ISRO successfully completes crucial hot tests of Gaganyaan Propulsion

By FnF Correspondent | PUBLISHED: 09, Jul 2025, 18:14 pm IST | UPDATED: 09, Jul 2025, 18:14 pm IST

ISRO conducted two successful short-duration hot tests of the Gaganyaan Service Module Propulsion System (SMPS). These critical tests were carried out at the ISRO Propulsion Complex (IPRC), Mahendragiri, and mark a major step forward in India's maiden human spaceflight program.

Two Hot Tests conducted at Mahendragiri

The tests lasted 30 seconds and 100 seconds, which aimed at validating the configuration and performance of the propulsion module in realistic conditions.
ISRO confirmed that both tests were successful, and all the engine systems performed normally, as per the test predictions.

All engines and thrusters performed seamlessly

During its 100-second hot test, ISRO successfully demonstrated the simultaneous operation of all five Liquid Apogee Motor (LAM) engines. Each engine delivered 440 Newtons of thrust and all 16 Reaction Control System (RCS) thrusters. Every engine offered 100 Newtons of thrust, and both steady-state and pulsed modes were tested. The test further simulated the full functionality of the propulsion system under flight-like conditions.

System refinement based on experience

The test for these hot trials has been included to note the improvements, which are based on feedback from earlier hot test campaigns.
This version of the SMPS is closer to the final flight model in terms of hardware and performance standards.
The improvements further ensured that the propulsion system can handle the demands of orbital manoeuvres and abort scenarios, which are the two key phases in crewed missions.

LPSC leads the development of SMPS

The Liquid Propulsion Systems Centre (LPSC), one of the key ISRO divisions, is reportedly leading the technology development of the SMPS for Gaganyaan.

This system is important for the orbital module’s navigation and crew safety, especially in complex in-space operations.

Full-duration test coming soon

ISRO has further announced that it will soon conduct a full-duration hot test to further validate the system.
The progress also indicates that India is moving steadily toward launching its first astronauts into space under the Gaganyaan program.
This milestone underlines ISRO’s commitment to safe, indigenous, and technologically advanced solutions for human space exploration.