STS-99
STS -99 (English Space Transportation System) is the mission name for the Shuttle Radar Topography Mission ( SRTM ), a flight of the U.S. Space Shuttle Endeavour ( OV -105 ) NASA for the purpose of creating radar-based remote sensing data of the Earth's surface. The launch took place on 11 February 2000. It was the 97th Space Shuttle mission and the 14th flight of the Space Shuttle Endeavour.
Team
- Kevin Kregel (4th space flight), Commander
- Dominic Gorie ( second space flight), Pilot
- Janet Kavandi ( second space flight ), Mission Specialist
- Janice Voss ( fifth space flight ), Mission Specialist
- Mamoru Mōri ( second space flight), Mission Specialist ( NASDA / Japan Japan)
- Gerhard Thiele ( first space flight), Mission Specialist (European Space Agency ESA / Germany Germany )
Mission objective
The aim of the Shuttle Radar Topography Mission was a height mapping of the Earth's surface between 60 ° north and 58 ° south latitude - a habitat of 95 % of the world's population - by an active radar synthetic aperture radar ( SAR). From the SRTM data obtained later a highly accurate elevation model of the Earth could be calculated.
The achieved (relative) accuracy of the altitude bases is thereby given as ± 6 m and is equipped with a grid spacing of 30 x 30 m for North America and 90 mx 90 m for the rest of the world freely available. Such an accurate elevation model is used in various applications in cartography, hydrography, air navigation, or radio wave propagation of benefits.
Such elevation models are also used in the control of guided missiles - therefore the published data is of reduced spatial resolution, while the fine gridded elevation values (ca. 30 x 30 m) can be handled as secret data and are primarily available to the U.S. military.
Mission
In the orbit ( orbit height about 233 miles), a 60 -meter mast was (where it was at that time the largest man-made structure built in space ) extended from the cargo hatch of the shuttle. In shuttle cargo space and at the end of the mast to antennas were to receive the reflections of the signals is also mounted in the loading space station.
During the flight over land areas of the transmitter sending radar waves in the C- and X-band to the ground. The backscattered signals have been received by the antenna mast and the antenna board. By evaluating the minimum run time differences of the received signals that arise across the flight direction by the distance of the antennas and in the flight direction by the movement of the shuttle, it was later the elevation model of the Earth's surface are generated ( radar interferometry ).
At the bottom, several teams were in use worldwide, which had always align exactly on the shuttle during the mission, the corner reflectors ( corner reflectors ). Thus, the data could be georeferenced later. For this purpose, were placed several corner reflectors worldwide in the crossing regions of the ascending and descending pathways.
The arm with the second radar antenna at the end
Corner reflector at DLR in Oberpfaffenhofen
SRTM was a joint project of NASA (USA), NIMA (USA), DLR ( Germany ) and ASI (Italy).
Technical details
The preparation of all data took two years.