Space travel can put a huge amount of pressure on the human body. There have been a lot of studies carried out by NASA and other agencies to find out just what effects this pressure can have in the long term. Most experts agree that in the long term, these effects will be predominantly negative. This article will look at what the effects of space travel are on the body and what is being done to try and reduce the problems that they may cause. The problems that space travel causes for the human body can be split into two groups – the issues that are involved with the environment in space and the effect that weightlessness has on the human body.
What Are The Problems With Traveling In Space Environments?
Humans are not able to exist in space because the conditions there are fatal to human life. Many of the factors that are harmful to human health can be protected against through the use of protective equipment such as space suits. However, this does not mean that the conditions in space are not dangerous and that the human body will be unaffected, even when all precautions are taken.
Vaccum – When gas exchange in the lungs of the human body takes place on Earth, harmful gases are removed but enough oxygen remains in the blood stream. This is not the case in space as all the gases are removed, including oxygen. This is because space is a vacuum. If there is not enough oxygen in the human body, then humans will enter a state of hypoxia which causes them to pass out after just a few seconds. As Wikipedia explains, after thirty seconds of hypoxia, there will be permanent physical damage to the body. Longer exposure will be fatal and there have been no recorded cases of anyone being resuscitated after their heart has stopped due to hypoxia. The space suits that astronauts wear are designed so that they receive a constant supply of oxygen. The space ships are also pressurized to recreate the atmosphere on Earth as much as possible.
Radiation – In space there is nothing to protect the human body from the effects of radiation from the sun. Astronauts will be exposed to ten times more radiation in low orbit of the Earth than they would when not in space. This radiation increases even further when they are out of low orbit. The increased amount of radiation that astronauts are exposed to in space are associated with a number of health problems. Radiation can lower the immunity in the body and it is widely recognized that when astronauts return to Earth their immune systems are often not as strong as they were before they went into space. It is also thought that radiation could be responsible for the high occurrence of cataracts in astronauts that is sometimes seen. Exposure to any type of radiation can also lead to an increased risk of developing cancer. If astronauts were exposed to radiation from a solar flare then they would be killed in less than a minute. However, the chances of this happening are extremely low. The worst effects of radiation can be combated in most cases with the use of medication and protective equipment. Concern about the levels of radiation on Mars is one of the reasons why human exploration of the planet has not yet been possible.
What Effect Does Weightlessness Have On The Human Body?
Although the effects of being in a vacuum and being exposed to radiation can be fatal to the human body, the spacesuits that astronauts wear will give them all the protection they need to remain safe. However, there is not a lot that can be done to counteract the issue of weightlessness as there will be a lot of time when astronauts are exposed to this when they are in space. Some of the most common problems are discussed in more detail below.
Space sickness – If you have ever experienced motion sickness, then you will know how bad this condition can make you feel. It may come as no surprise to hear that space sickness is even worse. Nausea and vomiting are not the only symptoms of space sickness, which is also known as space adaption sickness (SAS). Vertigo, headaches and lethargy are other common symptoms. Just less than half of all astronauts who have traveled to space have reported that they have suffered with SAS. The symptoms have usually passed in the first seventy two hours that the astronauts have been in space. The sickness will only be present when the bodies of the astronauts are still adjusting to life in space.
Deterioration of bone and muscle – The deterioration of bone while in space is such a common problem that it has even been given its own name, spaceflight osteopenia. NASA has done a lot of research into this condition with the aim of reducing the long term effects on astronauts when they return to Earth. Bone loss occurs in space because the lack of gravity affects the normal process of renewal that bones go through on a daily basis. Astronauts go through an extensive physical therapy program before they go into space and they also have exercises that they carry out while they are on board the space station. However, this alone is not enough to stop the condition of spaceflight osteopenia which is the reason why NASA has been developing medication to also help with the condition. Once they have returned to Earth, the bones will start to regenerate but this will be at a much slower rate than at the rate at which bone loss occurred.
Muscle wastage is also a serious issue with space travel that astronauts can face. When they are in space, the muscles in the legs and the lower back are hardly used because they are unable to stand up properly due to the lack of gravity. The muscles don’t do any of the work in space that they would back on Earth and this can lead to the muscles wasting. One of the only ways to prevent muscle wastage in space is to exercise as much as possible. It is for this reason that the space station will usually have a specially designed treadmill on board as well as a stationary bike. Astronauts are sometimes required to do as much as two hours of exercise each day in order to try and counteract the effects of muscle wastage. They will also need to find some way of tying themselves down when using the exercise equipment.
Redistribution of fluids – One of the major concerns when space travel was first being developed was the way that blood would flow around the body in orbit compared to on the Earth. According to Science Clarified the effect of weightlessness in space means that the blood flows towards the head rather than towards the bottom half of the body. This is the reason that astronauts may end up with a puffy face when they are in space. They may also experience sinus problems and nasal congestion which can make them feel as if they have a cold. While these things can be annoying for the astronauts, they do not pose any real risks to health. A more serious concern with regards to the redistribution of fluids is that the heart does not have to work so hard to pump blood around the body and this can lead to atrophy. This will cause further problems such as low blood pressure. The ability of the heart to send oxygen to the brain is also impaired and this can lead to fainting and dizzy spells. All of these symptoms are usually temporary while the astronaut is in space and they will return to normal within a few weeks of being back home.
Disruption of senses – As is explained in Psychology Today at least three of the senses can be disrupted while in space. The sense of smell and taste can be dulled in space. The sense of smell is not lost completely but all smells will seem very faint, as if they seem further away than what they actually are. Astronauts have reported that there is always a slight metallic smell in space and that this smell never really leaves them until they return to Earth. The food that is served on board a space station is probably not that appetizing at the best of times, but it can be even more unappealing when you consider the fact that all food will be almost tasteless. However, it is necessary for the astronauts to follow healthy eating plan and so this food needs to be eaten. They may opt for food that is as strong as possible just so they can get some sense of the flavor.
Astronauts may also experience problems with their vision and this is often due to pressure building up behind the eyes. The reasons for this will be touched on in more detail shortly. This pressure may cause the vision to become blurry, although eyesight will usually return to normal once they are back on Earth. Dust and other small particles do not settle in space and this may lead to these particles ending up in the eye which can be very irritating. In rare cases it may even lead to the eye becoming infected.
Intercranial pressure – Intercranial pressure occurs because of the fluid that flows to the head due to the effects of zero gravity. The main effects of this increased pressure seems to be on the eyes and this would explain why many astronauts complain of blurred vision. It seems as if a lot of pressure builds up behind the retina, and in some cases the shape of the eyeball can even change. Methods for limiting the rate at which intercranial pressure increases need to be investigated and put into place before any manned missions to Mars can take place. If the intercranial pressure were to increase too much then there is a real risk that it could lead to brain damage.
Psychological Effects Of Space Travel
When the astronauts return to Earth they may still find that they are suffering with some psychological effects of space travel and this could continue for a prolonged length of time. These problems may be as a result of the physical symptoms that they have faced or simply because they are finding it difficult to adapt back to being home.
Stress – There are a number of problems that astronauts encounter with regards to space travel that can increase their stress levels. One of the biggest causes of stress is not that different to one that most people face back on Earth. Astronauts have a lot of work that they need to do when they are in the space station, and they do not always have a lot of time to get this work done. Michael Barratt, a doctor with NASA who has traveled to space has explained some of the most common stressful situations that he found himself in to Popular Science, and most of these were related to problems with the work that he and his colleagues had to carry out.
Another cause of stress is the feeling of isolation from friends and family on Earth. Life still goes on for the astronauts family while they are away and things will inevitably change if they are away for long periods. There have been cases of parents passing away and babies being born while astronauts are in space, and knowing that there is no way to get back home can be very upsetting and this can lead to future problems with mental health. Being in an enclosed space with just one or two other people may also lead to situations where arguments break out and stress can also be associated with conflict in the work place.
Sleep problems – Sleeping in space is incredibly difficult. As detailed by Space, astronauts need to have special training to teach them how to sleep on board a space station. Getting enough sleep is essential because it helps the astronauts maintain their body clock, but this is something that they are probably going to be struggling with anyway. Getting the right amount of sleep is also important in keeping astronauts alert and to minimize the chances of mistakes and accidents occurring.
One of the main issues that affects an astronauts sleep is that they are unable to lie down because of the zero gravity conditions. They are also affected by weightlessness when they are asleep which means they have to tie themselves down in order to prevent them floating around while they sleep. A space station is also a noisy place and because astronauts have to sleep in shifts, there is always something going on when someone is trying to get to sleep. There will be noise from equipment as well as the noise of the other astronauts going about their essential business. There is also not a lot of room for complete privacy and this can make it difficult for some people to get to sleep when there is a lot going on around them.
How Will Growing Awareness Of These Problems Help Astronauts In The Future?
As technology continues to develop, then it is very likely that space exploration will increase as we seek to find out more about the universe that we are such a tiny part of. Every time a space mission is completed, it gives NASA and other space agencies the chance to learn something about the physical and psychological effects on astronauts and this can be used to make progress in the future. This progress could include making advancements in technology that will mitigate some of the physical effects of space travel on the human body. The counseling and emotional support that is offered to astronauts can also be developed to help them better cope with the psychological effects that they have to deal with.
Many people believe that one day people will be able to travel to space for holidays, and maybe even to live. While this can not be ruled out completely, there is a lot more work that needs to be done to ensure that people can remain safe. It may be the case that conditions that allow humans to live as normally as possible can be created and maintained within a space ship, but people living on the moon is still a long way off. A previous article by How Stuff Works estimated that people could be living in space by 2058. While there is still a lot of time to go before this date, the crucial thing is still to make sure that any negative effects on health could be dealt with so that people are able to remain healthy.
Many of the health issues that astronauts face could be dealt with by being able to create artificial gravity while in space. This would mean that the bodies of the astronauts would not have to face any conditions that they would not have to here on Earth. It removes a lot of pressure that weightlessness puts on the body and mind and could make further space exploration even more likely.