Posted on 08/01/2005 1:19:26 PM PDT by LibWhacker
The radiation encountered on a journey to Mars and back could well kill space travellers, experts have warned. Astronauts would be bombarded by so much cosmic radiation that one in 10 of them could die from cancer.
The crew of any mission to Mars would also suffer increased risks of eye cataracts, loss of fertility and genetic defects in their children, according to a study by the US Federal Aviation Administration (FAA).
Cosmic rays, which come from outer space and solar flares, are now regarded as a potential limiting factor for space travel. "I do not see how the problem of this hostile radiation environment can be easily overcome in the future," says Keran O'Brien, a space physicist from Northern Arizona University, US.
"A massive spacecraft built on the moon might possibly be constructed so that the shielding would reduce the radiation hazard," he told New Scientist. But even so he reckons that humans will be unable to travel more than 75 million kilometres (47 million miles) on a space mission – about half the distance from the Earth to the Sun. This allowance might get them to Mars or Venus, but not to Jupiter or Saturn.
Risky business
Helped by O'Brien, the FAA's Civil Aerospace Medical Institute in Oklahoma City investigated the radiation doses likely to be received by people on a 2.7-year return trip to Mars, including a stay of more than a year on the planet. The study estimated that individual doses would end up being very high, at 2.26 sieverts.
This is enough to give 10% of men and 17% of women aged between 25 and
34 lethal cancers later in their lives, it concludes. The risks are much higher than the 3% maximum recommended for astronauts throughout their careers by the US National Council on Radiation Protection and Measurements.
The risks are smaller for older people because cancers have less time to develop. But women are always in more danger than men because they live longer and are more susceptible to breast and ovarian cancers.
The study warns that cosmic rays would also increase the risk of cataracts clouding the eyes. Furthermore, men exposed to a solar flare might suffer a temporary reduction in fertility, and the chances that any children conceived by travellers to Mars will have genetic defects are put at around 1%.
Serious brain damage
The study's lead author, the FAA's Wallace Friedberg, highlights other work suggesting that heavy nuclei in cosmic radiation cause "serious brain damage" in mice, leading to memory loss. "Heavy nuclei exposure must be a serious consideration for space missions such as a trip to Mars," he says.
Improving spaceships' shielding by using water, hydrogen or plastics can protect astronauts to some extent. But this is limited by the constrictions of craft weight and design, Friedberg points out.
"Increased speed would also reduce radiation exposure" by reducing journey times, he notes. "And drugs or food supplements that can reverse radiation damage are being considered."
Others suggest more radical solutions might be needed. "Radiation exposure is certainly one of the major problems facing future interplanetary space travellers," says Murdoch Baxter, founding editor of the Journal of Environmental Radioactivity. "Unless we can develop instantaneous time and space transfer technologies like Dr Who’s TARDIS."
***Seems to me a Lead coating***
Yes, but what about...
(drum roll...)
LEAD POISIONING!
Asbestos is a far better option!
Now we know why the leftists demoncraps are so bain dramaged.
Right.
If we could get a real base on the moon that could manufacture some sort of launch capability, it would be easier.
However, once we get out of a gravity well, there is less reason to drop into another, even if only 1/3 as deep.
I think the asteroids are the answer for our materials/mining needs once you get off the planet. That is a ways off however.
The amount of material added naturally to earth from outer space every day completely dwarfs the few tons that have been sent beyond earth orbit.
I thought cosmic rays were protons. Seems you could deflect them with an electric or magnetic field.
What the heck are humans going to do on Jupiter or Saturn that robots can't do?
We could already be mining asteroids. If we were serious about space development, we would have been mining space materials as early as ten years ago.
Not a problem. For a very reasonable price I can show NASA how to turn gold into lead.
Launch the gold, turn it into lead in orbit, problem solved.
Everybody knows that lead only protects against Krytonite rays.
Again I agree with you.
The problem is we are not serious (as we are not about most things it seems) about commercial space activities.
Maybe the times are changing, but for my entire lifetime everyone has thought we would be colonizing Mars any time now. Like fusion power, it's always 20-30 years away.
We could, in principle, launch a ship the size of the USS Ronald Reagan, with a crew of thousands aboard, fully armored with heavy steel or lead plate, three foot thick, if needed. These ships could cruise to Mars in a matter of weeks, and to anywhere else in the solar system in a few months. Only liberal, scared-of-their-own-shadows girlie-men are preventing us from doing it. Think about that: girlie-men are preventing us! We must be scared of them. . . . Sorry, I'm p***ed that we'd let those losers block such a magnificient future for mankind.
WHAT? And subject astronauts and unknown space microbes to the dangers of lead? What in the EPA is wrong with you? Sheesh! Just looking at lead will kill you, don't you know ;>)
What the heck are humans going to do on Earth that robots can't do? EVERYTHING.
I would think a good thick cement-like slabs from the moon and/or asteroids would do the trick.
Or frozen water/waste tanks surrounding the outside, with the people in the chewy inside. (For some reason, I vaguely recall water ice having better cosmic ray reflection than liquid water -- something to do with the crystal structure overlapping better so that rays would not so easily bounce through. Never quite sure I believed it.)
To all my conservative friends who give a rat's rump about space travel, I send my heartfelt well-wishes for their endeavors, and trust they will fund their hobby with their own money, just as I fund mine with mine.
We were children then. Gullible. We are older now, and wiser. Like the old saying, 'Too soon alt, too late schmart.'
'Way more, I'd speculate.
Though I'm neither a doctor, nor do I play one on TV.
"You know, I wonder whether running a magnetic field around the ship would serve to sheild the crew the way the earth's magnetic field sheilds us--and how much power would be needed to create an effective sheild."
This is a very interesting idea considering the power of superconductors in space and the use of those same dangerous rays as an energy source for an electromagnetic field. Some copper cable, some solar sails on copper rails and get the vessel corkscrewing opposite of the sails..... HMMMM. Very interesting.
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