SpaceX's mega-rocket has a 'decent chance' of making orbit on its next flight, Musk said. Last time, Starship blew up the launchpad and exploded in mid-air.

• Elon Musk said he thinks Starship has a "decent chance" of reaching orbit on its second test flight.
• SpaceX's mega-rocket was launched on its first flight in April, but it exploded a few minutes after liftoff.

SpaceX CEO Elon Musk said Thursday the company's Starship vehicle has a "decent chance" of making orbit on its second test flight.

Since its last flight, which ended in an explosion, the company has decided to introduce "hot-staging" to the rocket, a risky move as the spacecraft will light its engines as it is still essentially connected to its booster.

"Of course, it's the first time we're doing it. And I'd say that's the riskiest part of flight two," Musk said during a livestreamed interview at the International Astronautical Federation annual conference on Thursday.

"If the engines light and the ship doesn't blow itself up during stage stuff, then I think we've got a decent chance to reach orbit," he added.

Starship is SpaceX's most powerful rocket. It is crucial to Musk's plans to bring humans to Mars and NASA's plans to bring astronauts to the moon.

But it has yet to reach orbit. SpaceX attempted to reach orbit with the Starship spacecraft stacked on top of its booster for the first time in April, but the mega-rocket blew up after the two stages failed to separate a few minutes into the flight.

The rocket also unexpectedly blew a crater through its launchpad as it was taking off. Debris was reported to have rained down in a town about five miles away from the rocket's launch site.

Musk said in September the next iteration of Starship is "ready to launch," again. The company has not yet announced a launch date for the next test flight, which should aim to reach Earth's orbit, or just shy of it.

"Technically, it's a scooch below orbit," Musk said Thursday.

Since its first flight, SpaceX has introduced "more than a thousand changes" to the mega-rocket, Musk told the journalist Ashlee Vance in June. One of these is hot staging, a move that should give the spaceship a boost of energy as it lights its engines while its booster is still pushing it forward.

During the same interview in June, Musk also told Vance the chance of Starship reaching orbit the second time is "much higher than the last one."

"Maybe it's, like, 60%," he said, adding that "it depends on how well we do at stage separation."

Abhi Tripathi, former mission director for SpaceX's Dragon spaceship, previously told Insider that Musk is "usually not as optimistic" as he seems now.

Tripathi added that he would consider this second test flight to be a success if two things happen.

"One, the damage to the launch mound and ground infrastructure is minimal, and two, at least 32 of the 33 engines stay lit."

"If I see those two things," he said, "I don't care what happens afterward. I will consider this a smashing success."