NASA: Trip to Mars would exceed 'fatal cancer' radiation risk NASA has released the results of radiation measurements taken during the Mars rover Curiosity's trip to the Red Planet, and the data show doses received during a such a trip would exceed the space agency's current career limit for astronauts. "Using the words like 'showstopper' or not, it's difficult to say that," NASA …
Lots of exciting developments in the world of biology and medicine (cybernetics, stem cell research, retrovirus research etc), a good deal of this stuff in development today is likely to be in use by the 2030s (and more importantly, there have been a host of recent advancements in the prevention and treatment of cancer) so the problem may well be moot, or at least less of an issue by then. Of course, potential but not guaranteed technologies should be a basis for NASAa policies on astronaut safety but it's food for thought.
Ironically there will probably be lots of new science discovered about the effect of cosmic rays on such a trip so perhaps cancer treatments and cures will come out of such a trip, but you can't be a pioneer without taking risks. It's what makes us human. Actually I'm thrilled that NASA are even gearing up to go, I've been waiting for this since I read about the moon landings, aged 4!
You are absolutely right, by the by the mid-2030s treatment for cancer will have improved dramatically so the risk of getting what probably won't be a fatal condition is therefore a much more acceptable risk. Even better: the cancers most likely won't happen until two or three decades after making the trip, I'm confident that by 2060 we'll pretty much have cancer beat. Therefore, cosmic rays are no longer of concern.
Have no idea why anyone would object to your comments but have an upvote on me.
The problem will be that even if you have a cure for cancers you'd have to be able to treat them on any vessel where you'd think it'd be likely - that'd mean detection and treatment equipment would need to be factored into the cost of the trip and it may not actually be reasonable to have that equipment available.
There are lots of medical problems - humans are just not built for space. Hell if we're going to speculate then why not start genetically engineering people to cope better in space?
>I'm confident that by 2060 we'll pretty much have cancer beat.
Ya, think of how many 5k run/walks we can do by then.
Maybe this little rock we live on has more going for us than we comprehend.
You do realize that by far the biggest reduction in cancer would come from prevention, or so my clinical biochem prof told me.
Another up-vote from me, no idea why anyone would down-vote you for having the hope cancer will be beat..
There are many illnesses that are terrible, but cancer is one we have a very god chance of beating it soon...
The way I see it there are two types of research we need, and to do it in this order
1) Cure, A way to kill cancerous cells without damaging healthy cells, the great thing is there are plenty of ways to do this, this is a two fold problem, a) how to identify cancerous cells, b) how to deliver a death blow to those cells only.
2) Prevention, finding the causes and fixing the problem, which in the case of radiation induced is simply DNA damage, and as we are re-writing DNA with retroviruses already, this is something that is quite promising for the future, and would hopefully be usable to fix so many problems other than cancer.
Somehow it doesn't strike me as likely that you work in the field of cancer research.
Agreed. The "cancer won't be a problem in a few years" crew above are living in a dream world.
Cancer isn't "a disease". It's a large class of pathological syndromes characterized by undesirable cell duplication and/or the failure of cells to die. There are numerous mechanisms involved in various cancers and a tremendous range of symptoms and progressions. The term "cancer" is basically a catch-all for "your cell replacement processes - cytogenesis and apoptosis - aren't working right". "Curing" cancer would mean finding a way to fix anything that goes wrong in those hugely complicated areas.
Mid-century cancer researchers were sure they'd have a cure for cancer in a decade or two, too. That's what drove the "war on cancer" that emerged following the discovery of chemotherapy. But cytotoxic drugs didn't prove to be a panacea (far from it - that's why we use terms like "remission" and "cancer-free" rather than "cured"), any more than excision did. And neither have anti-angiogenic treatments (which seek to prevent tumors from growing blood vessels), or genetic therapy, or any of the other breakthroughs. Many of these treatments have proven useful for a great number of people, and I'm very glad they were developed, but in truth we're no closer to a "cure" for cancer than we were in the 1960s. What we have is a great deal more knowledge about cancer and a much wider array of treatments to ameliorate it, often to the point where we can get it sufficiently under control that the body can get cell growth back into normal equilibrium.
But many of the things researchers have discovered just show how pervasive and difficult cancers are in general. For example, we now know that many cancers - perhaps most - are small and localized and either successfully suppressed by the body, or so slow-growing that the subject dies of something else before the cancer is detected. It may be the case that everyone is to some extent cancerous much of the time, just usually not pathologically.
"1) Cure, A way to kill cancerous cells without damaging healthy cells, the great thing is there are plenty of ways to do this, this is a two fold problem, a) how to identify cancerous cells, b) how to deliver a death blow to those cells only."
Cancer cells grow faster than normal cells, and chemotherapy targets fast growing cells. Hence the hair loss associated with it.
By now I'd expect you would have learned that Hope is not a plan, but I guess there's no hope for low information voters.
You can hope for the cure all you want, but until there is at least promising research pointing at an imminent cure, you don't plan on it. And in this case I'm not talking about 'promising' the way they do when Jerry's on TV raising money for his Kids (laudable as both actions are), I mean 'promising' in the way an investor means it when he sinks 10% of his cash into a pharmaceutical company.
Full disclosure: I didn't mark him either way.
Re: down-votes and hope AC 9:41
Wish in one hand, shit in the other and see which one fills up first. There is no such thing as a 'cancer cell', only cells that have become cancerous. This is a very important distinction. Even the same cell at different times will have different characteristics due to its local environment as cells have para-endocrine function. You are entirely correct about the two things, however, your assessment of a good chance (sp?) is far from reality and simply rewriting DNA is not enough. Look up DNA methylation.
By adding or removing methyl groups, you greatly change the regulation of transcription as promoter regions and the gene itself can be occluded leading to up or down-regulation, different mRNAs being transcribed. This is to say nothing about pre or post-translation modifications that can occur. I'm not even going to expound on the fact that mutations and errors accumulate over ones life so how do we know what to rewrite. When we get a DNA sequence, it is the average representation of the individual bases if more than one cell is used in the replicated culture which is sequenced.
Likewise, Waspy and Martin show an ignorance of the true state of cancer research, prevention, and treatment. Even with the many developments, we have done little to budge the overall death rate from cancer as roughly 3 in 10 people in western nations die from complications arising from it. We have improved survival times and are able to detect it earlier, but that is neither here nor there for the purposes of this discussion.
It seems the more we learn about cellular biology, the things that we don't know get bigger an order of magnitude faster. To wit: when I was in uni over a decade ago, I argued with my profs (world renown nuclear cell bio experts) that the 'non-coding' regions were important. They countered that 'junk DNA' had no affect - the widely held orthodoxy at the time. Now we know better, but every time we make a new discovery, we think we know it all and will save us from ourselves, all the meanwhile 75-80% of cancer and cardiovascular disease (which kills around 60% of people in western countries) is due to environmental factors we could reduce: excess processed carbs and sugars, excess processed fats and oils, excess processed meat (no red meat won't kill you), excess alcohol, lack of green vegetable intake, lack of exercise, smoking, lack of quality sleep, and pollution.
Its funny how the overall rate of premature death at the hands of man hasn't changed much since prehistory, only instead of dying at the hands of our fellow man, it is now by our own. Ah progress.
Excellent points by oolor here.
The genetics example is telling: we now know a hell of a lot more about epigenetic factors like expression (oolor mentions methylation) and competition (the "junk DNA" myth), but mostly what we know is that this is a huge area, at least as big as genetics itself, which we've only started to learn about. And this is an area that is crucial for many aspects of understanding cancers. The same could be said about, say, endocrinology; we're only starting to see how "master hormones" like insulin and some of the estrogens (and until recently we didn't even understand that estrogen wasn't a single thing) coordinate other hormones,and this too seems to have huge effects on cancer pathology.
One point I don't agree on, though, is the statement that "75-80% of cancer ... is due to environmental factors". We know there are strong correlations between many environmental factors and many cancers, and it's reasonable to hypothesize that the factors are triggers for the cancers. But we don't know if they're simply triggering a predisposition that, in the absence of those factors, wouldn't likely be triggered anyway by other signals. Reducing carcinogenic environmental contaminants might just be another way to delay cancer onset for a few years. Which doesn't mean it's not worthwhile, of course; but for the foreseeable future, it looks like cancer will continue to remain the thing that will get you if something else doesn't get you first. Obviously that's a tautology, but I hope you see what I mean - eliminating some carcinogens may just slow the onslaught, and not make much difference to overall cancer rates.
>One point I don't agree on, though, is the statement that "75-80% of cancer ... is due to environmental factors".
You are correct, I wrote that poorly, rather I should have put that only 20-25% is caused by genetic and environmental (radiation, chemical exposure, etc.) factors that we know of. Also, it is an assessment quoted by an endocrinology prof of mine and more clearly the point is that we greatly influence the onset and severity of the majority of chronic disease that afflicts us by our own actions. But it is pretty obvious that the more than 50% of caloric intake (refined fats, sugars, and white flour is 55-60% of North American intake) from micro-nutrient poor food that we intake which didn't exist 200 years ago (not saying there was great nutrition prior, but better than now) is a major factor, easily as much as the rest of the environment and genetics.
0800 hours. No time to lose. He started rounding up the shipping papers. Everything was set for lift-off: hatches closed, health and port inspection out of the way, flight clearance, customs declarations…
There was a knock at the door.
“Come in!” he hollered, hurriedly gathering up the papers scattered on the desktop and stuffing them back into their folders. Two men entered but ventured no farther than the doorway.
“Boman, nuclear engineer.”
“Sims, engineer-electrician.”
Pirx got up from his desk. Sims was a young, lean man with squirrelish features, a nervous cough, and flickering eyes. One glance at Boman was enough for Pirx to know that he was dealing with a space veteran. His sunburned face had that peculiar orangish tint that comes from prolonged exposure to cosmic radiation. He barely came up to Pirx’s shoulder (ever since he had begun flying, Pirx had been accustomed to counting every kilo aboard ship). His face, in contrast to his scrawny build, was puffy, bloated, and there were dark bags under his eyes — the mark of a man who’s been tested many times over the years. He had a drooping lower lip.
“You’ll be looking like that yourself, one day”—it crossed Pirx’s mind as he went to greet them with outstretched hand.
You've got the trip to Mars, during which it sounds like you will surpass the career limit on radiation.
Then you land and have more exposure on Mars, which has a negligible magnetic field. Your added risk there depends on how much time you spend on the Red Planet, but I would think that one month would be the minimum surface time considering the time and expense of the transit to Mars.
Then you have the radiation on the trip home.
So my thinking is:
1) got to get a cheap way to get cargo into orbit, so you can build a more robustly shielded spacecraft
2) Advances in cancer therapy over the next couple decades will help
3) Send astronauts who are past their child-bearing ages (Don't want to pass along radiation-induced genetic damage to the young ones)
4) If all else fails--send the mission in a craft lined with bags of popcorn with real butter. It's light, hydrogen-rich and it's a long way to Mars and back! Have to make room onboard for a big-screen TV, a sofa and a chest of Blu-Rays as well......
"3) Send astronauts who are past their child-bearing ages..."
...and 3a) Send astronauts who are aware of the risks and think the reward is worthwhile.
There are many professions which are more dangerous than a 3% increased risk of cancer. I know a deep-water welder who can't get life insurance at any cost. He talks about a dive he was on where four people went down and two came back alive, as if it's not that exceptional a thing. Some American football players (specifically, defensive linemen) have a much higher risk of death from heart disease than men in the general population.
The right to risk--that is, the right to consent to activities which are dangerous, provided that what we know about those dangers is clearly communicated--seems like a reasonable thing to me. People voluntarily engage in risky activities all the time. Hell, strapping yourself in to a hollow tube filled with millions of gallons of volatile propellants seems inherently risky to me!
I bet if you were to say "There's a mission to Mars that has a 50% chance of killing you; want to go?" you'd still find qualified volunteers. I think it's reasonable to reduce the risk as much as we feasibly can, then still allow people the choice to go if they want to.
1) A lot of potential voyage of discovery sailors did do the fatality maths, which is why Columbus had to sweep the local prisons and rely on royal conscripts to fill out his crews.
2) Columbus' voyage had a SHORTER transit time than the legs to and from Mars.
3) Despite this shorter journey, Columbus' crew nearly did mutiny over fears of never seeing home again, and Columbus himself was a couple days from turning for home when he made landfall.
4) One of Columbus' captains sailed off on his own for most of the period after Columbus had made landfall. We don't exactly want people going their own way during your multi-hundreds of billions of Dollars space odyssey.
5) Columbus lost his biggest ship to a shipwreck, and consequently had to leave nearly 40 men behind in the Indies. These men all died by the time Columbus returned on his second voyage.
6) Columbus' crew was motivated by easy access to the fabled riches of the Indies and a chance to better their position if they did survive. A trip to Mars is not going to offer these powerful motivators.
1) I don't think prisons will be needed. Even if people knew it would be eventually fatal, you would still have plenty of volunteers.
2) It may have been shorter but they had no idea of where they were going. We can see Mars.
3) The ship would be flying a preprogrammed route. You can't turn around.
4) Only one ship
5) For the chance to stand on Mars, people would still go even for a one way trip.
6) They were motivated by greed. Mars would be motivated by fame. Nobody has forgotten Neil Armstrong
My point exactly on the number of ships. You are counting on one ship to get you there and back, if something happens, you are marooned on Mars or in space.
As for not being able to turn around, my point is that even Columbus was close to WANTING to turn around. Will people remain enthused about the mission over the whole transit?
Columbus and his crew were motivated by a desire for fame as well. I'm just saying that its nice to have additional motivations
I KNOW that the tragedies that befell Columbus were legendary - I used to live on Columbus Circle in NYC. You do some reading when a giant statue of the man abuts your building.
In fact, something like 1 in every 3 seamen or more died on his voyage, if not more.
But the point is...people KEPT SAILING WEST.......because that is the nature of mankind...
Not to mention that Columbus' two major achievements were 1) getting the circumference of the Earth wrong, when the correct value (to a first approximation) was widely known in his time, and 2) letting the European aristocracy know about the existence of the "New World", which prior to that the European merchant class had done a good job of keeping a (profitable) secret. He didn't discover anything; he just screwed up big. Twice.
No Mars mission could be such a colossal cock-up. You couldn't get to Mars by accident from the Earth.
NASA were going to look at the idea of radioprotective additives to food and atmosphere that would counter some of the effects.
Which sounds like the sort of thing you should be doing if you're serious about long term space expansion.
But the Senators wanted the SLS and a good 10-20 years more for the SRB casting shop in Utah.
I know that it is popular here to slam SLS. I am a USA taxpayer and I want all-this done as inexpensively as possible MORE than you. SLS is fundamentally a different platform from RP-1 stuff like F9-Heavy.
F9 Heavy needs to use ALL of its fuel within minutes of liftoff, the kerosene freezes within 100 minutes in space. SLS is based on cryogenic LH2 rockets that never-froze on the Moon trips, even after weeks. It also uses SRBs for the 'warm' launch to make up for LH2 weaknesses. LH2 is great-for-the-weight, but you need a LOT of it to lift big stuff out of Earth's gravity-well.
No matter what you choose, you would augment the lifting platform, so F9 H is far-from-useless. NASA is spending money on J2X, an enhanced second-stage rocket with LH2 propulsion. It is hopefully an improvement on the long-lived Centaur upper-stage devices.
I wish that the Senators were better on these kinds of budgetary decisions, but they do appear to be listening to NASA. NASA is proposing SLS for at least SOME work. Their feet are being held to the fire for cost-effective results, too.
We will see...
Oh, be fair now, Beachrider...
Falcon Heavy DOES use all its fuel on the way up to LEO. Stages one and two are used up (although there's some interesting work being done to get at least stage one back...) and it's only whatever is above stage two that's in the cold of space for any length of time.
It's the same for SLS. Whatever is launched atop SLS, assuming it makes it all the way to its first flight, will be the same. The fact that SLS has liquid hydrogen/oxygen means nothing here. The J-2X, the Earth-Departure Stage, can just as easily be mounted atop a Falcon Heavy.
In the end, the unit cost for SLS (1.6 billion, possibly dropping to 500 million dollars) as opposed to the very low unit cost for Falcon Heavy (125 million as a max figure, and 80 million as a minimum figure) is what will, I believe, kill SLS.
These Mars enthusiasts are so blase about just how well shielded Earth is by the Van Allen belt; it really isn't nice outside!
Water may stop the weak radiation, but forget it for hard radiation; that'll probably require a nice thick layer of Lead or other dense material; even Lead will not stop all hard radiation, as Three Mile Island proved when the containment dome cracked and leaked a hard radiation cloud outside, a Lead covered radiation sensor outside, picked up seriously strong radiation!
So some kind of nuclear engine will be required for propulsion (forget sissy rockets, or Solar-powered Ion engines), not nearly enough power to push a craft with two heavy, well shielded, spinning, counter rotating, living space rings, and a nuclear reactor to power the motors spinning the living space rings. Seriously expensive to push all that heavy material up the gravity well too, and quite an engineering feat for a survivable space craft too, which will probably have to be assembled in space, due to it's shear size and bulk; it'll make the current space station look tiny!
Erm, Three Mile Island didn't leak massive amounts of hard radiation outside. It also doesn't have a cracked containment unit. It's still there, now defueled and only a bit of radioiodine was detected briefly after venting the reactor to prevent an explosion. I've been by TMI a few times before and after the accident and live in Pennsylvania.
As for lead, they don't use lead in nuclear submarines. They use polyethylene.
Use polyethylene, food, water and add in magnetic shielding that is powered by a nuclear plant that also provides thrust for the ship. Make the ship large, such as a wheel station design that is a spaceship. Boost components to orbit (or better, from the moon and assemble them in orbit and plenty of heavy supply ships sent to Mars long before the manned trip.
No no no it will happen like this :
a big ship assembled on Earth orbit, and an *instant* travel to the Red planet; using quantum motor the Nasa is working on. No worries about radiations as it moves in old fashioned 3D space. The weird part is that the travel would be virtually non existent for the ship and its crew while still be perceived as a few month long from Earth's perspective.
Could happen in no more than a 100 year.
Now where's the tin foil icon when you need it? Ho well "Windows User" will do just fine.
There are a lot of interesting ideas for travel-to-Mars. Somehow, we have to broadly-tie costs to these ideas when we compare them to one another.
The attraction to Mars-One is that they put the first people on Mars for $6Bn. This is an amazingly lower number than NASA is planning ($30-100Bn). I don't care if you believe in Mars-One or not, you have to see IF their numbers are comparable and serious examine how-to-use the cost savings.
Minimal Mars-orbital support and not-bringing people home within 10 years are serious cost savings, if they are practical assumptions.
It's like NASA is trying to set the expectation they can't "invent" new technologies anymore so they can drop human exploration of space in the not so distant future. NASA seems less than willing these days. Maybe NASA can go plant trees or something. China will go to mars and beyond while NASA sits in the corner eating glue.
NASA really does want all automated exploration. Lower risk.
How many people cried over the probe that had the metric-imperial error and drilled itself into Mars? How many people cried over Apollo 1 and wrung their hands over Apollo 13?
I was an infant for Apollo 1, remember Apollo 13 all too well, I watched it live.
Still, if offered the opportunity to take a trip to Mars, radiation or not, I'd go.
I think the eventual solution will have to be mass-drivers built and stationed on the moon (using mostly moon materials). Craft will accelerated to ~20 miles/sec over 30-40 mile track and sent ballistically, with mid-course corrections by nuclear propellants, to the planets. This will reduce time and allow for more robust shielding. G-forces for humans would be mitigated by almost complete immersion in neutral buoyancy tanks.
Energy for launch would be nuclear or solar.
Yes, I thought the thumbs-down were disappointing. I have no idea if mass-drivers on the moon makes any sort of sense (relative to the alternatives, and assuming we want to send people to Mars), but just thumbing down a post that's just technical speculation is quite a display of intellectual laziness.
Had you posted something like "NUCLEAR THERMAL PROPULSION FAIL", I could understand some downvotes.
I wish there was a website where you can type in how much radiation protection you wanted, specify the material needed to do the protecting and it would tell you how much material would be needed.
For my money, I'd like to know how much water it would take to provide 75% protection, cutting the radiation dose to one-quarter. Having a Bigelow-type inflatable habitat wrapped around your vehicle and filled with water might be workable as long as the mass wasn't too much...
Three other ways to keep under 3% extra cancer risk:
1) Give the rest of us more cancer, until space is safer than staying at home. Pretty well on track for 2030 I reckon.
2) Send old people. You can't grow that much new cancer in a year or two. Should be able to part fund Nasa from the pension budget
3) Send people with cancer. You don't need to bring em home, and who knows the radiation might even cure them
When I was 5 or 6 I'd just watched a film/TV show, where someone falls out of a window and dies. I'd just learned about people with terminal diseases. But obviously not yet learned about stuntmen... So my theory was that they must pay loads of money to people who are dying anyway (for the relatives of course) and then push them out of windows and film it. Or shoot them, or whatever.
Obviously I didn't know much about life at that age, but I guess I was already an expert on Hollywood morality...
Given how expensive stunts and CGI are, I'm sure there's got to be a future for this idea. But I think I prefer option 1. NASA could get to Mars much more easily with a big spaceship. Did I say big? I meant huge. Project Orion would have triple benefits:
1. We get to use up all those old nuclear bombs that no-one really wants around the place.
2. Huge spaceships. And cheap, because the nukes already exist, and the engineering doesn't need to be all fiddly and small/light.
3. Increases global radiation levels, thus making space safer. Relatively, anyway...
What's not to like?
I have ordered nearly all the materials and parts needed to make a prototype superconducting energy shield that will in theory block HECR's and possibly low energy ones as well.
The principle of operation is very similar to a mu-metal shield for EM but using some tricks of my own that have not yet been published, preliminary experiments others have published in "New Scientist" in 1992 suggest it could work but at the time they were using NbTi because MgB2 hadn't been discovered.
NASA is aware of the effect or so I heard, and waiting patiently for some university to invent stable room temperature superconductors so they can see if the effect scales with Tc.
AC x520
These 'calculations' presumably rely on some fairly poorly tested models of what 6 months of exposure to a moderate level of radioactivity does to the human body. It's not clear to me that we have any reliable data in this area (airline pilots maybe being a good population to sample). With a 25% background level and many other environmental factors, +3% is bordering on difficult to measure without a large number of test subjects. I understand the experiment has only been done ONCE even on mice - about 50 years ago...
Of course LNT is well on the way to being thoroughly debunked as a PREDICTOR of cancer rates. It is a REGULATORY limit, and its predictions have failed to live up to expectation in every single case where people are exposed to long term chronic low level radiation.
But then that's not surprising: It was developed by drawing a straight line from where data did exist - people dying after massive exposure to high level radiation in the A-bomb attacks on Japan, and a few 'lab accidents' - to the origin.
Thus giving rise to the myth that 'there is no safe level for radiation - even the government thinks so'.
100msV/year is not unknown in a few places on earth. Ramsar for example. There are no detectable cancer increases there.
What cancers do occur from radiation appear to be intimately connected with the biological activity of the radionuclide responsible, and whether or not particles get lodged inside the body to act as hot spots.
In short its very much a threshold. And indeed some cell research suggest that DNA contains two copies of itself, and unless both match, the cell dies. Like digital transmission, it is 'parity checked' . So mutations are normally killed. Which would lead to the situation that seems to match reality, that the rate of 'successful' mutation requires strong PEAK doses and will exhibit strong non linearity around a threshold value.
Whether or not you believe the results or the logic, Wade Allisons 'radiation and reason' raises some interesting points.
There are a few other papers out there on cell division and mutation under mild chronic radiation that also seem to support the non-linear with threshold type models.
And the most significant long term result from Chernobyl, is not how many people died, but how many did not die.The LNT adherents were predicting hundreds of thousands of deaths. They simply never showed up in the data. The official death toll IIRC by the WHO stands at 78. Mostly those involved firefighting at the plant itself who received massive peak doses.
The simple fact is that as Wade says,
"Although the public accepts moderate to high doses of radiation when used benignly for their own health, non-medical international safety standards are set extremely low to appease popular concerns - these specify levels found in nature or as low as reasonably achievable (ALARA). Yet modern biology and medicine confirm that no harm comes from radiation levels up to 1000 times higher and realistic safety levels could be set as high as relatively safe (AHARS). Indeed the local damage to public health and the social economy caused by ALARA regulations imposed at Chernobyl and Fukushima has been extremely serious and without benefit."
(http://www.templar.co.uk/downloads/Public_Trust_in_Nuclear_Energy.pdf)
I.e. that the level at which a detectable increase in radiation induced cancer occurs is about 100-1000 times higher than the LNT guidelines currently in force.
You may not choose to believe that: but the evidence is slowly rolling in that LNT is almost useless at predicting cancer death rates. Although it is a laudable standard (the regulatory limits) to aim for.
>And indeed some cell research suggest that DNA contains two copies of itself, and unless both match, the cell dies. Like digital transmission, it is 'parity checked' . So mutations are normally killed.
No. Not even close. There is two homologous chromosomes, one from each parent. They match up for genes, but the DNA sequence does not match. The two strands of an individual chromosome can act as repair mechanisms, but even this is not 100%.
Some mutations can cause the daughter cells to die after cell division. Cell death is only one of 3 fates, the others are dormancy and unregulated division.
Your homework:
http://en.wikipedia.org/wiki/DNA_repair
http://en.wikipedia.org/wiki/Homologous_chromosome
http://en.wikipedia.org/wiki/Chromatid
While what you wrote about LNT is correct, we don't have enough data to make good conclusions about the so-called lack of after-effects of Chernobyl. Some of the isotopes released are long lived and this greatly confounds measuring effects. It is no just the death rate that is important, but other issues such as increased birth defects, non-fatal cancer, etc. Fuck it, only a few score of people died that we can attribute is a very shortsighted viewpoint.
Well, I know lots of people - knew lots of people - who have died of cancer or are dying of cancer, who never went into orbit, so your post isn't worth the bandwidth it occupied.
I think about 20% of people die of cancer one way or another. Eventually. The local GP is fond of saying '80% of male cadavers over the age of 80 show prostate cancer of some stage or another'
The longer you live the more chance that one of a thousand factors will randomly cause some cell to divide and mutate...into a cancer.
I think that the magnetic field protects us mainly from protons etc. from the sun. The glactic stuff seems to have a fair amount of neutrals that go straight through the mag field (they are also going very fast). The atmosphere really stops most of it (and as a consequence helps make the ozone layer).
Where the magnetic field of the Earth don't tend to help (e.g the poles), the stuff that gets through tends to get stopped by the atmosphere and make pretty patterns for a lucky few to watch.
- Being blown to pieces during launch.
- Being blown to pieces during TMI.
- Suffocating slowly en route due to life support system failure.
- Suffocating quickly due to blown out window/hatch/hull breach.
- Being fried by an on-board fire.
- Starving due to failed food storage system/logistics forgetting to load enough food.
- Dehydrating to death for reason explained above.
- Missing the target entirely and becoming an asteroid due to failure of the deceleration engine.
- Being blown to pieces during deceleration burn.
- Being squished and burned during aerobraking for mission support failing to convert kms to miles.
- Crashing into Mars when the parachute/terminal braking rockets fail to open/fire.
- Suffocating quickly on arrival due to broken window/hatch/hull breach.
OK, that's just on the way out....
Now, how about extra 3% lifetime risk of cancer? Oh, that's definitely a showstopper!
Surely the solution is to find a cure for cancer? or at least a way to fix the damage before cancer happens?
I remember hearing an idea floated around of carrying blood/stem cells/bone marrow? in a highly shielded container and then re-introducing that into the astronaut after arrival at the destination...
But at the very least you could fly with your water tanks/fuel facing the sun to shield in that direction.
Surely the solution is to find a cure for cancer?
No, the solution is to find a magical portal that offers instantaneous transportation between Earth and Mars. That's about as likely as "a cure for cancer" - see the first thread in the comments on this article - and a lot more effective at solving the general "trip to Mars" problem.
We've been pouring tremendous resources into cancer research for four decades, and while much has been achieved, there's nothing even vaguely like a "cure" in sight. One thing we have learned is how ridiculous the idea is. It's the height of folly to imagine that a couple more decades will see a complete reversal in that situation.
Ah, now I'm nostalgic for the days when medical science was going to achieve everything - when we were just a few years away from being able to treat all bacterial diseases with antibiotics, and we'd have a cure for the common cold, and Isaac Asimov could predict, with a straight face, that if you made it to the year 2000 you'd have a good chance at living forever. We certainly burned through at lot of that particular vein of hubris in a hurry.
It'll solve the radiation problem, and not blow billions of dollars on the mission.
I'm sure the money could be spent better elsewhere on earth where we will see a real difference, how about funding a cure for cancer here on earth instead of giving it to the astronauts.
What do you reckon NASA will find a cure for cancer, then the astronauts will steal it, and take it with them to Mars?
Come to think of it, where do you think NASA spends its money? I'll let you into a secret. They spend it on Earth. They don't sneak off to Galaxy Motors on Alpha Centauri, with pockets stuffed with gold, on the look-out for cheap second-hand spaceships.
They get some money from Congress and agree to spend it in the right bits of America that they can get enough votes to get their budget passed...
Cylons seem to be very advanced, and more designed to work in environments designed for humans.
Much better to work on flexible self-assembling robots built from a number of basic blocks. Depending on the requirements, they build a different configuration. Maybe they could even build new blocks from materials where they land. We could call them "relicators".
Discounting the radioprotective additives what's left?
Up the permitted exposure limit, which seems possible but note that (AFAIK) Astronaut exposure limits are substantially above civilian workers.
Faster ships.
NASA does have a (low key) nuclear thermal rocket programme that is currently doing engineering archeology on the NERVA programme to recover lost skills and knowledge. A longer shot is the NAIC replaceable liner fusion system using Lithium and the long awaited VASIMR test on the ISS
OTOH NASA also has a programme to divert a small asteroid into Earth or Lunar orbit
I can't help thinking that a 10m layer of solid rock would make quite an effective radiation shield and even with relatively low thrust you could cruise to Mars as slowly as you liked, the radiation would not be a problem.
Perhaps some parts of NASA are playing a longer game than people realize?
Good points. I find it incredible that they had NERVA and ORION plans in the sixties yet they estimate a 20 year+ lead on a workable nuclear propulsion system! The Russians had prototype nuclear-powered jet engines in the sixties. Surely we can move faster than the timescale that NASA are proposing!
Phil.
I thought that the VASIMIR test they wanted to do needed 250kW. IIRC that is about the total power of the ISS*, and means that after running it for half an orbit, you might have a few test results, but all the occupants will be dead from lack of life support and the comms resources to send the results back may also be fried.
*ISTR 400kW peak, but you have to stash roughly half that to cover the eclipse time.
Then you don't care about the risk, and don't have to worry about a return trip. I'm sure there would be plenty of volunteers, even some healthy people would volunteer for a one way mission knowing that they wouldn't last more than perhaps a year or so (you can recycle your food/water only so long with current technology)
Plus, as a bonus, you'd get free radiation treatments along the way :)
Not as far fetched as it sounds.
Essentially the transmit station scans, seuqences, stores (insert BIIIIIG stack of hard drives/magickal transport pattern buffer here) using hyperfield 81T MRI down to a level sufficient to store the DNA, extracellular proteins etc and then transmits those via quantum means to the Rx station in Mars orbit.
The Rx station then processes and stores the data, if needed it then requests retransmission of any of the damaged bits if the error correction can't fix it then 3D-prints the regenerated cells layer by layer into a human body at about 2 Celsius ie extreme cryostasis and resuscitates the subject.
Voila, humans on Mars minus all the risky bacteria/viruses/etc and damage during long voyage.
The advantage with this method is that if something goes wrong during transport the original isn't lost.
Some memories might be damaged during the process but this should be fixable by re-educating the rematerialised subject.
The information stored in the brain isn't anywhere near the atomic level, current estimates are that the data could be stored on about 20 4TB hard disks (ie 80TB) if the base pattern is intact ie all the cells are in the right place etc.
This is for a 21 year old with an above average IQ and University level education.
AC x520
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
