Stationed in space: Recent experience has important lessons for Isro

The stranding of astronauts Sunita Williams and Barry Wilmore at ISS until February 2025 highlights the challenges involved in manned space missions

The stranding of astronauts Sunita Williams and Barry Wilmore at the International Space Station (ISS) until February 2025 highlights the challenges involved in manned space missions. This highly experienced duo travelled to the ISS on the Boeing Starliner in early June. Their mission was supposed to last eight days. The Starliner had already negotiated two launches, but it was the first manned mission. Problems with its thrusters made docking difficult, and it had helium leaks, which added to the risks. While it is possible to return the Starliner to Earth unmanned, the capsule is deemed unsafe to carry humans. The National Aeronautics and Space Administration (Nasa) does not wish to risk a recurrence of the two space shuttle disasters, which cost many lives, including that of Kalpana Chawla in 2003. Hence, the astronauts will wait at the ISS until they can return on a SpaceX vehicle.

Nasa showed foresight when it tendered out for vehicles with life-support capsules, capable of ferrying goods and humans to the ISS. It opted to contract two designs, from Boeing and SpaceX. While SpaceX has successfully built a reusable design, Boeing has struggled. Despite decades of technical experience and its aerospace pedigree, Boeing’s project has cost at least thrice as much as SpaceX, and suffered time and cost overruns. The Starliner still has severe glitches. Its thruster array is still underperforming. The vehicle had issues docking with the space station since that requires delicate corrections. Now, Starliner requires a remote software upgrade before it can uncouple for the return journey.

However, there’s redundancy and the vehicle has enough propulsion capacity and manoeuvrability to return. The gas leaks are just as serious, since this may be life-threatening in itself. Without the SpaceX alternative, everyone on the ISS would be stranded. Instead of perishing in a fiery explosion, or crashing in uncontrolled descent, they would face the prospect of running out of food and oxygen. Manned space exploration carries such risks and both the Nasa-manned missions and the Soviet cosmonaut programmes have seen their share of tragedies. This is quite apart from the challenges of keeping humans healthy in space. Spaceflight requires periods of acceleration, which results in the body being subjected to 9-10 times normal gravity. There are also extended periods of zero gravity, which can lead to muscle atrophy and other ailments. Space is airless and subject to extremes of heat and cold, and there’s no atmosphere or magnetic field to protect humans from solar radiation. Space stations require recycling of waste and supply of oxygen. Atmospheric re-entry results in friction with heat that can melt metals.

Design failures in unmanned missions are a disappointment; in manned missions, design failures lead to loss of life. Keeping humans healthy in space is a big ask but research has led to many insights into bodily functions. Space medicine research has resulted in telemedicine tools, gym equipment, handheld MRI (magnetic resonance imaging) machines, etc. The Indian Space Research Organisation’s (Isro’s) stated plans include putting gaganauts into orbit in the near future, building a long-term habitat — that is, a space station — and carrying out a manned moon mission. Boeing’s failure indicates some of the pitfalls India’s space agency must avoid. There are important lessons here for Isro, and they need to be grasped and an entirely new set of technologies to safely achieve its ambitions of manned missions is needed.