SpaceX engineers have solved their exploding rocket mystery

Investigators looking into September's Falcon 9 explosion believe they have finally found their culprit, CEO Elon Musk said during an appearance on CNBC today. According to Musk, the explosion that destroyed the rocket and its payload was caused by a "really surprising problem that's never been encountered before in the history of rocketry."

Last week, the company said it suspected the problem had something to do with one of three carbon fiber helium tanks that sit inside the main fuel tank. As the New York Times reports, the liquid oxygen fuel froze solid as it was flowing into the rocket's second stage, which set off the chain of explosions. Although Musk didn't share any details about how the frozen oxygen may have affected the helium tanks, he did offer a vague explanation and confirmed that his engineers had been able to replicate a ruptured helium tank. "It basically involves a combination of liquid helium, advanced carbon fiber composites and solid oxygen," Musk said. "Oxygen so cold that it actually enters solid phase."

The New York Times also points out that oxygen freezes at –362 degrees Fahrenheit and the latest Falcon 9 rockets use supercooled liquid oxygen that is usually around –340 degrees. The helium inside the carbon fiber tanks is even colder at –452 degrees and may have caused the liquid fuel to freeze.

While NASA has already handed off the ISS supply run to SpaceX competitor Orbital ATK, Musk and company believe they will be ready to put another Falcon 9 on the launchpad by the middle of December.

www.engadget.com...


Found this just looking around. This is the official cause according to SpaceX. For the conspiracy folks, there was a "Ufo destroys rocket" thread posted here. If the official cause is true, I wonder if this is now going to be preventable in the future. What say you space and rocket guy's and gal's?

Still looked like something shot it in the video.

"Although Musk didn't share any details about how the frozen oxygen may have affected the helium tanks, he did offer a vague explanation"

A vague explanation? That doesn't sound very science.

Now I would like to see an explanation as to why the liquid oxygen fuel never froze on previous launches.

a reply to: BlueShaman

SpaceX uses LOX that's cooled more than normal LOX. It's caused them problems in the past.

qz.com...

originally posted by: Zaphod58
a reply to: BlueShaman

SpaceX uses LOX that's cooled more than normal LOX. It's caused them problems in the past.

qz.com...

According to that article a launch was aborted because they were worried the LOX had warmed up during pre-launch procedures, which would make it less dense and prevent them from storing more of it in the tank. In other words, it was the opposite problem of the one that caused the explosion.

a reply to: BlueShaman

And if they start running it a little cooler to try to compensate for the problem of it warming, they're going to run into it freezing. It's not a very large window between it warming and freezing.

a reply to: Zaphod58
Under ideal conditions they shouldn't have to compensate by making it a little cooler. The LOX only warmed up that time because a boat strayed into the safety area and delayed the countdown. Was there a similar delay when the rocket exploded? I don't recall reading about it.

a reply to: BlueShaman

They've had several aborts due to the LOX system. It hasn't been working as well as they hoped.

originally posted by: Tjoran
Still looked like something shot it in the video.

"Although Musk didn't share any details about how the frozen oxygen may have affected the helium tanks, he did offer a vague explanation"

A vague explanation? That doesn't sound very science.

The explanation is simple thermodynamic: liquid helium is substantially cooler than liquid oxygen. The helium tank could be a heat-sink and draw heat away from the oxygen tank and freeze the oxygen in places.

Solution: put an insulating barrier between helium tank and oxygen tank.

originally posted by: BlueShaman
Now I would like to see an explanation as to why the liquid oxygen fuel never froze on previous launches.

They could have gotten lucky, or the procedures were a little different, or the weather was different.

Or the oxygen did freeze before but fortunately the carbon fiber tank didn't combust. Perhaps some impurity was necessary to start that reaction, and slight manufacturing differences had an impact?

Rocket science actually is rocket science.

originally posted by: mbkennel
The explanation is simple thermodynamic: liquid helium is substantially cooler than liquid oxygen. The helium tank could be a heat-sink and draw heat away from the oxygen tank and freeze the oxygen in places.

Solution: put an insulating barrier between helium tank and oxygen tank.

Nice call.