Elon Musk's SpaceX Starship explodes in space, raining debris over Caribbean

SpaceX's Starship spacecraft has tumbled and exploded in space just minutes after lifting off from Texas.

The explosion doomed an attempt to deploy mock satellites in the second consecutive failure this year for Elon Musk's Mars rocket program.

Videos on social media showed fiery debris streaking through the dusk skies near southern Florida and the Bahamas after Starship's break-up, which occurred shortly after it began to spin uncontrollably with its engines cut-off.

The failure comes just over a month after the company's seventh Starship flight also ended in an explosive failure.

The back-to-back mishaps occurred in early mission phases that SpaceX has easily surpassed previously, indicating serious setbacks for a program Mr Musk has sought to speed up this year.

Debris streaked through the sky near Big Sampson Kay, Bahamas. (Supplied: Reuters )

The 123 metre rocket system had lifted off at about 6:30pm from SpaceX's Boca Chica, Texas, rocket facilities with its Super Heavy first stage booster returning back to land as planned.

But minutes later, SpaceX's live stream showed the Starship upper stage spinning in space, while a visualisation of the rocket's engines showed multiple engines shut down before the company confirmed it had lost contact with the ship.

"Unfortunately this happened last time too, so we've got some practice now," SpaceX spokesman Dan Huot said on the live stream.

The debris, as seen from Hog Cay, Bahamas. (Supplied: Reuters)

It was not immediately clear whether the explosion was caused by SpaceX's automated flight termination system, which triggers when something on the rocket goes wrong. The ship showed signs of failure before its explosion.

The Federal Aviation Administration issued ground stops at Miami, Fort Lauderdale, Palm Beach and Orlando airports because of "space launch debris" until at least 8pm local time.

"During Starship's ascent burn, the vehicle experienced a rapid unscheduled disassembly and contact was lost," SpaceX said in a statement.

"Our team immediately began coordination with safety officials to implement pre-planned contingency responses."

The Starship failure in January ended eight minutes into flight when the rocket exploded in space, raining debris over Caribbean islands and causing minor damage to a car in the Turks and Caicos Islands.

This week's flight was originally scheduled to occur on March 4 but the company pulled the pin on the mission due to an unspecified issue on the rocket system's core ship, delaying the launch for at least 24 hours.