Doctors believe that flying in space over large distances with the current level of technology is dangerous for health
American scientists at the deepest level examined the health status of the astronauts who flew to the moon in the mission Apollo, was analyzed the health status of the 24 astronauts that went into space. Scientists came to the conclusion that the chance of developing heart disease in them is several times higher than ordinary people living on Earth. Moreover, were conducted in the same comparison level body condition, with those who were in orbit, but did not fly far into space, it turned out that the space still has a detrimental effect on the condition of the body and the farther and longer you are from Earth, the more harm to all life cycles.
On the heart muscle is greatly influenced by gravity, or rather lack of it in space. Even if for a short time the astronaut leaves the bosom of the Earth, he`s already at great risk to any heart disease. There is no gravity, everything in the body works differently, the exchange of calcium is slows down muscle wasting and bone tissue. Also brains don`t work quite right, because there is the usual work of the vestibular apparatus, the head starts to be confused where the floor and the ceiling.
It turns out that inner ear, the brain tracks the movement, but in fact, the eye movement do not see! The brain receives different signals, he just doesn`t know what to do! Stress!
The rush to the head of liquid is also not a pleasant feeling, it in turn becomes the cause of headaches and not entirely comfortable state. The optic nerve expands, which in turn leads to some partial hallucinations.
Also changing the structure of the eyeball in the absence of gravity, the eyeball weakens and becomes flatter, leading to hyperopia. Blinded by astronauts have not yet been observed, but partial loss of vision in astronauts periods of case. One thing is clear that without a heart, strong motor the human body the problem will come much earlier than the astronaut will go blind or he will get dizzy. In the absence of gravity, the heart works less, it reduces the load, less to pump blood, which affects metabolic processes. If our astronauts get to Mars, they will need much a lot of training to be in shape and be healthy with it every day and not once.
Astronauts who work on the ISS is not heavily exposed to radiation, they are partially protected by the magnetosphere of the planet, but in space this radiation is fatal to all living things, it destroys the DNA chain. If the astronauts will fly to Mars, he will get a dose for the first 9 months equal to the floor of the life cycle on earth. Here he is deep space.