Captive carry

SpaceShipOne is carried beneath White Knight during a captive carry flight to test SpaceShipOne's aerodynamic and avionic performance. The two-vehicle system can both take off and land in this configuration.

Captive carry refers to a flight by a mothership (carrier aircraft) and spaceplane, rocket, or missile paired together in a parasite aircraft configuration. The two are not separated in flight, as would occur during a normal flight. This is often necessary in order to test aircraft systems. Another application is transportation, as in the case of NASA ferrying operations for the Space Shuttle, involving Boeing 747-100 Shuttle Carrier Aircraft.