The failure of a 60 cm strut caused a SpaceX Falcon 9 rocket to explode shortly after lift-off last month, although a wider issue of complacency may have played a part, the company has admitted.
SpaceX founder Elon Musk said the strut, inside a liquid oxygen tank, snapped “five times below its normal strength, which is crazy”. The part was from a supplier rather than manufactured by SpaceX, he revealed.
In response, the firm will switch to a different part design from a different supplier, and in the meantime will individually test each strut.
Musk noted the majority of SpaceX employees had previously only known successful launches, not counting tests, with the company’s numbers having increased eightfold to 4000 since the last rocket failure in 2008. The firm had become somewhat relaxed as a result, he explained.
"To some degree the company became a little bit complacent in the course of 20 successes in a row," Musk said. "This is certainly an important lesson and something we will take with us into the future.
"It's just the fundamental nature of rocketry: a passing grade is 100% every time. It's not possible to issue a recall or a patch. From the moment of lift-off it’s 100% or nothing."
The failed Falcon 9 was carrying a Dragon craft loaded with supplies for the International Space Station (ISS). The rocket exploded less than three minutes after its launch on 28 June.
Musk said the firm was still searching for debris and has been working with the US Federal Aviation Administration, NASA and the US Air Force.
"Dragon hit the water quite hard," he said. "It's at the bottom of the ocean, and we are trying to retrieve it."
This was the third loss of an unmanned supply mission to the ISS since October last year. In April, Roscosmos lost control of an orbiting Progress craft before it could reach the station, and in October an Orbital Sciences mission was terminated when propulsion failed 15 seconds after lift-off.
Caption: SpaceX’s rocket explodes during flight. Photo: NASA
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