Pieces of concrete ejected, bent metal and craters dug in the ground... The damage caused by the takeoff of Starship Friday on the launch pad will probably take several months to be repaired.
They could thus delay the next test flights, and therefore the development of this rocket on which NASA is quickly counting to send its astronauts back to the Moon.
Before Thursday's test flight, SpaceX boss Elon Musk's only wish was "
not to destroy the launch pad
."
His fear: that the rocket would explode before it had even torn itself from the ground, which it finally did after four minutes of flight, above the sea. But the company seems to have underestimated the damage that a simple takeoff of this 120 meter high mastodon could result.
"
The engines, when they ignited, may have shattered the concrete, rather than just eroding it
," Elon Musk tweeted on Saturday.
Read alsoSpaceX's huge Starship rocket explodes in flight, shortly after takeoff
The gigantic launch tower withstood the shock.
The huge base on which the vehicle rests (launch table) is also still there, even if it has been damaged.
But under him, a deep crater has been dug, according to images published by specialists on social networks.
All around reigns a landscape of desolation, noted an AFP photographer.
During takeoff, a shower of debris was catapulted into the nearby sea, SpaceX video shows.
A cloud of dust reached a small town several kilometers away, according to local press.
Not ready in time
"
The radius of debris and nuisance was probably greater than anyone anticipated
," Olivier de Weck, a professor in MIT's Department of Aeronautics and Astronautics, told AFP.
“
The main damage from the launch pad is below, where the flames (from the engines) attack the ground
,” explained Mr. de Weck, several of whose former students work for SpaceX.
“
The crater that has been created is going to have to be filled and repaired, and that will certainly take several months.
»
Starship's launch pad did not appear to be equipped with two facilities typically used for heavy launchers.
First, a “
deluge
”: phenomenal quantities of water poured out at the precise moment of the ignition of the engines, in order to attenuate the acoustic waves, limiting the vibrations.
Then, a "
jet deflector
" (or flues): a system of tunnels to redirect the gases emitted, protecting both the concrete and the rocket.
But building them is extremely expensive, especially since they must be adapted to the size of the rocket, disproportionate in the case of Starship.
After the test, Elon Musk explained that the company had started to build “
a steel plate cooled by water
” to be placed under the base of the rocket, ultimately not “
ready in time
”.
The company " wrongly
" thought
the launch pad would withstand the test, he admitted, adding that a new take-off would probably be possible "
in one or two months
".
No injuries
Such a steel plate "
would make sense, I think it will work
," Philip Metzger, a former NASA employee who worked on launch pad physics, told AFP.
Spraying it with water would prevent the plaque from “
melting
,” he explained.
This would not solve the problem of acoustic waves, but "
you can build a rocket strong enough to withstand it
", estimated this scientist at the University of Central Florida.
Designing a launch pad is as complex as developing a rocket, he pointed out.
NASA's new mega-rocket, SLS, which took off for the first time in November from Florida, had also caused damage, in particular putting out of service the elevators of its launch tower.
Before being able to fly again, in addition to reinforcing its launch pad, SpaceX will have to determine the cause of the problems encountered in flight.
Several engines failed, and the rocket's two stages failed to separate as expected, forcing SpaceX to activate the self-destruct command.
Finally, it will be necessary to convince the air regulator, the FAA, to authorize Starship to take off again, noted Olivier de Weck.
The agency confirmed that the test on Thursday did not cause any injuries, and said it was overseeing the investigation into the explosion.
She assured that a new test flight would be conditional on public safety.
Counterintuitively, this first test remains “
more a success than a failure
”, according to Mr. de Weck.
“
SpaceX gets to develop these amazing capabilities, because they're willing to take risks and break things -- but they learn from it.
»