Last night (Sunday October 7), SpaceX launched a Falcon 9 rocket with a Dragon capsule full of supplies on a mission to the International Space Station. The Dragon was deployed successfully (as were its solar panels to give it power) and it’s on its way to ISS.
However, not everything went as planned. One of the nine Merlin engines powering the Falcon 9 had a failure 90 seconds into the flight. It’s not clear what happened just yet, but there is pretty dramatic footage of the engine failure; in the slow motion video below you can see some sort of flash and puff of flame at the 30 second mark (I’ve set the video to start 22 seconds in):
You can see a bright spot glowing on the upper right engine, then what looks like shrapnel blowing back as well, so it appears something catastrophic happened to the engine. I can think of many things that could’ve caused this – a crack in the engine bell that failed when it got hot, a faulty valve, something in the pipes – but I’m just spitballing; hopefully the folks at SpaceX will be able to determine the cause from the engine telemetry.
[UPDATE: SpaceX issued the follow notice at 17:00 UTC today:
"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 immediately. We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9’s other eight engines were impacted 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, Falcon 9 is designed to handle an engine out situation and still complete its mission."]
Although this looks scary, the engine nozzles are coated with Kevlar to protect them specifically in case something like this occurs, so the other engines continued working. Also, the onboard computer immediately shut down the failed engine, and then on the fly – literally – recalculated all the needed changes to the thrust of the other engines to compensate. In the end, the first stage boost lasted an extra thirty seconds to cover for the failed engine. It’s important again to note that the Dragon capsule was delivered on orbit and will rendezvous with ISS on Wednesday.
Having said that, there may have been another problem as well: my friend Jonathan McDowell of Jonathan’s Space Report is reporting the upper stage didn’t make its second burn, so an Orbcomm satellite that was carried as a secondary payload didn’t make the correct orbit. I don’t have any more information about that, but I’ll update this post when I hear more.
[UPDATE: ORBCOMM has confirmed the satellite was placed into the wrong orbit due to the engine failure. They, along with aerospace company Sierra Nevada, are looking into using the satellite's onboard propulsion system to raise the orbit.]
Elon Musk at SpaceX is expected to have an announcement later today about the launch. Again, I’ll update this post as info comes in.
Tip o’ the nose cone to AstroEngine for the alert about the video.
SpaceX successfully launched the first privately owned rocket (Falcon 9) and space capsule (Dragon) to the International Space Station in May. The engine that propelled them there is called the Merlin, built by the company based on known technology and NASA heritage.
Several generations of Merlin engines have been made, and the newest, the 1D, was recently test fired in May at the SpaceX facility in Texas. This video of it is pretty darn cool. Turn the volume up!
The full firing was a bit over three minutes long. The 1D performed well by all accounts, and will be used for the first time next year on an upgraded version of the Falcon 9 rocket. The 1D has the highest thrust-to-weight ratio of any engine of its kind ever used, meaning it produces a lot of bang for its weight.
There will be two versions of this engine: one to be used on the first stage of the Falcon 9, and designed for use in air, and another for the second stage, to be used in a vacuum. The exhaust from an engine behaves differently in air (where the pressure of surrounding air changes the way the exhaust expands) versus in a vacuum, so different designs can be used to optimize the thrust. These will be used on the upgraded Falcon 9 as well as the in-production Falcon Heavy rocket.
I’m even more interested in the proposed Merlin 2, which SpaceX claims will have 1.7 – 1.9 million pounds of thrust — more than the Saturn V F5 engines did! These will be used on a future generation Falcon heavy-lift rocket.
Image credit: SpaceX
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