Within a week of launching the rocket from the factory to the launch pad, SpaceX appears to have successfully upgraded the Starship’s serial number 9 (SN9) to two routine pre-launch tests.
On December 22, much less than two weeks after the Starship SN9 suffered a major handling or production accident that knocked it over several degrees and impacted the walls of its production facility, SpaceX completed rapid repairs. and transported the rocket about 1.5 km down the road. .
In some combination of a minor miracle and the exceptionally rugged design of the Starship, the rocket – at a height of about 50 meters (~ 165 feet) and weighing about 75 to 100 metric tons (175,000-220,000 lbs) – has tilted sideways on two of its four pre-installed shutters. Although they were subjected to non-nominal forces, the much more powerful structural mechanisms connecting these flaps to the Starship’s main airframe were apparently unscathed, and SpaceX was able to remove and replace the crumpled control surfaces just days after the incident.
On December 28, this work began in earnest with what is commonly referred to as a room temperature pressure test, filling the Starship SN9’s propellant tanks with nitrogen gas at benign air temperature. Used to check for leaks, verify basic performance of vehicle valves and plumbing, and ensure a basic level of structural integrity, SN9 appeared to pass its resistance test at room temperature without issue – albeit late in the process. window.
Testing ended shortly after ambient proof on Monday and was followed by the main event – a cryogenic proof test – just under a day later on Tuesday. The exterior of the Starship SN9 began to develop a layer of frost after SpaceX began charging its oxygen and methane tanks with liquid nitrogen at around 2:30 p.m. CST (UTC-6). While similarly used to verify structural integrity such as an ambient pressure test, “ cryo proof ” adds the challenge of thermal stress to ensure Starship can safely load, hold, and discharge liquids. very cool.
In the case of SN9, it’s unclear whether SpaceX fully or only partially charged the rocket’s main propellant tanks with liquid nitrogen, while a lack of frost at the tip of its nose implies that the smaller Starship’s liquid oxygen tank was not filled. of the test. In total, Starship is expected to be able to hold around 1,200 metric tons of liquid nitrogen if fully loaded.
SN9’s LOx header tank’s lack of participation in Tuesday’s cryogenic proof tests is intriguing in itself, as it implies that SpaceX will perform a second cryogenic proof later this week or is sufficiently confident in the tank of LOx header and transfer tube performance to forgo any testing. . In the latter case, SpaceX would likely simply use the preparation for Starship SN9’s first Raptor static fire test as a wet dress rehearsal (WDR). and cryo proof for the smallest tank system.
According to NASASpaceflight editor-in-chief, if the room temperature and cryo stress tests on Monday and Tuesday went without incident and as successfully as they appeared, SpaceX could move straight to static fire preparations. triple-Raptor. As a first step, the Starship SN9 was transported to the launch pad last week with two of the three mid-mounted Raptor engines already installed and the missing third engine was installed a few days after its arrival. SN9 is also the first Starship to attempt its first proof tests with any Raptor – let alone three – installed.
If SpaceX goes straight from cryogenic proof testing to a three-engine static fire, this will mark another first for the Starship program and signal growing confidence and a desire for faster check-testing, which will help speed up flight testing. . As of yet, SpaceX has yet to cancel a scheduled road closure for Wednesday, December 30, but it is much more likely that a trio of 8 a.m. to 5 p.m. CST closures requested on January 4, 5, and 6. will host the Starship SN9’s first static fire. attempts). According to NASASpaceflight.comStarship SN9 is expected to attempt a 12.5 km (~ 7.8 mi) launch similar or identical to SN8 within days of this static fire. Stay tuned for updates!