The Ley was a Federation Type 15 shuttlepod that was in service with Starfleet in the mid-24th century, attached to the USS Enterprise-D. It was shuttlepod 09.
In 2366, Lieutenant Commanders Data and Geordi La Forge investigated the Barzan wormhole from aboard the Ley. Along with a Ferengi shuttle, the Ley entered the wormhole and arrived in the Delta Quadrant, despite the fact that the terminus of the wormhole was supposed to be in the Gamma Quadrant. This inconsistency allowed Data and La Forge to realize that the wormhole was unstable and therefore useless, and they returned to the Alpha Quadrant with the news. (TNG: "The Price")
The Ley was possibly named after Willy Ley, a German-American writer who popularized the idea of spaceflight in both Germany and the United States. A crater on the far side of Luna is named for him.