Polar (satellite)

The Global Geospace Science (GGS) Polar satellite was a NASA science spacecraft designed to study the polar magnetosphere and aurora. It was launched into orbit in February 1996, and continued operations until the program was terminated in April 2008. The spacecraft remains in orbit, though it is now inactive. Polar is the sister ship to GGS Wind.

Launch

It was designed and manufactured by Lockheed Martin, and launched at 06:23:59.997 EST on February 24, 1996 aboard a McDonnell Douglas Delta II 7925-10 rocket from launch pad 2W at Vandenberg Air Force Base in Lompoc, California, to study the polar magnetosphere.

The spacecraft was placed into a highly elliptical orbit with apogee at 9 earth radii and perigee at 1.8 earth radii (geocentric), 86 degrees inclination, with a period of around 18 hours. The apogee was initially over the northern polar region, but has since been precessing south at about 16° per year.

Operations

Sensors on the spacecraft gathered multi-wavelength imaging of the aurora, and measured the entry of plasma into the polar magnetosphere and the geomagnetic tail, the flow of plasma to and from the ionosphere, and the deposition of particle energy in the ionosphere and upper atmosphere.

The nominal mission duration was two years, but was extended several times. Polar Mission Operations were finally terminated on April 28, 2008.

Other Names

• POLAR* GGS/Polar
• ISTP/Polar
• Polar/GGS
• Polar/ISTP
• Polar Plasma Laboratory (PPL)
• NORAD Satellite Catalog Number: 23802
• NSSDC International Designator: 1996-013A

External links

• NASA's Polar Satellite Webpage
• Polar site on ISTP