Alan Boyle on the preliminary findings of telemetry analysis of the failed SpaceX Falcon 9 launch last month:
The June 28 loss of the Falcon, plus SpaceX’s robotic Dragon capsule and more than two and a half tons of cargo, will set back the company’s launch schedule by at least a few months and is likely to result in hundreds of millions of lost revenue, Musk told reporters.
SpaceX’s workhorse Falcon 9 rocket is grounded pending the conclusion of the company’s investigation and the Federal Aviation Administration’s signoff. Also, the debut of its Falcon Heavy launch vehicle will have to be put off until next spring, Musk said.
He said that the strut assembly would be redesigned and readjusted before the Falcon flies again, and that SpaceX would readjust its attitude as well.
“This is the first time we’ve had a failure in seven years, so to some degree the company became complacent,” Musk told reporters. “When you’ve only ever seen success, you don’t fear failure quite as much.”
Musk emphasized that the focus on a faulty strut was only a preliminary rather than a definitive determination of the cause, but here’s how he and SpaceX’s investigators think it went down, based on an analysis of data from 3,000 channels of telemetry: One of the steel struts holding down a bottle of helium inside the Falcon’s second-stage liquid-oxygen tank assembly broke loose during the first couple of minutes of flight. The helium is supposed to be released in a controlled fashion to keep the liquid oxygen under stable pressure, and the struts connected to the bottles are supposed to withstand 10,000 pounds of force.
But on June 28, something went wrong when the stress on the struts amounted to only 2,000 pounds. “It failed at five times below its nominal strength, which is pretty crazy,” Musk said.
