Engine Fails During Testing at McGregor

[Grendal]

Here is an article with the details. The content pushes an inflammatory agenda.

Elon Musk's SpaceX suffers a rocket-engine failure during testing

An engine failed and there was an explosion on one of the test stands at the McGregor testing facility. No one was hurt and we don't know how badly damaged the test stand is. This is why SpaceX tests the engines. So far, this will have no effect on the launch manifest. The reality is that SpaceX has lots of engines available to them. The only thing that could potentially slow things down is to not be able to test engines for a while. SpaceX does have two test stands at McGregor. If testing can be moved over to the other stand then this is a minor incident.

 

[mongo]

Sounds like the testing worked.
Thanks for the article.

 

[Buook]

Great article. Looking forward to Falcon Heavy testing

 

[comanchepilot]

There is a deep learning curve in space. Even where Elon has hired engineers from the US space program, space is a very expensive place to operate. The learning curve on building a rocket motor is intense. Especially when its designed for multiple uses and switching on and off - the only three motors we have ever been successful with were the S-IVb Saturn third stage motor - and that basically single use - on and off once, and the SPS motor at the end of the Service Module in Apollo. Again, that was single mission also.

Then we had the descent module motor in the Apollo 13 which was not designed to be turned on and off - I think they used a circuit breaker there.

OF course the Agena in the Gemini program was throttleable and on / off capable. But wasn't man rated - and it failed more than it succeeded.

 

[Grendal]

Emre Kelly is a reporter for Florida Today with information on this.
Emre Kelly on Twitter

"SpaceX engine failure not expected to have any impacts on 2017 or 2018 launches. Test stand repairs will take about 2-4 weeks. NASA, FAA, USAF, etc. all notified of incident."

 

[ecarfan]

The article is poorly written. Right after talking about the engine test failure it mentions the two F9 failures in 2015 and 2016 which were unrelated to the engines but readers may well assume they were.

I remain amazed by the reliability of the Merlin engine.

I’m sure SpaceX will learn from that engine test failure.

 

[Grendal]

Apparently the engine was a Block 5 qualification engine. So Block 5 might be delayed as components are tested individually. SpaceX still has Block 4 engines. According to SpaceX, 2018 launches will not be affected. A little early to know for certain though.

 

[kevinof]

Engine wasn't running at the time. They flow LOX through the engine to check for leaks and it was during the leak test that an "anomaly" happened. Sounds like the LOX ignited.

 

[Grendal]

More details:
SpaceX suffers Merlin engine test mishap - SpaceNews.com
It happened during a test for leaks called a "LOX drop."

 

[Cloxxki]

Well, sign me an my whole family up for a space flight!

 

[comanchepilot]

Engine wasn't running at the time. They flow LOX through the engine to check for leaks and it was during the leak test that an "anomaly" happened. Sounds like the LOX ignited.

Oxygen doesn't burn. . . .

if someone left some fuel, or grease, or pretty much anything it will ignite in the presence of 100% O2, especially if its being driven under pressure by a turbo pump.

 

[roblab]

Oxygen doesn't burn. . . .

if someone left some fuel, or grease, or pretty much anything it will ignite in the presence of 100% O2, especially if its being driven under pressure by a turbo pump.

 

[roblab]

"burn" also requires heat. And "pretty much anything" has to be something that has not been oxidized, so a rock, SiO2 will not burn, even in pure oxygen. "grease" would maybe burn if it was hot and vaporized. It doesn't sound like an ignition, but a pressure explosion.

And I guess someone will point out that certain elements just won't combine with oxygen -- like oxygen.

 

[Doug_G]

If there's a leak, then pure oxygen was in a place it wasn't supposed to be. Just about anything that can burn, will burn extremely violently in pure oxygen. If it is an enclosure of some kind it could cause an explosion.

That said, you can sometimes get quite a dramatic flame/pop even if uncontained. The Challenger "explosion" wasn't... it was an uncontained fireball on the outside of the orbiter.

 

[oneday]

SpaceX says this will not effect their 2018 manifest, I hope they’re right.

I don’t see how it won’t delay commercial crew however. They said that they won’t test more block V engines at McGregor until completion of an investigation. They intended to begin flying block V boosters this year, that seems highly unlikely now. They also need to have five block V flights in frozen configuration before the first crewed flight. So maybe it doesn’t effect their current manifest but it seems likely it will push back crewed flight. Hopefully it’s only a month and no big deal. And more importantly hopefully they gain valuable info from the investigation.

Just glad it happened on the test stand and not on the launch pad.

 

[miimura]

From The Verge:

Correction November 8th, 3:48PM ET: SpaceX originally said that all engine testing would be suspended at McGregor, in error. A SpaceX representative subsequently contacted The Verge correcting that only Block 5 engine testing would be suspended at the facility. Additional details were given about the state of the second test bay at the McGregor facility.
​

Apparently the second test stand was also damaged but will be ready to go in "two to three days".

 

[Nikxice]

The original Post article read like a snarky tabloid story, describing the event as an "accident". That term has since been dropped in an updated version, referencing SpaceX's explanation as a "qualification test". Maybe the Post now understands that a test is a test is a test and you don't have to be rocket scientist to figure out that results can often be unpredictable.

 

[Grendal]

I don’t see how it won’t delay commercial crew however. They said that they won’t test more block V engines at McGregor until completion of an investigation. They intended to begin flying block V boosters this year, that seems highly unlikely now. They also need to have five block V flights in frozen configuration before the first crewed flight. So maybe it doesn’t effect their current manifest but it seems likely it will push back crewed flight. Hopefully it’s only a month and no big deal. And more importantly hopefully they gain valuable info from the investigation.

Just glad it happened on the test stand and not on the launch pad.

According to possible insiders, SpaceX has a very good handle on what went wrong. If so then the investigation should be short and shouldn't really have an impact on future testing and Block 5 implementation. The crewed launch isn't until August. At SpaceX's current launch rate, they should have over 15 Block 5 launches complete before an astronaut launches on one. The worst that happens is SpaceX extends Block 4 for a couple months into 2018. They would still have ample time and launches to pass the NASA certification before DM-2.

 

[kevinof]

So the update is that this wasn't a problem with the engine at all (wasn't running). It was a leak in the test set up that allowed LOX to come in contact with a fuel (grease, oil etc). They now just have to find the cause of the fault with the test setup and go again. No changes/mods needed for the engine.

 

[jaguar36]

No changes/mods needed for the engine.

That's very speculative. Depends entirely on what caused the leak. It could have been an issue with the test stand itself, or it could be a design flaw with the engine. Could also be a manufacturing issue.

The problem is that while engineers always expect that tests could have failures, the schedulers don't. This is certainly going to push out this portion of the Block 5 qual. Whether that is the long pole in the schedule or not will determine if the overall schedule is affected. Their claim that it won't be indicates that they either have some float in the schedule or that this qual test wasn't a critical schedule driver. As an outsider, there is no way to know for sure. My guess would be that it will have an effect on something else, particularly with how over-worked the SpaceX team already appears to be.