Falcon 9 Experienced Engine Anomaly But Kept Going to Orbit

by Nancy Atkinson on October 8, 2012

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During last night’s launch of the Dragon capsule by SpaceX’s Falcon 9 rocket, there was an anomaly on one of the rocket’s nine engines and it was shut down. But Dragon still made it to orbit – just a little bit later than originally expected. At about 1:20 into the flight, there was a bright flash and a shower of debris. SpaceX’s CEO Elon Musk issued a statement about the anomaly saying:

“Falcon 9 detected an anomaly on one of the nine engines and shut it down. As designed, the flight computer then recomputed a new ascent profile in realtime to reach the target orbit, which is why the burn times were a bit longer. Like Saturn V, which experienced engine loss on two flights, the Falcon 9 is designed to handle an engine flameout and still complete its mission. I believe F9 is the only rocket flying today that, like a modern airliner, is capable of completing a flight successfully even after losing an engine. There was no effect on Dragon or the Space Station resupply mission.”

UPDATE (2 pm EDT 8/10): SpaceX has now provided an update and more information: the engine didn’t explode, but (now updated from a previous update), “panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines.” Here’s their statement:

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V (which experienced engine loss on two flights) and modern airliners, Falcon 9 is designed to handle an engine out situation and still complete its mission. No other rocket currently flying has this ability.

It is worth noting that Falcon 9 shuts down two of its engines to limit acceleration to 5 g’s even on a fully nominal flight. The rocket could therefore have lost another engine and still completed its mission.

We will continue to review all flight data in order to understand the cause of the anomaly, and will devote the resources necessary to identify the problem and apply those lessons to future flights. We will provide additional information as it becomes available.

In their initial press release following the launch SpaceX had originally described the performance of Falcon 9 as nominal “during every phase of its approach to orbit.”

During the press briefing following the launch SpaceX President Gwynne Shotwell replied to a question about the flash and said “I do know we had an anomaly on Engine 1, but I have no data on it. But Falcon 9 was designed to lose engines and still make mission, so it did what it was supposed to do. If you do end up with issues, you burn longer to end up where you need to go.”

SpaceX’s website also mentions this capability, saying, “”This vehicle will be capable of sustaining an engine failure at any point in flight and still successfully completing its mission. This actually results in an even higher level of reliability than a single engine stage.”

Dragon made it to orbit about 30 seconds later than originally planned, but Shotwell said it made it into the correct orbit, “within two or three kilometers in both apogee and perigee and Dragon is now on its way to Station.” The anomaly happened right at the time of Max-Q, just as the vehicle went supersonic.

The Space Shuttle was also designed to make it into orbit even if one of its three engines failed – after a certain point in the flight – and did so at least once to this reporter’s knowledge, on STS-51-F which resulted in an Abort To Orbit trajectory, where the shuttle achieved a lower-than-planned orbital altitude.

This was the first time SpaceX made lift-off at their originally planned “T-0” launch time, Shotwell noted. And they also deployed a tag-along, secondary payload in addition to the Dragon capsule, a prototype commercial communications satellite for New Jersey-based Orbcomm Inc. However, A report by Jonathan McDowell indicates the Orbcomm satellite is being tracked in low orbit instead of its elliptical target orbit because the Falcon 9 upper stage failed its second burn. (More info here from Jonathan’s Space Report).

SpaceX will undoubtedly review the anomaly, and we’ll provide more information about it when available.

SpaceX Launches to the International Space Station. Credit: NASA

About 

Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with Astronomy Cast. Nancy is also a NASA/JPL Solar System Ambassador.

Patrick Ahles October 8, 2012 at 1:45 PM

Whoa, that was one big anomaly! Looking at the pieces flying around you wonder why nothing else was damaged.

zetetic elench October 8, 2012 at 2:45 PM

yea it looks like one of the outer ones. fast shutdown though.

Neowolf October 8, 2012 at 3:54 PM

There is some kevlar shielding to protect the engines from each other, in case of behavior like this.

Kristoffer Rodin October 8, 2012 at 3:16 PM

Doesn’t look good .. engines should not behave like this.
Yes it went on as planned, but the bad news are bigger.

William Gunther October 8, 2012 at 6:50 PM

Of all the things that can go wrong, this is one of the OK things. The craft is designed to suffer an engine failure, and when it does compensation occurs among the other systems. Everything worked, and that is a great thing.

SJStar October 8, 2012 at 5:24 PM

…I just pray they don’t destroy the ISS!!!

Probably turn out to be some shoddy work by some second-rate American supplier. More like corporate stupidity and gross incompetence will show the day!

Look forward to a bigger mistake, where the rest of us can sue their tails off for wanton neglect. Few of those mistakes, and no one will insure them. Even more, like cutting of LEO, and nobody will be able to use the space at all and the whole planet will turn into a technological backwater with failing communications and no way to keep planet Earth on track – and human survivability into the future. Pah! (Americans pretending false superiority – I tell you – your day is soon gonna come!)

William Gunther October 8, 2012 at 6:49 PM

What the heck did you say? Are you sad that your country doesn’t go to space too?

Stan Taylor October 8, 2012 at 6:57 PM

SJStar is from the planet of grumpy mondays.

forj October 8, 2012 at 2:42 PM

i see after reading this post from you that i shouldnt have given lip service to your post in the other article.. although i must say this one comes off as having more than a hint of sarcasm.. intended or not

Dan Egelhoff October 8, 2012 at 7:58 PM

Who pissed in your Cheerios?

Deepsky_hunter October 8, 2012 at 5:34 PM

Better to have this Engine issue rear it”s head now then when crew is aboard.
This is a opportunity to correct the anomaly in engine performance without
jeopardizing a crew.

TerryG October 8, 2012 at 8:18 PM

Engines 1, 3, 7 and 9 are located at the corners of the square-shaped engine bay and are sheltered from exposure to the supersonic air-flow by fairings on each corner. “Panels designed to relieve pressure within the engine bay” seems to be a reference to these fairings and associated skirting and what we see as debris in the exhaust plume.

The current Falcon 9 will be replaced by the soon to be introduced Falcon 9 v1.1 which will have a different engine bay arrangement – one engine in the centre and the other eight arranged in an octagonal shape and the corner fairings will no longer be required.

In other words this shouldn’t be a problem by the time crewed flights are under way.

Torbjörn Larsson October 9, 2012 at 5:59 PM

As a technical note, since I happened to stumble on a NASASpaceflight thread that described v1.1 and could confirm it by clicking through to the Wikipedia source on their v1.1 description :

The octagonal engine configuration is pure speculation at this point, taken from eye-balling a 2D overhead illustration and making a 3D projection. There is no official SpaceX source on this.

Why Wikipedia has let such a reference through is anybody’s speculation.

TerryG October 9, 2012 at 7:17 PM

Hi Torbjörn,

Here’s a SpaceX source for you.

Aviation Week interviewed SpaceX
President Gwynne Shotwell about the Falcon 9 v1.1 in an on-line
article published here.

http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_09_17_2012_p40-495349.xml&p=2

Quote “Another change, she says,
involves the rocket’s nine Merlin 1D engines, which will be
positioned in an octagonal configuration, rather than the
“tic-tac-toe” placement on the current Falcon 9.”

It would also seem that the new shape
might give the center engine more room to gimbal when landing
re-usable Falcons.

Cheers.

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