10 pounds of plutonium dioxide (nuclear fuel for probe) to be launched next week to Mars.

[Poll_Blind]

It's the onboard reactor for http://www.space.com/13689-nasa-amazing-mars-rover-curiosity-science.html">NASA's $2.5Bln Curiosity probe. Amazing piece of machinery, hands down. I was watching the laser zapping rocks in the video at the link and I was all "Damn! How big are the solar panels going to unfold to power that thing. Hey...where are the solar panels?"



If you want to see the most complex and improbable-looking landing sequence for a space probe, ever, check out the video at the link.

I hope a hundred million things fail to fuck up- especially during the launch, which is happening this Saturday.

PB

[RKP5637]

1. Amazing, absolutely amazing! n/t

[stevedeshazer]

2. Cool, but I hope it doesn't screw up.

4.8 kg of plutonium dioxide isn't the kind of gift we want to send to potential Martians.

http://en.wikipedia.org/wiki/Plutonium(IV)_oxide

[lonestarnot]

3. Do they have to sling shot this one like Cassini?

[Warren DeMontague]

9. No, it's going straight to Mars. Mars is a much closer trip than Saturn.

But honestly, the concerns about the slingshot re: Cassini were horribly overblown and displayed a serious lack of understanding of science. A risk of explosion during lift-off? That's real... Rockets DO explode. But the idea that "and then they're swinging it by the Earth AGAIN!!!!" presents some serious additional risk.. it doesn't. The gravitational math that governs how we get probes to places like Saturn is pretty friggin' solid and exact. The idea that we'd slingshot Cassini around Venus but then somehow -whoops- send it back into Earth's atmosphere by accident... not gonna happen.

And even if it DID happen, well, it's already happened. There were, I think, 4 RTGs on the Apollo 13 Lunar Module for the ALSEP science packages the Apollo 13 astronauts were to leave on the moon, and when Tom Hanks (no, no, not really) used that LM as a lifeboat to get himself and Bill Paxton and Kevin Bacon back to Earth, that stuff entered the atmosphere and burned up, too.

As I said elsewhere in the thread, you want to worry about massive plutonium contamination, look to Fukushima, not NASA.

[lonestarnot]

11. I am not over being pissed back then. :)

[OneTenthofOnePercent]

4. Just for clarification... It's an RTG, not a Reactor.

A reactor actvely reacts and moderates nuclear fission chain reactions. RTGs are more like a battery than a "reactor".

An RTG, Radioisotope Thermoelectric Generator, just converts decay heat from highly radioactive materials into electric.
Basically there's a pellet of plutonium that glows red-hot and thermo-electric generators convert the heat to current.
Kind of like a Peltier TEC chip cooler, only it works in reverse... the heat differential produces electric.
Sometimes referred to as "nuclear batteries", several space vehcles/satallites have used larger RTGs.
Some of the more notable examples include the Pioneer, Voyager and Galileo missions.

Fun Facts: Several russian sattelites containing an *actual* uranium reactors have crashed in Canada.
Even a few US spacecraft have crashed containing RTGs

[Nevernose]

5. IIRC the Voyagers are also plutonium powered

And they're still breaking new ground, in a manner of speaking, 35 years later.

[Liberal Veteran]

15. Those two probes put the energizer bunny to shame.

It never fails to amaze me when we get yet another piece of news about the Voyager probes.

What is really fascinating is how long it takes to send instructions to the probes.

[Doc_Technical]

6. Solar Panels?

We no got no solar panels
we don't need no solar panels
I no got to show you no stinkin' solar panels!!

[Desertrose]

7. But if things do go wrong....that's a lot of radioactive shit in the sky.....

.....isn't it??

That said...I 'm with you & hope the f'ups DON'T happen!

[jeff47]

12. Nope.

The "sky" is a big place.

In a more serious response, the most likely failure mode would be something going wrong on liftoff, and the debris from that isn't going to land anywhere populated. So no immediate danger, and finding the hunk of plutonium would be fairly easy for any recover/clean-up team.

[_ed_]

16. You are 100% incorrect

My father-in-law is the lead Medical Doctor advising NASA about the radioactive danger of this launch. He's the lead doctor on a team of doctors employed by Homeland Security to deal with domestic nuclear/radiation incidents and treat affected populations. He's both a PhD in Nuclear Physics and an MD. Let's just say he would laugh at your "the sky is a big place" nonsense. Your "more serious response" is also 100% wrong. The launch threatens a significant area of human population, and the most significant danger is not at liftoff. Also, there would be no "hunk of plutonium" for anyone to find.

Please don't spread falsehoods about something you have no idea about.

[OneTenthofOnePercent]

13. The casks containing the nuclear material are designed to withstand massive failures.

Also, the fuel is ceramic of PuO2, so it can withstand high rentry temperatures without atomizing, becoming aeresol, or dissolving easily. It's actually rather safe compared to something like an actual nuclear reactor.

In fact, several vehicles, US and Russian made spacecraft with RTGs have reentered and crashed back to earth.
Some russian spacecraft containing actual uranium nuclear reactors have crashed too!

Sleep easily!

[Xithras]

14. As already stated, a rocket explosion won't compromise and RTG

The worst case scenario is an unguided re-entry, which could cause the RTG to rupture when it hits the surface (if it hit a sufficiently hard rock). While thhat would cause a leak, the damage would be very localized...as in no more than a few hundred yards from the impact site.

[Warren DeMontague]

8. Yeah, I remember the protests about the RTGs on Cassini, too.

And the science Cassini has returned has been nothing short of spectacular.





Look, Plutonium is bad shit- you'll get no argument from me there, but the concerns around RTGs; while not nonexistent, are relatively minor compared to the issues surrounding, for instance, the TONS of plutonium basically, now, out in the open somewhere like Fukushima. We have plutonium concerns here in this part of the US, too, with the Hanford Site.

I think the risk/benefit equation for something like the Curiosity rover, or the Voyager or Cassini probes, weighs heavily towards the 'benefit for humanity' side. That's not to say there is ZERO risk, but I do think in these cases it's small enough to be worth it.

[joshcryer]

10. +1, thanks for the pic.

Sometimes science is worth the risks. The Atlas it's launching on has a very good track record, though, so I'm not too worried.