Gaganyaan: Why is crew escape module important? Recalling Apollo 1 disaster

New Delhi, Feb 4: When humans need to be launched into space, the mission becomes much more complex than sending satellites, in which the ISRO has mastered the technology. ISRO has sent probes to the Moon and Mars, but when sending humans to space is considered, the mission becomes complicated because the safety of lives is paramount.

For a manned mission, the key distinguishing capabilities that ISRO is working on includes the ability to bring the spacecraft back to Earth after the flight, and to build a spacecraft in which astronauts can live in Earth-like conditions in space.

Re-entry of the spacecraft into earth's atmosphere is also a challenge. But there is another technology called crew escape mechanism which is extremely vital. The crew escape system is an emergency escape measure designed to quickly pull the crew module along with the astronauts to a safe distance from the launch vehicle in the event of a launch abort.

If something goes wrong at any point during the launch, then there has to be way for the crew to escape so that lives can be saved. The mechanism ensures the crew module gets an advance warning of anything going wrong with the rocket, and pulls it away to a safe distance, after which it can be landed either on sea or on land with the help of attached parachutes. The system is typically controlled by a combination of automatic rocket failure detection, and a manual backup for the crew commander's use.

ISRO in July last year carried out the first in a series of tests to qualify a crew escape system. According to the ISRO, the five-hour countdown was smooth. The crew escape system along with the simulated crew module with a mass of 12.6 tonne, lifted off at 7 am at the Satish Dhawan Space Centre in Sriharikota in Andhra Pradesh. The test was over in 259 seconds, during which the crew escape system along with crew module soared skyward, then arced out over the Bay of Bengal and floated back to Earth under its parachutes about 2.9 km from Sriharikota.

When crew escape system saved lives:

There has only been one occurrence of a launch escape system being used during an active mission: In 1983, the crew of the Soviet Soyuz T-10-1 were carried away from their launch vehicle via their LES two seconds before the launch vehicle exploded due to a pad fire. The crew survived.

In 2018, the crew of Soyuz MS-10 separated from their launch vehicle after a booster rocket separation failure occurred at an altitude of 50 km during the ascent. However, at this point in the mission the LES had already been ejected and was not used to separate the crew capsule from the rest of the launch vehicle. Backup motors were utilized to separate the crew capsule resulting in the crew landing safely and uninjured approximately 19 minutes after launch.

Apollo 1 disaster:

Planned as the first low Earth orbital test of the Apollo command and service module with a crew, to launch on February 21, 1967, the mission never flew; a cabin fire during a launch rehearsal test at Cape Kennedy Air Force Station Launch Complex 34 on January 27 killed all three crew members.

Apollo was the name of the program to land the first men on the Moon.