It will take about six to eight months to reach Mars. It’s a long time to be enclosed in a spacecraft. It makes it difficult to stay healthy and sane in a variety of ways. One of the obstacles involved in the mission to Mars is ensuring that astronauts stay fit in space. Before British astronaut Tim Peake went aboard the International Space Station (ISS) for 180 days, NASA said his muscular strength could decrease by between 11 to 17%, muscular endurance by 10%, and bone density by 2 to 7% (1). So astronauts have to keep fit, not just for the reasons that apply to us on planet Earth, but also to offset the effects of microgravity on the body.
NASA has developed the Advanced Resistive Exercise Device (ARED) to mitigate the atrophy of bone and muscle in the microgravity environment. NASA points out that the muscle mass that is lost could be difficult or even impossible to regain back on Earth (2). ARED’s main goal, therefore, is to help astronauts maintain muscle strength and mass in astronauts during long duration spaceflight. Astronauts will need to exercise for about two hours every day in order to achieve this.
Exercise machines on Earth involve gravity, like lifting weights or running, to build strength and fitness. But in space you’re weightless. So the ARED helps astronauts to stay fit in space by using a piston and flywheel system to simulate free-weight exercises, such as squats, dead lifts and calf raises. The results that you get from using the ARED are similar to those seen with free-weight training. This machine can also help improve endurance, which will make a difference when it comes to physically taxing tasks, such as space walks.
NASA has also released video footage on their Tumblr page of the Miniature Exercise Device (MED-2) in action. It is a compact, all-in-one exercise device, and it takes up way less room than the ARED. Deep-space vehicles (like the Orion Spacecraft) aren’t as spacious as the ISS, so the less space that an exercise device takes up the better (3).
With the MED-2 astronauts are able to do both aerobic and resistive exercises. Weighing in at 65 pounds, it is extremely light. It is also a flexible machine, offering 5-350 pounds of resistance, which caters to the different strength abilities of the astronauts. Also essential to the Mars mission is the efficient use of resources. MED-2 charges during aerobic exercises, and this power is then used for the resistive exercises.
However, experts still don’t know how much bone and muscle loss would result after a three-year round trip to Mars. The loss could be so significant that exercise devices and diet plans will still need to be improved greatly in order to account for it.
Since astronauts can’t exercise all the time, there are other ways that they can stay fit in space. Dr Graham Mann, from Murdoch University’s School of Engineering and Information Technology, says:
“By arranging uniforms with special elastic straps connecting, say, your legs with your upper torso, it is possible to apply a constant artificial tension across the body.” (4)
This tension will help to continue muscle toning as the crew carry out their daily work. However, even if an evidence-based exercise routine can protect astronauts against the dangers of bone and muscle atrophy, they will still have to commit to doing these exercises every day. It’s hard enough to motivate yourself on Earth to go to the gym, even once a week, to exercise for an hour. It will definitely take a different kind of discipline to exercise every day for two hours.
Image credit: Nasa.gov
Mental health concerns
There are also some psychological challenges that could get in the way of crew members keeping fit in space. For example, it has been suggested that the isolation, loneliness, limited social contact, intense homesickness and conflicts experienced during the mission to Mars may result in depression among some astronauts. While mental health screening and a highly vetted selection process may mitigate this risk, it doesn’t eliminate it.
Anyone who suffers from depression knows that one of its most frustrating symptoms is the lack of motivation. You know that exercise will help to relieve the other symptoms, such as low mood, but it’s hard to find the energy to actually get yourself to the gym and exercise. This would be risky, since if an astronaut refuses to exercise, what can the other crew members do? Force them to exercise? Not likely. So then what you have on your hands is one crew member with not only psychological problems, but now also physical issues, as his fitness starts to deteriorate due to lack of exercise. It would therefore become much more difficult for them to carry out their duties. This is a potential problem that experts need to carefully consider.