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Congressional Investigators Warn of SpaceX Rocket Defects
- skolos 10y ago>The Government Accountability Office’s preliminary findings reveal a pattern of problems with turbine blades that pump fuel into rocket engines >The crack-prone parts are considered a potentially major threat to rocket safety, the industry officials said, and may require redesign of what are commonly called the Falcon 9’s turbopumps. >A SpaceX spokesman said “we have qualified our engines to be robust” to such cracks but are “modifying the design to avoid them altogether.” The pending changes “will be part of the final design” for the Falcon 9, he added, “in partnership with NASA to qualify engines for manned spaceflight.”
- skolos 10y agoAnother interesting bit: >For Boeing, these officials said, GAO investigators—among other items—raised questions about the status of tests to determine the reliability of its parachute systems designed to help returning manned capsules land safely. >The GAO also has determined that both companies face an uphill struggle to meet NASA’s statistical goal of no more than one projected astronaut fatality in 270 flights, industry officials said.
- c3534l 10y agoThat's a weirdly specific, yet round number.
- saalweachter 10y agoI suspect it is not so much round as rounded. You don't really need more than two significant figures for the number.
- zellyn 10y agoMy "expected value" knowledge has atrophied, but I'm guessing this is just a weird way of saying a success rate of 99.5% or something. 0.995^135 is about 0.5, so you blow up on average half the time in 135 flights, or once every 270 flights.
- froindt 10y ago> no more than one projected astronaut fatality in 270 flights > success rate of 99.5% or something. 0.995^135 is about 0.5 Method seems pretty good, but unfortunately that math would only work if there was exactly one astronaut per flight. Per Wikipedia, the capacity is up to 7 crew members, so I reckon at full capacity, that would be 1 full vehicle failure with 7 lives lost in 1,890 flights. My math is a bit rusty too though. https://en.wikipedia.org/wiki/Dragon_2 https://en.wikipedia.org/wiki/Dragon_2
- Already__Taken 10y agoNot a rocket buff but I thought the soyuz rocket (R-7) was one of the most proven and reliable rockets there are. In 60 years that family has had 1,859 launches[1]. So statistics aside it's interesting just how high those standards are if you bore them out. Going to look stupid with some maths here; If spacex launch every 2 weeks which I thought was the goal, that's like 72 years to prove that reliability record. 72.69 = (1890 * 2) / 52 Number of 1 week periods divided by weeks in a year. 1: https://en.wikipedia.org/wiki/R-7_(rocket_family)#Summary_of_variants https://en.wikipedia.org/wiki/R-7_(rocket_family)#Summary_of...
- merpnderp 10y agoWasn't NASA's record with the space shuttle more like 1 in 2.5 fatalities per flight? 14 fatalities in 135 launches? Must have been good enough for government work.
- jackmott 10y agowith modern material and computation advances it would be reasonable to raise the bar
- merpnderp 10y agoThey're asking for nearly 2 magnitudes better safety than they could provide. Granted the space shuttle was dumb from the beginning and we'd be flying around in our flying cars and vacationing on Mars if they'd stuck with the far superior Saturn launch system. But who could of known that, besides the plethora of scientists who pointed this out?
- bsder 10y agoExcept that the options at the time were space shuttle or NOTHING--not space shuttle or Saturn V. NASA threw in with the only folks willing to fund spaceflight--the military. And the military demanded an orbiter that could do circumpolar orbits--which was totally crazy from an engineering standpoint.
- colordrops 10y agoWhat does it mean for an orbiter to support circumpolar orbits, and why is it crazy?
- Arnt 10y agoIt means being able to reach more kinds of orbits, which adds requirements. So does reentry capability. Why add those two sets of requirements to the same vehicle, see?
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- celticninja 10y agoPerhaps this is somewhere where Trumps less regulation stance will benefit Musk.
- tptacek 10y agoIn what way does SpaceX benefit from permission to launch unreliable rockets into space?
- convalleysili 10y agouh, in trump world?
- hhuhggvhg 10y agoIn the same way that companies benefit by being able to pollute their local environment by pumping chemicals down the local river.
- Robotbeat 10y agoRealize the article is written by Andy Pasztor. If there is ever a negative SpaceX angle, he'll find it. I'm not disputing the factual content of the article, nor do I have reason to believe he's paid off to do hit pieces, but it's important to realize he almost constantly has a chip on his shoulder with respect to SpaceX. Another thing to keep in mind: SpaceX produces more liquid rocket engines than any other domestic provider by a VERY large margin.
- crikli 10y agoWell said. This smells like a hatchet piece put together by the gray hairs at StratCom who've continued to be incredulous that a private enterprise can put things in orbit and have hoped for SpaceX to fail from the outset.
- planteen 10y ago> incredulous that a private enterprise can put things in orbit What's with this commonly repeated narrative that SpaceX is the only private company in space? I think the formation of ULA between Boeing and Lockheed was garbage as much as the next person. Just like Boeing buying McDonnell Douglas was garbage. But look at a list of rockets to take something to space and they are all private (ULA, Orbital, and SpaceX). SpaceX plays the game just like everyone else. They hire the retired generals from the military. They bid on government launches. They use government ranges for launching.
- kevin_thibedeau 10y agoAll of the incumbent's R&D was paid for by US taxpayers. Their bloated pricing is a product of not having to compete commercially on cost. SpaceX has to seek business where the opportunities are. They in turn plow their profits back into the business rather than waiting for the next handout.
- sidlls 10y agoAnd what R&D do you think SpaceX is built on? I'll give you a hint: you mentioned it in your comment.
- jobu 10y agoSpaceX addressed the issue with the turbine cracks today in an email Reuters: SpaceX said it has "qualified our engines to be robust to turbine wheel cracks. However, we are modifying the design to avoid them altogether,” said spokesman John Taylor. http://uk.reuters.com/article/us-space-spacex-idUKKBN15H307 http://uk.reuters.com/article/us-space-spacex-idUKKBN15H307
- josho 10y agoThis strikes me as an example of everything in the system working. -GAO analyzes SpaceX processes and discovers a shortcoming -Media reports on this to create public awareness -SpaceX is compelled to respond and fix the problem (something their engineers were probably already aware of anyway) -Space Travel continues to move safely forward This is quite refreshing from other government initiatives at the moment.
- rtkwe 10y agoReally step 2 isn't necessary at all beyond transparency and a voracious curiosity about SpaceX from some circles. NASA would simply not qualify SpaceXs' rockets for manned flight without these fixes.
- throwanem 10y ago> step 2 isn't necessary at all Isn't it? One wonders what would've followed from a decision on the part of Thiokol's engineers to take to the media their concerns about SRB segment seal reliability. Absent such external pressure, I see no a priori reason to assume NASA management won't make the same errors it did in 1986 and 2003.
- rtkwe 10y agoWith each of those NASA has changed and put more safeguards in place in their process. And (as I recall because the article is refusing to open for me now even through google in incognito) NASA was already requiring changes before the GAO report was coming out. So it seems like this was already behind handled properly by being redesigned before human certification.
- more_corn 10y agoStop posting WSJ articles. Do you want a paywalled future? Because that's how you get a paywalled future.
- hyperbovine 10y agoDo you want an ads-tattooed-onto-your-retina uture? Because that's how you get an ads-tattooed-onto-your-retina future.
- neolefty 10y agoCharging for your articles to support journalism is a legitimate business practice. Produce something valuable, using skill and effort, and make a living at it.
- Sabinus 10y agoWhat if OP posted a pastebin of the paywalled text?
- imron 10y agoGiven a paywalled future vs a clickbait driven present, the choice doesn't sound so bad.
- wtf_is_up 10y agoI love my WSJ subscription. $50/year for students. Much better quality than the clickbait journalism you get elsewhere for "free".
- bb611 10y agoI didn't realize there was a student tier, thanks for the note!
- Gravityloss 10y agoTheir climate journalism has historically been negative information.
- gozur88 10y agoHow did they discover the turbine cracks? It seems a bit unfair if this is a result of examination of returned engines, since other companies leave evidence of similar problems at the bottom of the ocean.
- JshWright 10y agoAny rocket engine design used on modern launch vehicles has undergone extensive ground testing, including multiple full mission duration burns on test stands.
- gozur88 10y agoThat's true, but it doesn't really address the question. If the cracks are a result of flight stresses, test stand burns won't reveal them.
- aeturnum 10y agoIf the tests don't simulate flight stresses, they are bad tests.
- xorxornop 10y agoIt's simply not possible to test that. This much is obvious if you've thought deeply about the nature of rocket testing. You MUST fly to _really_ test.
- scott113341 10y agoIs there a good way that you're aware of to simulate the acceleration experienced by a rocket?
- JshWright 10y agoYou're talking about a turbopump spinning at several tens of thousands of rpms, at very high temperature. Yes, a couple g's of lateral acceleration adds a bit too those stresses, but it's a fairly minor effect, I'm sure. I think it's vastly more likely they're cracking from the rotation speed, temperature, and pressure.
- PinguTS 10y agoI think that totally underwrites the behavior of Elon Musk how I see it. Even if engineers know better that there are problems with certain design decisions and things have to be redone, Elon overwrites and say: "just do it, we will fix it later." That basically to be able to run its marketing machine that he is the innovative guy. It is this IT thinking principle of MVP with knowing design flaws. "But we will fix the flaws later." which is different from the engineering principle. In the engineering principle if design flaws become obvious, yes things gets delayed, because it has to be redone to eleminate the design flaws from the beginning. Because we know, things you can fix early may delay, but it is cheap. Things you need to fix later are expansive. Like if your production is set up and running and then you need to change things, you need also to change production. He has shown this behavior with the Autopilot in the Tesla. Now it also becomes obvious for SpaceX: "Industry officials have known about problems with cracked blades on Falcon 9 versions for many months or even years. But cracks continued to be found during tests as recently as September 2016, Robert Lightfoot, NASA’s acting administrator, confirmed in an interview with The Wall Street Journal earlier this week."
- _ph_ 10y agoWell, considering that they fly 10 of those engines with every Falcon9 launch, and so far only a single of them has actually failed (and just shut off), it does not seem to be an actual problem so far. It might be interesting to see if this changes as the engines are reflown with the recovered first stages. If this might create an actual safety hazard for manned missions, it all makes sense to postpone a final solution till you are getting close to doing the manned flights. No reason to delay cargo missions for something that might affect manned rating.
- Gravityloss 10y agoI think this is plausible if they've been increasing performance a lot in the recent years. With a rocket engine, up to level, you can get that mostly by just increasing pump speed.