INTEGRATED AIR DROP TEST (IADT-1)

• The Integrated Air Drop Test (IADT) is meant to assess the parachute-based braking system that ensures the Gaganyaan crew module lands safely after reentry. In the first trial, IADT-1, the parachutes were expected to open in a fixed sequence once the module was dropped from nearly 3 km altitude.
• Even though the capsule carried no crew and was released from a helicopter, the experiment replicated the final stages of an actual mission.
• In a real operation, the capsule would first decelerate due to atmospheric drag and its heat shield, then be stabilized by small drogue parachutes, and finally slowed by three large main parachutes, each 25 meters in diameter.
• The objective was to bring down the descent speed to about 8 m/s before it hit the sea surface

3. How was the test conducted?

• During IADT-1, a Chinook helicopter of the Indian Air Force airlifted a 4.8-ton dummy crew module and released it from the set altitude. Once released, the automated systems activated and deployed the parachutes in the planned sequence.
• According to ISRO, the landing parameters matched predictions, confirming the system’s effectiveness under real-world conditions.
• The trial required extensive simulations, instrumentation, and collaboration across several organisations. While the Air Force handled the airlift, the DRDO provided inputs on materials and safety mechanisms.
• The Indian Navy and Coast Guard were tasked with recovery preparations after splashdown. A. Rajarajan, Director of the Vikram Sarabhai Space Centre, noted that his centre carried out nearly 90% of the activities for IADT-1.
• In human spaceflight, ascent, descent, and recovery are considered the most critical stages. Even with a successful launch and stay in orbit, astronauts’ safety ultimately depends on the capsule’s ability to slow down safely for re-entry and landing. Any malfunction in parachute deployment could have disastrous consequences, making ground trials essential

• The Gaganyaan mission ultimately aims to place Indian astronauts in low-Earth orbit using a human-rated LVM3 launch vehicle. Before this goal can be realized, ISRO must complete a series of rigorous trials to verify all safety mechanisms.
• Unlike satellite or planetary launches, crewed missions require human-rating of every system, which means building in redundancies, fault-detection features, and life-support capabilities.
• As part of this process, Crew Escape System demonstrations are carried out to ensure astronauts can be safely separated from the rocket if a launch failure occurs. The first test vehicle mission, TV-D1, was conducted in October 2023, while the upcoming TV-D2 will simulate a more advanced abort scenario.
• The first uncrewed mission, Gaganyaan-1 (G1), will send a crew module into orbit atop the LVM3. Inside it will be ‘Vyommitra’, a humanoid robot created to replicate astronaut tasks. The recent success of IADT-1 has laid the groundwork for TV-D2 and G1.
• Additional drop tests, subsystem validations, and multiple IADTs will continue simultaneously to fine-tune the systems before human spaceflight is approved. By the time the inaugural human mission (H1) is attempted, ISRO would have completed thousands of individual tests.
• Key technologies being developed include the Environmental Control and Life Support System (ECLSS) to manage oxygen supply, temperature, waste, and fire protection; the Integrated Vehicle Health Management System (IVHMS) for autonomous fault detection and abort activation; and an upgraded LVM3 rocket, strengthened to meet human-rating reliability standards.
• Since many of these critical technologies were unavailable internationally, India has had to indigenously develop components such as escape motors and specialized composites. Every subsystem must undergo hundreds of trials before certification for crewed use