Slashdot Mirror

← Back to Stories (view on slashdot.org)

NASA Selects Landing Site for Phoenix Mars Lander

Posted by Soulskill on from the just-keep-your-units-straight dept.

Earlier this week, NASA made a course adjustment for its Phoenix Mars Lander which puts it on a path to land in "Green Valley" on the Red Planet late next month. The site was chosen for being a broad, flat expanse that is relatively free of rocks capable of damaging the lander when it sets down. The location will be confirmed pending further reconnaissance from an orbiting satellite. The probe's mission, which we've previously discussed, is to investigate subsurface ice. "The landing area is an ellipse about 62 miles by about 12 miles (100 kilometers by 20 kilometers). Researchers have mapped more than five million rocks in and around that ellipse, each big enough to end the mission if hit by the spacecraft during landing. Knowing where to avoid the rockier areas, the team has selected a scientifically exciting target that also offers the best chances for the spacecraft to set itself down safely onto the Martian surface."

39 comments

  1. Ironic by calebt3 · · Score: 3, Funny

    We land these things in rock-free regions so that they can look at rocks.
    (Yes, I know this one is looking for ice)

    1. Re:Ironic by Anonymous Coward · · Score: 1, Funny

      It's really to aid in the faking of the landing.

    2. Re:Ironic by SegFault · · Score: 1

      This spacecraft does not have any means of detecting and avoiding rocks on the surface. In addition, due to the physics of how the landing radar works, it will actually steer the spacecraft into any obstacles on the surface.

      As a result, we're targeting for a landing location that's flat and relatively free of large rocks in order to provide the least risk to mission success.

      The science payload on this mission is not dependent on landing near any rocks for success. In contrast, it needs to land near dirt that its arm is capable of digging into.

    3. Re:Ironic by davolfman · · Score: 1

      You'd think in this day and age we could build a lidar system to identify bumps to avoid.

    4. Re:Ironic by notepad_doodler · · Score: 0

      Ice is flat. Why not land it on the pole ice if you're looking for ice?

    5. Re:Ironic by CowboyNealOption · · Score: 1

      In addition, due to the physics of how the landing radar works, it will actually steer the spacecraft into any obstacles on the surface. Couldn't they find the routine that checks to see where to steer and simply have it return a 0 instead of a 1???
    6. Re:Ironic by Anonymous Coward · · Score: 0

      Except that this is basically a surplus Mars Lander (similar to the ill-fated Mars Polar Lander) originally intended to be used in 2001, built with parts and designs developed in the early 90s. It's not like they went out last year and whipped up a design and bought all new parts. Even if you were, I suspect that you couldn't build such a device.

    7. Re:Ironic by tftp · · Score: 1

      The last time they tried that the lander decided that it's not worth landing at all, and missed Mars :-)

  2. Re-Name That Lander by Anonymous Coward · · Score: 5, Funny


    In other news today, NASA announced that the Phoenix Mars Lander will now be called the Firebird Mars Lander.

    UPDATE: Make that Firefox Mars Lander.

    1. Re:Re-Name That Lander by ELProphet · · Score: 1

      That would be sweet, especially if they put a Firefox logo on the solar panels. Extra points if it's visible in orbiter photos.

    2. Re:Re-Name That Lander by uncoveror · · Score: 1

      The problem with the original name is that it reveals that the landing site is a lot closer to Phoenix than Mars. NASA has done this before. Read more!

      --
      The Uncoveror: It's the real news.
  3. Need to think of other ways of landing by NorbrookC · · Score: 4, Interesting

    At some point, it might be useful to think of other methods of landing probes. Not all of the scientifically interesting areas are going to be near easy-to-land on sites, free of large rocks or unexpected features. In order to get to them, probes are going to have to land on rough terrain, or be able to move there. Which ought to pose some nice challenges for the engineers designing these probes.

    1. Re:Need to think of other ways of landing by Anonymous Coward · · Score: 4, Insightful

      Yeah, but rovers are more expensive. The Phoenix lander was one of NASA's throwaway missions (the Mars Scout missions). They didn't throw in all the bells and whistles nor did they expect a 100% chance of success. It was launched because it was cheap and there is a moderate chance of success. If it fails it won't be a big deal since it was cheap. At least that is the logic behind it.

      I'm not sure I agree with this philosophy. It sounds good on paper but we need to remember what happened to the Mars Polar Lander, part of Dan Goldin's Better-Faster-Cheaper program. I think we all remember how that program worked. It seems to me that the Phoenix lander is just another Better-Faster-Cheaper probe. I hope it doesn't die like many of the others. I like the idea of getting science on the cheap, but the engineer in me is extremely skeptical.

    2. Re:Need to think of other ways of landing by ceroklis · · Score: 4, Informative
      You should apply to the JPL, I'm sure they never thought of that.
    3. Re:Need to think of other ways of landing by Ngarrang · · Score: 2, Informative

      They do have a better way. Retro rockets to slow the descent to a crawl + springy legs because 1 to 2 m/s is still a hard landing. It comes down to cost. This solution is more expensive.

      --
      Bearded Dragon
    4. Re:Need to think of other ways of landing by SegFault · · Score: 4, Informative

      Phoenix is a re-fly of MPL using flight-spare MPL hardware. The difference is that since the spacecraft and instruments were already on the shelf, there was relatively more budget for the kind of investigation, review, and rework that the original mission should have had. As a result, we've identified and fixed a sobering number of fatal errors in the original design.

      The disposition of the team at this time is "cautiously optimistic", which is more confidence than we had on MER at the same time. That said, there is always residual risk and the chance of just having a bad day.

    5. Re:Need to think of other ways of landing by Tablizer · · Score: 1

      It sounds good on paper but we need to remember what happened to the Mars Polar Lander, part of Dan Goldin's Better-Faster-Cheaper program. I think we all remember how that program worked. It seems to me that the Phoenix lander is just another Better-Faster-Cheaper probe.

      No, they've done exhaustive landing tests this time. The BFC philosophy is a thing of the past. However, it did have some merit because of the successful AND cheap Soujerner rover mission, which was about 1/8 the cost of a MER rover, and pioneered some of the technologies used later by MER. A 50% success rate at 1/5th the cost versus 85% success rate for "expensive" missions seems like a reasonable deal to me. But, pride and loss-of-face play a bigger role in such decisions. Managers and politicians just don't like uncertainty. The "Vegas" approach may be scientifically worth it, but results in too much nail-biting.

      I'd like to see a dozen or so cheap "micro-rovers" sent high-risk areas to check them over for later, more instrument-laden missions. If you have a dozen little rovers, you are less paranoid about failure because you have spares.

      --
      Table-ized A.I.
    6. Re:Need to think of other ways of landing by CowboyNealOption · · Score: 1

      It sounds good on paper but we need to remember what happened to the Mars Polar Lander... I thought that this mission was declared a success after it had been renamed the "Mars Impactor" to study crater formation on Mars?
    7. Re:Need to think of other ways of landing by DancesWithBlowTorch · · Score: 2, Interesting
      I actually find it quite intriguing that this sort of thing works at all. As the blurb claims (of course I didn't RTFA):

      "The landing area is an ellipse about 62 miles by about 12 miles (100 kilometers by 20 kilometers). Researchers have mapped more than five million rocks in and around that ellipse, each big enough to end the mission if hit by the spacecraft during landing.
      Assuming those rocks lie at least somewhat evenly spread apart, that's about one of those big dealbreakers per 4000 square feet. In other words, the spaceship has to be directed with such a precision, it could land in a suburb on Mars and be able to avoid hitting a house. Impressive!
    8. Re:Need to think of other ways of landing by DerekLyons · · Score: 1

      They do have a better way. Retro rockets to slow the descent to a crawl + springy legs because 1 to 2 m/s is still a hard landing. It comes down to cost. This solution is more expensive.

      Um... Retro rockets and springy legs is exactly what Phoenix is equipped with.
    9. Re:Need to think of other ways of landing by Cassius+Corodes · · Score: 1

      I thought it was supposed to settle the question of whether there is a difference between feet and meters?

      --
      Control is an illusion, order our comforting lie. From chaos, through chaos, into chaos we fly
    10. Re:Need to think of other ways of landing by Carnildo · · Score: 1

      The problem is that the "Faster better cheaper" probes are neither fast enough nor cheap enough for losses to be no big deal. If you're only launching one probe every launch window, it doesn't matter how cheap it is: failure will still hurt.

      --
      "They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
  4. exciting stuff by Gearoid_Murphy · · Score: 2, Funny

    this is a really exciting experiment, our understanding of life has progressed dramatically since the viking landers, if there is any viable trace of life down there, this robot will find it. The nature of the presence of water also stands to be dramaically confirmed by this spacecraft, can't wait to spark up a j and watch pictures from another world roll in...

    --
    prepare the survey weasels.
    1. Re:exciting stuff by kcbrown · · Score: 1

      this is a really exciting experiment .... if there is any viable trace of life down there, this robot will find it.

      It would be even more exciting if this were a Terminator robot, complete with remote Authentic Terminator Display, minigun, etc. As you say, if there's any trace of life down there, it'll find it...and kill it! And it'll all be televised. Exciting stuff!

      The only problem is, where is it going to find the right clothes to blend into Martian society? The Martian idea of a "bar" is probably vastly different from what any terminator knows of...

      --
      Use 'slashdot stuff' in the subject line in any email you send me if you want to get past the spam filter.
    2. Re:exciting stuff by mrvan · · Score: 2, Funny

      Obligatory:

      http://video.google.nl/videoplay?docid=1628597280384324194

  5. ft - m by Anonymous Coward · · Score: 0

    Now, lets see if they can select the correct conversion from feet to metres!

  6. Let's hope this time... by hyades1 · · Score: 5, Insightful

    ...they come up with a good answer to that single most important question: "Will that be metric or imperial?"

    --
    I've calculated my velocity with such exquisite precision that I have no idea where I am.
    1. Re:Let's hope this time... by Count_Froggy · · Score: 1

      At least they don't have to worry about US or Imperial in measuring distance! Trinary not spoken here.

      --
      If I am not for myself, then who will be for me? If I am only for myself, what am I? If not now, when?
    2. Re:Let's hope this time... by SegFault · · Score: 4, Informative

      Considering that Phoenix is a re-fly of the 1998 Mars Polar Lander mission, this was the subject of an intensive study of the command dictionary, flight software, and ground software.

      Please remember that the 1998 MPL and MCO missions were part of NASA's "Better Faster Cheaper" movement. These were budget class missions that exchanged significantly increased risk, in the form of less internal and external oversight and review, for significantly lower cost. The problem is that landing on another planet is a very hard problem, especially Mars. This mission carried "flagship" mission difficulty (ala MER) but wasn't given the budget to address anywhere near all the higher order risks. Keep in mind the atmosphere on Mars is too thick to use retro rockets all the way to the ground, like on the Moon, and too thin to use parachutes all the way down, like we have done on Earth. Also keep in mind that MPL and Phoenix missions use a landing system which is closest to a system that we hadn't flown in over 20 years (Viking). And it was chosen primarily for budgetary not technical reasons. I'm not even going to get started with the landing radar...

      The kinds of errors that killed MPL and MCO were exactly the kinds of risk that NASA bought by forcing the budget low. They purchased a mission with flagship risk on a budget that precluded mitigating those risks.

      Phoenix is a three-quarter measure to fix the errors of MPL. It's a re-fly of the 1998 MPL mission with the kind of oversight and peer review that the original mission would have had if it were designated the kind of budget that it deserved. The results of these ongoing studies have led to numerous design changes in hardware, radar firmware and antenna design, flight software, and fault protection. The team at Lockheed and JPL is cautiously optimistic.

  7. Tee-hee! A Rock! by Etherwalk · · Score: 1

    Tee-hee. Man stepped out of the cave, made fire and saw that it was bright, invented the wheel and the agricultural revolution, passed through the ancient times when some groundwork for science and philosophy was laid, and then dark ages. Then he saw the new nation-building necessitated by the infantry revolution, which helped lead us towards the renaissance and the industrial revolution, literacy rates climbed and productivity multiplied a thousandfold, we climbed into the sky and walked on the moon, and now we send probes to other worlds...

    But then a rock interrupted the process! =) It was always a perfectly nice little rock, sitting there minding its own business, just contemplating inertia for a few million years, when suddenly BAM!

    Ouch.

  8. Breaking news... by g0dsp33d · · Score: 4, Funny

    An anonymous engineer at NASA stated that the landing site will be in the Arizona desert just outside of Phoenix, hence the lander's name.

    --
    lol: You see no door there!
    1. Re:Breaking news... by rabiddeity · · Score: 1

      But Green Valley is pretty far from Phoenix, almost 150 miles if I remember correctly. Do you think it's a metric/imperial error?

  9. "I poop, therefore I am" by Tablizer · · Score: 1

    if there is any viable trace of life down there, this robot will find it.

    But Mars tends to surprise us. After the Viking experiments showed what may be life, researchers started pondering the Mars soil chemistry carefully and discovered ways in which inorganic chemistry may mimic it. Just because you can't think of a way that inorganics may mimic organics when you design the experiment, does not mean that one does not exist. Until cultures are seen wiggling, eating, pooping, and growing under powerful microscopes, the question will not likely be settled.

    --
    Table-ized A.I.
  10. Landing site by PPH · · Score: 1

    ... the team has selected a scientifically exciting target... Very near a rock outcropping that resembles a Martian plasma cannon.


    whatcouldpossiblygowrong

    --
    Have gnu, will travel.
    1. Re:Landing site by Anonymous Coward · · Score: 0

      They'll welcome us as liberators!

  11. namesake by v1 · · Score: 1

    Let us pray they don't have hopes of it rising from the ashes in the crater, in case it makes an abnormally hard landing.

    --
    I work for the Department of Redundancy Department.
  12. Phoenix, Mars, and Imminent Discovery by Anonymous Coward · · Score: 0

    According to the book "Imminent Discovery", Phoenix has a real chance to find life on Mars - based on the observations of pre-1965 astronomers, the ability of bacteria to live on Mars, and a few other reasons. This could be a truly historic event. Too bad the public isn't more interested.

    Good luck to Phoenix!