ISRO Successfully Tests Gaganyaan Propulsion System

ISRO has finally successfully completed two hot tests of the Gaganyaan Service Module Propulsion System (SMPS) at the space agency's Propulsion Complex in Mahendragiri on July 3, 2025.

According to a statement released by ISRO on Wednesday, the purpose of the brief tests—which lasted 30 and 100 seconds, respectively—was to check the test piece configuration.

ISRO Successful Tests Propulsion System

According to pre-test predictions, the propulsion system's overall performance throughout the hot testing was standard. It was also successfully proved that all Liquid Apogee Motor (LAM) engines and all Reaction Control System (RCS) thrusters could operate simultaneously in both steady state and pulsed modes throughout the 100-second test.

One Step Closer to Gaganyaan Mission

The Liquid Propulsion System Centre (LPSC) of ISRO is in charge of the Gaganyaan SMPS's technological development efforts. According to the space agency, SMPS is a crucial component of the Gaganyaan Orbital Module and is necessary for both orbital maneuvering and certain abort situations.

Full-duration Test Soon

It consists of 16 Reaction Control System (RCS) thrusters (each with a thrust of 100N) and five Liquid Apogee Motor (LAM) engines (each with a thrust of 440N). Improvements based on experience from previous hot testing were introduced into the SMPS test piece for these tests to emulate the propulsion system conditions closer to flight.

"Based on the trust acquired through these hot tests, ISRO is planning to conduct a full-duration hot test soon," added the release.

Gaganyaan Program Aim

The goal of the Gaganyaan program, according to ISRO, is to show that India is capable of launching a crewed spacecraft into low Earth orbit. The success of this mission will be greatly aided by the experience and knowledge acquired.