GFO, Geosat Follow-On was launched in February 1998. Its mission is to provide real-time ocean topography data to the US Navy. Scientific and commercial users have access to these data through Noaa. Its primary payload is a radar altimeter.

GFO follows the 17-day repetitive orbit of Geosat. After an onboard problem of overheating reaction wheels in September 2008, GFO's transmitter was turned off for the final time the November 26, 2008.

Further information on :

Satellite  GFO
Launch on  10/02/1998
End Date  26/11/2008
Altitude  800 km
Inclination  108°
Repetitivity  17 days
Agency  US Navy /Noaa
Goals  Measure ocean topography