A Dropship is a fictional transport vehicle featured frequently in science fiction, in particular Military Science Fiction and Space Opera genres. A dropship is a common fictional spacecraft archetype, generally depicted as designed to drop troops and equipment onto a planet surface at a short range. Notable examples of dropships include the "Retrieval Boats" from Robert A. Heinlein's novel Starship Troopers, the "Pelican" craft from the Halo series, and the UD4L Cheyenne from the 1986 film Aliens.
Although spacecraft designed to operate in space and fly within Earth's atmosphere have been constructed (the NASA Space Shuttle being a prime example), a dropship is commonly defined by both its military nature and support from a larger, non-atmospheric Mothership.
Dropship descriptions vary greatly from source to source, but are defined by a central core of attributes. Dropships typically possess short range, designed only to work in conjunction with a larger orbiting mothership, itself possibly too large or ill suited to land on the surface. Dropships are usually capable of both Atmospheric and Space flight (or, in some examples, underwater travel), differing from craft only capable of flight in one of those mediums. The roles of Dropships are generally military in nature, including landing troops or equipment on a planet. Dropships featured tend to be portrayed as heavily armed and armoured, providing protection for troops from surface fire, similar to helicopters currently employed by military forces.
Differing depictions of dropships either tend toward strictly functional to those more artistic or organic in operation. Often Dropships are designed using current technology or principles in mind, such as Scramjet engines, VTOL and Lifting Bodies. The UD4L Cheyenne from the 1986 film Aliens was designed with both the AH-64 Apache attack helicopter and the F-4 Phantom fighter jet as a basis. Commonly space-flight principles including Delta-V, Orbital insertion and Aerobraking are used to describe the flight-characteristics of Dropships.
Dropships are shown to serve a similar role to modern day utility/transports, typically helicopters or tiltrotor aircraft. Vehicles such as the UH-60 Blackhawk or the MV-22 Osprey, also capable of deploying men and equipment whilst maintaining fire support. Currently no real-world examples of Dropships exist, although research into their application has and continues to be explored by military forces around the world (see Militarisation of space).