Space News reports:
The fully stacked Starship vehicle, consisting of a Super Heavy booster designated Booster 7 and a Starship upper stage named Ship 24, was filled with liquid oxygen and methane propellants during the test at SpaceX’s Starbase test site in Boca Chica, Texas.
Emphasis added. How did this ever pass environmental review?
<science>It passed because methane is a cleaner burning fuel than the RP-1 kerosene used in most other rockets, including the SpaceX Falcon series.</science>
<engineering>While liquid methane is very cold, its temperature is much warmer than the liquid hydrogen used in NASA’s SLS. It’s in the same range as liquid oxygen, so the thermal stress in the rocket’s plumbing is less severe.</engineering>