During the last 20 years flight simulation has become of increasing importance in commercial, military, and space applications because of the significant transfer of training experience to the actual flight task, and the economy in usage of equipments, personnel, and fuels. Simulation has also aided in the definition of man's capability to deal effectively with new and different flight control tasks especially in space flight. In the case of space flight no other means of astronaut training exists other than simulation for much of the mission, a fact that NASA recognised in the beginning of the space programme. As a result a major effort has been made to obtain the highest simulation fidelity possible to insure the safety of each 'one of a kind’ space mission carried out. Link has been actively involved in the US space programme since 1962 when it employed simulation techniques to aid in astronaut training for Gemini flights. Shortly thereafter Link built three command module simulators and two lunar module simulators in which Apollo astronauts trained for their successful moon missions. Subsequently Link was selected to build the simulator in which astronauts trained for the Skylab missions, and was awarded NASA contracts for an Orbiter aeroflight simulator and a Shuttle mission simulator. The Orbiter aeroflight simulator has been functional since 1976 and has been in continuous use in preparation for the recent orbiter aeroflight tests at Edwards AFB, CA. The Shuttle mission simulator has been in design and construction since April 1976, and is scheduled for a phased delivery beginning early in 1978. It represents a major milestone in mission simulators in terms of sophistication, completeness, and magnitude of systems simulated.