do you want to be one of the Fantastic Four or not?
Aspiring astronauts might want to think twice before going to Mars, as scientists estimate that the risk of cancer doubles for long-term missions outside Earth’s magnetic field. A study by Francis Cucinotta, professor at the department of Health Physics and Diagnostic Sciences and Eliedonna Cacao, a PhD student at the …
Has there been much in the way of practical experiments over what we can feasibly use for shielding for such a mission? Or would it be possible to say have a Mars bound ship do a lot of gravitational slingshots to boost it's speed before the astronauts get onboard? (think Using a much smaller, faster ship to catch the larger and slower to accelerating ship to cut down on journey time. That being said even when they get to Mars, there's not much in the way of atmospheric shielding so it's probably a moot point anyways).
It's Buzz Aldrin. And it's his Mars Cycler.
It means you can have a big enough ship to be comfortable for the trip to Mars, which I think takes 3-4 months, instead of 6, and also of course that ship is reusable. So every time it swings by Earth you send it some more food and supplies, and then the astronauts can get on it when it's ready, but do it in a smaller craft that doesn't need so much fuel to match speeds.
It does mean you have to spend longer on Mars though. As Aldrin's plan means the cycler has to come back to Earth after they get off at Mars, and then fly back to them - so I think minimum time on planet is about 7 months. Unless you built two cyclers. Obviously that would allow you to have more supplies as you wouldn't need to carry supplies for the journey back - your on Mars stuff sees you through if there's an emergency and you can't land, and the cycler can be re-stocked on its swing past Earth. Though I doubt that's a risk anyone would actually take.
But to do a fast return you then need 2 cyclers in counter phase. So the fast leg is Mars/Earth, not Earth/Mars.
But the best solution is to hollow out an asteroid.
Nothing provides radiation shielding like 2-3m of solid rock and its mass is way bigger than anything any real LV is going to put into LEO anytime soon.
"My money is on the invention of better shielding. Eventually."
Cosmic rays are the least of their worries once they arrive. The mars soil dust is full of rather nasty perchlorates which you really wouldn't want to get on your skin or breath in so any trips outside the module will require some serious clean up techniques when the astronauts come back inside. Even exposure to tiny amounts of this stuff could cause some serious illnesses such as thyroid disease, anemia and lung cancer in a relatively short period of time.
Don't worry too much about the perchlorates. We have to add a removal system to our airlocks. This is an engineering problem that is currently under development.
One question I am currently working is investigating whether the perchlorate concentrations are high enough for industrial processes or if we'll have to spend payload mass on concentration equipment. So far it appears that we will need concentration equipment. Ideally we will locate places where areological processes gives us far higher concentrations than the 1-2% we've found so far.
When life hands you lemons, make lemonade. When Mars hands us perchlorates we just need to make water, CO2, chloride salts, and thermal energy. Hopefully we find an extractable methane source for our metaphorical sugar.
Nope from 6 percent to 12% for death and double for getting a radiation induced cancer. These cancers occur earlier in life than background types and are more aggressive. So if 6 person Mars crew one dies in their early 60's from space radiation and 1 other gets a radiation cancer but treatment is successful. So not quite a one-way mission for the 4 persons not impacted. Maybe invest in development of countermeasures to lower the 12% a bit would be smart.
But their cognition including memory are degraded also from space radiation so may not remember they went to Mars 10 to 20 years earlier.
When Scott Manley is commenting on how KSP will never be 100% realistic, no matter how many mods you use and citing radiation dosage leading to cancer risk as an example in 2014, I feel that releasing a paper saying that going to Mars will cause increased radiation dosage leading to cancer risk is a bit superfluous...
To escape the surly bonds of Earth and visit a different planet, who cares about the risk.
After all, there's also the chance something might go wrong and (if Mars is even reached, that crew are stranded there ) so making it a one way trip regardless of extra tumour risk
Full disclosure, I (like many people), lvie in a Radon area, plenty of people are exposed to slightly above average background anyway
The Earth's magnetic field is physically large but as magnets go it's really weak.
You could create a comparable magnetic field around a small craft without adding much weight or energy requirements, just needs a coil with a few amps going through it.
The solar wind / cosmic rays would then be deflected and the borealis would give the astronauts something to look at whilst they're trapped inside for the trip.
I know there was the idea of filling the hull with a skin of water but that's going to add a lot of mass which makes it harder to get it up there.
Well some of the stuff you need to shield against isn't charged (X-rays and gamma rays) and the Earth has a shit load of shielding -- sufficient for life to survive without a magnetic field.
And the Earth's magnetic field may not be strong, but it extends 10 times the Earth's radius so has plenty of room to "bend" particles round the Earth. (It's much more complicated than bending - plasma physics with induced currents. Urgh.) So a couple of dipole magnets aren't going to do it.
And I don't know what the consequences of a larger field would be on our biology.
My understanding of this is rather limited, but when talking about Earth's magnetic field we are talking about magnetic flux density at the surface. Which is nice when you want to compare magnetic strength from one place to another, but when you are to compare magnets or create an equivalent one you have to integrate over the whole field (or something like that). So we can either look at this like standing on a large body comprised of matter with weak magnetic properties, but which in sum creates a huge field and due to it's large radius will extend far out before it diminishes. Or we can say that is an extremely powerful magnet far away in the core where the field out here on the surface is rather weak, it is will extend far out since the density of the field will weaken relative to current distance to the source which is already big. Kind of like if you double the distance to voyager the signal will only weaken to a quarter, and by now double is long long way.
Well, if I am right. I tried to read up on this, but I seem to recall that I really understand this at uni, and I have not improved since. Enlightenment please.
Lots of fuel can provide lots of shielding. I still wonder whether a supergun could be used to chuck up lots of bits . Bull managed to get a 50kg shell to 40km and while I wouldnt want to live next to one of these I'm sure we could make a gun capable of launching a serious amount of shit into orbit to be put together in 0g.
I dont know how much the propellant for a gun like this is but I'd bet its a shit load cheaper than rocket fuel and you could launch several dozen fuel containers a day into orbit from the middle of the pacific and only piss off a few seagulls... and a lot of fish.
Something like this could even, after much testing, be deemed reliable enough to pop up some plutonium for some serious engine building.
Bull managed to get a 50kg shell to 40km
Wikipedia says it was 180 kg to 180km. Then, because the US was angry with Canada for not supporting their invasion of Vietnam his funding was cut. The was assassinated for making weapons for Iraq.
Pity, if it weren't for political BS we might be able to send stuff into space relatively cheaply today. Oh well, I guess it's more important to have the money for endless war.
"I dont know how much the propellant for a gun like this is but I'd bet its a shit load cheaper than rocket fuel ..."
If one used a railgun then one isn't dealing with a propellant at all, just a source of electricity.
Another advantage is the lack of noise from the explosive combustion of the said propellant, leaving only the sonic boom, so watch out for a sudden brown-out followed by a loud bang (and the sound of breaking glass)!
Let's keep this in perspective. The first people living on Mars are not candidates for a quiet retirement. They will face a number of risks, including (but not limited to) their rocket blowing up, their rocket crashing on arrival, decompression by a punctured space suit, decompression of their accommodation module, running out of oxygen or water or food, a war on Earth interrupting their supply ships, and so on and so on. If they live long enough to die of cancer they will be lucky.
Absolutely, Adalat. And it surprises me how many folk still seem unaware of the Bigelow Aerospace habitats - those give much better radiation (and meteorite) protection than the ISS does, and similar technology could be used for trips to and from Mars.
There are easily sufficient number of people who would like to go to Mars, are aware of the hazards, willing to take the risks, and either already have astronaut training or could pass astronaut training, given the opportunity. And if sickness not curable whilst on the mission is a problem, then, lets face it, drugs usable for voluntary euthenasia could be provided. It's not a nice thing to have to contemplate, but it is a sensible one to consider. Exploration is never entirely safe. If exploration is wanted, let those who want to do the exploring judge whether they're happy to go under the circumstances, not a bunch of folk who'll never get off-planet (and probably wouldn't want to).
And it surprises me how many folk still seem unaware of the Bigelow Aerospace habitats
The one that's currently stuck to the ISS will be done testing in April of 2018 and it seems to be doing very well. I really look forward to seeing where the technology will be going after that.
drugs usable for voluntary euthenasia could be provided
IMO we could use that on this planet too. The idea that life ends when the heart stops as opposed to sometime between being able to go for a walk and spending ten years hooked up to a respirator, screaming from dementia seems a bit off to me.
Or we just stop removing CO2 from the air. My understanding, I have no first-hand experience mind you, is this is a relatively painless way to go.
God, no. That's about as wrong as wrong can get.
CO2 drives the urge to breathe; mounting CO2 causes an increased breathing rate and the feeling of suffocation. Under some circumstances - such as under pressure - it has been shown to create feelings of doom, despondency and panic. It's a truly dreadful way to die.
If you want to do this, what you do is to maintain the removal of CO2, but remove the resupply of O2. This means that the breathing urge is not over-stimulated, but the body becomes hypoxic. Hardly anyone - certainly not anyone healthy enough for such a mission - can detect impending hypoxia, so the subject simply goes to sleep peacefully and never wakes up.
And isn't that a nice subject for this time of the morning?
 That's where I encountered hypercapnia; I was diving, and I'd screwed up my preparation.
 Those were the symptoms I experienced.
Biting the hand that feeds IT © 1998–2019