THE NEW SPACE RACE: Elon Musk wants to avoid another ‘rock tornado’ next time Starship launches. SpaceX just tested a way to prevent it.

The new water deluge system is designed to dampen the powerful effects caused by igniting the rocket’s engines during launch. Starship’s massive Super Heavy booster, needed to propel the vehicle into space, has 33 Raptor engines at its base — all of which are meant to fire simultaneously at liftoff.

Read more: SpaceX Starship Has Much Better Chance After Overhaul, Musk Says

The force of igniting so many Raptor engines at once proved to be quite damaging to the launchpad, as SpaceX learned during the first test flight of Starship. Though only 30 Raptor engines were initially ignited, they still caused what SpaceX CEO Elon Musk called a “rock tornado” underneath the launchpad. The launch sent chunks of concrete and debris thousands of feet into the air, damaging the pad and littering the nearby landscape.

To prevent another explosive event, SpaceX’s engineers have been installing steel plates underneath Starship’s launchpad, meant to deflect the immense heat and forces caused by the Raptor engines. Sunday’s test marked the first time that SpaceX attempted to test the deluge system while igniting the engines.

SpaceX didn’t immediately clarify if the ignition test was considered a success, however the host of the livestream, John Insprucker, said after the firing that Starship’s “pad looks good. The launch vehicle looks good.”

Launch pad debris might have been responsible for some of the engine troubles on Starship’s first orbital test flight in April.