SpaceX Rocket Engine Explodes During Test (space.com) 115
According to The Washington Post, a SpaceX rocket engine exploded Sunday (Nov. 5) at the company's test facility in McGregor, Texas. The explosion reportedly occurred during a "qualification test" of a Merlin engine, the type that powers SpaceX's workhorse Falcon 9 rocket. Space.com reports: SpaceX has suspended engine testing while it investigates what caused the incident, which didn't injure anyone, the Post added. In a statement provided to the Post, SpaceX representatives said they didn't expect the explosion to affect the company's launch schedule. That schedule has been pretty packed this year. SpaceX has already launched 16 missions, all of them successful, in 2017 -- twice as many as its previous high in a calendar year. And all but three of these missions also involved landings of the Falcon 9 first stage, for eventual refurbishment and reuse.
Incident occured during a LOX test (Score:5, Informative)
The incident in question did not occur during an engine firing. Rather they were performing a "LOX drop" test which basically involves pumping LOX through the engine and checking for leaks. Something went wrong in this process, causing the damage. Until the investigation is completed, there's no way to know whether it was an issue with the engine, the test rig, or the setup. It might be that a tech just dind't tighten something adequately, or a filler hose leaked or whatever. SpaceX won't know until they complete their investigation, and we may never know.
To quote Adam Savage of Mythbusters fame "LOX makes anything flammable. LOX makes something flammable into a high explosive." So even if they just had a sufficiently large leak, and the LOX leaked onto/into asphalt or similar, all it takes is a spark to cause that asphalt to detonate like a bunch of dynamite.
Re:Incident occured during a LOX test (Score:5, Informative)
Also, this was a block 5 engine. There are newly designed un-flown parts in that engine, ironically because NASA asked for higher reliability for human missions. For example no more turbopump impeller cracks, which SpaceX had characterized and was tolerating on cargo missions using the older impellers. For something to go wrong during a test of new designs is to be expected.
Re:Incident occured during a LOX test (Score:5, Interesting)
We should also remember that SpaceX had an engine fail destructively on the CRS-1 mission. The design of the rocket contains such a failure in one engine without damaging the others. The rocket had an engine-out capability that can cope with one or more failures. It compensated and completed the mission, achieving all expected parameters on the remaining 8 first-stage engines.
Re: Incident occured during a LOX test (Score:3)
That just means that F9 has been over engineered for every mission where an engine didn't fail! /s
Re: Incident occured during a LOX test (Score:1)
It's not over engineering because A) it matters where the engine explodes. T+1s is way worse than T+50. I'm not even sure if it can safely clear the pad on 8 engines. B) There are performance costs. In the car of CRS1 NASA required spacex to abort a secondary payload and on a reusable GTO launch it probably wouldn't have enough fuel to land which would turn a reusable launch into an expendable launch without the commiserate price increase passed on to the customer.
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I suppose you also think a spare tire is over engineering.
Technically it is.
Over-engineering is also known as planning for failure, or safety margin.
Similar to SSDs over provisioning the memory array to make up for expected failures. You know that 1TB SSD you bought? It's actually 1.25-1.5TB of raw capacity, but because they know cells will fail, rather than having drive space decrease over time they just pre-reserve a block.
In Space-X's case the over engineering of an "extra" engine increases the expected reliability, much the same way the SSD's over provisionin
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This is why NASA is paying SpaceX significantly more than SpaceX gets on its cargo missions. There's a pretty big markup for dealing with all of the extra process that comes with NASA manned projects. I can't say this particular one is wrong, though. Having lost its share of astronauts, NASA would like to make sure that the next ones are not victims of a process fail
Re:Incident occured during a LOX test (Score:5, Informative)
There is probably a nitrogen test before the LOX is let in to the engine. But remember that LOX is its oxidizer, and it has to be run with it eventually because the engine can't work without it. And you don't want to test more than one variable at once if you don't have to, so the LOX gets let in without the fuel first. So, this test is essential.
LOX is very nasty stuff and it is prudent to test with it. Suppose you had a vendor issue and you got an organic rubber O-ring in the system rather than one that can deal with LOX? You would find out, destructively, when the LOX came in.
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You need something that has the expansion characteristics of LOX and is a liquid at the same temperatures. Good luck finding it.
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Maybe they tried something else first, but sooner or later you have to test with the actual chemicals that the system is designed for.
Slight differences in temperature or pressure can cause/prevent leaks, so it is entirely possible that the engine tested good with another chemical. You can't get identical temperature, pressure, flow rate, and turbulence from two different substances.
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I've heard good things about Chlorine Triflouride.
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I've heard good things about Chlorine Triflouride.
If you see me running, try to keep up.
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Well.. (Score:4, Insightful)
Re:Well.. (Score:5, Funny)
I'm no Musk fan, but what's why you test?
No, who's why you test.
What's on second.
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no he's on third
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No, who's on first.
Re:Well.. (Score:5, Insightful)
Yea, I'm not sure why this is news. They did a test and it failed with no injuries because they did the test safely. Other than some acceptable losses and likely the loss of the engine, there was no harm. This is why you test things like this.
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I'm not sure why this is news.
Perhaps because it marks the end of a long string of successes. Not big news, thankfully, since big news in a rocket test would probably mean someone was killed or injured. Still news though.
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Because the next mission will probably feature the 20th first-stage recovery. Which is totally in-f**king-credible if you ask me. And it's really hard to find anything to take them down with at the moment, even though there are folks who seem determined to do so.
Re:Well.. (Score:5, Interesting)
I for one, am glad its news. I would like to get back to "news for nerds" with stories like this.
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It's news because the Washington Post is owned by Jeff Bezos, who owns a rival space company.
Didn't pass the test (Score:2)
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Obviously failed the test.
We learn about flying from that.
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Merlin engine? (Score:3)
That's a 1650-cubic inch V-12.
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Yes, Packard produced the Merlin for the Mustang fighter, under license from Rolls-Royce.
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That's a 1650-cubic inch V-12.
Somebody please mod this up, this is the first thing I thought of when I heard the name of the engine.
https://en.wikipedia.org/wiki/... [wikipedia.org]
I wonder if Rolls-Royce (now BMW) still owns the trademark for the Merlin name?
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The aero engines Rolls Royce are a separate company to the car makers these days, and BMW just own the car bit. They've got various agreements between the two for use of the badges and names so it could be either, both or neither have IP for the Merlin.
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Thanks. Fun fact: The Merlin is named for a bird, not a sorceror. Rolls-Royce named a long series of aero engines after birds, beginning with the Eagle in 1915. They switched to rivers for their gas turbine engines, like the long-running Dart series -- but that's also the name of a bird!
For that matter, Arthur's sorceror was named for the bird too: Druids named their children after living things.
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Sorry, sorcerer.
Merlins engines powered the Spitfires (Score:2, Informative)
Most famous British engine in the war. Bit rude of SpaceX to reuse the name.
Re: Merlins engines powered the Spitfires (Score:4, Insightful)
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They named it after the falco columbarius? (Score:3)
The Rolls Royce "merlin", like other Rolls Royce aero engines of the time, was named after a bird of prey. The bird they named the engine after is a type of falcon which is called a "pigeon hawk" in North America and "merlin" in Europe.
So, did SpaceX name their engine after the bird (and Rolls Royce's engine) or the mythical wizard?
Doing a quick search and there's no clear answer.
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That their rocket is called the FALCON 9 should give a big clue.
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SpaceX ocean landing barges also take names from science fiction. They are named after Minds, superhuman artificial intelligences in the in Bank's Culture Universe. [wikipedia.org]
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Given that the engines on the Falcon 1 were Kestrel, and the BFR engines are Raptor, I'm going with "named after the bird"
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To say that those things "drink" fuel is something of an understatement.
Re:Merlins engines powered the Spitfires (Score:5, Insightful)
amazing how you have invented up new ways of being offended.
test (Score:3)
the nature of test is to find faults
if everything was perfect by design the test people would be flipping burgers or work as perfect-design engineers
by design (Score:2)
it is an EXTERNAL combustion engine is it not?
Good job. (Score:2)
The test was successful (Score:2)
The engine, not so much.
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Yep, you're the only one.
Ignition! (Score:5, Interesting)
There is a marvelous history of the development of rocket fuel called, "Ignition!", written by John D. Clark, one of the field's insiders who has an ascerbic wit. The foreword was written by Isaac Asimov, which contains the following fantastic quote:
Now it is clear that anyone working with rocket fuels is outstandingly mad. I don't mean garden-variety crazy or a mere raving lunatic. I mean a record-shattering exponent of far-out insanity.
There are, after all, some chemicals that explode shatteringly, some that flame ravenously, some that corrode hellishly, some that poison sneakily, and some that stink stenchily. As far as I know, though, only liquid rocket fuels have all these delightful properties combined into one delectable whole.
Explosions are par for the course. Rocket science is hard.
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A link to a downloadable copy is probably a good idea at this point. Scroll down a bit to the download options.
https://archive.org/details/ignition_201612 [archive.org]
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Many thanks, kind AC
So what? (Score:2)
They were testing an engine, and this particular test failed... That's the whole point of testing, try new things and see if they work.
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Sure, but this is a more pleasant article to be discussing than the usual dreck that goes on.
Sometimes things explode (Score:2)
If you aren't blowing things up now and then, you aren't on the frontier of exploration. You cannot know where the line designating the frontier is unless you occasionally step over it.
Sounds like a good test (Score:2)
At least they have an idea now that there's a problem somewhere that needs fixing, and it's not hidden for an actual launch.
Good test. Try and break it.
Re:Well (Score:5, Insightful)
That’s what happens when you cut corners and half ass things to make things cheaper.
Launch costs need to be cheaper. The trick is to figure out which corners can be cut, and which can not. Engineers learn by trying and failing, and I am sure SpaceX learned some valuable lessons today.
"Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better." - Samuel Beckett
Re: Well (Score:1)
Exactly!
âoeWhy do we fall sir? So that we can learn to pick ourselves up.â -Alfred Pennyworth
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Re: Well (Score:5, Interesting)
Ok, then, can we get ULA on a level playing field with cutting corners?
You are being silly. This was R&D, not a production launch.
Right now ULA is required to do the full engineering work up for every launch, v.s. spaceX not
1. This was not a "launch"
2. It should be up to the market.
ULA provides expensive reliability. SpaceX provides discount access to orbit. If you are launching a 5 billion dollar GSO comsat, you will go with ULA. If you want to dump a van load of cubesats designed by high school science clubs into LEO, you go with SpaceX.
SpaceX will get more reliable much faster than ULA will get cheaper. In ten years, ULA will be out of business.
Re: Well (Score:4, Informative)
SpaceX provides discount access to orbit. If you are launching a 5 billion dollar GSO comsat, you will go with ULA. If you want to dump a van load of cubesats designed by high school science clubs into LEO, you go with SpaceX.
DoD is launching with SpaceX now, so they have definitely jumped up in the rankings compared to ULA, and the various state-owned launchers. Cubesats and science projects are becoming the domain of start-ups that NASA is funding [spaceflightnow.com]
FWIW the accident involved a new block-5 merlin engine that was undergoing lox load testing for leaks and 'something' caught fire, damaging the test facility, and presumably the engine, severely. It has not been determined if the engine, which was not firing, was at fault.
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I suppose those expensive GSO sats (TV & comm) that SES, largest commercial sat operator, is having launched by SpaceX, even on refurbished SpaceX launchers (SES being first commercial customer), must be cubesats... NOT!
SES being a for-profit corporation, they run the numbers... and they don't seem to do much business with
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>I suppose those expensive GSO sats (TV & comm) that SES, largest commercial sat operator, is having launched by SpaceX, even on refurbished SpaceX launchers (SES being first commercial customer), must be cubesats... NOT!
You win today's internet for not getting the point.
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What is the point? Companies are launching important payloads with SpaceX.
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1. This was not a "launch"
This was not even an engine firing. It was during a LOX Drop test, where the engine is tested for leaks. And since pure Oxygen outside of where it is supposed to be is nasty, it could be just about anything in the area.
The post you were replying to was pure did not RTFA classic Slashdot.
You never ever ever take shortcuts with rocket engines. They are channeled explosions or deflagrations if you wish. They might be made cheaper, but shortcuts are instantly punished.
https://arstechnica.com/scienc... [arstechnica.com] he
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Grandparent's arguing with ULA is stupider for another reason, too: SpaceX is the only company in the recent US history to have manufactured 1000 rocket engines worth 700 MN of total thrust in a timeframe of several years. Nobody else is doing anything like this in the US anymore, so clearly nobody can possibly have any failures in engine manufacturing in the US. The closest "competitor" is Aerojet currently manufacturing no more than 15 small RL-10 engines per year for ULA on their old manual production li
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Right now ULA is required to do the full engineering work up for every launch
Not really; since they're not making the engines, they're clearly not "required to do the full engineering work up for every launch".
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Oh, yes. A failure during a test is nothing unexpected. It is where failures are supposed to happen. Anybody that does not understand that does not know the first thing about engineering. And a "qualification test" in particular serves to find the occasional manufacturing fault still present before it does real damage.
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I was thinking the same thing.
Mishaps on the test stand is what the thing is built for.
Even a massive explosion with all equipment lost is a success because it thus did not happen on a launch pad where in addition to the lost equipment you very well may/will lose:
* The Payload.
* The Launchpad Facility.
* The actual Launchpad.
* Lives.
* Delay to future launches of unknown duration because of aforementioned damage.
Sure it's a suboptimal success, but it is still not a failure.
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Indeed. It is one form of redundancy employed to make the final product as reliable as it reasonably can be. Definitely not a failure.
Re:Well (Score:5, Informative)
The current Series 4 engines have been pretty reliable so far...
Some other sources (Score:5, Informative)
At least this happened with the new Merlin Series 5 redesign, scheduled for flight next year.
Exactly. That's important-- this is the next generation engine, not the one currently flying.
Some alternate sources, some with more information:
https://www.space.com/38712-spacex-rocket-engine-test-explosion.html [space.com]
https://www.geekwire.com/2017/next-generation-spacex-rocket-engine-goes-flames-texas-test/ [geekwire.com]
https://arstechnica.com/science/2017/11/an-experimental-spacex-rocket-engine-has-exploded-in-texas/ [arstechnica.com]
[theverge.com]https://www.theverge.com/2017/... [theverge.com]
Re: Well (Score:3, Insightful)
No, then they wouldn't test at all.
My reaction to this is more like:
Yeah so, this is why they test.
Re: Well (Score:5, Insightful)
Zero parts failures in test = too expensive (Score:3)
You're partly right. If you're being smart economically, or advancing technology, you'll test some things that don't work. If everything you test works, you're a) doing the same boring shit that's been done and b) over-engineering, making things much more expensive than they should be.
Testing is how you find out what works and what doesn't, and how much you need to spend to make things work reliably.
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If everything you test works, you're a) doing the same boring shit that's been done and b) over-engineering, making things much more expensive than they should be.
or
c) you aren't testing correctly (thoroughly enough)
Why do people always overlook that one?!?!
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it is looking more like it was the test itself, lox loading to test for leaks, that was the source of the failure than the engine itself
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That was what struck me. Whilst I understand the need for cryogenic liquids to test for leaks in this instance, surely liquid nitrogen would have been a safer first choice?
So true. Testing only valid / expected conditions (Score:2)
You're so very right. Software developers in particular sometimes test software only with valid, expected inputs. Unexpected inputs then result in a security failure.
Back when software ran locally, we we used to say "garbage in, garbage out". That's no longer acceptable for internet-connected software. With Heartbleed, the garbage that came out was random memory contents, which could include the server's private key.
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I am reasonably new at my current (very small) company. I am the second (and still not fully dedicated) QA person.
I came from 17 years at a multinational Corp with huge QA.
To say I encountered culture shock is an understatement.
I have started implementing things like automated regression tests, and Fuzzers. My Fuzzer based tests break the shit out of things and the devs look at me with the "why would you do that?" look. They still have to go fix the issue though.
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"The devs look at me with the "why would you do that?" look. "
It's not just small companies which suffer that.
Airbus have suffered a number of "why would a pilot do something that stupid?" issues where pilots DO these kinds of things when testing to trying out the aircraft to see how it will react under worst case conditions.
Certain switch/router manufacturer R&D departments have come back with the same question when I've asked them to check certain conditions. They may not ever happen under normal oper
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I completely concur that tests on all inputs (external to the system) are mandatory.
By external I mean any input from outside the code.
Last big project I worked on there were two "rings" in ring 0 code, one that faced userland and one that only faced ring 0 code. The former validated *everything* the latter, not so much. Embedded system where memory and compute cycles were at a premium.