ISRO Conducts Successful SOLVE Test for Gaganyaan Crew Module Descent Validation

On July 3, 2026, the Indian Space Research Organisation (ISRO) successfully carried out a ground test of the Sub-Orbital Launch Vehicle for Experiments (SOLVE) at the Static Test Facility in Sriharikota. The test focused on validating the solid motor stage of SOLVE, which is derived from the PSLV’s strap-on motor but modified for Gaganyaan mission needs. Key changes include a slow-burn rate propellant and a straight nozzle with secondary injection thrust vector control. Unlike the PSLV, SOLVE is a sub-orbital vehicle designed solely for testing critical systems under simulated mission conditions.

The primary purpose of SOLVE is to serve as a test platform for Integrated Parachute Tests. These tests will simulate the descent phase of the Gaganyaan mission by carrying the Crew Module to an altitude of 10–17 km before releasing it. The module will then deploy a sequence of 10 parachutes—two apex cover parachutes, two drogue parachutes, three pilot parachutes, and three main parachutes—to ensure a controlled, low-velocity splashdown in the Indian sea. This system is vital for ensuring astronaut safety during re-entry and landing.

The Gaganyaan mission aims to launch three astronauts into low Earth orbit and return them safely to sea-based splashdown sites. The descent phase, which includes de-boost maneuvers and parachute deployment, is among the most critical and risky. SOLVE enables ISRO to conduct multiple test missions under varied conditions to certify key systems like the deceleration and crew escape systems. These tests complement earlier Integrated Air Drop Tests (IADT) conducted using a Chinook helicopter, but now offer higher-altitude simulations closer to actual flight conditions.