Just under a month ago, a SpaceX Falcon 9 rocket exploded just over two minutes intotakeoff. SpaceX responded by postponing its upcoming launches and digging into the cause of the problem. The issue, it seems, was a bad strut within the rocket itself. The Falcon 9 uses RP-1 for fuel (a highly refined kerosene derivative). As the fuel tanks empty, helium is pumped in to keep fuel tank pressure constant. The helium tanks themselves are held in place by struts, and it’s one of these internal struts that’s believed to have failed. Once the strut failed, the helium tank is believed to have leaked helium into the still-full second stage fuel tank. SpaceX’s internal monitoring revealed that the second stage of the rocket recorded over-pressurization before the entire rocket exploded, but does not record an extreme over-pressurization event that would indicate the helium tank had ruptured. The rocket’s first stage, in contrast, was still firing normally right up to when the rocket was lost. What’s odd about this failure is that it occurred when the rocket was under just 2,000 lbs of force. The struts are capable of absorbing up to 10,000 lbs of force at lift-off. While all struts appeared to be installed correctly and there were no visible flaws found in the video examination prior to launch, post-flight examination of struts still on the ground discovered that several of them were weaker than expected. SpaceX has stated that it intends to resume flying once it has nailed down the cause of the problem and talked to its suppliers.
Software Update Would Have Saved Payload
The Falcon 9’s Dragon payload capsule survived the initial explosion and was still transmitting telemetry, right up to the point when it vanished over the horizon and smashed into the Atlantic shortly thereafter. According to SpaceX, a new software update will be installed on future launch vehicles to enable the Dragon to deploy its parachutes in the event that a future rocket explodes again. The parachutes aboard Dragon aren’t new — they’re a part of how the capsule lands on Earth — but the software necessary to make them deploy in the event of a rocket explosion (a feature planned for future crew-carrying) hadn’t been implemented yet. “The software on Dragon to initiate the parachute deployment was not in Dragon version 1. It was planned for version 2, so if something like this happens in the future, the Dragon spacecraft will save itself,” said Musk. “In Dragon 2, it would thrust itself away from the vehicle quite rapidly and once it reached a decent distance, it would initiate the parachute.” SpaceX’s next scheduled launch is currently set for September, though that date could still change depending on the nature of the problem.