Gaganyaan : Long haul before crewed flight takes charge

The recent announcement by ISRO chairperson V Narayanan regarding the Gaganyaan mission has once again followed a familiar script: ambitious goals tempered by pragmatic delays.Speaking on the sidelines of the Emerging Science, Technology and Innovation Conclave (ESTIC-2025), Narayanan stated that while nearly ninety per cent of subsystem progress is complete, the mission now enters a critical phase of integrated testing to verify that every component can withstand the thunderous launch, the hostile space environment, and the infernal heat of reentry.The ambitious Gaganyaan project, initiated in 2018, aims to send Indian astronauts to space and bring them back safely using an entirely indigenous spacecraft and launch vehicle. Once successful, India will be the fourth country to do so, after the Soviet Union/Russia, the US and China.The original schedule, which envisioned the launch coinciding with India's 75th anniversary of Independence in 2022, has been significantly altered. The initial setbacks were primarily due to the global COVID-19 pandemic. Nonetheless, the recent hurdles include extensive technical preparations, the rigorous process of human-rating systems and delays in hardware realisation.Compounding these technical challenges, as the Parliamentary Standing Committee on Science and Technology has adversely observed, has been the issue of erratic fund flows from the Union government. Significant budget reductions in the past few years have hampered consistent progress. When these factors are combined, a crewed Gaganyaan mission now seems a realistic prospect, not before 2027 or even 2028.Despite the recent conduct of an important test on Main Parachutes for the Gaganyaan Crew Module, in a notable shift from the earlier plan, Narayanan revealed that the first fully uncrewed orbital flight, designated Gaganyaan1 or G1, is now scheduled for December 2025.This mission had previously come tantalisingly close, with its launch campaign initiated in December 2024 for an expected launch in early 2025. The further delay until the end of 2025 highlights the complexities involved. More intriguing, however, is the revised sequence of tests. The G1 mission will now take place even before the second test vehicle abort mission, TV-D2, which is designed to validate the Crew Escape System (CES) under more challenging conditions than the first successful test, TV-D1, conducted in October 2023.A crewed mission demands a human-rated launch vehicle, with a robust crew emergency escape system and a reliable spacecraft. The Crew Escape System is a critical pillar of this safety architecture. It is an emergency evacuation mechanism designed to instantly separate the crew module from a malfunctioning launch vehicle during liftoff or ascent, swiftly transporting the astronauts to safety.ISRO has developed a tower-based CES that sits atop the human-rated version of its LVM3 rocket, called the HLVM3. In an emergency, powerful rockets on this tower can detach the crew module and carry it to a safe distance.Perfecting this system has been methodical. A Pad Abort Test in 2018 demonstrated the system's ability to pull the crew capsule away from the launch pad. The first in-flight test, TV-D1, successfully validated the CES while the launch vehicle was travelling at 1.2 times the speed of sound.The upcoming TV-D2 mission is intended to test this escape under greater duress, at speeds exceeding 1.4 times the speed of sound, followed by further tests in even more complex abort scenarios. Similarly, the recent Integrated Air Drop Test validated the parachute system's performance, a crucial factor for a safe splashdown.The process of human-rating a rocket is painstaking and time-consuming. For example, a special facility, the Hypervelocity Expansion Tunnel Test Facility, that can simulate the hypersonic conditions encountered during spacecraft atmospheric reentry, has been established at IIT Kanpur.It also involves subjecting every component, down to the cryogenic engines, to extreme wear and tear to ensure unparalleled reliability. It is the difference between the safety standards of a passenger bus and a goods lorry.This requires not only extensive ground qualification tests but also test-flying some human-rated components on previous LVM3 launches to rate their actual performance in flight. Every system must be tested individually and then again as an integrated whole.The heart of the crewed mission is the spacecraft itself, which houses the astronauts. The crew cabin provides a livable environment by managing the oxygen supply, removing carbon dioxide, and regulating temperature, humidity and air pressure through a complex Environmental Control and Life Support System (ECLSS).Initially, ISRO explored procuring key elements of the ECLSS from Russia, but when that did not work out, the organisation embarked on developing every aspect indigenously, adding another layer of complexity and time to the programme.The road to the crewed mission is long and necessarily sequential. Before astronauts board, three uncrewed missions — G1 to G3 — are planned to ensure safety and reliability. Each will carry the robotic humanoid Vyommitra to monitor the environment that the crew will eventually experience.However, with several critical tests like TV-D2 and Integrated Air Drop Tests delayed, the decision to proceed with the G1 mission ahead of some of them is glaring. It is also learnt that this first uncrewed flight will carry only a limited integrated vehicle health monitoring system, a scaled ECLSS demonstrator and an unpressurised crew module, meaning it will not fully mimic an actual crewed flight.While the announcement of the G1 mission brings India a step closer to its goal, the reshuffled order of tests and the scaled-down nature of the initial flights are an enigma. The delays, while disappointing to the public, reflect the immense technical challenges and the non-negotiable priority of astronaut safety.The path to Gaganyaan is not a simple sprint but a meticulous marathon, where every step, however slow, must be firm and sure.

Gaganyaan : Long haul before crewed flight takes charge

The reshuffled order of tests and the scaled-down nature of the initial flights are an enigma.

TV Venkateswaran

Gaganyaan : Long haul before crewed flight takes charge

The reshuffled order of tests and the scaled-down nature of the initial flights are an enigma.

TV Venkateswaran

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