Does anyone know what this is?

So I landed in Detroit airport (KDTW) a few weeks ago as I got back home from my vacation and saw this metal hangar type of thing and I had no clue what it was I never saw any planes at it either, does anyone know what this is? Here’s a photo of it on flightradar24.

So I landed in Detroit airport (KDTW) a few weeks ago as I got back home from my vacation and saw this metal hangar type of thing and I had no clue what it was I never saw any planes at it either, does anyone know what this is? Here’s a photo of it on flightradar24.