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NASA Revives Plan to Put Nuclear Reactors on Mars

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Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#61

Post by davedx »

Symmetry wrote: post #43
davedx wrote: post #39

I looked into some numbers on this, comparing theoretical costs of nuclear power with a solar PV solution on Mars. Kilopower (NASA's research project for a Martian nuclear fission reactor, from the article): 7,200 kg for 40 kW. [1] ISS solar arrays: 14,515 kg for ~100 kW in Earth orbit. [2] If we assume 40-50% Earth solar insolation on Martian surface, the ISS PV array probably isn't far off 40 kW output on Mars Conc…

A robotic rover can afford to shut down during the night but humans aren't able to do that. So you need to average out the power generated over the day night cycle and add mass for enough batteries to store daytime power for use at night. Last I did the calculations that roughly doubled the weight. So more like a factor of 8 than 2. But still, power generation won't be the majority of the mission weight so it's not a…

You are correct. I updated my post with some battery calculations. Only enough battery energy for one night adds another Falcon Heavy of payload. The dust storms will be a huge intermittency problem too.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#62

Post by Kubuxu »

aphextron wrote: post #57
davedx wrote: post #39

I looked into some numbers on this, comparing theoretical costs of nuclear power with a solar PV solution on Mars. Kilopower (NASA's research project for a Martian nuclear fission reactor, from the article): 7,200 kg for 40 kW. [1] ISS solar arrays: 14,515 kg for ~100 kW in Earth orbit. [2] If we assume 40-50% Earth solar insolation on Martian surface, the ISS PV array probably isn't far off 40 kW output on Mars Conc…

>The build cost of the ISS arrays was around $300 million (space PV is way more expensive than terrestrial). That was 20 years ago, on a government contract, for panels that must survive the rigors of actual space. Panel manufacturing costs have dropped almost 10x since then, and the environment (assumed under the protection of martian atmosphere) which they will operate will be far less extreme than Earth orbit, nec…

Space applications use single crystal GaAs (Gallium arsenide) process instead of wide spread c-Si (Crystalline silicon, currently usually multi-Si), due to their superior performance and weight.

Process of producing c-Si panels has become a lot cheaper but this doesn't apply to GaAs process.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#63

Post by simias »

tehwalrus wrote: post #54
simias wrote: post #10

Earlier quoted context omitted.

I agree with your sentiment but let's face it, sending humans to Mars is as much PR as it is scientific research (maybe even more). Look how we ended up on the moon in the first place. If NASA wants to get the funding it has to make it as marketable as possible. If there's a big push back from the general population it will be hard to convince the politicians to invest billions in an unpopular project with no short-t…

I would say, given the state of politics and the general attitude to the climate and natural resources, our first priority should be colonising another planet. Putting some scientists on Mars for a few years is step 1 in that very important insurance scheme!

I don't know if I agree. Creating a self-sustainable colony on Mars will take a very long time and even if we manage to do it can we really afford to "lose" the earth? Mars is an inhospitable hell for humans and practical terraforming technology is still in the realm of science fiction. Maybe if we manage to destroy earth completely out of selfishness and hate we don't really deserve to spread the virus throughout the galaxy?

And running away won't solve our problems. How long until our current earthly political and environmental issues are reproduced on Mars? We have "human" issues, not "earth" issues, simply moving the problem is not a solution. If we can't sustain our development in a civilized manner on a lush and hospitable planet I don't think we'll fare much better on Dune.

Not that I'm against colonizing Mars but I'd prefer if we did it out of a shared dream of a trans-planetary humanity rather than out of fear of self-destruction.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#64

Post by moovacha »

DanielBMarkham wrote: post #32

There are a few obvious things that need to be stated in order for the public to prepare for a manned Mars mission. The fact that we're going to have to use some sort of atomic batteries is one of them. Another is that we can't search the entire planet for life before we go visit. It's impossible to disprove a negative. My preference would be to see every piece of gear have an integrated solid-state nuclear battery a…

It's easy to disprove a negative. Simply find life on Mars.

I think you meant, it's impossible to prove a negative. More specifically, to prove that something does not exist.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#65

Post by mtgx »

sp0ck wrote: post #2

It's about time. Engineering decisions shouldn't be made based of irrational fears of general population. If nuclear power plant is best option for space mission we should use it.

Are the nuclear reactors we're transporting to Mars safe in case of rocket explosion? Because rocket explosions/failures happen way more often than Fukushima type situations.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#66

Post by [deleted] »

cortexio wrote: post #23
8draco8 wrote: post #17

Earlier quoted context omitted.

Genuine question: If it's possible to use mini nuclear reactors in satellites then why they just can't land that thing somehow on Mars (like they did with Curiosity) and use it on planet surface to power lab?

Mini reactors are useless on Mars. The power they generate is waaay to low compared to the money that is needed to bring them there. Also putting nuclear reactors on sattelites almost never happens and is VERY DANGEROUS. It's what the Soviet Union did in the 70s-90s. The last sattelite launched with a nuclear reactor was in 1988. You have to be pretty insane to launch large amounts of nuclear material from earth in a…

[deleted]

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#67

Post by ams6110 »

simias wrote: post #63
tehwalrus wrote: post #54

Earlier quoted context omitted.

I would say, given the state of politics and the general attitude to the climate and natural resources, our first priority should be colonising another planet. Putting some scientists on Mars for a few years is step 1 in that very important insurance scheme!

I don't know if I agree. Creating a self-sustainable colony on Mars will take a very long time and even if we manage to do it can we really afford to "lose" the earth? Mars is an inhospitable hell for humans and practical terraforming technology is still in the realm of science fiction. Maybe if we manage to destroy earth completely out of selfishness and hate we don't really deserve to spread the virus throughout th…

Very unlikely that we could do anything on Earth that would make Mars look like a better place to live.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#68

Post by DougWebb »

mikejb wrote: post #58
DiThi wrote: post #52

Earlier quoted context omitted.

It's very safe if you don't disable safety systems put in place (like it was explicitly done in Chernobyl to do dangerous experiments, even though they labeled it as "routine tests"). And if you don't ignore many warnings given in the industry (like TEPCO ignoring many recommendations of raising their tsunami protection walls many years before the catastrophe, like other plants closer to the epicenter that were unaff…

I fully agree that newer designs are safer, but ignoring the human factor in the equation is IMO not very reasonable. Without the human factor, driving a car is very safe. That argument is valid, but it doesn't reflect reality.

Good engineers take the human factor into account and include backups in their designs to handle failure modes caused by the human factor.

What they can't do is work around politics or budgetary constraints which force trade-offs between safety and cost. Anything can be made as safe as necessary, if you're willing to pay for the redundancies.

When it comes to reactors on Earth, a very large proportion of the budget is diverted to bureaucratic paperwork, lobbying, and PR, which could instead be used to pay for additional safety measures.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#69

Post by valuearb »

mtgx wrote: post #65
sp0ck wrote: post #2

It's about time. Engineering decisions shouldn't be made based of irrational fears of general population. If nuclear power plant is best option for space mission we should use it.

Are the nuclear reactors we're transporting to Mars safe in case of rocket explosion? Because rocket explosions/failures happen way more often than Fukushima type situations.

Yes, it's been much tested. They aren't operational until they make orbit.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#70

Post by camiller »

ams6110 wrote: post #67
simias wrote: post #63

Earlier quoted context omitted.

I don't know if I agree. Creating a self-sustainable colony on Mars will take a very long time and even if we manage to do it can we really afford to "lose" the earth? Mars is an inhospitable hell for humans and practical terraforming technology is still in the realm of science fiction. Maybe if we manage to destroy earth completely out of selfishness and hate we don't really deserve to spread the virus throughout th…

Very unlikely that we could do anything on Earth that would make Mars look like a better place to live.

"Very unlikely that we could do anything on Earth that would make Mars look like a better place to live. "

Humanity: Hold my beer....

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