SpaceX Super Heavy Booster Engine Testing Ends With An Unexpected Blast

SpaceX started to perform pre-flight testing of the gigantic stainless-steel Super Heavy rocket prototype designed to propel a Starship to orbit from Boca Chica Beach, Texas, this year. The prototype, identified as Booster 7, has been undergoing testing for a few months. It underwent a cryogenic proof test in May then engineers installed 33 Raptor V2 engines. On Monday, July 11, SpaceX performed the first engine tests on Booster 7 and the testing ended with an unexpected blast. The explosion caused a shockwave that was captured by LabPadre and NASASpaceflight livestream cameras, shown below. SpaceX founder Elon Musk shared via Twitter that the "[...] Team is assessing damage." 

HOLY SHIT!! Check out this shockwave and the sound of this explosion

🔥🔥🔥🔥🔥🔥🔥🔥

I hope that was planned...sure didn't look like it to me!

🎥: @LabPadre pic.twitter.com/FZUdUo6Qhr

— Zack Golden (@CSI_Starbase) July 11, 2022

Yeah, actually not good. Team is assessing damage.

— Elon Musk (@elonmusk) July 11, 2022

According to Chief Engineer Elon Musk, SpaceX performed a "spin start test" of Booster 7's 33 powerful Raptor V2 engines that led to the explosion. During the test, the rocket was fueled with cryogenic liquid methane and liquid oxygen propellant. When the vehicle was fueled it caused significant venting that was seen from underneath the rocket before the massive blast occured. In a short Twitter conversation under the explosion video, Astronomer Jonathan McDowell wrote to Musk - "In the big picture still early days with Raptor 2. Still learning I guess. Good luck with the analysis." To which Musk responded -"Cryogenic fuel is an added challenge, as it evaporates to create fuel-air explosion risk in a partially oxygen atmosphere like Earth. That said, we have a lot of sensors to detect this. More [details] later," he wrote. 

Cryogenic fuel is an added challenge, as it evaporates to create fuel-air explosion risk in a partially oxygen atmosphere like Earth.

That said, we have a lot of sensors to detect this. More later.

— Elon Musk (@elonmusk) July 11, 2022

A Twitter user suggested that SpaceX should try to burn/evaporate the fuel leaks before ignition to avoid explosions, like NASA did with the Space Shuttle, and Musk agreed with the method. "That is one of the things we will be doing going forward," wrote Musk in response. "This particular issue, however, was specific to the engine spin start test (Raptor has a complex start sequence). Going forward, we won’t do a spin start test with all 33 engines at once," said Musk. 

SpaceX is waiting for a spaceflight license from the Federal Aviation Administration (FAA) to launch Starship to orbit this Summer. It is unclear whether the explosion caused any damage that would potentially delay the long-awaited debut orbital flight test. Regarding the amount of damage the blast caused, Musk said that the "base of the vehicle seems ok by flashlight," he wrote on July 12 at midnight, "I was just out there about an hour ago. We shut down the pad for the night for safety. Will know more in the morning."  

That is one of the things we will be doing going forward.

This particular issue, however, was specific to the engine spin start test (Raptor has a complex start sequence).

Going forward, we won’t do a spin start test with all 33 engines at once.

— Elon Musk (@elonmusk) July 12, 2022

Base of the vehicle seems ok by flashlight. I was just out there about an hour ago. We shut down the pad for the night for safety. Will know more in the morning.

— Elon Musk (@elonmusk) July 12, 2022

Featured Image Source: LabPadre via YouTube & Twitter