Acing the Indian space dream
India is set to launch its first manned mission to space. The Indian Space Research Organisation (ISRO) has already set the process in motion. Gaganyaan will become a reality in 2022, in line with Prime Minister Narendra Modi’s plans. But ISRO needs to be ready on 10 vital aspects before the Gaganyaan can take off.
Powered by the indigenous cryogenic engine, the GSLV MkIII, with a capacity to take a 4-ton payload to geosynchronous transfer orbit and 10-ton payload to low earth orbit, is amply suited for the Gaganyaan mission, with an estimated payload of 5–6 tons. However, the critical challenge is to make the craft carry humans.
There is no single protocol for human-rated certification but there are several safety features and built-in redundancies that make the craft safe for carrying humans to space. Redundancies are built into a space programme to meet unexpected challenges and human rated missions require a very high degree of redundancy.
ISRO has set the reliability target of 0.99 for the launch vehicle, which means only one out of a hundred launches can fail.
The space body is building three sets of GLSV Mk III variant rockets along with crew and service module. It will undertake two unmanned dry runs during December 2020 and June-July 2021, before the final launch with 2–3 Indian astronauts, sometime in December 2021 or early 2022. Other space agencies have often used chimps and dogs during the dry run. However, ISRO is proposing to use a humanoid robot resembling a human during the experimental launch.
[Dry run will not be that dry: ISRO proposes to use the humanoid robot during the two test missions to carry out useful research. Forty projects on microgravity have already been shortlisted.]
Launching a satellite and sending humans to space is not the same thing. Once the satellite is tested, assembled and readied for launch, it is packed inside the nose cone of the last stage. The payload is then placed on top of the rocket and taken to the launch pad. However, humans have to board the craft only just before the launch.
ISRO is augmenting its second launch pad for human flights even while planning a third one capable of launching a human mission to space. The second launch pad at Sriharikota will be fitted with an umbilical tower. It will also have a bubble lift for the crew to board the crew module once the launch sequence is initiated. The crew access will be foldable and have flexible platforms.
A human-worthy launch vehicle must show not only fitness in flight but also during failure. In 2018, a routine human mission, Soyuz MS-10 to the Internal Space Station carrying Russian cosmonaut Alexey Ovchinin and US astronaut Nick Hague was launched.
The launch had to be aborted midway after the technicians found about the booster failure after 165 seconds into flight. If they had not pressed the emergency abort button, initiating a sequence of mechanisms that led them to safety, both the crew might have died.
The human variant GSLV Mk III has an extra small rocket on top of its nose cone, called escape tower. The orbital module is attached to this emergency escape system. When something goes wrong with the rocket, seven specifically designed quick-acting solid fuel motors in the escape tower fires up and pulls the module with humans away from the main rocket. Once it reaches a safe distance, parachutes are deployed, and the crew module is landed safely.
A crucial crew escape assembly test was conducted by ISRO on July 5, 2018. Called Pad abort test, the mock crew module with a mass of 12.6 ton was attached to the escape tower and tested.
The Crew Escape System along with the mock crew module soared skyward for about 2.75 km before unfurling its parachutes and floating back to the Earth’s surface safely. More tests will be undertaken before the humans are flown to space.
What it takes to get to space
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