ISRO has achieved a major milestone in the development of rocket systems for satellite launches. Cryogenic Upper Stage for GSLV was hot tested today (28th October 2006) at 6.20 pm for a duration of 50s. The test was carried out at the Liquid Propulsion Systems centre (LPSC) test complex at Mahendragiri. The performance of the test was as predicted. This test is first of its kind in the country.
ISRO has taken up indigenous development of cryogenic stage with regenerative cooled engine, which produces a thrust of 69.5 kN in vacuum, to replace the existing procured stage from Russia currently used in GSLV flights. As part of this effort, the cryogenic engines have been realized and tested earlier for a cumulative duration of 6000s. In the stage level hot test all stage elements like engine, insulated propellant tanks, booster pumps, fill and drain systems, pressurization systems, gas bottles, igniters, cold gas orientation and stabilization system, etc as per flight standards are working in unison.
The stage uses the cryogenic propellants namely liquid hydrogen at -250º C and liquid oxygen at -196º C. The turbo pumps used for drawing the propellant from the tanks operate at the very high speed of 42,000 rpm. The materials used to operate at cryogenic temperatures, chilling processes, interplay of various critical engine parameters and a host of other technical aspects make the development of cryogenic stage a very challenging task.
Liquid Propulsion Systems Centre (LPSC), the lead centre for Liquid Propulsion systems is responsible for the realization of the indigenous cryogenic stage and the associated test facilities with the support of Vikram Sarabhai Space Centre (VSSC) and Satish Dhawan Space Centre, SHAR. The Indian industries have significantly contributed in the realization of the cryogenic stage.
This hot test has demonstrated the design adequacy and performance of the integrated flight system, further tests for this flight unit are planned to validate robustness of the design. After completion of the qualification tests, the indigenous cryogenic stage is planned to be flight tested in GSLV- D3 mission next year.
