In-Universe:
The U.S.S. Defiant, a Klingon Bird-of-Prey and an Excelsior-class vessel fire a lot on the heavily shielded power station with no effect.
Production:
The Digital Muse V2 CGI model is used in this scene. This confirms that this is the same model used in the episode "Valiant' because the registry number on the nose is not the Defiant's NX-74205, but the Valiant's number: NCC-74210.
