SHABIHA NUR KHATOON,OP
While cosmic mysteries have always aroused profound passion in humans to explore the
unfathomable, awareness on the need to adopt survival strategies in space has
developed only recently
Since the dawn of civilisation humans were seized with the curiosity to explore the mysteries of space. Some of the questions that have intrigued astronomers from antiquity to the present day are how was the solar system — and the universe — created, and how, for that matter, the stars came into being on the vast canvas of the sky. Not only children but adults too are fascinated by the manifold mysteries of space. However, only spacefarers have the golden opportunity to unearth the secrets hidden inside the numerous galaxies and the liberty to disentangle cosmic riddles.
Watching videos of astronauts aboard the International Space Station (ISS) and spacefarers floating around in microgravity might look like a lot of fun, as explorers isolate themselves from worldly affairs. But there is always a story inside a story. What appears interesting, and even fascinating, is not exactly so. In fact travelling beyond our dear planet could trigger a range of negative effects on the mind and body.
Be it Neil Armstrong, Kalpana Chawla or Rakesh Sharma, each astronaut has had to face some kind of health problems while exploring space. So, what are the main risks encountered by spacefarers and what does latest research have to say about solving these problems during long space missions?
Sunday POST speaks to experts on the health hazards involved in epic space flights and how these could be mitigated.
Ashok Kumar Rath, faculty at KIIT University, says humans venturing into space are wary of the negative effects on the body like muscle atrophy and deterioration of the skeleton, which is known as spaceflight osteopenia.
“There are significant effects on the body that include a slowing down of cardiovascular functions, decreased production of red blood cells, balance disorders, eyesight disorders and a steady weakening of the immune system,” says Rath.
“Other symptoms include fluid redistribution (causing the “moon-face” appearance typical in pictures of astronauts experiencing weightlessness), loss of body mass, nasal congestion, sleep disturbance and excess flatulence.”
“During spaceflights the environmental conditions experienced by humans are different from those on Earth. However, technology is able to shield people from the harshest conditions, such as that offered by a spaceship or spacesuit. The immediate needs for breathable air and drinkable water are addressed by a life support system – a group of devices that allow human beings to survive in outer space. This life support system supplies air, water and food. Shielding against harmful external influences such as radiation and micro-meteorites is also necessary.
“The most important factor affecting physical wellbeing in space is weightlessness, more accurately defined as the ‘Micro-g environment’. Living in this type of environment impacts the body in three important ways: loss of proprioception, changes in fluid distribution, and deterioration of the musculoskeletal system,” adds Rath.
Pointing to latest research into the problems involved during long distance missions, the scientist says space medicine is a developing practice that studies the health of astronauts living in outer space.
“The main purpose of this academic pursuit is to discover how well, and for how long, people can survive the extreme conditions in space, and how fast astronauts can readapt to the Earth’s environment after returning from space. Space medicine seeks to develop preventative palliative measures to ease the suffering caused by living in an environment which is alien to humans,” says Rath.
“Human physiology is adapted to living within the Earth’s atmosphere, and a certain amount of oxygen is required in the air we breathe. The minimum concentration, or partial pressure, of oxygen that can be tolerated is 16 kPa (0.16 bar) below which, the astronaut is at risk of becoming unconscious and dying from hypoxia. In the vacuum of space, gas exchange in the lungs continues as normal but results in the removal of all gases, including oxygen, from the bloodstream. After 9 to 12 seconds, the deoxygenated blood reaches the brain, and it results in the loss of consciousness. Death would gradually follow after two minutes of exposure, although the absolute limits are uncertain,” he adds.
An expert in civil engineering, Rath explains that there is scientific concern that extended spaceflight could slow down the body’s ability to protect itself against diseases. Radiation can penetrate living tissue and cause both short- and long-term damage to the bone marrow stem cells, which create the blood and immune systems.
“In particular, spaceflight often causes ‘chromosomal aberrations’ in lymphocytes. As these cells are central to the immune system, any damage weakens immunity, which means that in addition to increased vulnerability to new exposures, viruses already present in the body, which would normally be suppressed, become active. In space, T-cells (a form of lymphocyte) are less able to reproduce properly, and the T-cells that do reproduce are less able to fight off infection. Over time immunodeficiency results in the rapid spread of infection among crew members, especially in the confined areas of space flight systems,” Rath explains.
On May 31, 2013, National Aeronautics and Space Administration (NASA) scientists reported that a possible manned mission to Mars may involve a great radiation risk based on the amount of energetic particle radiation detected by the RAD on the Mars Science Laboratory while travelling from the Earth to Mars in 2011–2012.
The psychological effects of living in space have not been clearly analysed but analogies on Earth do exist, such as Arctic research stations and submarines. The enormous stress on the crew, coupled with the body adapting to other environmental changes, can result in anxiety, insomnia and depression.
Tapan Mishra, director of Space Applications Centre, ISRO, says long duration space travel can take a heavy toll on the mental wellbeing of the space traveller. Reports have emerged of astronauts reporting problems such as insomnia and loss of appetite, and most spacefarers have complained of lack of privacy in the confines of a spacecraft.
“Apart from the technical content of the ground training, a fair amount of physical training is given to prepare the crew to withstand the rigours of a space flight. While medical tests might be able to reveal the physiological effects of spaceflight on the body, people might be less inclined to self-report on psychological stresses or problems they encounter.
It deserves mention that NASA has been paying particular attention to these psychological effects. A 2016 report on human health risks highlighted several areas that needed further study. These include the effects of long-term disruption to sleeping patterns and ‘circadian rhythm desynchronisation’. This is a condition in which the body’s internal cycles of temperature regulation, metabolic activity and wakefulness are disrupted. The report recommended more research into how diet and nutrition can affect the circadian rhythms, and whether the timing of meals, for example, might help solve the problem. One of the best ways of studying psychological effects is in similarly isolated situations back on Earth.
A study of the longest spaceflight, Gemini VII, concluded that the first three weeks represent a critical period during which attention is adversely affected because of the demand to adjust to the extreme change of environment. The ISS working environment includes further stress caused by living and working in cramped conditions with people from very different cultures who speak different languages. First generation space stations had crew who spoke one language, while the second and third generation stations have crew members from many cultures who speak different tongues. Space colonisation efforts must take into account the effects of space on the human body.
The sum total of human experience has resulted in the accumulation of 58 solar years in space and a much better understanding of how the human body adopts. In the future, industrialisation of space and exploration of inner and outer planets will require humans to endure longer and longer periods in space. The majority of current data comes from missions of short durations and so some of the long-term physiological effects of living in space are still unknown.
Currently only rigorously tested humans have experienced the conditions of space. On October 29, 1998, John Glenn, one of the original members of Mercury 7, returned to space at the age of 77. His flight, which lasted nine days, provided NASA important information about the effects of space on older people. Factors such as nutritional requirements and physical environments, which have so far not been examined, will now become gradually more important. Overall, there is little data on the manifold effects of living in space, and this makes attempts toward mitigating the risks during a lengthy space habitation difficult.
The environment of space is still largely unknown, and there will likely be as-yet-unknown hazards. Meanwhile, future technologies such as artificial gravity and more complex bioregenerative life support systems may someday be capable of mitigating risks.
