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.
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-term dividends.
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.
Humanity: Hold my beer....
Even if the biosphere were to go to hell, it would still have an atmosphere, and a magnetic field. Fantasists have wildly impractical ideas for fixing the former on Mars, but nothing for the latter.
Arrakis at least had an oxygen and nitrogen rich atmosphere.
If we're talking about something like a huge asteroid colliding with the earth and/or a huge volcanic episode that would trigger a mass instinction, wouldn't the pale blue dot still be more hospitable than Mars? We have access to technology the dinosaurs didn't have, our chances of survival would probably be much better overall.
Even in case of man-made devastation, such as mass pollution or a nuclear winter I think it's safe to assume that Earth would still be more habitable than Mars.
How about something even more destructive? Maybe something like a gamma ray burst? Well then Mars is probably not far away to put it out of harm's way, although maybe they would be more likely to be unaffected by it if it hit the other side of the planet due to its very thin atmosphere? I'm not sure.
Sure, we need to be better stewards of our environment, but I fail to see how our species is inherently worse then a meteor destroying a planet.
The argument could be made that Martian humans would be supremely motivated to move the environmental parameters there toward a survivable state for lightly-outfitted humans.
Contrast this with Earth, where space exploration is a four-order or fifth-order concern for most people, and long-term environmental issues are treated as abstract exercises in reducing economic externalities. This is because Earthlings have (mostly) had it easy. We're biologically evolved and culturally adapted to survive here, and thus don't have a strong intrinsic motivation (yet) to maintain the long-term health of the biosphere.
We could accidentally fire nukes, accidentally let a GM smallpox strain out, accidentally start WW3, we could do so much as it is. That is beside the point anyway.
Presumably the first people to go to Mars are going to be vetted for some level of education and skill. This will likely prevent the fear mongering, demagoguery and other forms of lying that allow some successful politicians argue against singularly true facts, at least for a little while. Likely until the mars colony is self sufficient.
Even then it seems unlikely you will get an anti-global warming lobby on Mars, because it is good for every business (presuming breathable air is government utility/service).
No, not immediately.
This isn't much different from other colonization missions in human history: humans from one place got sick of the people living there, and went somewhere (relatively) uninhabited so they could live the way they wanted without the political problems they had back home. Eventually, there were new political problems of course, but that took generations; for the initial travelers, it was a sensible move. And the political problems that came were likely different, as so much time had passed.
I personally feel that having a "fallback" in case something literally Earth shattering happens is compelling enough a reason to colonize other bodies in our solar system, Mars included.
That said, it's possible that even Mars' relatively low gravity is enough to stave off the health problems associated with prolonged microgravity/freefall, so that might be good motivation. If there's some lower bound on how high g needs to be in order for our bones to not become brittle, and Mars is above it while - say - the Moon is below it - then Mars is really the only option besides the moons of the gas/ice giants (and their respectively-giant gravity wells) or Venus (with its Earth-like gravity well and its hellscape of a surface).
So there's another scientific motivation: to measure the effects of low but existing gravity on human health.
Because, you know, there's a chunk of me that thinks we can be less risk averse in trying to do things on an uninhabited planet. Nuclear meltdown is pretty awful on earth, on Mars I don't see it with the same fear.
I also feel like this is not dissimilar from dumping rubbish in the neighbours yard because who cares it's not mine but on a planetary scale. Which seems bad but I want to rationalise it away and say "but this is different".
Now, as soon as you turn the reactor on you start turning the relatively safe U235 into all sorts of nasty things with half lives that are much, much shorter than 700 million years like strontium 90 with a half life of 30 years. That stuff is indeed horrible and getting it spread over Florida would be a disaster. But the solution is to make sure you don't turn the reactor on until it's safely in orbit.
That makes them much safer than the RTGs we've been using to power space probes far away from the sun previously. Because the P238 isn't in a critical mass it has to be a synthetic isotope with a low half life in order to generate enough heat to power a spacecraft when it's outside a reactor and would be quite deadly if you interacted with it without shielding.
[1]: http://www.popsci.com/plutonium-238-is-produced-in-america-f...
The reality though is that failure of the rocket doesn't mean the reactor or fuel is vaporized and thrown to the wind. It's possible to construct the payload fairing to survive sudden, rapid disassembly and crash land intact off the Florida coast for recovery.
A nuclear-armed intercontinental ballistic missile is visually identical to a launch rocket carrying a peaceful payload to LEO. The neural association between "nuclear missile" and "rocket with nuclear reactor payload" is very strong.
It doesn't matter how many facts you throw at it. In the mind of the public, all launches have the possibility to result in another Apollo 1 or STS-51-L (Challenger) or STS-107 (Columbia). Every "nuke" is the Castle Bravo test. Every reactor is Chernobyl. And the public generally is terrible at risk assessment and actuarial math.
You could actually make the launch safer than an afternoon stroll on a Florida golf course, but no one is going to lie down in front of your golf cart screaming, "lightning strike!" or "angry gator!" or even "cardiac infarction!" or "terrorists!"
People may have no problem at all if you just call it "an NCG power plant" (for neutron-cascade generator) and say the details are classified for security reasons--that "security" being the type associated with a toddler's blanket.
By humans. By other life-forms is yet to be proven one way or another. There is already discussion of treaties to prevent contamination of any Mars biosphere by human missions there.
Also: what about the future? There's no point in sending a nuclear reactor to Mars if a future colonisation mission can't go ahead because the reactor has melted down...
Solar irradiance is approximately 50% less than on Earth. PV with high efficiency modules (the same ones they use on satellites) is also viable. I wonder if anyone has run the numbers on the cost of shipping a reactor Vs. the cost of shipping a football field of PV modules there.
As to contamination, it's a planet we did not abandon earth when Chernobyl melted down. Worst case nobody goes within 100 miles of it for a few decades. But frankly people are unlikely to go to 99% of Mars anytime soon and can't walk outside without significant protection anyway.
I assume the nuclear reactor would be a pretty much "sealed unit" which just needs to get rid of a lot of heat. There is no reliable water/evaporative cooling on mars, nor is the atmosphere thick enough for fans etc. to be effective. Instead it will need huge thermally emissive panels. For them to be effective, they need to be very hot.
Now imagine how many such cubes would fit inside your favorite mountain.
It must have something to with the state of technology and not being able to do it safe until now.
So the chance is much lower than people think, if plans have measures to avoid such corruptions. And that's not counting the many safer designs we have nowadays. Many plants today don't even need backup electricity to automatically shut down by themselves.
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.
I mean, how can someone design a communist-proof nuclear reactor?
Not a bad idea though.
As far as I understand, making a reactor built in the last 25 years go 'wrong' in any way like that is very difficult, and would take much more than negligence or incompetence.
Fukushima is an example of this – the reactor that had issues was over 50 years old, but all the modern ones were fine.
Most of the space flight technologies using nuclear power were devised for manned flights beyond Earth's gravitational influence, and were on the drawing boards as early as the fifties. Once America successfully landed on the moon and the Soviets gave up, there was immense political pressure to scale back the US space program. With the Space Race won, it was harder to justify the costs of manned interplanetary spaceflight, so a lot of more exotic (read: expensive) plans were shelved. This included more than a couple nuclear propulsion ideas for spacecraft, including one for a nuclear thermal rocket that had been successfully prototyped in the lab and was ready for an actual launch.
Lots of stuff we could have done and could be doing in space if there was money for it.