Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Mars NASA Space Science

NASA's Phoenix Finally Fills Oven 134

JoeRobe writes "Phoenix has successfully filled oven #4 of the Thermal and Evolved-Gas Analyzer instrument (TEGA). They have spent several days now vibrating the screen above the oven, trying to get a significant amount of soil sample into it. From the article: '[T]he oven might have filled because of the cumulative effects of all the vibrating, or because of changes in the soil's cohesiveness as it sat for days on the top of the screen.' Either way, this is the first step toward getting some interesting data from this instrument."
This discussion has been archived. No new comments can be posted.

NASA's Phoenix Finally Fills Oven

Comments Filter:
  • IT would be great(laughablity wise) if the whole thing tipped over because of them vibrating the screen.
  • Cookies (Score:4, Funny)

    by LeoDavinci578 ( 795523 ) on Wednesday June 11, 2008 @05:02PM (#23754677)
    Who wants cookies?
    • Oh, come on now people. Who modded this off-topic? It's completely on-topic. Think little, skinny, cookies made from Mars soil by a robotic travler? What's next? Mod down a Shake and Bake joke? NASA got that bot down, safe on the ground and their making sweet, soil cookies! What's not to love and laugh about?
    • Re:Cookies (Score:5, Funny)

      by Mr2cents ( 323101 ) on Wednesday June 11, 2008 @07:02PM (#23756263)
      Just imagine that in a few days from now, the news headline could be "NASA cooks the first extraterrestial life - tastes like chicken".
      • Are you saying there's a bun cooking in NASA's oven?

        I was going to say something else about phoenicis and bursting into flames, but it would've probably been too much.
  • invalidate the tests (Score:5, Interesting)

    by phrostie ( 121428 ) on Wednesday June 11, 2008 @05:03PM (#23754689)
    couldn't this invalidate the tests.

    it seems to me that the clumps could be caused by the very ice we are looking for.
    by screening it out, the samples won't be representative of the soil
    • Re: (Score:3, Interesting)

      From my limited understanding of the properties of H2O on mars, I would imagine that letting a clump of dirt sit up above the soil would cause the ice to sublime after being directly exposed to sunlight. Anyone know if this is possible? Obviously they aren't going to get a false positive... but a false negative seems likely (although I'm sure that they will know this if it happens to be the case, and will try again to find water).
      • by osu-neko ( 2604 ) on Wednesday June 11, 2008 @05:31PM (#23755077)
        There's no such thing as a "false negative" for the kind of tests they're doing. They're not conducting the kinds of experiments that would falsify a theory. The only results possible from the tests they're doing are "confirmed" or "failed to confirm" (and nothing much can be concluded from the latter in any case).
        • Re: (Score:3, Informative)

          by eonlabs ( 921625 )
          What I'm sure the 'grandparent' article is referring to as a false negative is that if there were water (ice) in the original sample when it was taken, there's a risk that several days vibrating it in under low atmospheric pressure may cause it to evaporate. If it's a small enough sample, or the pressure is low enough, it could sublime, converting directly from ice into steam.

          This would result in a false negative if the original sample did, in fact, contain water, because spending that much time between ga
          • The oven is being used to detect organic compounds in the presence of water if I'm not mistaken. Orbital scans have pretty much proven the existence of water up till now. any water ice sublimating would still leave the organics behind in the sample. Kind of silly to go all that way just to boil some water.

            • by eonlabs ( 921625 )
              based on this article: http://phoenix.lpl.arizona.edu/science_tega.php [arizona.edu]
              the TEGA ovens go up to about 1000 degrees C...

              This means they're likely to be able to vaporize water, many organic compounds, but not silicon dioxide (sand/glass), and not most metals. It would be interesting to know what they hope to detect at that temperature...
    • by SBacks ( 1286786 )
      Flawed data is better than no data.

      • Re: (Score:2, Informative)

        by osu-neko ( 2604 )

        Flawed data is better than no data. Right?

        No. But that's not the issue here. What we're talking about here is getting less data than we'd like (because of what was excluded from the sample). Data is not "flawed" for being a smaller quantity, it's just, less. Some data is better than no data at all.

        • Re: (Score:3, Insightful)

          by profplump ( 309017 )
          Why isn't "flawed data" at least sometimes the same as "some data" and therefore better than "no data"?

          For example, what if you had a rain meter that leaked -- you couldn't accurately determine accumulation, and you couldn't conclusively ascertain that no water had fallen just because it was empty, but if the meter read 1.28" when you looked at it you could conclude that at least 1.28" of water had fallen since last time the collector was drained. The 1.28" reading would flawed, but the device would still p
      • Wrong, it is better to know that you have no data on a subject than, to hope that data you have might be correct on it.
    • Re: (Score:3, Insightful)

      by osu-neko ( 2604 )

      couldn't this invalidate the tests.

      I don't think so. What would they be testing for that would be invalidated by this? If they find presence of life, or evidence of past life, the fact that they screened something out doesn't invalidate what they found in what was left. If they fail to find anything like that, there's no valid conclusion that could be drawn in any case (absence of evidence is not evidence of absence), so a conclusion of "there's no life and never was" would be invalid regardless of whether parts of the sample were scree

      • Re: (Score:2, Interesting)

        (absence of evidence is not evidence of absence)

        Yes, it is:

        Absence of proof is not proof of absence. In logic, A->B, "A implies B", is not equivalent to ~A->~B, "not-A implies not-B".

        But in probability theory, absence of evidence is always evidence of absence. If E is a binary event and P(H|E) > P(H), "seeing E increases the probability of H"; then P(H|~E) < P(H), "failure to observe E decreases the probability of H". P(H) is a weighted mix of P(H|E) and P(H|~E), and necessarily lies be

        • by maxume ( 22995 )
          Did the post include a hilarious pontification on being a Bayesian reasoner, with no hint of acknowledgment that a Bayesian decision depends on its input?
        • While I'm sure you think you're being clever, in this instance absence of evidence is not evidence of absence. Just because I can't find evidence of a platypus outside my house does not prove that no platypuses(platypae?) exist on the planet. The mere fact that the page you referenced singles out probability theory as the exception should have been enough to figure out that maybe your assertion has limited application.
      • Re: (Score:2, Insightful)

        by cetitau ( 951106 )
        I don't want to sound like an expert in this field but I don't understand this response. This science doesn't look for life. Here it's looking for some specific chemical content in the oven at the conclusion of the test. If clumpiness was a result of soil mixed with frozen volatiles, i.e. soil particles stuck together by water or other ices, then evaporation of the volatiles over these days of shaking could certainly alter the outcome. I believe none of these tests are designed to prove or disprove the
        • by bytesex ( 112972 )
          Look man, I'll just wave into the camera next time I walk past it Ok ? I mean, I know where they landed the thing, it's just that I always walk through the park.
      • Re: (Score:3, Funny)

        by antic ( 29198 )
        "If they find presence of life..." ...let's cook it!
    • My first instinct was to dismiss your concern outright. I mean why wouldn't they have tested the apparatus in a lab on earth, before sending it to mars? But NASA is capable of making mistakes on complex missions,as we saw from the mars climate orbiter experience [cnn.com]From that incident we got this priceless quote:

      "People sometimes make errors," said Edward Weiler, NASA's Associate Administrator for Space Science in a written statement.

      • another thing to realise is that afaict martian "soil" isn't something we have a huge ammount of experiance with. All our knowlage comes from instruments on probes which are way way behind what we have on earth.

        has anyone even tried sieving the stuff before?

        • has anyone even tried sieving the stuff before?
          No. But I thought they could have done better than spreading a mountain of the stuff over the oven lids when they only needed a few grains. They have contaminated the other ovens.
      • by Anonymous Coward on Wednesday June 11, 2008 @07:26PM (#23756555)
        It is a real concern, but it isn't a mistake.

        The JPL engineers who designed it knew from the start that certain compounds, including water ice, would begin to sublimate once the soil was disturbed. For this reason, they wanted to get the samples into the chamber relatively quickly. It is very likely that the 3-4 day delay caused some loss of volatiles. It doesn't completely invalidate this sample because it's unlikely that all the ice sublimated, and water isn't the only thing they're looking for.

        Also, there are 7 other chambers in this instrument, and they believe they've figured out how to avoid this trouble in the future.

        They did test the aparatus pretty thoroughly on earth, but the soil properties ended up being quite a bit different from what they expected. No mission before has handled soil in quite the way Phoenix does, and the soil at the north pole may well be different from that in locations where previous landers have touched down.
    • couldn't this invalidate the tests. it seems to me that the clumps could be caused by the very ice we are looking for.

      The instrument in question isn't looking for ice, but is measuring the chemical properties of the soil.
    • by SiliconEntity ( 448450 ) on Wednesday June 11, 2008 @06:44PM (#23756037)
      This is just the first test. At this point, Phoenix is supposed to be testing the soil, not the ice. Later, they are going to dig down into the ice. They have a special drill-like object on the digging tool which will drill into the ice and produce fine shavings. These shavings will then be scooped up and dumped into the oven. But that will come later, first they are testing the soil. This is what has been a problem so far, it's good that they have managed to make progress with it.

  • by Volante3192 ( 953645 ) on Wednesday June 11, 2008 @05:16PM (#23754877)
    Great, now all Phoenix is going to say to NASA is TILT!

    We're gonna have to fly someone up there to deposit a dollar in quarters into Phoenix now...
    • by JosefG ( 1306077 )
      I hear they tried this already, but when they converted a dollar into quarter they ended up with three and the mission was a failure. At least they only wasted $0.75 this time.
  • by elrous0 ( 869638 ) * on Wednesday June 11, 2008 @05:16PM (#23754889)
    Why would they have designed the thing to have such a low tolerance filter in the first place? Hell, most *terrestrial* soil wouldn't even make it into that oven. I sure wouldn't use it for a soil whose composition was largely a mystery. And, even if they get something, will it truly be representative of the Martian soil, or just the finest particles of it that finally made it through?
    • by SBacks ( 1286786 ) on Wednesday June 11, 2008 @05:27PM (#23755035)

      Why would they have designed the thing to have such a low tolerance filter in the first place?
      Cuz they had to strap it on a rocket and shoot it to Mars? I kinda doubt a full sized lab furnace would be under the weight requirement.
      • They also had to drop it on the surface without making a new impact crater. Again, low weight makes that easier.
    • by Ihlosi ( 895663 )
      Why would they have designed the thing to have such a low tolerance filter in the first place?

      Probably because heating a larger amount of soil would have been too much of a drain on the batteries of the thing.

      But I agree. 1 mm diameter particles are tiny.

      • by Sponge Bath ( 413667 ) on Wednesday June 11, 2008 @05:45PM (#23755263)

        1 mm diameter particles are tiny.

        For the common man who needs a frame of reference: This is the same length as the distance between the solder balls of many BGA IC packages.

        • by Changa_MC ( 827317 ) on Wednesday June 11, 2008 @05:54PM (#23755351) Homepage Journal

          1 mm diameter particles are tiny.
          For the common man who needs a frame of reference: This is the same length as the distance between the solder balls of many BGA IC packages.
          Good lord, that didn't help him at all. For the common man: a dime is about 1mm thick.
        • 1mm isn't really all that small.

          Thing is that under a BGA you need a grid of vias and if you don't want to use blind vias (which are expensive and complicate the design process) you have to get tracks between the vias.

          If you have a minimum hole size of .25mm and a minimum track gap and annular ring of .1mm (theese are not hypothetical figures, they are zot's "standard production" figures). With a 1mm pitch BGA you can get two tracks between a pair of vias on each layer. With an 8mm pitch BGA you only get o
        • 1mm is not tiny when the diameter of the test chamber is about 2mm.
        • Re: (Score:1, Informative)

          by Anonymous Coward
          Gee, and all this time I thought of it merely as a tenth of a centimetre :-)

          Another easy frame of reference is twice the diameter of the most common mechical pencil lead size: 0.5mm. Wooden pencils usually have 2mm leads. Virtually all of them are metric.
    • by drrck ( 959788 ) on Wednesday June 11, 2008 @05:43PM (#23755227)
      We're talking about introducing material into an oven to be vaporized for Mass Spec analysis. You don't want or need to deal with huge amounts of material to tell what compounds are in the soil.
      • Re: (Score:3, Insightful)

        You don't want or need to deal with huge amounts of material to tell what compounds are in the soil.

        You also don't want half of the contents to sublimate by leaving them exposed to sunlight and friction/heat from a vibrating screen. Considering how important it was to land where there was ice (polar landings are tough) you think they would be a bit more careful to preserve that ice since that is where they hoped to find the organic compounds.
        • Why do you say polar landings are tough? Why would they be any tougher than landing anywhere else on the planet?
          • by Ihlosi ( 895663 )
            Why do you say polar landings are tough?

            Same reason why you usually don't launch rockets from the poles - delta-V.

            Why would they be any tougher than landing anywhere else on the planet?

            Because you need to deal with a much higher delta-V when landing on the pole compared to landing on the equator (provided that you're landing on the side of the planet that rotates in the direction that your spacecraft is coming in - if you try the other side, you're going to have to deal with twice the delta-V of a

            • Because you need to deal with a much higher delta-V when landing on the pole compared to landing on the equator

              Let's see... Mars diameter... sidereal rotation... carry the two... 240 m/s. Earth-Mars velocity difference 2649 m/s [phy6.org]. The delta-V due to rotation is a tenth of what needs to happen to burn off the delta-v from getting to Mars in the first place. It's an extra handful of seconds behind the heat shield, plowing through the atmosphere. It's not really all that tough.
              • by Ihlosi ( 895663 )
                The delta-V due to rotation is a tenth of what needs to happen to burn off the delta-v from getting to Mars in the first place.

                And 1/10 of additional velocity roughly translates to 20% more energy that needs to be dissipated.

              • The trajectory of the spacecraft will be in the plane of the solar system, which is pretty much the plane of Mars's equator. If you want to land near the equator you're already going the right way for aerobraking in an equitorial orbit; you more or less just spiral down (that is of course a gross oversimplification). If you want to land at the pole you'd need to transfer from the 'natural' equitorial orbit to a polar one, which requires a bit more than merely an extra few seconds of aerobraking.
                • Mars, as seen from Earth subtends 25.1 seconds of arc, or 0.00697 degrees. The plane of Mars's orbit is 1.85 degrees off of the plane of Earth's orbit. So to do a Mars polar insertion means using a launch angle of 1.8535 degrees instead of 1.8500 degrees (and possibly as low as 1.8505 degrees depending on where Mars is in it's orbit at arrival time).

                  Look at it this way. Imagine you're at mid course in your transfer orbit and Mars is dead center in your crosshairs. It's going to take roughly the same am
    • There are two different questions in your post - subject line and slightly different focus in comments.

      Tolerance is not an issue here. It is highly likely that all components used were machined with a very high degree of tolerance (say +/- .01% or better of nominal value). Size of that opening 1mm, probably what you are talking about, is very close to what is used in an ordinary sieve. If soil is wet or even damp, it would not get through, as you mention. May be NASA thought that when they blasted the groun
  • Hooray (Score:5, Funny)

    by Haoie ( 1277294 ) on Wednesday June 11, 2008 @05:18PM (#23754919)
    We've come along way from the Easy-Bake Oven.

    But I still bet the Phoenix can't make smores.
    • But I still bet the Phoenix can't make smores.

      It could but it would require 1mm graham crackers and marshmallows.

    • by Chrutil ( 732561 )
      >> But I still bet the Phoenix can't make smores.

      Right. All they've got is "shake and bake"
    • I was just about to post a comment about the easy-bake. You're too quick... cooking cakes with that 100W light bulb and all.

      Imagine how long an ez-bake would take today with all of our "green" CFLs using 20-ish watts and putting off a very small amount of heat.

      "Mom, I just put the cake in the 'green EZ-bake', set the timer for 72 hours please!!"
  • by nguy ( 1207026 ) on Wednesday June 11, 2008 @05:21PM (#23754961)
    To their surprise, NASA scientists discovered that, try as they might, roasting a phoenix in an oven never results in well-done meat.
  • Let the baking begin.
  • by kharri1073 ( 1036550 ) on Wednesday June 11, 2008 @05:40PM (#23755191) Homepage
    They should have consulted willitblend.com before they sent the craft to mars. I'm sure the people at will it blend would have had no problems getting some martian dirt through a micro screen.
  • by exp(pi*sqrt(163)) ( 613870 ) on Wednesday June 11, 2008 @05:44PM (#23755239) Journal
    ...you didn't want a bun in the oven.
  • Today the most Illustrious Council of Elders confirmed that the plan to paralize the terrifying invasor from the sinister blue planet was a success.

    But first, a word from our sponsors:


    Tonight, in "Our Council Answers": The S'karr is a lie? Find out the latest conspiracy theory and the REAL reason why the traitors want to have K'Breel, our most benevolent and enlightened speaker from the Council of Elders, - Gfa'rdmn forbid - removed. After all questions are answered, you can witness how blasphemers have their gelsacs ripped appart, and then kicked to the *IMPROVED* Snarpat pit of death! You can't miss it!

    K'breel, speaker for the Council, calmed down the population:

    Gentle Citizens, please do not be alarmed. The terrifying metallic creature sent here by the sinister blue planet has been slowed down. We have been reported that the plan to paralyze its feeding organs has been a success, with the creature unable to eat for at least five days.
    K'breel said that the creature was only paralized and not destroyed so the Council would have more time to think of an effective plan. The public cheered when they heard speaker K'breel say the following words:

    What is important is that the metallic creature does not record any sign of intelligence under our beloved red sky. But do not be afraid, for soon we will elliminate it, making it look like an accident.
    When a subversive traitor accused the speaker for the most Illustrious Council that the slowdown was simply a malfunction in the metallic creature's machinery, K'breel ordered to have him imprisoned and executed tonight for High Blasphemy.
  • From my reading of the FA, it seems that oven #4 is the first oven they tried. That's important, because it seems that whether the soil gets there or not, they only get one try with each oven. So they still probably have 7 more to go. Hurrah, NASA!
  • GO!

    These two teams are shakin' things up trying to fill four thermal and evolved-gas analyzer instrument ovens past the line. Whoever does it first will win $20, and control of the most interplanetary game show on television...

  • Considering all the difficulties in a shake & bake, a set of microphotographs at different magnifications, say 10X to 100X would have revealed more about the composition. Given a choice between seeing something and reading a chemical analysis to understand unknown matter, what would you prefer?
  • I know that yeah, its too cold for that happen on Mars, but, maybe there's something or some chemistry that acts like a wetting agent. Thus, once the soil filled up the beaker, it had lost the effects of the wetting agent that had "glued it together" - just like mud can be sticky before it possibly powders up as it dries. So, really, the whole experiment is botched and the lander blew it, again.
  • Nothin' says lovin' like Martian soil in the oven!
  • its depressing how feeble and unreliable the space probe design are compared to the insane amounts of investment. a shovel, to scoop up dirt, instead of some decent drilling apparatus that could get samples from much deeper and from harder surface. days to fill a small hole. solar panels that get covered in dust because someone is too lazy to add windscreen wipers. making things heavier and more robust than needed resulting in insane liftoff prices. everything designed like alpha stage prototype. no conside
    • Re: (Score:3, Insightful)

      by Ihlosi ( 895663 )
      its depressing how feeble and unreliable the space probe design are compared to the insane amounts of investment.

      And you're ... qualified to make this statement ? Are you any kind of engineer (ME or something along those lines would be best) ?

      shovel, to scoop up dirt, instead of some decent drilling apparatus that could get samples from much deeper and from harder surface.

      Yes, of course, a drill. How brilliant. So where do you get all the power to run that drill ? How do you keep it lubricated ? H

      • heh not quite engineer but smth along the lines for sure, i doubt a drill would be heavier than a robot arm + shovel, the do manage all other moving parts wo lubricants, thre are plenty(arm joints, wheels etc). one could easily spend a lot of time drilling the hole so it could be powered by solar panels, it would still be lot faster and power efficient than robot arm + shovel method. you can brush anything clean of dust wo any liquid right? solar panels are covered with protective glass anyway so i wouldnt
  • They have to do some cooking and measuring. How long does that all take?
  • You've probably seen the "real" Mars Phoenix twitter page: http://twitter.com/MarsPhoenix [twitter.com] Check out the "alternative viewpoint": http://twitter.com/fakemarsphoenix [twitter.com]

The moon is a planet just like the Earth, only it is even deader.