Astronauts, Cosmonauts And The Danger Of Cancer

Gemini Astronauts
Photo Source: NASA

Yes space is dangerous. It is not only dangerous because of what can go wrong, like being hit by an asteroid or even space dust or engine failure, but by just the fact that you are out in it. All that radiation in space is such a hazard to the human body, that it turns out that the danger has been underrated. First of all I think that it is important to know exactly what types of radiation that we are talking about. Cosmic rays come mostly from flares that are released from our own sun. We are protected from them because of Earth's atmosphere, but people out in space, even those in spaceships are not, unless there is some sort of shielding. A cosmic ray travels at incredible speed and is actually an ion, which is the heavy central portion of an atom that was stripped of its outer layer of orbiting electrons. One of the most common types are the ones with the iron nucleus. If this hits us it can cause all sorts of problems and even kill us if we are exposed to enough of these rays. It is like being shot by a microscopic bullet.

It is said that there are three sources of radiation in space that we know about and they are:
1, Cosmic rays from the sun and stars.
2. The Solar Wind from the sun.
3, Radiation and particles trapped in the Van Allen Belts.
It turns out that cosmic rays that are Galactic, not from the sun, sometimes have an antimatter component. Can you imagine the damage that would occur to the human body if it is hit with these things? We also have to remember that our sun produces bursts of X-rays. If we were to go outside the solar system we would encounter gamma rays. Just a few minute burst releases more energy than the sun has produced in its entire lifetime.

Repairs In Space
Photo Source: NASA

It turns out that if an astronaut has spent too much time in space he or she is risking premature aging and cancer. It also turns out that a recent study by the respected Georgetown University Medical Center in Washington, DC has discovered that exposure to radiation in space may be far more damaging to humans than was previously thought. Aside from the recent discovery that there are certain brain cells that are easily killed that change one's personality, tests have shown that mice that were exposed to some of the particles that we commonly find in space developed stress response and their cells generated a large number of the destructive free radicals that damage DNA and lead to cancer. Are we asking all our astronauts to risk getting cancer by sending them up in the shuttle and putting them on the space station?

One of the reasons that we haven't sent astronauts to the planet Mars is that the trip takes too long and the exposure to the astronauts would probably eventually hasten their death, or at the very least age them and give them cancer down the road. It was thought that maybe a lead shield could be used on the space ship, but lead is too heavy and only one room could be shielded, so it was considered impractical. Astronauts getting cancer has been on the minds of scientists at NASA for quite awhile now. In 2003 millions were given to Colorado State University of Fort Collins, Colorado. When asked about this a NASA representative stated, "What we're trying to do is to make sure that our astronauts don't incur unacceptable risks from exposure to radiation". One of the cancers that astronauts may be at risk from is Colon cancer stated the American Association for Cancer Research. They stated, "Radiation exposure, either intentional or accidental, is inevitable during our lifetimes,"

Apollo 16
Photo Source: NASA

It has been discovered that astronauts who are in space and cancer patients receiving radiation therapy on Earth suffer the same bone loss. This means that both groups are more likely to develop fractures when compared to the general public. So how do astronauts come to suffer the same bone loss as cancer patients being treated with radiation? We keep hearing that it is the lack of gravity causing this, but they are all exposed to radiation that could easily cause the same problem. A doctor stated, "Recent exams of astronauts who were on the International Space Station showed signs of bone loss in the neck and vertebrae. Even five years after returning to Earth, they have not completely recovered from this loss,"

It is very hard to figure out what percentage of astronauts and cosmonauts that went into space have gotten cancer from being out there. There are several reasons for this:
1, Different duration flights.
2. Not knowing the average amount of them that would have gotten cancer without going into space.
3. Multiple flights were made by some.

When Russian cosmonauts that had gone on long duration space missions were examined, here is what their doctors found, “A statistically significant increase in the yield of chromosomal aberrations was measured following long-term space missions in lymphocytes from cosmonauts at their first flight. No significant changes in aberration frequencies were observed for short-term taxi flights.”

Now the good news, scientists now believe that they can build an electrical shield around a vehicle, or structures that will block incoming cosmic rays along with other types of radiation. If a large chunk of rock is heading for you however, don't think for one second that this will protect you.