1ft は 30.48cm で 400feetは？(約121.92m)になりますね！米国でもずいぶん昔にメートル法が施行されてはいるのですが、未だにフィートやポンドが使われています...
SpaceX has achieved another major milestone in its Starship fully reusable launch system: It stacked the Starship spacecraft itself on top of a prototype of its Super Heavy booster, which itself is loaded up with a full complement of 29 Raptor rocket engines, and the Starship on top has six itself. The stacked spacecraft now represents the tallest assembled rocket ever developed in history.
This stacking, which happened at SpaceX’s development site in south Texas, is a significant development because it’s the first time the two elements of the full Starship system have been united as one. This is the configuration that will be used for launching the next Starship prototype on its test mission that will hopefully achieve orbit.