July 11, 2025

ISRO has successfully completed the development of Service Module Propulsion System (SMPS) for Gaganyaan Mission with the completion of the qualification test programme. A full duration hot test of SMPS for 350s was conducted to validate the integrated performance of the SMPS for flight off-nominal mission profile of SM based mission abort on July 11, 2025. The overall performance of the propulsion system during the hot test was normal as per pre-test predictions.

The Service Module (SM) of Gaganyaan is a regulated bi-propellant based propulsion system that caters to the requirements of the Orbital Module for orbit circularization, on-orbit control, de-boost manoeuvring and Service Module based abort during the ascent phase. The Liquid Apogee Motor (LAM) engines provide the main propulsive force during the orbit circularisation & de-boost phases, while the Reaction Control System (RCS) thrusters ensures precise attitude control.

A System Demonstration Model (SDM) test bed was realised emulating the fluid circuit of the Service Module Propulsion System, encompassing the propellant tank feed system, helium pressurization system, flight-qualified thrusters, and control components. SDM for Service Module Propulsion System has undergone 25 tests under nominal and off-nominal conditions for a cumulative duration of 14,331s for various Gaganyaan mission scenarios and human rating requirements.

The Gaganyaan Service Module Propulsion System is designed, developed, and realized by Liquid Propulsion Systems Centre (LPSC) and the tests were carried out at ISRO Propulsion Complex (IPRC), Mahendragiri.