July 09, 2025

ISRO successfully conducted two hot tests of the Gaganyaan Service Module Propulsion System (SMPS) on July 03, 2025 at ISRO Propulsion Complex (IPRC), Mahendragiri.

Two short duration hot tests were conducted for 30s and 100s to validate the test article configuration. The overall performance of the propulsion system during these hot tests was normal as per pre-test predictions. During the 100s test, simultaneous operation of all RCS thrusters in different modes (steady state; pulsed) along with all LAM engines was also successfully demonstrated.

ISRO’s Liquid Propulsion System Centre (LPSC) is leading the technology development activities for the Gaganyaan SMPS. SMPS is a critical system of Gaganyaan Orbital Module and is required during orbital manoeuvring as well as specific abort scenarios. It comprises of 5 Nos. of Liquid Apogee Motor (LAM) engines (each 440N thrust) and 16 nos. of Reaction Control System (RCS) thrusters (each 100N thrust). In order to simulate the propulsion system conditions closer to flight, the SMPS test article for these hot tests incorporated improvements based on experience gained from earlier hot tests. With the confidence gained through these hot tests, ISRO will conduct a full duration hot test shortly.