On Friday, the Federal Aviation Administration issued a license for SpaceX to launch the first orbital test of Starship, the largest rocket in human history, as soon as this Monday, April 17th. I predict this will be a foolish and reckless decision, and impacts from even a nominal launch could prove catastrophic and significantly worse than presented to the public.
SpaceX and the FAA submitted extensive data as part of the NEPA environmental permitting process that started in September of 2020 to demonstrate the impacts launches and operations would have on the surrounding area.
In May of last year, I demonstrated that SpaceX used modeling data from early 2019 to seek approval for the launches; at that time in Starship’s development, the megarocket’s total thrust was estimated at 61.8 meganewtons (MN). Today, the rocket that sits on a pad in Boca Chica, Texas is rated at 74 MN, a 20% increase in size
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This week, I received a Freedom of Information Act from the US Fish And Wildlife Service regarding information collected by US officials from the surrounding Lower Rio Grande Valley National Wildlife Refuge. An FWS employee measured a sound intensity reading of 110 decibels (dB) three miles from the launch site during a static fire test conducted in February.
This is a concerning development because the existing noise surveys indicate that the maximum reading that should have been detectable at this point is between 90-100. Decibels
are a logarithmic scale (by tens), meaning that the FWS employee measured sound that is between 10x and 100x more powerful than what was predicted by SpaceX’s models. I’ve diagramed it here:
Further compounding the issue is that the February static test fire of Starship Superheavy’s 33 engines was done at just 50% of total thrust. A full-throttle test would have produced a significantly larger noise impact.
These noise surveys and other factors, such as sonic boom intensity and heat plume that provide the basis for FAA’s rushed approval for SpaceX’s launch facility are all based on the smaller 2019 design version of Starship. These inputs provide the basis for all impacts measured in the NEPA document, meaning that the resulting damage to the community and the environment predicted are certainly understated, inadequate, and inaccurate.
Nearby cities Port Isabel and South Padre Island are under 5 miles away from the launch site; by comparison, the nearest cities to NASA’s Cape Canaveral 39-A launch complex, one of the only other sites permitted to launch supersized rockets, are 15 miles away.
The same model inputs that were used to (inaccurately) determine sound impacts from a static fire test also predict the maximum sound intensity expected during the first orbital launch attempt, which may occur as soon as tomorrow:
I won’t extrapolate the rather large miss for the static fire model on a granular basis onto the existing launch model because sound attenuation is a complex field of study. Still, it wouldn’t take much imagination to visualize a scenario where the nearby cities of Port Isabel and South Padre Island are exposed to significantly more powerful sound levels than predicted by this model.
Indeed, in approving SpaceX’s launch operations last year, the FAA didn’t even consider property damage in inhabited areas from a normal launch as a potential outcome because “the Lmax values of 111 dB and 120 dB may be used as a very conservative threshold for potential risk of structural damage claims.
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SpaceX and FAA refused to update their models when pressed by the FWS during a review of operations’ impact on endangered species in February of last year, when the Service pointed out that the company had drastically increased engine sizing, stating that these same models used for approval under the Endangered Species Act were adequate.
Going beyond shattered glass and damaged foundations of beachside homes situated on stilts over sandy loam, the other potential impacts from a miscalculated sonic blast from a launch loom large.
SpaceX’s Boca Chica facility sits amid one of the most unique natural habitats in the northern hemisphere. The area is home to countless endangered species and provides a wintering home to the piping plover and red knot. These two federally protected shorebird species use the productive but ecologically sensitive low tidal marsh to nest and forage. SpaceX operations have already drastically reduced populations that return to the same spot year after year, per a study completed by the Coastal Bend Bays & Estuaries Program.
The company narrowly received authorization to “take” (e.g., legal term for kill, maim or displace) birds residing in dozens of acres of surrounding habitat from the FWS under an Endangered Species Act review
. But this study was, again, predicated on 2019 models that are already showing to be inadequate and inaccurate. An expanded radius for the noise bomb to occur upon launch could kill hundreds of additional wildlife, to an extent neither predicted nor disclosed to the public.
Put into context, human hearing is nearly instantly and permanently damaged at 120 dB; your eardrums will rupture at 130 dB. Birds are likely even more sensitive to high sound exposure. Inaccurate sound models will necessarily lead to inaccurate harm predictions.
SpaceX’s Starship Superheavy launch system is massive, generating nearly 10x the thrust of the company’s workhorse, the Falcon 9 rocket. The pad and launch complex at Boca Chica is almost laughably tiny
