In Gerry Anderson's puppet science fiction series Captain Scarlet, Cloudbase is the skyborne headquarters of international security organisation Spectrum, resembling a large aircraft carrier, complete with flight deck, that hovers continuously at a height of several thousand feet and can be moved above any point on Earth as needed. Its altitude theoretically renders it invulnerable to attack, but The Mysterons are always looking for ways to penetrate its defences. Its primary defence is its fleet of Angel interceptor planes, "manned" by female pilots (who have faster reflexes than men). One plane is manned around the clock, and the others are on permanent standby. Because of its altitude the entire structure is pressurised; pilots entering or leaving aircraft on the flight deck do so inside airtight capsules.
In reality Cloudbase was a large model filmed, by Derek Meddings' special effects unit, in front of a painted sky backdrop; the floating effect was achieved by concealing the supports behind the model. Larger sections of the flight deck were built for scenes showing aircraft taking off and landing.
See also Cloud base for cloud structure.
