SpaceX postponed the launch of a Falcon 9 rocket from a historic launchpad in Florida seconds before lift-off.

A possible problem with the steering system in the upper stage of the booster caused the latest setback.

Saturday's flight, the first for the company from a launchpad at the Kennedy Space Center once used for NASA's space shuttle programme, has been rescheduled for Sunday.

The rocket will carry a cargo ship bound for the International Space Station.

SpaceX said the problem concerned an issue with the steering system of the rocket's upper stage.


Elon Musk, founder and chief executive of Space Exploration Technologies Corp wrote on Twitter: "Standing down to investigate."

SpaceX has not flown from Florida in six months.

SpaceX rocket in first blast off since explosion

Flights were suspended after a rocket exploded while being fuelled ahead of a routine, pre-launch test at Cape Canaveral Air Force Station, south of Kennedy Space Center.

The accident destroyed the rocket and its cargo and heavily damaged the launchpad, which is being repaired.

SpaceX resumed flying last month from a second launch site in California while it pushed ahead to finish work on the shuttle's old launchpad.

The rocket blasted off from the Vandenberg Air Force Base in January to put 10 satellites into orbit for the Iridium communications company.

But it landed vertically on a platform at sea shortly after sending its payload into orbit.

Originally built for the 1960s-era Apollo moon programme, the Florida launchpad was refurbished for the space shuttles, which flew from 1981 to 2011.

SpaceX rocket blasts off and returns to sea platform in comeback mission

SpaceX signed a 20-year lease for the launchpad in 2014.

NASA hired SpaceX and Orbital ATK to resupply the station after it retired the shuttles.

The US space agency last year added a third company, privately-owned Sierra Nevada Corp, for making cargo runs to the station beginning in 2019.

By then, SpaceX aims to be launching NASA astronauts, breaking Russia's monopoly on flying crew to the space station.