Note: I wrote this on my earlier blog hosted as https://blogs.seds.org/pradeep. I recovered the text from the WayBack Machine. This post appeared on November 19, 2007 as per the timestamp. I’m trying to collect here again all my old writings spread on various blogs.
The third stage of India’s latest satellite launch vehicle, the GSLV is cryogenic. On November 15, 2007, ISRO successfully tested the indigenously built cryogenic rocket engine that will power the GSLV third stage. Till now, India depended on Russia for its cryogenic third stage but the test now allows India to use its own.
Developed by the Liquid Propulsion Systems Centre and supported by ISRO centres, public and private companies, it’s a milestone worth taking note of.
The press release describes the rocket as:
The indigenous Cryogenic Upper Stage (CUS) is powered by a regeneratively cooled cryogenic engine, which works on staged combustion cycle developing a thrust of 69.5 kN in vacuum. The other stage systems include insulated propellant tanks, booster pumps, inter-stage structures, fill and drain systems, pressurisation systems, gas bottles, command block, igniters, pyro valves and cold gas orientation and stabilisation system. Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) from the respective tanks are fed by individual booster pumps to the main turbo-pump, which rotates at 39,000 rpm to ensure a high flow rate of 16.5 kg/sec of propellants into the combustion chamber. The main turbine is driven by the hot gas produced in a pre-burner. Thrust control and mixture ratio control are achieved by two independent regulators. LOX and Gaseous Hydrogen (GH2) are ignited by pyrogen type igniters in the pre-burner as well as in the main and steering engines.
Congragulations to ISRO for a successful test firing.
Parallel Spirals 