The Indian Space Research Organisation (ISRO) is testing and validating the Crew Module of Gaganyaan, India's first human spaceflight mission. The capsule is designed to bring astronauts safely back to Earth through the extreme conditions of atmospheric re-entry.
Gaganyaan was formally announced in 2018. It aims to send a crew of three to a 400 km Low Earth Orbit for three days and return them by splashdown in Indian sea waters. The Human-rated Launch Vehicle Mark 3 (HLVM3) is to place the Orbital Module in the desired orbit.
Before the crewed flight, ISRO is running uncrewed test missions to validate the Crew Module, the Crew Escape System and HLVM3. The G1 uncrewed mission will carry the Vyommitra humanoid robot to simulate human presence and test the life-support systems. Four astronauts-designate have been named: Group Captains Prasanth Balakrishnan Nair, Ajit Krishnan and Angad Pratap, and Wing Commander Shubhanshu Shukla.
The Gaganyaan spacecraft is officially called the Orbital Module and has two parts. The Crew Module is a pressurised, habitable capsule carrying the Environmental Control and Life Support System (ECLSS), which recreates Earth-like living conditions for the crew. It also holds a Thermal Protection System, avionics and deceleration systems.
The Service Module is unpressurised. It supplies propulsion, power, thermal control, avionics and deployment mechanisms in orbit, then separates before re-entry and burns up in the atmosphere. Russia's Soyuz and China's Shenzhou use a three-module configuration. ISRO has dropped the additional module, which makes the spacecraft lighter.
Re-entry cannot begin until the Service Module is cleanly detached. The Connect & Disconnect System, a redundant pyrotechnic mechanism, does this. A failure would alter the spacecraft's centre of gravity and make re-entry fatal.
The Crew Module has a sphere-cone shape. The blunt base produces a detached shockwave that deflects intense heat, while the conical section gives controlled lift that reduces g-forces. An ablative heat shield, the core of the Thermal Protection System, gradually chars and erodes, carrying heat away during hypersonic re-entry. Reaction Control System thrusters hold the capsule's orientation, which prevents dynamic instability and keeps the heat shield correctly aligned.
For the final descent, drogue parachutes first stabilise the capsule and main parachutes then slow it to a safe splashdown velocity. The parachute system is redundant.
Because of its internal mass distribution, the module is hydrodynamically bi-stable and can float inverted. If that happens, the Crew Module Up-righting System (CMUS) activates. Stored cold gas inflates flotation bags, shifting buoyancy to roll the capsule upright and exposing communication beacons for Indian Navy recovery teams.
Success would make India the fourth country, after the United States, Russia and China, to independently conduct a human spaceflight. It would also allow microgravity research in biological sciences, material science and medicine, and validate life-support, radiation shielding and safe re-entry technologies.
These capabilities are meant to lay the foundation for the Bharatiya Antariksh Station by 2035 and a crewed lunar mission by 2040.
With reference to the Gaganyaan spacecraft, consider the following statements:
Which of the statements given above are correct?
Which one of the following best describes the function of the Crew Module Up-righting System (CMUS) of the Gaganyaan Crew Module?
Consider the following statements:
Statement-I: Re-entry of the Gaganyaan Crew Module cannot begin until the Service Module is cleanly detached.
Statement-II: A failure of the Service Module to detach would alter the spacecraft's centre of gravity and make re-entry fatal.
Which one of the following is correct in respect of the above statements?
