Implementation and testing of International Space Station flight software for the pointing and support portion of guidance, navigation and control

Boeing engineers designed and implemented these algorithms using MOODS (Multibody On-Orbit Dynamics Simulation), a Boeing/NASA Ada non-realtime simulation running on a DEC Alpha platform in Boeing Tower 2 in Houston, Texas. The Ada flight software was then written in MatrixX superblocks on Hewlett Packard computers, using the MatrixX autocode capability to generate the Ada code. After Flight Stage 5A of the International Space Station (ISS), the Pointing and Support (P&S) subsystem is activated and provides the Guidance, Navigation, and Control (GN&C) interface for most of the other U.S. subsystems. P&S supplies state vector (ISS position and velocity), attitude, and attitude rate data to other ISS systems