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Space Technology

SpaceX Launch Failure Due To Timing Problem 244

Posted by CmdrTaco
from the ironically-he's-an-atheist dept.
FleaPlus writes "Private orbital spaceflight company SpaceX recently announced that last weekend's Falcon 1 rocket launch failure was caused by a collision between the first and second stage of their rocket. This was due to a timing problem, when their brand-new engine design produced residual thrust for 1.5 seconds longer than expected; they're currently working to fix the problem and launch again, perhaps as early as next month. In a recent interview with Wired, SpaceX CEO Elon Musk remarked on their efforts: "Optimism, pessimism, f-ck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work.""
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SpaceX Launch Failure Due To Timing Problem

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  • Wow (Score:5, Informative)

    by Anonymous Coward on Thursday August 07, 2008 @08:44AM (#24508563)

    Optimism, pessimism, f-ck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work

    Now that sounds like a man who gets things done.

  • by th1nk (575552) on Thursday August 07, 2008 @08:58AM (#24508687)
    I think it's the part in the wired article that goes like this:

    Musk: Do I sound optimistic?

    Wired.com: Yeah, you always do.

    Musk: Optimism, pessimism, fuck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work.

  • Re:I must ask (Score:2, Informative)

    by dontPanik (1296779) <ndeselms&gmail,com> on Thursday August 07, 2008 @09:34AM (#24509053)

    Did it have the mortal remains of any famous actors onboard?

    From TFA

    the ashes of 208 people, including astronaut Gordon Cooper and James Doohan, the actor who played Scotty in the original Star Trek television show

  • by dontPanik (1296779) <ndeselms&gmail,com> on Thursday August 07, 2008 @09:36AM (#24509087)
    There was a DoD satellite and a NASA thingie on board when it failed.
    Also there's plans to make deliveries to ISS once the shuttles are through.
  • Re:Timing? WTF? (Score:5, Informative)

    by X0563511 (793323) on Thursday August 07, 2008 @09:48AM (#24509245) Homepage Journal

    Bottom stage detached, continued burning. Less mass against the thrust, it accelerated and pushed on the top stage (but not perfectly centered as it would when still attached).

    I'm sure they do communicate, but after detaching that's gone.

    Basically the thruster(s) dieseled - continued running for a moment after fuel/whatever was cut.

  • Re:Wow (Score:5, Informative)

    by oliderid (710055) on Thursday August 07, 2008 @10:03AM (#24509433) Journal
    if you invest into spaceX Obviously:
    • You are aware of the risk
    • You don't expect any return on investment in a short/medium term...Or better you don't expect anykind of return at all.
    • You know it will waste large sum of money.
    • You are looking for fun.

    What you need are fanatics investing all their energy in the project and leading the team. Like him. And then it could be a success IMHO. Cold blood/rationnal manager would have left this project already.

  • It's called passion. (Score:3, Informative)

    by JonTurner (178845) on Thursday August 07, 2008 @10:21AM (#24509693) Journal

    General Patton would have disagreed. He understood the problems faced by his "team" and inspired them to overcome incredible odds. Sometimes a little profanity can be inspiring, if not used gratuitously.

    >>Would you like to work for such a man?
    Yes, actually I would. Because that sort of man, and the people who work for him, are going to do great things! That's real passion, which is sadly lacking from most corporations. He's not just your average CEO coasting toward a golden parachute and a retirement filled with golf and tea parties -- he's trying to overcome incredible odds to get a vehicle into space.

  • Re:Timing? WTF? (Score:5, Informative)

    by Anonymous Coward on Thursday August 07, 2008 @10:28AM (#24509797)

    I AM a Rocket Scientist.

    Traditionally, no, they wouldn't be timed individually. That's kind of a silly thing if you asked me.

    Typically you should wait until the first stage stop accelerating the rocket before dropping it. A sensor typically detects that condition and initiates seperation. To be safe, it may wait a beat or two before taking action to make sure the booster isn't just "chuffing". Or the sensor could have just been faulty, initiating seperation too soon.

    If the booster begins accelerating again (as in blows up) or gives a last burst of unexpected glory, that's just bad design or manufacturing issue. If it's a solid-fuel booster, that could happen from time to time, but if the motor is liquid fueled it should just cut off fuel and be done with it.

    Now, you could put the stages on their own timers, but there are risks. Usually the problem is a failed booster, and the timer on the upper stage fires with the rocket pointing the wrong way.

  • Re:Timing? WTF? (Score:1, Informative)

    by Anonymous Coward on Thursday August 07, 2008 @10:50AM (#24510133)

    Not quite. You normally want some seperation between the first and second stages before igniting the 2nd stage motor(s). That way, your own burning fuel doesn't get reflected back at the bottom of the 2nd stage. It sounds like the first stage pushed back against the second stage, when the 2nd stage motor fired, "cooking" the bottom of the second stage (thing burned fuel lines, control wiring, structural pieces, etc...).

  • Re:Hell-bent (Score:5, Informative)

    by Rei (128717) on Thursday August 07, 2008 @11:41AM (#24510817) Homepage

    The problem being that the sets 'folks who share that passion' and 'folks who have significant money to invest' have essentially zero overlap.

    There's pretty much a whole class of dotcom-wealthy geeks in Silicon Valley who are a living contradiction to that statement. Let me tell you, for the most part, it's not movie stars who are plopping $100k down for Tesla Roadsters.

    Investments as far out on the bell curve as SpaceX have always had a hard time finding capital.

    SpaceX's third failure in a row just occurred and they just got a brand new influx of investment capital.

  • by Seraph787 (859123) on Thursday August 07, 2008 @12:07PM (#24511175) Homepage
    according to the interview they have "12 flights ahead of us"
  • Re:Wow (Score:3, Informative)

    by PeterBrett (780946) on Thursday August 07, 2008 @12:28PM (#24511473) Homepage

    Management needs someone who can do for businesspeak what Edward Tufte did for the visual presentation of information. It's not just the PowerPoint that kills astronauts, it's the use of phrases like "the stresses imposed by the frozen deposit upon the RCC were in excess of design parameters" as opposed to "Are you fucking nuts? We never tested for that shit, so none of us has any fucking clue how bad the damage is until someone gets the fuck out there and actually looks at it!" (Challenger), and "The performance of the O-ring under this thermal profile is not guaranteed, but is likely to be adequate" over "Well, I'd bet $50 that nobody dies this time, but I sure as fuck wouldn't want to be flying on it. If you really wanna get the teacher in space in time for the State of the Union speech, it's your call, boss. Don't fuckin' blame me if you kill 7 people." (Columbia).

    You got those shuttles wrong way round. Just sayin'.

  • So close... (Score:5, Informative)

    by ClayJar (126217) on Thursday August 07, 2008 @12:37PM (#24511577) Homepage

    Actually, that's basically what happened. The Kestrel engine on the second stage ignited, and the exhaust from it pushed the first stage away. The problem is that the second stage is designed to have the exhaust expanding into the vacuum of space, and having the first stage right there meant that the exhaust was contained within (or perhaps I should say, was redirected by) the interstage. Normally, the first stage and second stage are pneumatically pushed apart just before the second stage fires.

    The exhaust was only in contact with the second stage for a very short period of time, but that was sufficient to "roast" the second stage enough to cause failure, either due to direct thermal effects or the forces created by the expanding exhaust (or to a combination of those factors).

    By the way, the nozzle of the Kestrel engine is radiatively cooled. Before the sloshing doomed flight two, it was cool (figuratively only!) to see the bell glowing brightly. Some people watching with me thought it was failing until I explained that it's supposed to look like that. ;)

  • by Chris Burke (6130) on Thursday August 07, 2008 @12:54PM (#24511821) Homepage

    To be blunt, a serious outfit would know how long their damn engine burns for.

    Yeah, maybe. Maybe not. Everything you would call a serious outfit had many more failures than Space X has had so far.

    Yes they need to pull it together. Yes they need a successful launch or it will call into question their whole business plan.

    No having three failures, and miscalculating an engine parameter, does not prove they aren't a serious outfit. Because no serious outfit has entirely avoided these mistakes.

    So, for all Musk's bluster, your lean mean private enterprise doesn't seem to have much of an edge over decades old Soviet engineering.

    You say "decades old" as if it's supposed to mean that lowers the bar for Space X, as if it's the same as saying "your new microprocessor doesn't seem to have much of an edge over decades old Intel parts". They're nothing alike. "Decades old" in this case means that the Soviets just got all their on-the-pad and mid-air explosions out of the way decades ago. If you assume that having such accidents means an outfit is non-serious, then what you're really saying is that there can never be a new serious outfit again.

  • New Engine (Score:3, Informative)

    by iamlucky13 (795185) on Thursday August 07, 2008 @01:52PM (#24512763)
    Yes, the events are synchronized. Main engine cut-off occurs 1.5 seconds before the stage separation pyros fire.

    When engine cut-off occurs, valves close to shut off fuel from the pumps. However, there is still fuel left in the lines that finishes burning resulting in a little residual thrust. In their previous test flight, this finished within that 1.5 seconds. However, this launch used a new engine design.

    The previous engine design was ablatively cooled. This means the engine nozzle is kept from melting by small amounts of material continuously burning off and carrying heat away. It's pretty analogous to sweating. The newer Merlin 1C is regeneratively cooled, which increases the performance and efficiency of the engine by running the cold fuel through small pipes that surround the engine nozzle for cooling.

    These cooling channels means there's more volume of fuel left in the system at cut-off, and the burn ends up being slightly longer. Musk has stated that this didn't show up as a problem on the test stand because of the pressure difference at sea level versus the near vaccuum where staging occured. 14.7 psi across a half-meter or so rocket nozzle amounts to a few thousand pounds of thrust. However, if you watch the test videos they've published, there's noticeably more flame after cutoff in the regenerative version, so I'm frankly kind of surprised they didn't increase their timing margin.

    The end result was that the 1st stage bumped back into the 2nd stage after separation, and then got toasted by and deflected flame back at the 2nd stage, apparently seriously damaging it.

    I have to nitpick one of Musk's other statements. He claimed that the performance of the first stage was picture perfect. However, while the engine appeared to perform great, it seems the avionics could have done at least slightly better. The video shows a back and forth rolling motion that is probably due to the torque created as the fuel swirls through those cooling channels. Ideally the control system would have been able to account for that smoothly.

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