An orbital airship is a proposed space transportation system that uses lighter-than-air vehicles to carry payloads to and from low Earth orbit. JP Aerospace's "Airship To Orbit" concept has three components: 1. An atmospheric airship (Ascender), which travels between the ground and the station. 2. A two-mile-wide station (Dark Sky Station) at 140,000 ft. 3. A 6,000-ft-long orbital airship (Orbital Ascender), which travels between the station and orbit. It uses electric propulsion to accelerate over several days to orbital velocity.