INSAT-3 was a multipurpose satellite design, providing telecommunications, television broadcasting, meteorological and search and rescue services, the payload being varied by mission.

Design Life: 7 years. Typical orbit: Geoynchronous. Length: 2.40 m (7.80 ft). Basic Diameter: 1.15 m (3.78 ft). Maximum Diameter: 1.65 m (5.41 ft). Span: 10.90 m (35.70 ft). Mass: 1,950 kg (4,290 lb). RCS Coarse No x Thrust: 8 x 22 N. RCS Fine No x Thrust: 8 x 10 N + Momentum/reaction wheels + Magnetic torquers. Main Engine: LAM. Main Engine Thrust: 400 N (90 lbf). Main Engine Propellants: MON-3/MMH. Main Engine Propellants: 1,130 kg (2,490 lb). Electrical System: Solar panels + two 24 amp-hr Ni-Cd batteries. Electric System: 2.04 average kW.

• 2001 April 18 - GSAT-1 - Program: Insat. Launch Site: Sriharikota. Launch Complex: PSLV. Launch Vehicle: GSLV. Mass: 1,530 kg (3,370 lb). Perigee: 33,825 km (21,017 mi). Apogee: 35,814 km (22,253 mi). Inclination: 0.00 deg. Period: 1,387.00 min.
  Experimental Rural Communications satellite. Launch delayed following pad abort on March 28. First launch of the Indian GSLV launch vehicle. GSat 1 was an Indian, 1500 kg scaled-dow) test model of a future geosynchronous communications spacecraft with a 440 N ISRO liquid apogee motor, and S-band and C-band ommunications transponders, similar to the Insat-2 satellites. The motor for the cryogenic, hydrogen-oxygen upper stage had been purchased from Russia but the design had never flown in space before. The stage cut off without providing the required delta-V - preliminary analysis revealed a shortfall of 0.5% in the thrust. An attempt was made to reach a usable orbit using the station-keeping motor of the GSAT satellite itself. After a series of burns, GSat 1 ran out of propellant - 10 kg more fuel would have been required to reach a stationary orbit. In the end, the parameters of the drifting (about 13 deg/day) orbit were period 23 hours, apogee 35,665 km, perigee 33,806 km, and inclination 0.99 deg. The fully functional transponders and transmitters on board were deactivated on instructions of the International Telecommunications Union. As of 4 September 2001 located at 54.88 deg E drifting at 13.212 deg E per day. As of 2007 Mar 10 located at 50.16W drifting at 12.778E degrees per day.

• 2003 May 8 - GSAT-2 - Program: Insat. Launch Site: Sriharikota. Launch Complex: PSLV. Launch Vehicle: GSLV. Mass: 1,825 kg (4,023 lb). Perigee: 35,782 km (22,233 mi). Apogee: 35,790 km (22,230 mi). Inclination: 0.00 deg. Period: 1,436.10 min.
  Experimental Rural Communications. Launch delayed from original target of late 2001, then October 2002, then February 2003. The satellite carried four C-band transponders, two Ku-band transponders and a Mobile Satellite Service (MSS) payload operating in S-band and C-band for forward link and return link respectively. GSAT-2 also carried four piggyback experimental payloads: Total Radiation Dose Monitor (TRDM), Surface Charge Monitor (SCM), Solar X-ray Spectrometer (SOXS) and Coherent Radio Beacon Experiment (CRABEX). As of 2007 Mar 10 located at 47.97E drifting at 0.005E degrees per day.

• 2004 September 20 - GSAT-3 / Edusat - Program: Insat. Launch Site: Sriharikota. Launch Complex: PSLV. Launch Vehicle: GSLV. Mass: 1,950 kg (4,290 lb). Perigee: 35,772 km (22,227 mi). Apogee: 35,801 km (22,245 mi). Inclination: 0.10 deg. Period: 1,436.10 min.
  Gsat-3 / Edusat was the first Indian satellite built exclusively for the educational sector. It was mainly intended to meet the demand for an interactive satellite based distance education system for India. Edusat was launched into a geosynchronous transfer orbit by its launch vehicle. Edusat was to reach geostationary orbit by firing, in stages, its on board Liquid Apogee Motor (LAM). In geostationary orbit the satellite was to be co-located with Kalpana-1 and Insat-3C satellites at 74 deg East longitude.

  Compared to earlier satellites in the Insat series, Edusat used several new technologies. The spacecraft was built around the I-2K standardised spacecraft bus. It had a multiple spot beam antenna with a 1.2 m reflector to direct Ku band spot beams, a dual core bent heat pipe for thermal control, high efficiency multi-junction solar cells and an improved thruster configuration for optimised propellant use for orbit and orientation maintenance. The satellite used radiatively cooled Ku-band Travelling Wave Tube Amplifiers and a dielectrically loaded C-band demultiplexer for its communication payloads. Edusat carried five Ku-band transponders providing spot beams, one Ku-band transponder providing a national beam and six Extended C-band transponders with a national coverage beam. It was to join the Insat system that already provided more than 130 transponders in C-band, Extended C-band and Ku-band for a variety of telecommunication and television services.

  First operational flight of launch vehicle. Launch delayed from July, August and September 10. Dry mass 820 kg. As of 2007 Mar 9 located at 73.92E drifting at 0.006W degrees per day.