The aircraft features a twin-fuselage design and the longest wingspan ever flown, at 385 feet (117 m), surpassing the Hughes H-4 Hercules "Spruce Goose" flying boat of 321 feet (98 m). The dual fuselage and high-wing design allow for multiple launch vehicles to attach and release from the aircraft centerline. The Stratolaunch is intended to carry a 550,000-pound (250 t) payload and has a 1,300,000-pound (590 t) maximum takeoff weight.