With these successful tests, ISRO has moved a step closer to India's first human spaceflight mission, Gaganyaan.
The Indian Space Research Organisation announced on Wednesday, July 9, 2025 that it successfully carried out two hot tests of the Gaganyaan Service Module Propulsion System (SMPS) on July 3, 2025.
The tests took place at the ISRO Propulsion Complex in Mahendragiri, Tamil Nadu.
These short-duration tests -- lasting 30 seconds and 100 seconds -- were designed to validate the configuration of the SMPS test article.
ISRO confirmed that both tests went according to pre-test predictions, with the propulsion system performing normally.
During the longer, 100-second test, ISRO successfully demonstrated the simultaneous operation of all Reaction Control System (RCS) thrusters in both steady-state and pulsed modes, along with the full functioning of the Liquid Apogee Motor (LAM) engines.
The Service Module Propulsion System is a vital part of the Gaganyaan Orbital Module, responsible for orbital manoeuvres and specific mission abort scenarios.
The system consists of five LAM engines, each providing 440 Newtons of thrust, and 16 RCS thrusters, each delivering 100 Newtons of thrust.
ISRO's Liquid Propulsion Systems Centre is spearheading the development of the SMPS.
The latest tests incorporated enhancements based on insights from previous trials to better simulate flight-like conditions.
With these successful tests, ISRO has moved a step closer to conducting a full-duration hot test of the SMPS as part of preparations for India's first human spaceflight mission, Gaganyaan.
Under this mission, India aims to send two astronauts into Low Earth Orbit aboard its own rocket and spacecraft.
Venkatachari Jagannathan can be reached at venkatacharijagannathan@gmail.com
Feature Presentation: Aslam Hunani/Rediff
© 2025