A family portrait of SpaceX’s Raptor engines.
Credit:
SpaceX
SpaceX has now encountered engine problems on each of the three Starship flights that have used Raptor 3s. During a May flight, one Raptor engine shut down prematurely on the Super Heavy booster, and another stopped running on Starship’s upper stage a few minutes later. Multiple Raptor engines failed to ignite on the launch pad for the next flight in July, prompting a last-second abort. SpaceX swapped out two of the engines before proceeding with a successful launch a week later.
Elon Musk, SpaceX’s founder and CEO, wrote on his social media platform X that the changes introduced with the Raptor 3 engine “greatly reduces mass and leak paths, but makes it harder to replace some parts.”
“While deleting parts sounds easy in theory, it is actually very difficult to figure out how to do so in practice and requires many iterations,” Musk continued. The inside of the Raptor 3 engine “has very complex geometry that can only be manufactured using highly modified 3D metal printing,” he wrote in another post.
Although the Raptor 3 is still a work in progress, the propulsion issues have not stopped SpaceX from making headway with Starship, and it’s unlikely the engine problems on Monday’s flight will delay the next Starship launch.
The FAA is also giving SpaceX the all-clear on Monday’s flight. The regulatory agency will not require SpaceX to conduct a formal mishap investigation. An FAA spokesperson told Ars: “All flight events for both the Starship vehicle and the Super Heavy booster occurred within the scope of planned and FAA authorized activities.”
Next on SpaceX’s to-do list will likely be an attempt to bring Starship back to Starbase for a catch by the launch pad’s giant mechanical arms, repeating a feat engineers have already accomplished with Super Heavy booster. Returning Starship to the launch site will require a reentry over land, necessitating additional safety reviews to ensure no undue risk to populated areas as the vehicle approaches Starbase. Eventually, SpaceX aims to make these landings routine enough to enable full and rapid reuse of Super Heavy and Starship.
Other near-term objectives for Starship include longer-duration orbital flights and then the first demonstration of in-orbit refueling, a prerequisite for future missions to land astronauts on the Moon under the auspices of NASA’s Artemis program.
In the meantime, expect Starship to launch many more Starlink satellites. Commercial and government demand for Starlink services, along with SpaceX’s longer-term plans for orbital data centers, will keep Starship plenty busy as engineers bring the rocket’s more advanced capabilities online.