Development of a 10-N Liquid Bipropellant Thruster for Geostationary Spacecraft Program of Indian Space Reseach Organization

** Group Head, Spacecraft Engine & Thrusters Group, LPSC venkateswaran@lpscv.dos.gov.in # Dy Divisional Head, Spacecraft Propulsion Engines Division , LPSC t_madhukumar@lpscv.dos.gov.in * Engineer (AOCS), Spacecraft Propulsion Engines Division, LPSC c_rajeevsenan@yahoo.com 1 Development of a 10 N liquid bipropellant thruster for Geostationary spacecraft programme of Indian Space Research Organisation C.G.Balan, S.Venkateswaran, T.Madhukumar, C.Rajeev Senan Liquid Propulsion Systems Centre, Indian Space Research Organisa tion, Valiamala, Trivandrum-695 547, India Low thrust level engines which can deliver small impulse bit are very much essential to provide better controllability of spacecrafts. A 10 N liquid bipropellant thruster with Nitrogen tetroxide and Monomethyl hydrazine has been developed by Liquid Propulsion Systems Centre of Indian Space Research Organisation to improve the attitude and orbit control capabilities of its geostationary spacecrafts. The thruster comprises of a coaxial swirl type injector, radiation cooled nozzle and series redundant valve with latchable upstream valve. Thrusters were qualified to meet the extreme conditions like injection pressure variation, propellant temperature variation, mixture ratio variation etc. At normal supply pressures it delivers a specific impulse more than 290 s. More than 100 flight thrusters were re alized and delivered for eleven geostationary spacecrafts.