Come October 2023 and the Indian Space Research Organisation (ISRO) is expected to conduct a key test as part of its ambitious crewed space mission, Gaganyaan, project director R. Hutton told new agency Reuters. The different tests hold utmost significance as ISRO has time and again emphasized human safety as the top priority for this mission. The Gaganyaan mission is expected to be launched before the end of 2024 from Sriharikota, the country’s main spaceport.
The Gaganyaan mission is India’s first human spaceflight programme which aims to send 2-3 astronauts into an orbit of 400 kilometres (250 miles) for a 3-day mission before safely splashing down in the Indian Ocean. The ISRO is currently training four astronauts. In the October test, the agency plans to check the crew-escape system (CES) which can be used to quickly get astronauts out in emergencies. They will carry out other tests, too, before the final launch.
“The orbital module (OM), which will orbit the Earth, consists of both the crew module and the service module (SM). The OM is equipped with advanced avionics systems, offering redundancy to ensure the safety of the crew. The crew module (CM) serves as a habitable space in space, simulating Earth-like conditions for the astronauts,” explained space expert Girish Linganna.
According to publicly available information, the ISRO is scheduled to conduct two abort test missions this year. The first test vehicle to achieve this end was launched in September 2021. The second test vehicle mission and the first uncrewed mission of Gaganyaan are planned for the first quarter of 2024. The second series of test vehicle missions and the second uncrewed mission of Gaganyaan with a humanoid robot are planned after the first uncrewed mission.
The mission includes various tests to ensure the safety of the crew and the spacecraft such as the Integrated Air Drop Test (IADT) which demonstrates the recovery of the crew module after landing in the sea. The test involves dropping a scaled-down version of the crew module from an aircraft and deploying parachutes to slow down its descent. The test also verifies the performance of the flotation system, which keeps the module afloat until it is retrieved by a ship. This was conducted by ISRO’s Vikram Sarabhai Space Centre at the Babina Field Fire Range in Jhansi district of Uttar Pradesh on November 19, 2022. This test was the first in a series of integrated parachute airdrop tests planned to simulate different failure conditions of the parachute system before it is deemed fit for use on the maiden human spaceflight. The test involved dropping a 5-ton dummy mass, equivalent to the crew module mass, from an altitude of 2.5 kilometres and deploying parachutes to slow down its descent. The test also verified the performance of the flotation system, which will keep the module afloat until it is retrieved by a ship.
Then there is the Pad Abort Test (PAT) which validates the crew escape system, which can be used to eject the astronauts from the launch pad in case of an emergency. The test simulates a launch abort scenario and evaluates the functioning of the solid rocket motors, the separation mechanisms and the recovery system. This test was also conducted by ISRO’s Vikram Sarabhai Space Centre at the Babina Field Fire Range in Jhansi district of Uttar Pradesh on July 5, 2018. The test was the first in a series of integrated parachute airdrop tests planned to simulate different failure conditions of the parachute system before it is deemed fit for use on the first human spaceflight.
This test, too, involved dropping a 5-ton dummy mass, equivalent to the crew module mass, from an altitude of 2.5 kilometres and deploying parachutes to slow down its descent. The test also validated the crew escape system, which can be used to eject the astronauts from the launch pad in case of an emergency.
“There would also be abort missions test and these missions will test the crew escape system (CES) in different phases of flight—such as ascent, orbit and re-entry—in case of a failure. The abort missions will use a modified version of the crew module, which will carry a humanoid robot instead of human astronauts. The abort missions will assess the reliability and robustness of the escape system under various conditions. These tests are significant for ensuring that the Gaganyaan mission meets the international standards of human spaceflight and fulfills India’s aspirations of becoming a space-faring nation. ISRO has developed test vehicles to send the Gaganyaan’s systems up to a certain height, and then simulate a failure to check the escape system as it falls back into the Bay of Bengal,” remarked Linganna.
There would also be Test Vehicle (TV) Flights which will test the orbital and re-entry capabilities of the crew module. The test vehicles will be launched using a human-rated LVM-III (HLVM-3) rocket and will carry various sensors and instruments to measure the aerodynamic, thermal and structural parameters of the module. ISRO’s LVM3 rocket, known as the launch vehicle for the Gaganyaan mission, has undergone significant modifications to align with human safety standards and is now referred to as the human-rated LVM3 (HLVM3).
“The test vehicles will also demonstrate the guidance, navigation and control systems, as well as the communication and telemetry systems. The Indian Navy’s specialized marine commando unit, Marcos, will play a role in recovering India’s first human spaceflight mission when it returns from space and lands in the sea. ISRO has already provided the Navy with the crew module recovery model to train the crew. The sequence begins with the first test vehicle mission, known as Test Vehicle TV-D1. It will be followed by the second test vehicle mission, TV-D2, and the first uncrewed Gaganyaan mission labelled LVM3-G1. Subsequently, ISRO will carry out the second set of test vehicle missions, TV-D3 and D4, along with the LVM3-G2 mission, which will include a humanoid robot named ‘Vyommitra’. HLVM3 incorporates a crew escape system (CES) powered by a set of high-performance solid motors designed for quick response. This system ensures that, in case of an emergency either on the launchpad or during the ascent, the crew module (CM) and its occupants can quickly move to a safe distance,” Linganna told THE WEEK.
ISRO has also recently carried out a series of Drogue Parachute Deployment Tests at the Terminal Ballistics Research Laboratory’s Rail Track Rocket Sled (RTRS) facility in Chandigarh. A critical component of the Gaganyaan mission is the deployment of drogue parachutes, which play a crucial role in stabilizing the crew module (CM) and reducing its velocity to a safe level during re-entry. In the first abort test of the special test vehicle (TV), the space agency will raise the vehicle to a near-supersonic condition before executing the abort command, taking the CM and the CES through simulated conditions that could arise during the mission.
