aboard a Russian space station and worked, picked up. With him also many scientific samples and some equipment including a system for the measurement of minimal accelerations by the movements of astronauts on board (Space Acceleration Measurement System) and a cell culture experiment to observe the long-term development of certain cell types in weightlessness were brought back to earth ( coculture ). During the phase coupling to the coupling module of the Mir also air and water samples were taken to determine the change in environmental conditions aboard the station can. After undocking from the station I was out of the Discovery of by a green fluorescent gas held that had been pumped into the damaged Spektr module. This was to find out exactly where the leaks are.

Important scientific payloads aboard Discovery were the Alpha Magnetic Spectrometer ( AMS), an equipment complex for the study of combustion processes in microgravity ( Solid Surface Combustion Experiment), and a new system that, via Inmarsat stations and satellite direct communication via phone should allow fax and data transmission between the astronauts and scientists on Earth. However, due to technical difficulties, this system could not be used. Similar problems you had with the Ku - band - antenna of the space shuttle, so no television broadcasts were possible. In addition, the measured values ​​of the AMS had to be extensively recorded. The evaluation was made on the ground, but did not yield evidence of antimatter in the cosmic radiation. A total of about 3 million helium atoms were detected. But among them was not a single anti-nuclear. In any case, the AMS has only been tested with the Discovery mission. The long-term use of such a particle detector was installed on the International Space Station with AMS -2. Two amazing results yielded the experiment, however. There are near-Earth space four times as many positrons as electrons. So far it has been assumed that these particles occur with equal frequency. In addition, slow protons that originate from the sun, initially held for long periods in the magnetic field 2000 km around the equator, before they fly to the poles.

Multiple the Space Vision System was used to facilitate working with the manipulator arm. Over several cameras and measuring points in the cargo bay and at the top of the robotic arm, a virtual image of the loading bay environment is created in a laptop. Here you can determine distances more accurately than by the view out the window. Observation object was initially the outer skin of some modules of the Mir space station, and later a leak in a water tank of the energy system.

For the first time launched a space shuttle with a new main tank ( Super Lightweight External Tank ), which consists of an aluminum -lithium alloy. It is through a honeycomb-like structure of its surface, although lighter, yet about 30 % stronger than the previous model. It may also cause the maximum working load of the Space Transportation Systems increased by about 3.5 tons. The Discovery landed as planned in Florida.