Proton-K payloads included all of the Soviet Union's "Salyut" space stations, almost all Mir modules (with the exception of the Docking Module, which was launched on the United States Space Shuttle), and the Zarya and Zvezda modules of the International Space Station. It was intended to launch the crewed TKS spacecraft, prior to the cancellation of that programme, although a few robotic flights of spacecraft were fulfilled. In addition it was intended to launch the 1970s LKS spaceplane that was never realised.