Star Trek: Voyager

The Swarm (3x4)

Air date: Sep 25, 1996

Stardate: 50252.3 Voyager encounters a region of space owned by a mysterious race of aliens that would take 15 months to go around. Upon crossing the boundaries, a swarm of ships attach themselves to Voyager's hull - an act which drains the ship's power supplies and threatens to destroy it.