OMG this is NEVER going to work!

Posted by Greg Laden on June 29, 2012
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On August 5th, NASA will attempt to do what may be the dumbest thing they ever did.

Or, possibly, the most brilliant thing they ever did. Hard to say.

Perhaps you’ve heard about the Seven Minutes of Terror. This pertains to the process of landing the robot Curiosity on Mars. There are several steps and most of the steps have the following characteristics:

1) It won’t work if the previous step doesn’t happen just right;
2) It really can’t work anyway; and
3) The outcome of any given step is very likely to screw up the next step.

A kind of cycle of potential failure. Some of the steps are designed just to address the inter-step interference problem. For instance, the landing craft will be slowed down by a parachute, but that won’t slow it down enough, so rockets will takeover. But they can’t have rockets pushing the craft back up into the parachute. So there is this intermediate step where the landing craft free falls down from the parachute (thus speeding up a little) then rockets shoot it off to the side, horizontally, then the rockets slow it down and at this point the parachute needs to fall freely past the now rocket-propelled robotic rover.

Yeah, good luck with that, NASA!

Man, I wish they had run this by me first, I would have told them to simplify. Like by using a big spring or something.

But this could be an opportunity. We can generate a betting pool to determine which step goes wrong and why, with “nothing went wrong” and “we don’t know it seems to be missing” as two of the options. Any takers?

Here’s a video from NASA in which they hype the hell out of this thing. I think the approach here is to make failure exciting. Just in case.

Embedded video from

NASA Jet Propulsion Laboratory California Institute of Technology

So, what’s your wager?

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Image of landing site from NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS

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Comments

  1. #1 HP
    June 29, 2012

    I’d never wager against JPL. With Spirit and Opportunity, AFAIC, they’ve joined the ranks of such legendary engineers as Eiffel, Roebling, and Brunel.

  2. #2 Greg Laden
    June 29, 2012

    I know, but then there was that other Mars lander thingie ….

  3. #3 Artor
    June 29, 2012

    Why is this such a problem? It’s not like we have already successfully landed probes on Mars before. Spirit & Opportunity anyone? Was the method used then this screwy?

  4. #4 Michael Richmond
    June 29, 2012

    This lander is much more massive than the earlier landers. The airbag approach won’t work on an object of its mass.

  5. #5 Art
    June 29, 2012

    The plan massively violates the KISS principle. And it isn’t just complicated. Pretty much every step, and a whole lot of parts, are critical. Failure of any one of them has high odds of ending up with lander and vehicle ending up as a fill for a rather unimpressive crater.

    On the other hand this is sort of like attempting a hole-in-one bouncing the ball off the clubhouse, a tree, and a golf cart driven by a drunk. Failing big makes you a ballsy optimist, a dreamer, and a character. And, if you just happen to pull it off, you have secured your place in history.

    Failure will be an ‘opportunity to learn’, a noble attempt, a good try. Success means you have a shoe in for engineering/ design/ planning/ process/ project God.

  6. #6 Doug Alder
    June 30, 2012

    They should have talked to Wile E Coyote first :)

  7. #7 Greg Laden
    June 30, 2012

    Let’s just hope this contraption didn’t come out of a box labeled “Acme Spacecraft Inc.”

  8. #8 Cameron
    New Zealand
    July 1, 2012

    It seems to me that most things NASA do are complicated, some more so than others, yet they still do a damn good job. I was disappointed to see this post from someone within the scientific community as I thought they would have a better understanding of how NASA engineers and scientists go about their work than people from non-scientific backgrounds.

    I’m sure NASA didn’t go out of their way to make this complicated. Generally, the chosen solution is probably the most simple. That, or it’s the most likely to succeed. If they could have had made it more simple, I would be inclined to believe they would have done so.

    Some of the steps aren’t that difficult anyhow. They’ve nailed the part about getting spacecrafts in to the right position before landing many times. They know what to expect in terms of speed, acceleration, deceleration, heat, drag and everything else as they too have nailed this with previous missions (and its largely down to physics). Some aspects of the landing sequence have been done before on the previous missions. Removing the heat shield and getting the parachute to work probably aren’t any more difficult than sequences on previous missions. The timing is probably quite crucial but computers are good with that. There should be plenty of software to help the module adjust its thrusters and what not. Really, the biggest problems are probably the ones that can’t be controlled, like debris interfering with sensors.

    I doubt NASA are showing-off and making it go through all of these complicated steps for nothing. If they think this is the best option, it probably is. I can’t think of a better way to land it.

    Anyhow, I wish NASA good luck and I hope things go well.

  9. #9 Greg Laden
    July 1, 2012

    Cameron, the whole “this is never going to work” think is tongue in cheek. I’m merely playing off of NASA’s hyping up how amazingly hard this is going to be. I fully expect it to work, and I expect this rover to outperform its expectations like the others have! Or at least I hope it does.

  10. #10 John Roberts
    Portland
    July 1, 2012

    Five rails and a kiss…in the side pocket. No problem?! I wouldn’t put money on this game but it will be a huge thrill if they pull it off. Weirder things have happened.

  11. #11 Cameron
    July 5, 2012

    Thanks for clearing that up Greg. I had been on edge regarding this topic as I’ve had to defend it to people who think all science does is throw away money (made worse now that everyone knows the LHC cost $10 billion and all it did was find a ‘particle’).

  12. #12 Cameron
    July 5, 2012

    Thanks for clearing that up Greg. I had been on edge regarding this topic as I’ve had to defend it to people who think all science does is throw away money (made worse now that everyone knows the LHC cost $10 billion and all it did was find a ‘particle’).

  13. #13 Greg Laden
    July 5, 2012

    Yeah, and it wasn’t even a particle. It was a wigilly diggilly wavey sort of thing.

  14. #14 Art
    July 11, 2012

    I didn’t mean to imply that this is a drunk’s long shot made needlessly complicated. It is a complex problem with tight parameters for success further complicated by limitations of cost and launch weight. Yes, there are simpler solutions.

    You could build the lander with large rocket motors that would fire pretty much all the way down. It would be a single solution and much simpler. But, because the much larger rocket motors and fuel needed to run them, it would also involve launching a much heavier lander package. Which means a much larger launch vehicle and everything in turn getting heavier and more expensive.

    The ablative heat shield and parachute combination is a lower cost and lighter way of doing a good part of the job slowing things down. But it adds complications and modes of failure as the lander has to undergo transitions from riding the heat shield, to hanging under a parachute, to rockets.

    Given the constraints, it is hard to imagine another way of doing it.