Gaganyaan Takes Flight: ISRO Successfully Qualifies Service Module Propulsion System for Human Space Missions

ISRO has successfully completed the development and qualification testing of the Service Module Propulsion System (SMPS) for the Gaganyaan human spaceflight mission.

This achievement marks a critical step toward human-rating the Gaganyaan systems and ensures readiness for crew safety and mission reliability.

A 350-second full-duration hot test was conducted on July 11, 2025, at the ISRO Propulsion Complex (IPRC), Mahendragiri. The test validated the integrated performance of SMPS under off-nominal mission abort conditions. Results showed normal performance, aligning with pre-test predictions.

The Service Module (SM) uses a regulated bi-propellant propulsion system. It supports:

• Orbit circularization
• On-orbit control
• De-boost manoeuvres
• Abort capability during ascent phase

Liquid Apogee Motor (LAM) engines provide the main thrust. Reaction Control System (RCS) thrusters ensure precise attitude control.

A test bed emulating the SMPS fluid circuit was developed, including:

• Propellant tank feed system
• Helium pressurization system
• Flight-qualified thrusters
• Control components

The System Demonstration Model (SDM) underwent 25 tests under nominal and off-nominal conditions, totaling 14,331 seconds of firing time.

SMPS was designed, developed, and realized by the Liquid Propulsion Systems Centre (LPSC), with tests conducted at IPRC, Mahendragiri.