San Francisco, Apr 11 (IANS): SpaceX's Starship is likely to launch on the first orbital flight by April end, CEO Elon Musk said.

"Starship launch trending towards near the end of third week of April," Musk wrote in a tweet on Monday.

A day ago, he had said that the "Starship is ready for launch. Awaiting regulatory approval".

The US Federal Aviation Administration (FAA) is yet to grant licence approval for the orbital test flight.

The agency on Monday issued a revised notice that said the launch could now happen on April 17.

Another hurdle is federal environmental compliance review.

Meanwhile, SpaceX has been long gearing up for the flight. The company has rolled its Ship 24 out to Starbase's orbital launch pad.

It has also conducted fueling tests with Booster 7 on the orbital launch mount, with Ship 24 on the ground nearby.

Starship is the world's most powerful rocket and will be used to send humans to the Moon and then eventually to Mars.

It consists of a giant first-stage booster called Super Heavy and a 50 metres upper-stage spacecraft known as Starship.

Both stainless-steel vehicles are designed to be fully and rapidly reusable, and both are powered by SpaceX's next-gen Raptor engine -- 33 for Super Heavy and six for Starship.

Moreover, Musk recently said that there is only a 50 per cent chance that the first-ever orbital mission of SpaceX's huge Starship vehicle will be a success.

But he also stressed that SpaceX is building multiple Starship vehicles at the South Texas site.

These will be launched in relatively quick succession over the coming months, and there's about an 80 per cent chance one of them will reach orbit this year.