The Development of Turbopumps for Low-Thrust Cryogenic Rocket Engine

Abstract

AbstractThe Indian Space Research Organisation (ISRO) envisaged a launch vehicle to put 4 ton class satellites to Geosynchronous Transfer Orbit (GTO). GTO is Geosynchronous Transfer Orbit of 170 km perigee and 35,975 km apogee, where the satellites are injected. It is further raised to the Geostationary orbit by firing satellite thrusters. The upper stage of this launch vehicle is powered by a cryogenic engine of 200 kN nominal thrust working in gas generator cycle using liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants. The engine has independent LOX and LH2 turbopumps, with their turbines operating in series mode. The turbopumps were successfully developed through a series of development tests, which included subsystem level tests for pumps, turbines, bearings and seals with simulated fluids. Subsequently, tests were carried out in the turbopump level with different pump fluids like water, liquid nitrogen, liquid oxygen and liquid hydrogen. Finally, tests were carried out in closed-loop mode (boot-strap) with gas generator and turbopumps operating together. The successful completion of these tests demonstrated the design validity of these turbopumps. Subsequently, turbopumps have undergone flight duration and extended flight duration tests as part of engine. The third development engine was used in the successful flight testing of the launch vehicle in 2017. The efforts towards the development of turbopumps are detailed in this paper.KeywordsLaunch vehicleCryogenic engineTurbopumps