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SpaceX Pressure Hammers Stuck Valves; Dragon's ISS Mission Back On Track 170

Posted by timothy
from the click-and-clack-the-tappet-brothers dept.
SpaceX's Dragon launch to the ISS earlier today went off smoothly, but the mission encountered trouble shortly after: three sets (of four) of the craft's maneuvering thrusters didn't work. CNET quotes SpaceX founder Elon Musk: "It looks like there was potentially some blockage in the oxidizer pressurization (system). It looks like we've been able to free that blockage, or maybe a stuck valve. We've been able to free that up by cycling the valves, essentially pressure hammering the valves, to get that to loosen. It looks like that's been effective. All the oxidizer tanks are now holding the target pressure on all four (thruster) pods. I'm optimistic we'll be able to bring all four of them up and then we'll work closely with NASA to figure out what the next step is for rendezvousing with space station," and follows up with the good news that "Shortly after the briefing concluded, engineers reported all four sets of thrusters were back on line and that testing was underway to verify the health of the system." Barring further problems, Dragon could reach the ISS as soon as Sunday.
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SpaceX Pressure Hammers Stuck Valves; Dragon's ISS Mission Back On Track

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  • Boeing (Score:5, Funny)

    by Anonymous Coward on Friday March 01, 2013 @09:34PM (#43051381)

    wonder if boeing will offer to help.

    • by Anonymous Coward

      It sounds like this is a minor issue which can be easily corrected for the future. Just improve the heaters around that piping, and they'll clear that problem up. Alternatively, could sonic transducers help?

      • by murdocj (543661)

        Yeah... or reversing the phase polarity, that always works on Star Trek.

        Really, right now they don't know what caused the problem, it's a little early to design the solution.

    • by mug funky (910186)

      this needs more funny mods.

  • by Baldrson (78598) * on Friday March 01, 2013 @09:45PM (#43051457) Homepage Journal
    Cryogenic valve failures are problems that seems to put about 50% of private launch service companies under or at least at serious risk from decades ago.

    I'm sure Musk is aware of this but really, it just seems to make sense to find the best cryo valve guy in the world and give him one and only one full time job: Make sure the damn things work!

    • by Taco Cowboy (5327) on Friday March 01, 2013 @10:08PM (#43051587) Journal

      It could be that Musk already got that guy under employment, but the very best guy in this world still fall short of getting this problem licked, once and for all

    • I have not seen a Dragon capsule put into a thermal-vacuum chamber (if it has, let me know). Such a chamber lets you run the hardware through the whole range of environments and temperatures from launch to orbit. Presumably the liquid helium pressurant is very cold, and that can cause valve icing. When the compartment has air around it, that can supply heat to re-warm it, but a vacuum will not do that. So either you simulate the heck out of the thermal environment in a computer, or a test chamber, or fi

    • by FatLittleMonkey (1341387) on Friday March 01, 2013 @10:56PM (#43051835)

      Dracos use hydrazine and nitrogen tetroxide. No cryo.

      • Point taken, I was thinking the same thing. However, it is possible for hydrazine to "freeze" at aerospace temperatures, correct? We justified a shoot down USA-193 on the basis of its massive load of hydrazine, I recall some mention of some of it possibly being frozen.

        They are nasty chemicals, just keeping that system under control is difficult.
        • SpaceX uses Monomethylhydrazine, which has a freezing point of -50C. So the Nitrogen Tetroxide would freeze first. (-10C). But that said, I don't know what a mono-prop mixture of MMH and N2O4 does to their gestalt properties. Similarly, releasing pressure on a cold, pressurised tank can cause the temp to drop sharply. And they might use a pressurant like Helium, so that's a possible factor too.

          But even with all that, it still seems more likely it was just a bad batch of valves than icing. I guess we'll see

    • This is just a learning curve for SpaceX. It's not going to be roses for these guys as much as the Internet-to-Space investors want it to be. And I'm sure Musk and his ex-JPL/NASA boys know this. There's going to be more (and even spectacular) failures initially than successes. Just ask Orbital--Orbital Sciences has been through this as the OP said... decades ago.

      Still rooting for them though.

      I'm wondering where Virgin G is nowadays...

    • by tp1024 (2409684)

      As others said, Dragon doesn't use LOX or other cryogenic fuel.

      However, the upper stage does - and I was rather impressed with the ice buildup inside Dragons trunk section during separation. So some parts of it might or might not have gotten colder than they were supposed to.

  • by pla (258480) on Friday March 01, 2013 @09:48PM (#43051481) Journal
    Please Please Please don't have a commercial spaceflight disaster this soon. I want to GTFO(ff) of this planet before I die. That sure as hell won't happen as long as we have nothing but NASA crippled by the same useless monkeys in charge who can't even balance the budget.

    Shit, even bugs can balance a budget (ie, ants storing food for the winter). Our leaders can't pull off a feat mere bugs can do.

    Go Elon! Make those valves your bitch, dude!
    • by AHuxley (892839)
      Nazi's Always Save the Adventure
      The men and woman mentored in the German way are always ready to help.
    • Brain Bugs? Frankly, I find the idea of a bug that thinks offensive!

  • by ozduo (2043408)
    Hal locked them out
    • by wierd_w (1375923)

      Slashdot Comedy Theater presents:

      The future of Commercial Spaceflight, Act I

      *scene: Inside the command and control center of the spaceX capsule. Dave notices a thruster reactant control system malfunction.*

      "Cycle the thruster pod valves HAL."

      'I'm afraid I can't do that, Dave.'

      *earnestly, more sternly*
      "Cycle the thruster pod valves HAL."

      'I'm afraid I can't do that, Dave.'

      *frantic, nearly panic stricken, as pressure indicator gauge begins to climb*
      "CYCLE THE THRUSTER POD VALVES HAL!"

      'Dave, you seem overly con

      • by goodmanj (234846)

        You need to work on your funny-to-wordcount ratio.

        • by wierd_w (1375923)

          Clearly, you have never seen how a screenplay is written. The verbose nature is part of the funny.

          • by mcgrew (92797) *

            It probably would have been better written as literature rather than video... but done right, that video would be pretty funny on YouTube.

  • Rediscovery (Score:3, Insightful)

    by DanielRavenNest (107550) on Friday March 01, 2013 @10:30PM (#43051719)

    SpaceX staff are rediscovering why we use clean rooms, thermal vacuum chambers, and a full understanding of the launch and space environment. Launch to orbit is unforgiving, and you need to make sure things are right before you try, or you get a higher failure rate.

  • They should had realigned the dilithium crystals, that would had been an easier fix.
  • by MarkRose (820682) on Saturday March 02, 2013 @02:20AM (#43052587) Homepage

    SpaceX has uploaded the CRS-2 launch video [youtube.com].

  • by rekoil (168689) on Saturday March 02, 2013 @03:03AM (#43052727)

    Could you imaging the CEO of Northrop Grumman or Lockheed being able to talk about the engineering issues at this level of detail? Or even the head of NASA? This is why I bought TSLA stock.

    • Anyone can "talk tech" at that (almost non-existent) "level of detail"*, all you need is cue cards and a ghost writer.,

      * Seriously, "the valves were stuck, so we cycled them" is about as technical and detailed as "the car didn't start, so we turned the key again" - I.E. not very technical or detailed unless you're not very knowledgeable to start with.

  • We've been hearing about stuck valves since the space program in the 1960's. Why hasn't anyone yet invented valves that don't stick?

    • by trout007 (975317) on Saturday March 02, 2013 @09:52AM (#43053669)

      The problem is with what you are using the valves for. Holding back dangerous things like Hydrogen and hypergols require very low leak rates when closed. You don't want to work around these things if they have a potential to leak. If you worked around the Space Shuttle on every RCS (Hypergol Thruster) nozzle there was a cover that had a desiccant pack that would absorb any leaks and turn color to indicate a leak. It's a giant pain in the ass to work with this stuff.

      When you make valves that can close this tight they sometimes get stuck. Also with spaceflight you need to optimize mass so you can't put a huge valve on everything or it will add up quickly. One thing some satellites do is use a pyrotechnic burst disk right off the tank. This was it stays perfectly sealed until you blow the disk. This is a problem with reusable crafts because you would have to replace them every flight.

  • Not so bad (Score:4, Interesting)

    by sjames (1099) on Saturday March 02, 2013 @04:34PM (#43055925) Homepage

    It's a little early for the doom and gloom here. It looks like they got the valves open and the thrusters working. There's no reason to believe the mission can't be completed at this time.

    Yes, it would be better if the valves didn't stick in the first place, and I'm sure they'll look at the problem again, but as problems go in spaceflight, this is just one of a VERY long list of things that have gone wrong that could have been mission ending but turned out OK that have been seen by government and private operations over the years.

"Love may fail, but courtesy will previal." -- A Kurt Vonnegut fan

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