India's Space Dream Inches Closer As ISRO Completes Service Module Propulsion System For Gaganyaan
Following two hot tests, ISRO completed the full-duration hot test of the Gaganyaan Service Module Propulsion System, readying it for crewed spaceflight missions.
Published : July 9, 2025 at 1:28 PM IST
|Updated : July 14, 2025 at 9:55 AM IST
Bengaluru: The Indian Space Research Organisation (ISRO) has taken another step towards the launch of the Gaganyaan human spaceflight as the space agency successfully completed the development of the Service Module Propulsion System (SMPS) for the Gaganyaan Mission. It is a critical component of the Gaganyaan Orbital Module, which is necessary for orbital manoeuvring and specific abort scenarios.
The space agency on Friday completed the qualification test programme for the propulsion system, as it conducted a full-duration hot test of SMPS for 350 seconds, validating its performance for flight off-nominal mission profile. This follows the success of two hot tests for the propulsion system at ISRO's Propulsion Complex in Mahendragiri earlier this month.
The full-duration test for the Gaganyaan Service Module Propulsion System was also carried out at the same facility in Tamil Nadu. ISRO said that the overall performance of the propulsion system during the hot test was normal as per pre-test predictions, adding that the SMPS has been designed, developed, and realised by the Liquid Propulsion Systems Centre (LPSC).
ISRO also shared key updates about the propulsion system for its Gaganyaan mission, which include:
| Component | Function / Description |
|---|---|
| Service Module (SM) | Regulated bi-propellant propulsion system for orbital operations and emergency aborts |
| Liquid Apogee Motor (LAM) | Main propulsion for orbit circularisation and de-boost phases |
| Reaction Control System (RCS) | Manages precise attitude control in space |
| System Demonstration Model (SDM) | Test bed emulating SMPS fluid circuit, including tanks, thrusters, and controls |
| SDM Test Details | Underwent 25 tests for a total duration of 14,331 seconds in various mission scenarios |
The system comprises five Liquid Apogee Motor (LAM) engines and 16 Reaction Control System (RCS) thrusters, each providing 440N and 100N of thrust, respectively. To better simulate propulsion system conditions closer to those expected in flight, the SMPS test article used in these hot tests had incorporated improvements based on insights gained from previous hot tests, ISRO said.
The Gaganyaan is ISRO's crewed mission, aimed at demonstrating India’s capability to launch a crew of three members to an orbit of 400 km for 3 days and bring them back safely to Earth, by landing in Indian sea waters.
The prerequisites for the Gaganyaan mission included the development of several critical technologies. These encompassed a human-rated launch vehicle to safely carry the crew to space, a Life Support System to provide an Earth-like environment for the crew while in orbit, provisions for a crew emergency escape system, and the evolution of crew management aspects such as training, recovery, and rehabilitation. The ongoing Axiom Mission 4, carrying Indian astronaut Shubhanshu Shukla, is expected to provide valuable hands-on experience and crucial data for India's Gaganyaan human spaceflight mission.
(Note: The story has been updated with the successful test of the full duration test for SMPS; with inputs from the agency)
