STARBASE, United States: Chunks of concrete were ejected, metal bent and craters dug in the ground… The force of the first launch of SpaceX’s new rocket, Starship, both the largest and most powerful in the world, seriously destroyed its launch block in Texas.

It will probably take several months to repair the damage caused. They could thus delay the next test flights and thus the development of this rocket, with which NASA will soon send its astronauts to the moon again.

Ahead of Thursday’s test flight, SpaceX CEO Elon Musk’s only wish was “not to destroy the launch pad.” His fear: that the rocket would explode before it even ripped off the ground – which it finally did after four minutes of flight over the sea.

But the company appears to have underestimated the damage a simple launch of this 120-meter-tall mastodon could do.

“The thrusters may have shattered the concrete when firing, rather than just eroding it,” Elon Musk tweeted Saturday.

The gigantic launch tower withstood the shock. The huge pedestal that the vehicle rests on (launch table) is also still there, even though it was damaged.

But under it, according to pictures published by specialists on social networks, a deep crater was dug.

All around is a landscape of devastation, noted an AFP photographer. A shower of debris was thrown into the nearby sea during the launch, a SpaceX video shows. According to local press, a cloud of dust reached a small town several kilometers away.

Not ready in time

“The radius of debris and nuisance was probably larger than expected,” Olivier de Weck, a professor in MIT’s Department of Aeronautics and Astronautics, told AFP.

“The main damage from the launch pad is down where the flames (from the engines) are attacking the ground,” explained Mr. de Weck, several of whom work for SpaceX alumni. “The resulting crater has to be filled in and repaired, and that will certainly take several months.”

The spacecraft’s launch pad did not appear to be equipped with two facilities normally used for heavy launch vehicles.

First, a “deluge”: phenomenal amounts of water poured out at the precise moment the engines are fired, to muffle sound waves and limit vibrations.

Then a “jet deflector” (or chimneys): a system of tunnels that allow the ejected gases to be redirected, protecting both the concrete and the rocket.

But their construction is extremely expensive, especially since they have to be adapted to the size of the rocket – disproportionately in the case of Starship.

After the test, Elon Musk explained that the company had started building “a water-cooled steel plate” to be placed under the base of the rocket, which ultimately “would not be ready in time”.

The company “mistakenly” thought the launch pad would stand up to the test, he admitted, adding that a new launch might be possible “in a month or two.”

To strengthen

Such a steel plate “would make sense, I think it will work,” Philip Metzger, a former NASA employee who worked on the physics of the launch pads, told AFP. Spraying with water would prevent the plaque from “melting,” he explained.

While that wouldn’t solve the problem of sound waves, “you can build a rocket strong enough to withstand that,” estimated this scientist at the University of Central Florida.

Designing a launch pad is as complex as designing a rocket, he stressed.

NASA’s new SLS mega-rocket, which took off from Florida for the first time in November, had also caused damage and in particular put the elevators in its launch tower out of operation.

Before SpaceX can fly again, it must not only strengthen its launch pad, but also determine the cause of the problems encountered in flight. Several engines failed and the rocket’s two stages did not separate as expected, forcing SpaceX to activate the self-destruct command.

Finally, the FAA must be persuaded to allow Starship to take off again, noted Olivier de Weck. The agency confirmed Thursday’s test did not cause any injuries and said it was overseeing the investigation into the blast. She assured that a new test flight would be made dependent on public safety.

Contrary to intuition, this first test is “more likely to be a success than a failure,” according to Mr. de Weck. “SpaceX can develop these amazing abilities because they are willing to take risks and break things – but they learn from it.”