GSLV-D3

GSLV D3 was the sixth flight of the Geosynchronous Satellite Launch Vehicle.It was its third developmental flight.This flight was the maiden flight of the GSLV Mk.II which used the new indigenous Cryogenic Upper Stage (CUS)was used as before the GSLV Mk.I used Russian KRB stages.However the launch was unsuccessful.

Design

GSLV D3 was a GSLV Mk.II which would be 40.39m in length without the nose cone.It used a solid S139 booster stage with 4 L40 strap ons which uses hypergolic propellants(UD25 and N2O4) as fuel.The GS2 second stage uses the same hypergolic propellants.The third stage is the newly developed Cryogenic Upper Stage (CUS).It would have carried the GSAT-4 satellite into orbit.

Launch

After a smooth countdown GSLV D3 was launched on 15 April 2010.The vechicle performed well untill the GS2(Second stage) stage burnout.However test firing of the CUS third cryogenic was unsuccessful.

Failure

The CUS(Cryogenic Upper Stage) ignited at 294.06 seconds after lift off as planned.Ignition was confirmed as observed from vehicle accleration and parameters of the CUS during the flight.However thrust build up did not progress due to non-availibility of Liquid Hydrogen.Investigation reveals Failure of Fuel Booster Turbo Pump(FBTP)was the cause.Later investigation reveals the CUS did not ignite either.

References

1.http://www.isro.org/gslv-d3/gslv-d3.aspx