Sad Day for SpaceX

I figured I wouldn’t be a good space pundit/SpaceX fanboy if I didn’t chime it with at least some irrelevant commentary on SpaceX’s launch failure today. I know some of the people there at SpaceX, and this has got to be a really lousy day for them. I can’t speak from experience regarding what a crash feels like, but from the few test engine failures we’ve had, and how sick those make you feel, I can’t even imagine what having a crash has got to be like. But I guess that when you have an incredibly complicated system like Falcon or like other existing orbital vehicles, where everything has to work just right, there are almost no margins, and nothing can be flight tested beforehand, risks and sucky days like these are inevitable.

I’m glad that for our suborbital vehicles we will be able to do things like cutting our teeth on takeoffs and landings hanging under a tether. While we’ll still probably have out ulcer-inducing moments where we have to push the envelope into some new regime that we haven’t tried before, and where something could go wrong, those will be fewer and farther between. Trying to get every part of a rocket vehicle like that, with all the subsystems working perfectly from the start is a real challenge. SpaceX has a phenominal crew, and I’m sure they’ll get this figured out, and probably make a whole bunch of money on this, but I’m glad that the approach they’re taking is not the only way to solve this problem.

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Jonathan Goff

Jonathan Goff

President/CEO at Altius Space Machines
Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and is the founder and CEO of Altius Space Machines, a space robotics startup in Broomfield, CO. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew. Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
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6 Responses to Sad Day for SpaceX

  1. Ed says:

    On the plus side: according to Kimbal Musk, when the rocket impacted the reef 250 feet from the island, the satellite was thrown into the air and came down on Omelek, punching a hole in the roof of SpaceX’s machine shop and coming to rest mostly intact on their machine shop floor.

  2. qwerty182764 says:

    “Mostly Intact”? I doubt “mostly intact” will suffice for the satellite owners. I hope their company survives.

  3. qwerty182764 says:

    BTW, if you’re interested in lunar stuff, maybe you would like my post “Moon-Comet run” on my space blog.

    I also read your post “Some Thoughts on SMED, EELVs and Lunar Tourism”.

    In talking about fully reusable rockets, one of the things that bothers me is that to compete with an EELV, the rocket will have to have a reasonably re-usable engine. That’s going to be a pain in the butt. First of all, EELV engines can get away with being non-regenerative (through ablative liners) which cuts an engine’s part count down absurdly. Reusable ones have to have the jacket, which is complicated to manufacture, plus the assorted turbomachinery and pressure sensitive loop closing to make it work. Not impossible, but expensive.

    But here’s where it seems hopeless to me: fatigue and temperature stress. The engine is going from 100K to 2500K+ on every startup. It’s going from 1 atm to 200 atm. It’s introducing massive vibration. After one launch the engine will have hairline fractures all over the nozzle, as well as brazing separations. To make the engine re-usable, we’d have to have massive improvement in the robustness of our engine design somehow.

    Without a reusable engine, it makes no sense to bring anything else back (except maybe re-entry vehicles for astronauts). The structure and fuel don’t begin to approach the costs of the vehicle. (In fact, the development cost is the largest hurdle, which makes low production volume, not reusability the main economic boogeyman).

    That’s my take anyway. What’s yours?

  4. qwerty182764 says:

    I was talking about a general cryogenic engine, not the one on SpaceX, just to clarify.

  5. Anonymous says:

    Re: querty182764

    Of course the operating environment of a rocket engine is challenging. But it can be argued that the operating environment of modern turbofan turbines is even more challenging.

    They also go through large temperature cycles and see a lot of vibration, yet they are reusable.

    The key to reusability is lots of incremental testing and decent margins. There are some reusable engines in existence, such as the rl10 and the russian rd171, so this is certainly not impossible.

  6. Jon Goff says:

    Qwerty,

    But here’s where it seems hopeless to me: fatigue and temperature stress. The engine is going from 100K to 2500K+ on every startup. It’s going from 1 atm to 200 atm. It’s introducing massive vibration. After one launch the engine will have hairline fractures all over the nozzle, as well as brazing separations. To make the engine re-usable, we’d have to have massive improvement in the robustness of our engine design somehow.

    Actually, even tube walled engines are often good for dozens of firings, with some good to up to 100 firings. Milled channel wall designs get closer to 200, and chamber-saddle-jacket designs could get as high as 1000 firings.

    The thing to remember is that even if the combustion gasses get over 2500K, the actual metal in the engine never sees more than 300-500C (depending on how good the cooling is). There are thermal stresses, and fatigue is an issue, but totally solvable ones.

    ~Jon

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