The maiden flight of the SpaceX SN9 Starship prototype appears to be days away following a triple-Raptor static fire test on Wednesday.
All three of the SN9 prototype’s next-generation Raptor engines burst into life at 22:07 UTC on January 6. The static fire burn lasted for around one second, several seconds shorter than is traditionally expected.
The shorter static fire burn will likely necessitate a second to be performed within the next day or two. According to road closure and flight restriction notices, this will then be followed by the launch vehicle’s maiden flight over the weekend.
The SN9 flight follows on the heels of the successful failure of the SN8 prototype in December last year.
The SN8 mission was the first high-altitude test of a Starship prototype. After a successful launch, the vehicle climbed to an altitude of 12.5 kilometers and performed its complex “belly flop” manoeuvre to bleed off speed as it returned to Earth. As the prototype’s three Raptor engines reignited to slow the vehicle for touchdown, a header fuel tank pressure issue left it unable to slow itself sufficiently leaving it to slam into the ground exploding on impact.
Since the SN8 failure, SpaceX has solved the header tank pressure issue by filling the tank with helium. SpaceX founder and CEO Elon Musk explained that this was a temporary solution while the company worked on a long-term fix.
In addition to a header tank pressure fix, SN9 required the replacement of two damaged aero surfaces after the prototype toppled in the Boca Chica High Bay assembly building mid-December. The vehicle was righted soon after its fall and repairs were made quickly.
As SpaceX prepares SN9 for flight, the SN10 and SN11 prototypes are nearing completion with elements of SN12 through 17 already underway. This rapid production schedule is not only an effort to accelerate development of the Starship launch system but also to refine the construction processes that will be required to construct as many as 1,000 vehicles.
“Production is hard, prototypes are easy,” said Musk. “Building ~1000 Starships to create a self-sustaining city on Mars is our mission.”