SpaceX has successfully fired all six engines on its latest Starship prototype, taking an important step toward ensuring that the upper stage will be ready for the rocket’s first orbital launch attempt.
Unfortunately, the same successful static fire of an upper stage Starship – potentially producing almost twice as much thrust as amplifier of SpaceX’s Falcon 9 rocket – superheated debris scattered hundreds of meters away, igniting a massive brush fire. It’s not the first major fire caused by Starship’s operations in South Texas, and it likely won’t be the last.
Starship S24 completed its first successful static fire on August 9, igniting two Raptor engines. Several unsuccessful attempts to test more engines followed during the rest of the month, and SpaceX eventually decided to replace one of Starship S24’s three Raptor Vacuum engines in early September before trying again. After workers installed the new engine and replicated Ship 24, the stars finally aligned on September 8.
Starting the test, SpaceX pumped a few hundred tons of liquid oxygen (LOx) and a much smaller amount of liquid methane (LCH4) fuel into Shuttle 24 in about 90 minutes, producing a sharp layer of frost wherever the cryogenic fluids touched the shell and uninsulated steel tanks of the rocket. No frost formed in Starship’s overhead methane tank, implying that SpaceX only loaded methane fuel into the internal ‘header’ tanks intended to store landing fuel. The hundreds of tons of liquid oxygen, then, were likely intended as ballast, reducing the maximum stress the Starship could exert on the test stand while keeping it grounded.
This potential stress is substantial. Equipped with upgraded Raptor 2 engines, Starship S24 could have produced up to 1,380 tons (~3M lbf) of thrust when it ignited for the first time at 4:30 PM CDT. In addition to breaking the record for the most thrust produced during a Starbase rocket test, the ship’s 24 engines burned for almost 8 seconds, making it one of the longest static fires ever conducted on a Starship test stand.
Several brush fires were visible almost immediately after the clouds of dust and steam cleared. More likely than not, the combination of extreme force, heat and duration of the burn would have likely obliterated the almost entirely unprotected concrete surface beneath the ship 24. Despite continued evidence that all Starship static fire operations would be easier and safer with the systems, SpaceX still refuses to install serious water deluge or flame deflector systems on the Starbase test stands and launch pads.
Instead, under its steel Starship test stand, SpaceX relies on a single mid-flood spray nozzle and high-temperature (likely marty) concrete that probably wouldn’t pass for a rocket ten times over. less powerful than the Starship. In many cases, Starships have chipped away at that weak marty layer, creating high-velocity ceramic shards that damage their bottoms or Raptor engines, requiring repairs and creating dangerous situations. Basically, with no attempt to moderate the Raptor’s high-velocity exhaust several thousand degrees, the static fire tests at the Starbase thus almost always start small grass fires and cause minor damage, but those fires rarely spread.
Ship 24’s first six-engine test was not so lucky, although the Starship made it through seemingly unscathed. Most likely, the eight long seconds of blast furnace conditions melted the surrounding top layer of concrete and sent a barrage of tiny superheated globules flying in almost every direction. Indeed, in almost every direction there was something that could burn immediately, a fire started. In several locations to the south and west, brush caught fire and began to burn unusually aggressively, quickly growing into walls of flame that swept across the terrain. In the east, the debris even turned into a SpaceX bin, the contents of which caught fire easily and burned for hours.
Eventually, around 21:00 CDT, firefighters were able to approach the safe launch site and rocket, but the main fire had already spread south, out of reach. Instead, they started controlled burns near the SpaceX checkpoint, hoping to clear the brush and prevent the fire (though unlikely) from spreading to SpaceX’s Starbase factory and the homes and residents of the village of Boca Chica.
The estuary-like nature of the terrain and wetlands means it is many easy to stop fires at chokepoints, so the fire likely never posed any real threat to the residents of Boca Chica, SpaceX employees, or onlookers. It was also unlikely to damage SpaceX’s launch facilities or return to damage Starship S24 from launch, as both are surrounded by a combination of concrete platforms, empty fields and a highway.
However, the fire-burnt “brush” is a protected habitat located in a State Park and Wildlife Refuge. While fire is a natural and often necessary element of many habitats, including some of those in Boca Chica, this is the second major fire caused by Starship testing since 2019, which may be less than desirable. At the very least, fighting fires around Starbase generally requires firefighters to walk or even drive into protected wetlands and salt flats, the impact of which can ultimately be just as bad for wildlife and habitats. as fire itself.
SpaceX’s Federal Aviation Administration (FAA) Programmatic Environmental Assessment (PEA), which fully illuminated the company’s existing Starbase Texas facilities and launch plans earlier this year, only discusses the fire [PDF] a handful of times. Repairing and preventing future damage to the wetlands, however, is a dozen times over and is subject to numerous conditions that SpaceX must meet before the FAA grants Starship an orbital launch license.
Ultimately, since the FAA approved that the APP in full knowledge of a 2019 brush fire caused by the Starhopper (an early Starship prototype) that may have been as bad or worse than the one in 2022 has a chance to play a small role in the ongoing launch licensing process, but the chances of it being an indicator of exposure are close to zero. However, it is likely to benefit SpaceX at least as much as the desert surrounding Boca Chica if it can implement changes that prevent large brush fires from becoming a regular ‘accidental’ occurrence.