MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov 

          Shuttle Radar Topography Mission Status  
           Friday, February 11, 2000, 6 p.m. PST

     Space shuttle Endeavour astronauts have successfully 
deployed the longest rigid structure ever built in space and 
continued work to check out the equipment they will use to 
produce unrivaled three-dimensional images of the Earth's surface 
using a JPL-developed radar.

     Extension of the Shuttle Radar Topography Mission's mast 
began at 3:27 p.m. PST, and after 17 minutes, all 87 cube-shaped 
bays of the structure were deployed.  Total length of the mast is 
60.95 meters (just under 200 feet).  Space Shuttle Endeavor was 
launched from NASA's Kennedy Space Center, Florida, at 9:44 a.m. 
PST (12:44 p.m. EST) today.  The Shuttle Radar Topography Mission 
is managed by NASA's Jet Propulsion Laboratory.

     The shuttle was also successfully maneuvered into the proper 
attitude, or orientation, for mapping. This orientation points 
the shuttle payload bay -- and its inboard and outboard radar 
antennas -- at the Earth.  Endeavour's tail is leading the way as 
the shuttle orbits about 240 kilometers (about 150 statute miles) 
above the surface.  The astronaut crew then began a series of jet 
thruster firings to test the ability of dampers to absorb the 
force of planned maneuvering jet firings and keep the inboard and 
outboard antennas properly aligned. This alignment is crucial for 
scientists who will need to combine the radar images received by 
the two sets of antennas.

     The Shuttle Radar Topography Mission will record radar data 
in both C-band and X-band radar wavelengths. This data eventually 
will be processed into 3-D maps of the Earth that are 30 times 
more exact that those currently available. These maps will be 
important to scientists in many disciplines, ranging from ecology 
to geology to hydrology, as well as a number of military and 
commercial applications.
 
     Radar mapping operations are schedule to begin late tonight.

     Endeavour is orbiting the Earth in an orbit inclined 57 
degrees to either side of the Equator for the radar mapping of a 
majority of the Earth's surface. The shuttle completes one orbit 
every 90 minutes at an altitude of about 240 kilometers (150 
miles).

     The mission is a partership between NASA and the National 
Imagery and Mapping Agency.  Also collaborating are the German 
Aerospace Center (Deutsches Zentrum fur Luft- und Raumfart) and 
the Italian Space Agency.  JPL manages the project for NASA's 
Earth Sciences Program in Washington, D.C.  JPL is managed by the 
California Institute of Technology in Pasadena.

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