Private space firm SpaceX was planning to make a third attempt atlanding the first stage of its Falcon 9 rocket following a launch on Sunday, but that didn’t happen. The rocket was lost about two minutes after takeoff, and with it over 4000 pounds of supplies and equipment intended for the International Space Station. This is the second launch failure in a row for the ISS resupply project and the third in the last year.
This is sure to be an embarrassment for SpaceX, which hopes to receive approval from NASA to ferry astronauts to and from orbit in the Dragon 2 crew cabin. Still, the company is maintaining its standard open approach to public relations. The video of the launch, complete with explosion, is still available on the official SpaceX YouTube page, and preliminary data on the “anomaly” has been released.
Elon Musk has hinted at a “counterintuitive cause” for the explosion, but specifics are slim. Musk has further stated that mission control didn’t get any warning messages from the Falcon 9 prior to this event, but an “over-pressure event” was detected in the second stage fuel tank. Shortly before the rocket disintegrates, you can see a cloud of vapor forming around the junction of the first and second stage. That’s most likely the result of a boiling liquid expanding vapor explosion (BLEVE). This is what happens when a vessel containing liquid (like the liquid oxygen in the second stage fuel tanks) at or above its boiling point experiences a sudden drop in pressure that causes it all to boil simultaneously. Things go wrong at about 23:20 in the video below
It appears that the first and second stages broke up, followed by an explosion that destroyed the first stage. According to SpaceX, mission control did get telemetry from the Dragon capsule after the explosion, indicating it was still intact. Dragon has parachutes, but it’s unclear if any of them could be deployed before it hit the water. It’s likely that it had enough speed to breach on impact and sink. The cargo is probably toast, but there could still be useful data if the capsule could be recovered.
As for the ISS crew, they’re not yet in any real danger. It’s standard procedure to have a substantial excess of supplies on the station in case of situations like this. Even with two failed supply runs in a row, the crew won’t need to start rationing until late July, and more resupply missions are scheduled before then. In a worst-case scenario, there’s a Soyuz capsule docked at the station as a lifeboat, so the crew can just hop on-board and return to Earth if need be. One of the biggest setbacks is the loss of new docking adapters that were on the Dragon capsule. These components are needed to ready the ISS for private crew vehicles to dock with the station, which is supposed to start happening in 2017.
A Russian resupply mission is currently scheduled to go up later this week, and additional crew are heading to the station in a few weeks. SpaceX will be investigating the incident with the help of government agencies so the problem can be fixed before the next Falcon 9 launch late this year.
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