SpaceX’s next Starship launch still waiting on a successful Raptor test

Several days after the last test attempt, SpaceX’s next Starship launch remains delayed pending a successful static fire of the prototype’s three Raptor engines.

Delivered from SpaceX’s Boca Chica, Texas rocket factory to nearby launch and test facilities on December 22nd, less than two weeks after Starship serial number 8’s (SN8) high-altitude launch debut, successor Starship SN9 completed its first crucial test on December 29th. Known as a cryogenic proof test, SN9 was loaded either partially or fully with a large volume of liquid nitrogen to simulate the thermal stresses caused by liquid methane and oxygen propellant and ensure that pad systems and the rocket’s plethora of valves, pipes, and avionics were working as expected.

Cryoproof more or less completed on schedule, SN9’s follow-up static fire test continued in a similarly smooth fashion, with the first attempt once again falling within a planned three-day window – albeit on January 6th, the last of those three days. Near the end of the 8 am to 5 pm window, Starship SN9 ignited all three preinstalled Raptor engines but NASASpaceflight.com ultimately revealed that the test had been shorter than SpaceX expected.

Relative to all previous Starship testing, even ignoring the facts that a handling error damaged SN9 just one month ago and that the rocket is only the second prototype to have a full nose section installed and plumbed, SN9’s test campaign has been smooth. Despite the unique hurdles SN9 faced, the Starship completed a cryoproof and a static fire on its first respective day of attempts. Minor slips along the way – including recent static fire re-do delays – simply serve as a reminder that the Starship program and its prototypes have yet to reach operational maturity.

Why SN9’s first static fire ended prematurely is unclear and could have been caused by just about anything. The fact that all three Raptors shut down early points a finger to something other than the engines themselves and the clean abort SN9 seemingly commanded points to a relatively minor issue as far as rocket prototypes go.

Two days later, SpaceX tried again but had even less luck, seemingly never making it more than 10-20 minutes into a usual 40-60 minute static fire test flow in several consecutive attempts. Due to an apparent agreement with Cameron County to avoid road closures on the weekend, Starship SN9’s next shot at a second static fire was delayed three days to Monday, January 11th. Possibly due to high winds and generally unfavorable weather, Monday’s static fire attempt was called off before the window opened.

Later that day, SpaceX delivered notices confirming that the next SN9 static fire attempt was now scheduled no earlier than (NET) 8 am to 5 pm CST (UTC-6) on Tuesday, January 12th. Whether SN9 actually pulls off a full-duration static fire, weather forecasts remain unfavorable for a low-velocity, high-altitude launch. Cancelled FAA Temporary Flight Restrictions (TFRs) more or less confirmed SpaceX’s agreement with those forecasts, leaving Starship SN9’s 12.5 km (~7.8 mi) launch debut scheduled no earlier than Friday, January 15th or Saturday, January 16th.

Eric Ralph: I write about space, among other things.
Disqus Comments Loading...