SpaceX's Starship rocket blows up minutes after take-off| Watch

SpaceX's new rocket Starship, the biggest and most powerful ever built, blasted off on its first test flight, thundering into the South Texas sky in an attempt to orbit the world but fell short of reaching space as the towering rocket suffered a mid-flight failure.

Elon Musk's company launched the nearly 400-foot (120-metre) Starship rocket from the southern tip of Texas, near the Mexican border.

"As if the flight test was not exciting enough, Starship experienced a rapid unscheduled disassembly before stage separation," the company tweeted.

The plan called for the booster to peel away and plummet into the Gulf of Mexico shortly after liftoff, with the spacecraft hurtling ever higher toward the east in a bid to circle the world, before crashing into the Pacific near Hawaii.

No people or satellites were aboard for this debut launch.

Throngs of spectators watched from several miles away from the Boca Chica Beach launch site, which was off-limits.

The company plans to use Starship to send people and cargo to the moon and, eventually, Mars. NASA has reserved a Starship for its next moonwalking team, and rich tourists are already booking lunar flybys.

It was the second launch attempt.

The first scheduled launch on April 17 was scrapped less than 10 minutes ahead of time by a frozen booster valve.

Starship comprises a 164-foot spacecraft that sits atop a 230-foot tall first-stage Super Heavy booster rocket.