SpaceX says it has determined the cause of a launchpad explosion that destroyed a satellite in September and is ready to start launches again as early as Sunday.

An unmanned SpaceX Falcon 9 rocket exploded September 1 in Cape Canaveral, destroying a satellite that Facebook planned to use to beam high-speed internet to Africa.

That marked a setback for the California-based private space firm and its founder Elon Musk, who wants to revolutionize the launch industry by making rocket components reusable.

In a statement Monday, SpaceX said it had traced the problem to a pressure vessel in the second-stage liquid oxygen tank. It said it will change the way it fuels for now, and in the future will redesign its pressure vessels.

SpaceX said it hopes to launch 10 Iridium NEXT communications satellites from a base in California on Sunday.

The Federal Aviation Administration has to approve the conclusions of the SpaceX investigation of the September failure.

That accident -- the second of its kind since SpaceX was founded in 2002 -- came just over a year after a Falcon 9 rocket failed after liftoff on June 28, 2015, destroying a Dragon cargo capsule bound for the International Space Station.

Before that, SpaceX had logged 18 successful launches of the Falcon 9 -- including six of 12 planned supply missions to the ISS carried out as part of a $1.6 billion contract with NASA. 

It carried out another eight successful launches since June 2015, including in August of last year when a Falcon 9 successfully placed a Japanese communications satellite in orbit, and then landed intact on a floating drone ship.

Before then the firm lost several rockets as it attempted to land them upright on an ocean platform at the end of a flight -- a crucial part of its strategy for reusable spacecraft.