US-based SpaceX has found the source of the Falcon 9 rocket explosion that occurred last year at Cape Canaveral Air Force Station in Florida.

According to the company, the failure occurred as oxygen accumulated between the composite overwrapped pressure vessel (COPV) liner and overwrap in a void or a buckle in the liner.

"SpaceX plans to implement design changes to the COPVs to prevent buckles altogether, enabling faster loading operations in the future.?"

This led to ignition and the subsequent failure of the COPV.

During the last four months, SpaceX collaborated with the US Air Force (USAF), the Federal Aviation Administration (FAA), Nasa and the National Transportation Safety Board (NTSB) to investigate and determine the cause of the explosion.

As the failure occurred, investigators could review umbilical data, ground-based video, and physical debris.

In order to validate investigation analysis and findings, SpaceX performed several tests at its facilities in Hawthorne, California, and McGregor, Texas.

Each stage of the Falcon 9 rocket uses COPVs to store cold helium with which tank pressure can be maintained.

Each COPV consists of an aluminium inner liner with a carbon overwrap.

Investigators found that the loading temperature of the helium was cold enough to create solid oxygen (SOX), which intensifies the possibility of oxygen becoming trapped.

SpaceX plans to implement design changes to the COPVs to prevent buckles altogether, enabling faster loading operations in the future.?