Is living in space all that it’s cracked up to be? Sure, you would get to explore the vast reaches of the galaxy, to examine the curious moon rocks on the celestial Moon, to experience the heat and sandstorms of ruby-hued Mars, to jump and frolic amidst the low gravity of other planets. It will be a truly novel experience, one far removed from the mundane reality of planet Earth.

Might you be one of those people, given the opportunity? To say that space travel is a cherished dream for many people is in itself an understatement, as the number of applicants (202,586, to be exact) received by Mars One during its open call for future Mars residents can attest to.

What about your body, though? Scientists say our bodies are not built to live on other planets, which is why astronauts have to go through extremely intense training and exercise to condition and prepare their bodies to withstand the thrust into space. To some extent, they must contend to go against the inbuilt physical triggers that will cause changes in the body due to zero gravity.

Our skeletal system is meant for Earth

Human beings have adapted over a long and slow process to live in Earth’s gravity. To adapt to microgravity, our bone density drops significantly, as seen in astronauts who have spent over a month in space. This is because the skeleton no longer needs to support the body’s weight as much in space as we float rather than subject our bodies to impact when walking or running on the ground.

However, a loss in bone density could lead to bones breaking down as the calcium lost is reabsorbed into the body. According to the National Space Biomedical Research Institute, an astronaut loses as much bone mass in just one month as a postmenopausal woman with osteoporosis would in a whole year (up to 1 or 1.5% of bone mass).

But on the upside, at least you are getting taller. On Earth, discs between each of the small bones that make up your spinal column are more compressed due to the effect of gravity. In space, these discs expand, making the spine longer and thus, elevating your height somewhat.

Our muscular system is meant to be used

Why do people have to work out regularly to keep their muscles? Simply because muscles deteriorate without frequent use. In the zero gravity environment of space, it is far easier to move about due to the lowered resistance experienced by our muscles.

The lack of environmental factors such as air and wind also contributes to this lowered resistance to movement. In effect, for the same amount of exercise, we use our muscles less in space than on Earth. This causes muscle mass to slowly decrease.

To prevent muscle loss from hitting fatally low levels, it is compulsory for astronauts to undergo intensive exercise training to build up their muscles. Although there are in-space exercises that astronauts can work on, researchers are still developing ways to better combat this problem.

The circulatory system goes topsy-turvy

For blood to circulate around our bodies, it needs the aid of gravity. In its absence, our internal body fluids travel towards the upper parts of our body, especially the head. This can lead to lightheadedness which is persistent and makes it hard to go about the day in the usual manner. Moreover, since the heart is also a muscle and does not have to work as hard, our hearts could literally shrink over time in space.

The mind needs to stay healthy, too

How would you feel, if you were on a trip away from Earth? Leaving your home, family and friends behind to ascend to the cold, empty inhospitality of space? Astronauts report experiencing a complex mix of emotions, including fear, excitement, wonder, and anxiety.

Over time, they may feel isolated or lonely, especially when the realisation sinks in of just how long it would take to get back. It takes a vast amount of mental and physical resilience to be able to deal with the effects of space travel which include both psychological stress due to emotions, and physiological stress such as interrupted sleep cycles.

Thus, a growing sense of disconnect from everything familiar is likely, and this needs to be combated immediately because there is no possibility of “taking time off work” or “seeing a therapist” when you are up in space.

Dying in space

If we are to contemplate the possibility and effects of living in space, the next (natural but morbid) step would be to contemplate our deaths in space.

We all know that special equipment is needed to sustain life on space. Hence, a common and most obvious cause of death would be exposure to the vacuum of space due to spacesuit failure or equipment malfunction.

Does it sound innocuous? Not according to Brit Lab’s Mark Miodownik, who says it is more likely you will die a lingering and painful death. Exposure to vacuum means an exposure to a sudden and dire drop in pressure. This would cause your blood to boil, because its vapor pressure goes down drastically.

The large amount of latent heat needed to boil the blood would be taken from your body, resulting in you freezing to death. If that is not terrifying enough, there’s more. It is not just your blood that will boil, but all the fluids in your body. This could include the vitreous humour in your eyes and the stomach acids in your belly.

But then again, why worry about that as you will have more pressing concerns; namely, the lack of air to breathe in, causing you to asphyxiate in a matter of mere seconds. Perhaps you think you would be able to hold your breath? Sorry, but that doesn’t exactly work – the gases in your lungs would expand rapidly, causing your lungs to explode.

Mankind has always held a fascination for the many wondrous celestial bodies out there. Certainly, the promising rate of technological advancement has instilled hope that humankind could one day conquer the vast reaches of space. But in the meantime, are we really prepared for the possibility of living and dying in space? MIMS