Star Trek: Voyager - Season 3 Episode 4 The Swarm Charting the new frontier
Overview: 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.