The Indian Space Research Organisation (ISRO) successfully completed one of the milestones to Gaganyaan, its first crewed space mission. The TV-D1 mission launched on Saturday was crucial as it tested the Crew Escape System of the future Gaganyaan mission, which will kick in to take astronauts safely away from the launch vehicle in case of an emergency. The TV-D1 mission is just the first in a series of tests that ISRO will have to go through before it can finally put an astronaut in space. When it does that, India will join the very small list of countries that have launched a crewed space mission. This list currently includes the United States, Russia (and the Soviet Union) and China. The Prime Minister earlier this week spelt out even loftier ambitions for the space agency—to build a space station by 2035 and to send an Indian astronaut to the Moon by 2040. But the road there is a long one, and ISRO has only begun taking its first few steps on the first part of that journey—putting astronauts in space. The test of the Crew Escape System was prioritised because the space agency puts the safety of its astronauts first. In case of any emergencies during launch, the Crew Escape System can separate the crew module from the launch vehicle and take the astronauts away safely for a splashdown. The crew module’s protecting its inhabitants begins at launch. During the actual Gaganyaan mission, the human-rated LVM3 rocket will fly towards space with acceleration four times that of gravity. At this time, the crew module will protect the astronauts from the massive air friction and the heat it generates. But the Crew Escape System can only keep the astronauts safe when they are still in Earth’s atmosphere. When in space, there are no escape systems. The crew module is the only place where astronauts can stay safely, and if there is something wrong with it, there is nowhere else to go. It will have to protect the astronauts from the zero-air, microgravity environment in a low-Earth orbit. It will also have to protect the astronauts from the intense radiation of the Sun, with no atmospheric layers to act as a barrier. The TV-D1 mission tested an early unpressurised version of the crew module. Of course, for the actual crewed mission, ISRO will be using a pressurised spacecraft in which the astronauts can live and breathe freely. Humans cannot last very long in the vacuum of space. The US Federal Aviation Authority estimates that humans can remain fully conscious for only between 9 to 12 seconds after being exposed to a vacuum. Interestingly, humans exposed to the vacuum of space will die for the same reason that humans die underwater—due to lack of oxygen. Yes, there is a lack of air pressure in space, and this can prove near fatal with the internal pressure of our body and its fluids. But our tissue and blood vessels are strong enough to handle this. So, while you don’t have to imagine a gory explosion of the human body, a deep space environment will kill you in a more silent manner, slowly choking you out. After spending days in space, the crew module will have to protect astronauts during its reentry into the planet, when air friction can cause temperatures higher than 2,500 degrees Celsius. That is hot enough for humans to instantly burst into flames and die. These horrors beyond our world are good enough reasons for space agencies to be very careful with crewed missions. The National Aeronautics and Space Administration (NASA), which already landed humans on the Moon, took nearly two decades to develop the Orion spacecraft. Even after that, the Orion spacecraft was only truly validated after it went on an uncrewed test mission around the Moon and back with Artemis 1. During the Artemis 1 flight test, Orion spent more time in space than any previous spacecraft designed for astronauts without docking to a space station. When it was in distant lunar orbit, it surpassed the record for distance travelled by human-rated spacecraft, which was set during Apollo 13. And all of that from a space agency that has led more than 200 crewed missions into space. Gaganyaan will be ISRO’s first. The Gaganyaan crew module will have to be put through rigorous tests in space, in the form of an uncrewed mission, before ISRO ever thinks of sending astronauts to space in it. And that is after many other tests that will happen right here on Earth. So, 2035 and 2040 may seem like they are far away. But in space exploration terms, they are just moments away, and we still don’t know whether ISRO will be able to achieve ambitious targets of a space station and a moon landing by then. But even if it doesn’t, it is perfectly understandable.
