GSAT-1 was an experimental communication satellite carried on the first test flight of India's GSLV rocket in April 2001. The rocket left it in a lower orbit than planned, and the satellite had to climb most of the way on its own engine.
No longer operational, according to the public satellite catalogue.
GSAT-1 carried C-band and S-band transponders. ISRO used it for trials of digital audio broadcasting, internet services and compressed digital TV.
It also tested new spacecraft parts before they went on working satellites: improved control thrusters, star sensors that recover quickly, and heat-pipe radiator panels.
GSLV-D1, the first development flight of the Geosynchronous Satellite Launch Vehicle, lifted off from Sriharikota on 18 April 2001. GSLV is a 49 m, three-stage rocket whose top stage burns liquid hydrogen and liquid oxygen (cryogenic).
The rocket reached 99.4 per cent of its target speed of 10.2 km/s. That small 0.6 per cent shortfall left GSAT-1 in an orbit of 181 km by 32,051 km, tilted 19.2 degrees, with a high point well short of the planned one.
Between 19 and 23 April 2001 the satellite fired its own engine six times. That raised its orbit to 33,806 km by 35,665 km and cut the tilt to about one degree.
The low point was still below the 35,786 km height of a geostationary orbit. The catalogue snapshot used by this site still shows its perigee at 33,846 km.