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NASA's Next Mars Rover
An anonymous reader writes "In August 2012, the NASA rover Curiosity is scheduled to touch down on the surface of Mars. The size of a small car, it's four times as heavy as predecessors Spirit and Opportunity, and comes with a large robot arm, a laser that can vaporise rocks at seven meters, a percussive drill and a weather station. Oh, and 4.8kg of plutonium-238. Wired has some high-resolution photographs from lab that is putting the next rover together."
Curiosity's destination on Mars has reportedly been chosen: Gale Crater. The 150-kilometer wide depression 'includes a tantalizing 5-kilometer-high mound of ancient sediments, [and] may have once been flooded by water.' The Planetary Society blog has a couple of additional pictures and a time-lapse video of the delicate, lengthy process of preparing the lander for transport. Curiosity will launch near the end of 2011. No cats were harmed during its construction.
Oh, and 4.8kg of plutonium-238
Oh goody! My explosive space modulator has finally been delivered! Now I can blow up Mars. Because it's obstructing my view of Jupiter!
From #4:
"If it works, it will be spectacular,"
If it doesn't , it will probably be more so, but we won't see it.
For justice, we must go to Don Corleone
...a laser that can vaporise rocks at seven meters...
I soooo want this on my car.
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
"...a laser that can vaporise rocks at seven meters..."
Everybody making a hilarious post about sharks can press ALT+F4 to skip the 20 second limit!
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
"no cats were harmed during its construction".
Well of course not. That would obviously come after activation. Good thing they are planning to send the malevolent entity to a feline-free Mars.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Mars eats orbiters for lunch and landers for dinner, unfortunately. It's called "rocket science" for a reason. If we limited our efforts to sure-fire bets, we'd still be squinting through telescopes and wondering who dug the canals.
I'm confident that if anyone can pull off a project this ambitious, the JPL folks can. If they fail, I'll be happy with raising my taxes by the $1.50/year it will cost to try again.
K'Breel, Speaker for the Council of Elders, addressed the planet thus:
AT LAST, the denizens of the blue planet expose their true intentions! No mere "explorers", these foul robotic beings. Despite their deceptive code names, these invaders from the blue world are no innocent space-mariners; they're Vikings! All they seek is an opportunity to wipe not only us from the world, but the spirit of our world itself from the solar system.
I have in my tentacle one particularly threatening communications intercept; hear the enemy in their own words.
Despite what you may have heard from certain circles of subversives, their own words betray them. They are not just here for the sake of curiosity!
K'Breel went on to confirm reports that the expected invader would indeed by powered by an advanced Pew-238 power source to extend its range and lifespan, K'Breel reminded all citizens that its expected capabilities would still be vastly inferior compared to their own recreational vehicles: "Our hot rods get a million klorbs to the frelpor; the blue planet ain't just across a minor tributary from Valles Marineris!"
When a junior intelligence analyst suggested that the intercepted transmission in question was merely referring to an animated cartoon that was more than thirty years old, there was a gelsac-shattering kaboom. (It was described as "lovely".)
A small robot dutifully removed the dust from the remains of the Speaker's disintegrating pistol and performed a short piece of traditional music while the Speaker exited the stage via an iris-shaped door after concluding his address with a brief "That is all, citizens."
Thanks for the link. It's got to be the only time on record - ever - really EVER - where Michio Kaku has said something completely and utterly forehead-smackingly, drool-inducingly ridiculous, laughably scientifically dishonest and hyperbolically absurd. Usually every word that comes out of his mouth is so balanced, well-informed, rigorously thought-out, carefully argued, and of course, completely and utterly plausible.
As an engineer, that skycrane contraption sets off my alarms of being an extremely complicated and scary solution. It lacks the simplicity of earlier landers with a sequence of chutes, retro rockets, and airbag expansions. Though still being single point failures, they were not actively controlled and could use simple backup timers to make sure everything deployed if at all possible. (Full disclosure: I'm a JPL engineer, but not in EDL and not working on MSL, and of course my opinions are purely my own).
Of course for a mobile vehicle that large, I can't think of a better solution that could fit on a launch vehicle, so I'll give it the benefit of the doubt.
Given that, though, if it fails, i doubt it would be resurrected. MSL already has a bad track record of delays and problems, and a reputation as a money sink (though not as bad as JWST). Also, I have a bias towards more smaller and cheaper missions (and as a deep space navigator, rovers are quite dull for me professionally) so I would actually rather have the money spent on more New Frontiers and Discovery class missions.
Heh, I can't tell if you're being sarcastic or not, because I haven't followed his work since the Cassini episode. But before that, he actually was a decent science writer, someone who could bring leading-edge physics down the mountain and talk intelligently to the people who are asked to fund it.
That's why I was so disillusioned when he went off the deep end. Science desperately needs good communicators like Kaku... and it needs them to not go full retard.
"I'll be happy with raising my taxes by the $1.50/year it will cost to try again."
So would I. Unfortunately they're going to cut our taxes by $1.50 and spend the money anyway.
Stop-Prism.org: Opt Out of Surveillance
Sadly, Six cats are used as parts of the foot(Paw) control mechanism, since feedback from Earth would be too slow to enable the needed precision.
Not to mention it's the only way to ensure it lands upright!
While every step has been taken to keep these cats happy and well fed, there are no provisions for these cats to be repatriated Earth...
Believe me, when they see how much sand is there it will be just fine with them. Imagine a whole world, where you could pee as much as you like with no-one to complain.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
No, it runs VxWorks
http://en.wikipedia.org/wiki/Comparison_of_embedded_computer_systems_on_board_the_Mars_rovers
My understanding (slight as that may be) is that the vehicle is too heavy to land by parachute in the thin Martian atmosphere.
BTW, what did you think of the DIRECT architecture?
When our name is on the back of your car, we're behind you all the way!
Yeah, I get butterflies thinking about this thing landing. I'm told that the skycrane has been tested extensively on Earth and the engineers involved are not any more worried about that than about the chain of other more mundane things that can go wrong between launch and instrument check-out in situ. As to previous elegant solutions, I think I would have been just as antsy about the beach-ball landing scheme of the MER had I been in the biz back then (disclosure: I'm a scientist at JPL).
I don't mind pilots assuming things will go smoothly. I definitely don't want those pilots to be dreaming up various failure scenarios or troubleshooting damaged indicator lamps to the point that they forget to fly the aircraft. If there is an issue they should function more or less automatically because they've done the whole "What if" business do death in the simulators.
I get your point though, blind confidence works, just until it doesn't, though in some occupations this kind of arrogance can also be beneficial.
Something people seem to misunderstand about this is that the concern is that rockets are known to fail at launch. It's a *huge* failure point. The consequences of such an event shouldn't be ignored.
Statistically, the radiation risk seems below the threshold of concern, but it's not distributed like one would think. With plutonium especially, it only takes a very small amount to be breathed in or ingested to essentially guarantee cancer. If it were to pass through the body completely, it wouldn't be a big deal (this is where it looks statistically negligible), but if it stays in the body it will sit there emitting gamma rays and alpha particles throughout the rest of your life.
This is also the major problem with (for example) Fukushima. There are other radioactive isotopes which are much more dangerous over the short term, but they don't last as long (which is primarily why they are more dangerous), but something like plutonium or uranium lasts a very long time, and provides a low but constant dose.
Fortunately, RTGs tend to be well protected (at least, I'm led to believe), but unfortunately, rockets can explode quite impressively, and somethings shit just happens. Also, some missions (although not generally for Mars) involve multiple Earth flybys. This increases the risks.
Engineers *LOVE* to get all worked in promoting nuclear power. That's because, from an engineering point of view, it's fucking fantastic. It's *AMAZINGLY* fantastic. But the problem isn't with the theory, it's with the practice. You can design yourself the best reactor, with all the safeguards, then an earthquake and a fucking tsunami ("which nobody could expect", it's claimed after the fact, even though this is on the coast of Japan), or a test goes awry and multiple points of human error happen in Chernobyl, which "isn't the fault of the reactor or the technology", even though somehow it still happened.
The point being, even if you are the best engineer in the world, and you manage to build a rock-solid device (and, seriously, what kind of ego do you have to have to think you've built a fail-proof reactor?), you can't account for the rocket engineers not realizing the o-rings become brittle as the temperature cools, or the guidance engineers are working in metric and the thruster engineers are working in imperial, or any of a billion other little things that can lead to the failure of your "perfect" design. Failure that is not your fault, sure, but failure none the less.
The consequences of such an event shouldn't be ignored.
And they weren't. End of story.
Everything else you wrote is either wrong or completely irrelevant. There are no lessons from Chernobyl and Fukushima that can be applied to RTGs, and no analogies between them can be drawn except for ones comparing apples with spoons.
RTGs don't work even remotely like a nuclear reactor of any type, well-engineered, poorly-engineered, or otherwise. It's not clear that plutonium is as dangerous as people have been told it is. In particular, there seems to be no scientific backing for the usual claim that a single inhaled particle is 'guaranteed' to cause cancer. RTGs containing various radioisotopes have been damaged in accidents before with no apocalyptic consequences,.
When you build an RTG you use such a small amount of radioactive material that it's feasible to encapsulate it in a manner that renders it reasonably safe under any reasonably conceivable failure conditions. (Launch-pad explosions are not all that violent, frankly -- Kaku's major concern with Cassini was the Earth flyby, where a miscalculation would have exposed the RTG to much greater heat and higher mechanical stress.)
The launch will probably be successful, and if it's not, it's very unlikely that anyone will die from plutonium exposure as a result. Those are the only guarantees you'll get from any honest engineer. They're good enough for me, they're good enough for you, and they're good enough for the good Dr. Kaku.
The consequences of such an event shouldn't be ignored.
And they weren't. End of story.
No, *not* end of story. They still launch RTGs, in spite of the real risks involved. They didn't "ignore" the risks completely (they did shield the reactors), but they still went ahead with these launches, even though there are risks involved.
Everything else you wrote is either wrong or completely irrelevant. There are no lessons from Chernobyl and Fukushima that can be applied to RTGs, and no analogies between them can be drawn except for ones comparing apples with spoons.
The lessons are that you can't engineer away disaster. Not a single thing ever invented is disaster-proof (in fact, there have been some notable "disaster-proof" inventions famously succumbing to disaster. Raise your hand if you can name two). Nuclear reactors are apt examples because they involve severe effects when things go wrong. Fukushima and Chernobyl suffered meltdowns. Something which RTGs cannot do, but they dispersed radioactive material (*especially* Fukushima), which RTGs very much can do.
RTGs don't work even remotely like a nuclear reactor of any type, well-engineered, poorly-engineered, or otherwise.
First off, that's absolutely false. They *are* nuclear reactors. However, I'll cut you some slack on that and assume you meant that they aren't similar in danger to traditional large-scale nuclear power plants. This is true, but I've never claimed otherwise.
It's not clear that plutonium is as dangerous as people have been told it is. In particular, there seems to be no scientific backing for the usual claim that a single inhaled particle is 'guaranteed' to cause cancer.
No one claimed a "single particle" would guarantee cancer. And the link you posted made the case that plutonium is very dangerous. Did you not read it first?
RTGs containing various radioisotopes have been damaged in accidents before with no apocalyptic consequences,.
No one is claiming "apocalyptic consequences". Speaking for myself alone, I'm talking about completely innocent bystanders being killed as a consequence of disaster, without being aware of any impact, decades later.
At least with most disasters, you know when you are at risk, the disaster is localized, and when it's over, it's over. Nuclear disasters have the distinction of not being so forthcoming with the aftermath.
When you build an RTG you use such a small amount of radioactive material that it's feasible to encapsulate it in a manner that renders it reasonably safe under any reasonably conceivable failure conditions. (Launch-pad explosions are not all that violent, frankly -- Kaku's major concern with Cassini was the Earth flyby, where a miscalculation would have exposed the RTG to much greater heat and higher mechanical stress.)
I'm not talking about "reasonably conceivable failure conditions". It's not the things you've planned for, it's the things you *didn't* plan for (which is why I brought up Fukushima and Chernobyl. Both were engineered for reasonable expectations, but they still failed because not everything that happens is reasonable).
The launch will probably be successful, and if it's not, it's very unlikely that anyone will die from plutonium exposure as a result. Those are the only guarantees you'll get from any honest engineer. They're good enough for me, they're good enough for you, and they're good enough for the good Dr. Kaku.
Who are you to speak for others? They may be good enough for you, but you have no business speaking on behalf of others.
I'm not saying that I'm particularly concerned about RTGs in general. I'm just trying to show that concern is reasonable. Engineer-types tend to mischaracterize anyone who dares question the safety of nuclear systems as some sort of crazy person.
http://en.wikipedia.org/wiki/RAD750
Not exactly something you pick up at Fry's or NewEgg.
Why is Snark Required?
First off, that's absolutely false. They *are* nuclear reactors. However, I'll cut you some slack on that and assume you meant that they aren't similar in danger to traditional large-scale nuclear power plants. This is true, but I've never claimed otherwise.\
I am pretty sure you have no idea what the hell you are talking about at this point. RTG's are not nuclear reactors. They use the excess heat shed by nuclear material to drive an electric current through semi-conductive materials. There is no nuclear reaction being sustained, they simply use the natural half-life of the material contained within them to provide energy. That's all. For more details please read Chapter 6, section 4.2.1 of Vincent L. Pisacane's Fundamentals of Space Systems, Edition II, aptly titled, "RTG Description," before commenting further on this topic.
That source gives a nice, compoenent-level description of how RTG's work. Until you have that basic knowledge, you really aren't qualified to be commenting on this topic in any authority. Thank you for your opinions, however.
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