|Glitch| said:
250 mSv is enough to cause nausea, fatigue, and loss of hair. That is the best case scenario.
250 mSv
short-term exposure. Not 250 mSv over several months, which will just increase the cancer risk a bit.
The 1 Sv is with very pessimistic shielding estimates, and over even longer timescales.
|Glitch| said:
The mice were exposed to their total radiation dose (higher than what is expected for astronauts) within minutes, not within months.
See my comparison in an earlier post: drinking a glass of wine per day for a year won't kill you, drinking 365 glasses in a row will do.
|Glitch| said:
If just one solar flare or a gamma-ray burst was directed at the astronauts, they would be dead within seconds.
Stop posting nonsense.
Here is a NASA reference. If the astronauts would have walked around outside in spacesuits during the 1972 flare, they would have gotten a dose of 400 rem - potentially deadly within a few days, but not necessarily, and certainly not "within seconds".
No one would schedule a Moon walk with a solar flare appearing, however. Inside the spacecraft , the dose would have been 35 rem. Unpleasant, leading to a headache and increasing the long-term cancer risk, but not critical.
The Apollo modules were lightweight - modern spacecraft have better shielding. The dose would be even lower. No headache.
We had astronauts living in space for decades now. You seem to believe that the magnetic field of Earth does magic. It does not. It reduces the low-energetic component of cosmic radiation. It does not shield against gamma-ray bursts at all (because they are not charged particles), and it does not shield against high-energetic particles (multi-TeV range) either.
|Glitch| said:
Mars can never be made to be self-sufficient and life-sustaining
I would be interested in a reference for that claim. How can you be so sure about that, especially as all the experts think otherwise?
|Glitch| said:
Even if we did violate the Outer Space Treaty of 1967, and use nuclear bombs in space, you would need a lot more than we have to move such massive objects. Furthermore, such large objects impacting Mars would have an effect on its rotation, and may even change its orbit.
Treaties can be modified in international agreement.
The gravitational binding energy of Deimos is just 1.4*10
16 J, or 3 megatons of TNT equivalent. The gravitational binding energy of Phobos is 4*10
17 J, or 95 megatons TNT-equivalent. Nuclear weapons have enough energy to disintegrate the moons, if we want. I don't see the point of that, but it would be possible. Removing Phobos from its orbit could be interesting for a Martian space elevator in the distant future.
The effect on its rotation? Having everything impacting the surface would make the day ~1/3 second shorter.
The effect on surface gravity? Utterly negligible.
The effect on its orbit? Non-existent because the center of mass of the system does not change.
Chronos said:
It also appears to have shortened the lives of astronauts, who tend to be very healthy compared to the average person. See
http://www.nature.com/articles/srep29901 for the disturbing details.
They found a p<0.05 effect with a sample size of 7 after potentially looking at more than 10 categories. Congratulations. More
here.
Dale said:
Are you saying that the delta v to Mars is less than the delta v to the moon?
Yes.
LEO -> Moon surface needs 5700 m/s.
LEO -> Mars surface with aerocapture needs ~4300 m/s, depending on the launch window.
The advantage of Mars is the atmosphere. Going back needs much lower delta_v starting from the Moon, of course. But even starting from Mars, a single stage rocket can work. The same rocket that landed on the surface, which means you just need to fuel it. And that is easier on Mars...