Risks and rewards of human deep-space travel

For all of the clamour around Elon Musk’s prognostications of a human colony on Mars by 2026, experts said that the limiting factor of humanity’s aspirations to reach other worlds is still dictated by the frailty of the human body.

At a recent talk organised by the French Embassy and Institut Francais, a panel of authorities pointed out any attempt to reach other planets and celestial bodies is massively challenged by the task of protecting and sustaining astronauts during long-haul space missions.

Among the obstacles are solar radiation, the need for safe habitations plus concocting ways to carry out agriculture or storing food on the austere new world or spacecraft, addressing the fearsome battery of physiological and psychological problems associated with long-term space travel worsened by a sense of disconnect from Earth and even the disposal of food and human waste that 'earthlings' take for granted.

It is this set of challenges that leaves Mathieu J Weiss, Space Counsellor and the Bengaluru representative of the French Space Agency, the National Centre for Space Studies (CNES), convinced that it is not so much the technicality of space technology or even propulsion systems holding back a deluge of human-crewed missions into space, but concern about how humans will survive missions that could take months or years to complete.

“The space sector has gone through tremendous changes these last years. Look at reusable technologies, look at sustainable technologies, solutions with artificial intelligence,” Weiss said. “In fact, the novels we were reading in the 20th century about science fiction are just becoming reality and we, as experts in the field, we are feeling it, living it every day.”

At the same time, Weiss cautioned that living on the moon or on Mars presents technical challenges which have never really been addressed by the earlier generations of space travel or even current missions at the International Space Station (ISS).

“We are at the cusp of a major leap in human space flight to other celestial bodies but whatever we learned from the fantastic Apollo program and all the work the Russians have done cannot be used for us to live on Mars. We need to now understand the physical limits of sending humans out there, which raises questions such as: How will they rehab from the prolonged flight duration and how will they fare from a physiological point of view and from a psychological point of view?” he said.

Physiological changes

What is known is that within four to six hours of a human being going to space, the individual starts to experience changes in the body’s cardiovascular system involving the heart and blood acid, according to Wing Commander Dr Stuti Mishra, a Flight Surgeon and Instructor at the Institute of Aerospace Medicine (IAM) in Bengaluru where the Gaganyaan astronauts are being trained.

“The moment we put a human behind a machine for a long duration, the human becomes the limiting factor,” she said.

This is because something similar to osteoporosis, the instantaneous fractures which happen to old people, occurs in space and as does muscle wasting in the lower limbs. "Demineralisation in the bones is one issue. The other is radiation because it has a long-term effect on cells,” Dr Mishra said, adding that natural sensors in the human body known as vero-receptors also are de-conditioned in low gravity.

This has particular resonance for India, whose long-term aspiration beyond the Gaganyaan-manned missions is to set up a space station in low-earth orbit with the eventual aim of going to the moon.

“Gaganyaan is just the foundation of a sustained manned space program and it will act as a stepping stone,” said V R Lalithambika, Director of ISRO’s Human Spaceflight Programme. “Beyond this programme, we would be thinking of permanent presence in low-Earth orbit first, and we need to develop a lot of enabling technologies for that, which we do not have at the moment — on the engineering side, docking technologies, on the human side, bio-asthmatics is one area where we do not have any expertise.”

“We need to develop that expertise and all the associated technology which would be required for a sustained presence in space,” she added.

Although data exist, going back some 60 years to the early US and Russian-manned missions showing how space travel impacts the human body, Isro officials told DH that the country would like to collect its own data through space expeditions because it could present new findings on how solar radiation affects Indians on a genetic level.

This is a statement corroborated by Dr Audrey Berthier, Executive Director of Medes (the French Institute for Space Medicine and Physiology at Toulouse) who said that there is still a long way to go before “individual susceptibility” to solar radiation can be established.

In ongoing French-Australian trials at Sydney, for example, scientists have been using a heavy-ion synchrotron to test new radiation-protective light materials for spaceflight on animal meat samples. “In our study, we found out that different people are reacting totally differently to radiation,” Weiss added.

New lessons to learn

While there is data accumulated in previous space missions, Dr Berthier stressed that additional data, such as that to be generated by Gaganyaan will help complete the picture. But for some facets of future space travel such as deep-space isolation, there is even less quantifiable data. Where studies at Concordia Station in Antarctica have presented some information on the reaction of people to isolation, deep-space missions remain a wildcard.

How this will play out in a mission going to Mars where all one will see is darkness and blinking stars for six to nine months is anyone’s guess, added the space entrepreneur, Dr Susmita Mohanty, the founder of Liquefier System Group (LSG), an aerospace architecture and design firm based in Vienna.

Psychological impact

“When in isolation, sometimes even fungus or mold can become your pet or friend,” she said, pointing to a brief stint in Antarctica where she found the sunlight as having an otherworldly quality. “It affects your mind and it starts to disorient you a bit in terms of time and space. Little things happen which have a big psychological impact,” she added.

Worse, current behavioural data from the International Space Station is of little help as astronauts in low-earth orbit can see the Earth from the window, which is a source of comfort, added Dr Berthier, who pointed out that the ISS astronauts also have the option of a relatively speedy trip back to an Earth hospital in the event of a serious medical emergency —a luxury that deep-space travellers lack.

But even if one survives the perils of spaceflight, there are more to follow on planetary surfaces. Future Indian astronauts who take up station on the moon may encounter problematic living conditions, according to Dr Mohanty.

“Because there's no weathering force on the moon, if you pick up dust, it's fine and sharp like glass. It gets into everything. It gets into the creases of your spacesuit, it gets into the mechanical parts of your buggy, if you breathe it and sort of bring it into your habitat it goes into lungs, and it smells like burnt gunpowder,” she said.

Ultimately solutions to all these problems will be found, experts said, adding that this will yield advances applicable even on the Earth.

Speaking at the event, Thierry Berthelot, General Consul of France in Bengaluru set the context for where humanity seeks to go. “If the Earth was the size of a tennis ball, the farthest astronauts have gone is two meters away from the tennis ball to the moon which would be the size of a marble. Now we are aiming for Mars, which is a golf-ball-sized object three football fields away from our tennis ball. What has to be achieved is tremendous,” he said.

But he added that the spin-offs: the benefits for our life on Earth will come in similar spurts - leapfrogging in the medical field, but also technical clues for adapting to climate change, new solutions to the conservation of the living and maybe new societal models. “There are intensive hopes in these programs to serve humanity,” he said.

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