SpaceX is set to return to the skies on Sunday January 8, four months after its Falcon 9 rocket exploded along with a $200 million AMOS-6 satellite payload.
The announcement coincides with the conclusion of an investigation conducted by the Federal Aviation Administration, the US Air Force, Nasa and the National Transportation Safety Board, into the cause of the September 1 explosion that occurred at Cape Canaveral Air Force Station. According to a release from Elon Musk’s SpaceX company, the fault lay in one of the composite overwrapped pressure vessels (COPVs) inside the rocket's second stage liquid oxygen tank. The composite vessels used to carry high pressure fluids are made of lighter weight materials than their all-metal equivalents.
Read more: Watch the moment SpaceX's Falcon 9 rocket explodes
“The failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner, leading to ignition and the subsequent failure of the COPV,” a statement from SpaceX reads. COPVs recovered from the site showed buckles in their liners. The team believes that the liquid oxygen pooled in these buckles, and when pressurised it became trapped. “Breaking fibers or friction can ignite the oxygen in the overwrap, causing the COPV to fail.” Investigators also found that the temperatures of the helium fuel were cool enough to create solid oxygen, which increased the chances of it becoming trapped and igniting.
SpaceX has taken measures to ensure this will not happen again, amending the COPV configuration so helium is warmer when loaded, and using past techniques for loading helium which have already proven safe. “In the long term, SpaceX will implement design changes to the COPVs to prevent buckles altogether, which will allow for faster loading operations,” says the company.
The next launch, scheduled to take place at the Vandenberg Space Launch Complex on Sunday with several Iridium NEXT satellites attached to the Falcon 9, will not incorporate the aforementioned design changes. But these long-term measures will likely take place before collaborations with Nasa begin.
This article was originally published by WIRED UK
