GSAT-4

Spacecraft nº:

Indian spacecraft nº: 54

Launch data: Designation  10F01 Launch date  15 Apr 2010 - 10:57 UT Launch site  Sriharikota, SLP Launch vehicle  GSLV Mk.2 (#D3) Mission  Experimental Communication Decay  15 Apr 2010

Spacecraft data: Prime contractor  ISRO Platform  I-2K (I-2000) Bus Operator  ISRO Mass at launch  2180 kg Dry Mass  1063 kg Basic shape  Box + 2 panels Dimension (m)   Equipment  Ka-band transponders, GAGAN Solar array   Stabilization   Propulsion  LAM, 4 plasma thrusters DC power

GSat-4 with one of its solar arrays deployed - Credit: ISRO

Two portion of GSLV-D3 payload fairing on either site of GSAT-4 - Credit: ISRO

Description:

• GSAT-4 was the nineteenth geo-stationary satellite of India built by ISRO and fourth in the GSAT series. GSAT-4 was basically an experimental satellite with the following new technologies intended to be tested:
  • Electric Propulsion System
  • Bus Management Unit
  • 1553 Bus for Data Communication
  • Miniaturised Dynamically Tuned Gyros
  • 36 AH Lithium Ion Battery
  • 70 V Bus for Ka band TWTAs

Mission details:

• The first flight of India's GSLV Mk II failed on Apr 15, 2010. The GSLV-D3's new CUS12 third stage engines did not operate and the vehicle tumbled after second stage separation, remaining in a suborbital -4400 x 137 km x 19 deg trajectory above the Bay of Bengal. The vehicle reentered 8 minutes after launch at 1105 UTC, probably over the Andaman Sea. The previous GSLV model used a Russian-built upper stage; this flight had the ISRO CUS12 using the Indian Cryogenic Engine. The ICE has a 69.5 kN LOX/LH2 main engine and two 2 kN vernier steering engines. The main engine reportedly ignited for one second but then the turbopump failed and the vehicle started falling back to Earth.
• Payload was GSAT-4, with a Ka-band communications system and a GPS-augmentation navigation transmitter.