Jim Sahli	                         	Jan. 18, 1996
Goddard Space Flight Center
Greenbelt, Md.
(301) 286-0697

PHOTO RELEASE NO:  96-003P

Polar Satellite Will Study Effects of Solar Plasma--NASA's Polar 
spacecraft shown here is being lowered on to a test stand in 
Building 836 at Vandenberg AFB in California. The spacecraft is 
scheduled to be launched the first week of February from Space 
Launch Complex-2 aboard a Delta II launch vehicle from the 
Western Space and Missile Center at Vandenberg. The Polar 
spacecraft is the second mission of NASA's Global Geospace Science 
(GGS) program.  Polar will perform simultaneous, coordinated 
measurements of the key regions of Earth's geospace, or space 
environment, with WIND, which was launched November 1994 to 
measure the solar wind properties.  A large array of ground-based 
scientific observatories and mission related theoretical 
investigations will also be involved.  The Polar spacecraft will carry 
11 instruments.  Its orbit around the Earth will be inclined 86 
degrees from the equator.  The furthest point from the Earth on the 
orbit–the apogee–will be eight Earth radii altitude (32,000 miles), 
and the closest point–the perigee–will be 0.8 Earth radius (3,200 
miles). Polar is a cylindrical-shaped spacecraft 7.9 feet in diameter 
and 6.9 feet high with many appendages for instrument sensors.  
The dry weight of the spacecraft is about 2,200 pounds with an 
additional 660 pounds of hydrazine propellant for orbit and attitude 
control.  The design life of Polar is three years. Goddard Space 
Flight Center in Greenbelt, Md., will be managing the mission and 
also will play a key role in the collection and dissemination of Polar 
science data.  

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