Musk’s spaceship back on launchpad after inquiry concludes

Elon Musk’s SpaceX rocket company has been cleared to resume flying following a launch pad explosion four months ago, the US federal aviation Administration (FAA) said at the weekend.

The decision clears SpaceX to attempt to launch a Falcon 9 rocket carrying 10 Iridium Communications satellites as early as Monday, a day later than originally planned.

SpaceX, owned by the Tesla Motors chief executive Mr Musk, declined to comment about what caused the delay.

Liftoff is set to take place from Vandenberg Air Force Base in California.

The FAA, which oversees commercial US space launches, monitored SpaceX’s investigation into why a Falcon 9 rocket burst into flames on a launch pad in Florida as it was being fuelled for a routine, prelaunch test on September 1.

The accident destroyed the US$62 million booster and a $200m communications satellite that had been partly leased by Facebook to expand internet access in Africa.

"The FAA has closed the investigation," the agency said.

"SpaceX applied for a licence to launch the Iridium NEXT satellites from Vandenberg Air Force Base. The FAA has granted a license for that purpose," the FAA said.

The launch will be SpaceX’s first since August. The company has a backlog of more than 70 missions for Nasa and commercial customers, worth more than $10 billion.

As a result of the accident investigation, SpaceX is changing the way it fuels its rockets to prevent canisters of helium, located inside liquid oxygen tanks, from bursting. The company said the long-term solution will be to redesign the helium canisters, which are made of an aluminium liner and a carbon overwrap. The helium is needed to maintain oxygen tank pressure.

The SpaceX rocket was briefly powered up on Thursday as part of a preflight engine test.

"All systems are go for launch next week," Mr Musk posted on Twitter.