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NASA Rover May Contaminate Its Samples of Mars
sciencehabit writes "The Curiosity rover will definitely find evidence of an advanced civilization if it lands safely on Mars. That's because rock samples the rover drills are likely to be contaminated with bits of Teflon from the rover's machinery, NASA announced during a press teleconference. The bits of Teflon can then mix with the sample, which will be vaporized for analysis. The problem for the scientists is that Teflon is two-thirds carbon — the same element they are looking for on Mars."
Fortunately, this problem isn't a showstopper: "...there are still mitigation steps to take if SAM's analysis is potentially compromised. Contaminant production appears to be stronger in the drill's percussion mode, when it pounds powerfully and rapidly on Martian rock. So ratcheting the percussion down, or switching over to the more gentle rotary mode, may make the issue more manageable. If that doesn't work, the MSL team could just take the drill out of commission, solely scooping soil instead of also boring into rock. Curiosity could still access the interior of some Martian rocks by rolling over them with its wheels, Grotzinger said. But all in all, he's confident that the team will figure things out in the next month or two."
I think somebody had another English-metric goof when they were doing their stoichiometry.
(CF2)n -> 24% carbon, 76% fluorine by mass, at least by my calculations.
It sounds like the teflon is from rings higher up in the assembly. It's not like they covered the bit in teflon and later did a full-on Picard facepalm.
They seem optimistic that they'll be able to work around it. I guess these lessons come with the territory when operating hugely complex projects to other friggin planets.
Right now, the rover is in *space*. I can definitely understand catching this problem in simulations or in on-Earth tests, or catching it belatedly when they finally get to Mars and wonder why all the rocks contain fluorine, but in space? Only thing I can think of is "someone re-ran some simulations and noticed they messed up", which doesn't seem very probable (unless the engineers had been suspecting this since before launch, and only now have sufficient "proof").
Then again, I'm not a rocket scientist, so I probably missed something.
They probably have an identical unit to mess with locally in case of electrics problems. If something goes wrong in space it is extremely helpful to have a physical replica you can actually put your hands on and experiment with to find the best fix.
I'm sure they caught it with the duplicate here on earth. For just about every NASA mission they make at least one duplicate to be used for troubleshooting and mission prep here on terra firma.
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Well, at least the samples won't get stuck.
Can't they find a nice abrasive rock to grind on till the Teflon wears off?
Don't know something? Look it up. Still don't know? Then ask.
I don't know how sensitive the detector they are using is, but they should also be able to detect the fluorine molecules (which outnumber the carbon 2 to 1, unlike what TFA claims). I don't imagine they expect to find a lot of fluorine in the rocks on Mars, so the presence of fluorine indicates the sample is contaminated and they should ignore the carbon. If the analysis is really sensitive, they could even correlate the amount of fluorine with the expected amount of carbon (since it should be exactly 2 to 1), allowing the contaminating carbon to be eliminate from the analysis.
This assumes the fluorine can be accurately analyzed, which may be a major issue since it is extremely reactive. I'm not a chemist, though, so I don't know how big an issue that could be.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
The Teflon is not on the drill bit; it rubs off of sealing rings in the main drill assembly. I know it's tough for you to believe, but the people who send robotic probes to other planets are, by and large, not idiots.
For this kind of thing, you typically deliver three pieces of hardware at the very least: The flight model (FM), flight spare (FS) and engineering model (EM). The FM goes on the rocket, the FS sits around in case you damage the FM before launch, and you run tests on the EM. You can keep running tests on the EM during cruise and surface operations. You might learn new things then. You certainly don't want the EM to teach you alarming new things after the FM has already launched, but it's better than having the FM surprise you later.
"First rule in government spending: why build one when you can have two at twice the price?" - S.R. Hadden in Contact
did you even read TFA ?
Lab testing of a backup version of the drill uncovered the contamination problem shortly before launch of the rover and its drill last November, according to Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland
They launched anyway knowing the drill bit was contaminated. if thats not a facepalm i dont know what is.
I'm a tetrachromat you insensitive clod!
Never mind the 720p part. phah!
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Well he didn't die..... they diacetyl just damaged his lungs so he had trouble breathing. Same thing happened to several Orville Redenbacher employees.
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They launched anyway knowing the drill bit was contaminated. if thats not a facepalm i dont know what is.
The alternative would probably have been a multi-year delay for the next launch window.
if that does NOT make them idiots i dont know what does.
Would you want to be the manager who had to tell everyone that the mission will be delayed three years because of possible contamination in one experiment?
Or do you launch anyway and live with 95% of the science returns while looking for a workaround for this problem?
For non stick I recommend a properly seasoned cast iron fry pan. For things where you want a bit of stick (pan fried chicken) or tasks like making gravy a nice stainless steel one.
Time to offend someone
Since the journalists Fd up everything else in the story, next we'll probably hear its actually kapton tape not teflon. That would really suck because kapton is made out of C N and O just like life and has no handy marker like being 2/3 F. Now that would be a real whoops.
The thing I don't get about the whole story is anyone doing anything with teflon knows it slowly deteriorates. So the first sample has 1 ppb carbon, the second 1.0001, the third 1.0002, fourth 1.0003 you know something is steadily falling apart. Just test each sample a whole bunch of times and look for a trend.
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What I would like to know is: what does it sound like on the surface of Mars?
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Meh, obviously someone doesn't understand basic economics (big shock it's Hollywood). Almost all of the cost is in R&D, physical production is probably a rounding error on a typical NASA project. Plus there have been instances where the mission primary has been damaged and the trainer ended up flying, in those cases the ROI for the backup is almost infinite when you compare the cost of fabrication to the cost of the mission as a whole.
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Invest in a good cast iron skillet, at least 12", and take good care of it. It will take good care of you for the rest of your life. If you're lucky, you can find a cheap one at a garage sale. Otherwise one from Lodge will do just fine. Some things just haven't been improved on.
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What is the purpose of teflon coated seals? Are they to battle Martian magma goblins? How do the seals survive exposure to the Martian atmosphere? My God man, it's inhumane!
You must gather your party before venturing forth.
We see here one of the primary strengths of robotics over human missions, namely, the speed with which one can correct errors . It'll be no more than 10 years, er, 20, no make that 30 or even... 40 years before they can get another mission up there with a drill that isn't contaminated, maybe. With a manned mission, they'd be able to troubleshoot the drill on the spot, which is clearly an inferior process.
The MSL uses an RTG power source. The problem with RTGs is that you can't turn them off, they start to run down as soon as they are built. MSL already missed a launch window due to delays and so was 2.5 years behind. Another delay would use up 5 years of the expected 10 years of RTG life.
Sometimes external factors force your hand.
Science is all about firing a drunk pig out of a cannon just to see what happens.
The multi-year delay for Galileo following the Space Shuttle Challenger explosion is what's believed to have caused its high gain antenna to get stuck in the closed position. When you have a million parts designed to start being used in 9 months, a 2 year delay introduces all sorts of unforeseen possible modes of failure. The drill is not the only experiment aboard Curiosity. At some point, a risk assessment was made which concluded that launching it with the faulty drill was a better option than delaying the whole mission by 26 months until the next launch window and potentially jeopardizing all the other equipment aboard.
Huh. They aren't exactly rocket scientists either. No, wait a minute....