Notice the continuous mention of bones.

16 points

What a dumbass. If we send people in the quickest possible way (or any way at all, really) and they all die in the attempt, that will set the whole project back decades.

The answer to the radiation problem is better shielding, not a fundamentally unsafe mission.

btw it is not the nuclear propulsion that I’m calling unsafe. It is the idea that we could do without redundancy. That’s just a monumentally stupid idea.

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7 points

Since the astronauts need water to survive, why not line the spaceship with reservoirs of it to provide the shielding? Or does water not block space radiation well enough?

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8 points

They did that in the novel “Seveneves”, used a massive chunk of ice as the bow of their ship on a one-way, twenty year plus trip. It didn’t stop all the radiation, though. Just enough to keep a minimum number of crew alive to complete their mission. They all developed different types of cancers, anyways,but the kinds that could be treated along the way and extend their chances.

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5 points

But then they’re drinking irradiated water, no?

Unless it’s really easy to remove the radiation safely, this doesn’t seem like the right solution.

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6 points

Irradiated water is fine.

You’re thinking of radioactive water, which is water with radioactive stuff in it.

Subjecting regular water to regular amounts of radiation is fine, even if it’s high-energy gamma rays. If there’s enough radiation to make water itself radioactive then you have bigger problems than radioactive water.

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5 points

“remove” what exactly? water is not alive so it’s okay to irradiate it https://en.wikipedia.org/wiki/Food_irradiation

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5 points

You wouldn’t want to drink reactor coolant water (mostly because of the chemistry additives) but water in a tank that just stays between the people and the hot stuff would mostly just get warm.

Most of what you’d get at that kind of distance is neutrons, and they are more likely to bounce off the hydrogen than to do something like activate the oxygen into N16 which dies off pretty fast anyway.

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4 points
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I don’t think it works that way. The water slows down the neutrons so that when and if they get to you they don’t have enough energy to hurt you. The radiation doesn’t contaminate the water any more than a microwave oven does.

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2 points

They used the ice for everything, including cooling and heating the ship as needed. They got the bad effects from the cosmic radiation pinging in from all other directions, not from using the water. The volume of ice was larger than that of the ship, I think it also absorbed physical damage from micrometeorites. Let’s hope someone in the Big Green Machine reads the novel.

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-1 points
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.

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3 points

You would need a pretty good thickness of water and it becomes complicated shipping it up into space.

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4 points

Well, the water is necessary for for life support and needs to be sourced somehow anyway. It kind of sets a minimum crew and passenger capacity if you want to make the most use of your shielding water.

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-1 points

Liquid and rockets is a death sentence.

Liquid and space vessels is worse.

Liquids on reentry is never going to happen.

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4 points

Water doesn’t have to be a liquid, but don’t actual spacecraft typically contain liquids during wall of those cases? What do you mean?

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2 points
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Calm down, he was answering “how fast could we get there”. It was never meant to be a realistic time frame.

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3 points

His disdain for NASA’s caution is obvious.

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2 points

Why?

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Because we (technically) can?

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