File:Gaganyaan Service Module Propulsion System (SMPS) System Demonstration Model (SDM) hot test conducted on 19 July 2023 at IPRC, Mahendragiri.webp

English: ISRO conducted Gaganyaan Service Module Propulsion System (SMPS) on 19 July 2023 at ISRO Propulsion Complex (IPRC), Mahendragiri.

The Service Module of Gaganyaan is a regulated bi-propellant based propulsion system that caters to the requirements of the Orbital Module, performing orbit injection, circularization, on-orbit control, de-boost manoeuvring and SM based abort (if any) during the ascent phase. The five 440 N Thrust LAM engines provide the main propulsive force during the mission ascending phase, while the sixteen 100 N RCS thrusters ensure precise attitude correction.

The hot test of the System Demonstration Model (SDM) emulated the fluid circuit of the Service Module Propulsion System, encompassing the propellant tank feed system, helium pressurization system, flight-qualified thrusters, and control components.

The first hot test of the Phase-2 test series demonstrated the integrated performance of the Gaganyaan Service Module Propulsion System. The test, conducted for a duration of 250 seconds, involved LAM engines firing in continuous mode, along with RCS thrusters, adhering to the test profile. As part of the Phase-1 test series of SM SDM, ISRO had previously conducted five hot tests, totalling a duration of 2750 seconds. The earlier phase involved five 440 N LAM engines and eight 100 N RCS thrusters. For the Phase-2 test series, the current configuration includes the full configuration of five 440 N LAM engines and sixteen 100 N RCS thrusters.