After a few wrong starts and a few minor delays, SpaceX’s 11th Starship prototype (SN11) made it through two of the three big tests standing in between and being chased away.
SpaceX rolled Starship SN11 from the factory to the launch site on March 8, just five days after Starship SN10 briefly became the first prototype of its kind to end up in one piece. One or two problems with the final landing of Raptor caused SN11 to hit faster than expected and eventually lead to the explosion of the rocket about 15 minutes later. The test flight was nevertheless an almost unequivocal success and apparently left SpaceX with more than enough confidence to speed up the preparations for the next flight test.
The next day, SpaceX was hoping to launch a cryogenic test, but Starship SN11 needed a little more attention than expected, and unknown bugs eventually meant that only an ambient temperature pressure test at the end of the test window could be completed. These issues appear to be pending at the end of March 10, preventing any form of probation.
On March 11, Starship SN11 was able to take its first real sting on a cryo-proof and was loaded with liquid nitrogen (LN2), a cryogenic liquid with a density and temperature similar to Starship’s liquid oxygen and methane propellant, but without the risk of a catastrophic fire or explosion. In the course of about three hours, it appears that SpaceX SN11 did not fully load with LN2, a possible sign of a technical error that could just as easily be a deliberate part of the test design.
Oddly enough, parts of the evening tests were in contrast to previous cryo evidence, and there is little chance that the activity was a static fire attempt that was well scrubbed before combustion, although it is impossible to say without official confirmation.
Otherwise, the most striking part of the cryo-evidence was a test of Starship SN11’s attitude control system (ACS) which involved firing each of the ship’s cold-gas nitrogen propellers at least 5-10 times for a total of a few dozen bars. The current generation of Starships mainly uses the thrusters to enlarge their valves and ways to rotate during the launch and landing of suborbital, while prototypes in the early orbital class can use the same propeller system to control their position in the airspace.
If the cryo proof test was successful last night and SpaceX provided the data needed to give SN11 a good health statement, the Starship could possibly try its first Raptor engine static fire early on March 12th. Historically, spaceX has never fired a Starship prototype less than twelve days after arriving at the launch site, meaning a static fire would shatter the previous record by a factor of three tomorrow. As such, it is more likely that SN11 will need a day or two and is ready for a static fire attempt as early as Monday 15 March.
Either way, Starship SN11 is undeniably on a faster track than any of its three-engine predecessors, and a clean static fire on Friday or Monday will leave a launch next week – SpaceX’s current target – well within reach.