SpaceX has successfully “anti-freeze” the nose-based propellant storage tank of the first fully assembled starship prototype, and used the tank to start the Raptor engine, breaking through the last 15 kilometers (about 9.5 miles) before the rocket launch A major test. Debut.
On November 4, after several erroneous attempts, Starship 8 (SN8) became the first prototype to permanently install the nose section, thus starting the first round of testing. On that Wednesday night, SpaceX is likely to pass some of the low-temperature certification test of the rocket, specifically testing the SN8’s new nose cone and the small auxiliary propellant box at its tip. The two header tanks of SN8 are intended to be used as auxiliary containers for relatively small amounts of propellant that need to be landed, and the two header tanks of SN8 may contain cryogenic liquid nitrogen-a safe, non-reactive alternative to liquid oxygen and methane .
Facts have proved that Starship SN8’s newly installed liquid oxygen main tank and related piping system can load, manage and unload tens of tons of cryogenic fluid while sailing in a vertical pipeline of 40 meters (approximately 130 feet) high, and is ready to proceed. Next step: Wet Clothes Rehearsal (WDR) and Raptor static shooting.
Although SpaceX has technically successfully completed eight Raptor static shots on four separate prototypes, including three Raptor static shots using the Starship SN8 for the first time in history, the company has never tried only from the header (landing ) Static shooting was performed by extracting propellant from the tank. For the spacecraft, all of these are indispensable, except that it can reliably reignite its Raptor engine in flight and keep the low-temperature landing propellant liquid for hours, days, weeks, or even months. A smaller header box makes it easier to keep the propellant at high pressure and in the correct position to supply the raptor.
After several days of testing windows moving back and forth, and a failed attempt on November 9th, Starship SN8 finally ignited one of its three Raptor engines, providing the engine with the engine stored in two separate main tanks. Liquid methane and oxygen. Curiously, a second or two after starting and ignition, the usual exhaust plume of the Raptor was accompanied by a shiny pyrotechnic shard. After a relatively normal five seconds, the Raptor suddenly turned off, although the engine seemed to be partially on fire for about ten seconds, which was still somewhat unusual.
In the end, the observed anomaly may be as simple as debris accidentally left near the Raptor plume, and the concrete is less likely to corrode. This may also be part of the Raptor’s complex turbopump or pre-burner, although if the engine loses so much internal hardware, it is unlikely that the engine will continue to run (run as it is).
(Update: Fortunately, NASA Spaceflight.com reporter Michael Baylor said that the debris cloud observed on November 10 was “not [Raptor performance] Concern” so that the mat fragments may be the source.)
SpaceX has cancelled another quiet fire window on November 11 and left a second (three-point) expected quiet fire on November 13 (Thursday) from 9 am to 9 pm CST (UTC-5) Opportunity.