SpaceX Explosion: Elon Musk Says Faulty Strut Was the Cause

The SpaceX Falcon 9 rocket likely exploded after liftoff from Cape Canaveral on June 28 because of a faulty two-foot-long, one-inch-thick strut, Elon Musk told journalists Monday.

The SpaceX mishap was the third time that a rocket with supplies for the International Space Station failed since last October. The Falcon 9 had some 4,000 pounds of supplies and experiments for the space station, Mashable reported.

"It just goes to show that rockets are a fundamentally difficult thing," Musk, the company's founder, said.

Musk said he was surprised by the strut's failure because it was designed to handle higher pressure that what it was subjected to.

"It failed at five times below its nominal strength which is pretty crazy," Musk said, according to Mashable.

Musk said when the strut, which failed in the second stage liquid oxygen tank, broke free during flight, it caused the helium bottle it held to shoot to the top of the tank, noted National Public Radio.

"What we think might have happened is as the helium bottle broke free, and it twisted around, it may have pinched off the line to the helium manifold and restored pressure in the helium system, but released enough helium into the liquid oxygen tank to cause the liquid oxygen tank to fail," he said.

Musk said that SpaceX would individually test each strut in the future and would no longer used the outside company that provided his company with them.

"This will result in some cost increase to the rocket, but not, we believe, of a significant amount," Musk said to reporters, per NPR. "And nothing that we would think should affect the actual price of the vehicle."

SpaceX has completed six of the 12 flights it is contracted to make for NASA in its current $1.6 billion contract. Musk said that it appeared that most of the Dragon space capsule on the failed Falcon 9 rocket survived and is in the Atlantic Ocean, noted Space.com.

Musk said that SpaceX will likely attempt to locate the capsule soon by sending a robotic submarine to the reported debris field.

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