# Mission to Mars, may use atomic propulsion



## Jeffbert (Aug 18, 2017)

Article talks about the limits of chemical fueled propulsion and the need for an alternative to it.

For me, I cannot imagine anyone getting away with launching an atomic powered space ship, as the protests and fears of an accident involving it would be massive.
NASA looks at reviving atomic rocket program


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## Vertigo (Aug 18, 2017)

Wouldn't surprise me if it isn't largely put together in orbit and doesn't actually launch from Earth.


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## Cathbad (Aug 18, 2017)

Vertigo said:


> Wouldn't surprise me if it isn't largely put together in orbit and doesn't actually launch from Earth.



That would be the way to go.  Would lessen the protests, for sure.


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## J Riff (Aug 18, 2017)

Just like the 60s!


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## Alexa (Aug 18, 2017)

Or they could find a 3rd option. Cold fusion maybe ?


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## Cathbad (Aug 18, 2017)

Alexa said:


> Or they could find a 3rd option. Cold fusion maybe ?



Wouldn't that be nice?


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## Alexa (Aug 19, 2017)

Yep. Especially if I want to be still alive for that voyage.


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## BAYLOR (Aug 19, 2017)

Nuclear Fusion would be a good option.


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## Serendipity (Aug 19, 2017)

There has been so much advancement in nuclear fusion (hot nuclear fusion I add, not the cold nuclear fusion we heard about in 1989) that given another ten to twenty years I expect all spacecraft carrying people to Mars will be using it. It also has the added benefit that plasma can help to produce a shield against solar radiation, one of the big problems that need to be solved if we want to go to that dust bowl of a planet.


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## Mirannan (Aug 19, 2017)

Serendipity said:


> There has been so much advancement in nuclear fusion (hot nuclear fusion I add, not the cold nuclear fusion we heard about in 1989) that given another ten to twenty years I expect all spacecraft carrying people to Mars will be using it. It also has the added benefit that plasma can help to produce a shield against solar radiation, one of the big problems that need to be solved if we want to go to that dust bowl of a planet.



Personally, I think that the solar radiation problem is overstated - at least, once they are there. Plain old dirt is a fairly effective shield against it; so covering the habitat in a metre or two of dirt would probably solve the problem. For the trip? Well, water is actually the best shield against the major component of the solar wind - protons. Put the water and fuel tanks on the outside.


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## Serendipity (Aug 19, 2017)

Mirannan said:


> Personally, I think that the solar radiation problem is overstated - at least, once they are there. Plain old dirt is a fairly effective shield against it; so covering the habitat in a metre or two of dirt would probably solve the problem. For the trip? Well, water is actually the best shield against the major component of the solar wind - protons. Put the water and fuel tanks on the outside.



Yes the water would act as a barrier to some radiation... the problem will be where does that water come from and how does it get onto the spacecraft. If it comes from Earth, it will all have to be lifted out of the gravity well. If it comes from the Moon it will have to be defrosted and then lifted out of that gravity well. If it comes from the asteroids, we will have to go and get it. 

That still leaves the deadly gamma radiation to deal with... (as opposed to the proton and alpha particle radiation).


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## Mirannan (Aug 20, 2017)

Serendipity said:


> Yes the water would act as a barrier to some radiation... the problem will be where does that water come from and how does it get onto the spacecraft. If it comes from Earth, it will all have to be lifted out of the gravity well. If it comes from the Moon it will have to be defrosted and then lifted out of that gravity well. If it comes from the asteroids, we will have to go and get it.
> 
> That still leaves the deadly gamma radiation to deal with... (as opposed to the proton and alpha particle radiation).



The point is that the water (propellant, maybe, coolant, and also required by the crew) and other hydrogen-containing liquids have to be carried anyway. That being so, one might as well get more than one use out of them. As for gamma radiation, the amount of that is actually rather low. X-radiation from solar flares might be a problem, but AFAIK such radiation is rather soft X-rays and a metre or so of just about anything will stop it.


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## Vertigo (Aug 20, 2017)

Mirannan said:


> The point is that the water (propellant, maybe, coolant, and also required by the crew) and other hydrogen-containing liquids have to be carried anyway. That being so, one might as well get more than one use out of them. As for gamma radiation, the amount of that is actually rather low. X-radiation from solar flares might be a problem, but AFAIK such radiation is rather soft X-rays and a metre or so of just about anything will stop it.


The only problem I see there is that using a consumable resource such as water means that the amount of protection will decrease as the mission progresses. Yes the internal water use will be as close to a closed loop as possible but, for example, the ISS currently consumes water for production of oxygen for the crew, with the hydrogen being vented. Of course in the case of a vessel under way that hydrogen would probably be used for propulsion. That water will therefore be consumed throughout the mission and its usefulness as a radiation shield would progressively diminish.


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## Jeffbert (Aug 21, 2017)

Interesting stuff! 

My point was that regardless of what method is used to move the nuclear fuel from Earth to space, it seems that there would be protesters fearing what might happen if the thing explodes or some other mishap occurs. Entire nations would likely be against it (governments, that is).


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## Vertigo (Aug 21, 2017)

But we already have nuclear powered satellites...


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## Vladd67 (Aug 21, 2017)

Vertigo said:


> But we already have nuclear powered satellites...


But they don't get any publicity, a trip to Mars will be a little more high profile and such details will not go unnoticed.


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## Cathbad (Aug 21, 2017)

Yes.  Unlikely many know about those satellites.


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## mosaix (Aug 21, 2017)

Voyagers 1 & 2 both carried nuclear material as a power source. 

I seem to remember there was  a bit of a 'discussion' but it was largely ignored.


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## Vertigo (Aug 21, 2017)

Wasn't there a bit of a ruckus over skylab when it was coming down as people seemed to think it might generate a nuclear explosion or something.


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