Shuttle navigation status

Shuttle navigation which is the determination of Orbiter position, velocity, and attitude and associated effort, together with guidance, flight control, consumables, and systems management, is required for classical navigation. Position and velocity propagation requires the measurement or modeling of the gravitational, aerodynamic, and rocket engine forces acting on the vehicle. Position and velocity determination is performed or observations of the distance to external features, the rate of change, and the direction toward the feature. Onboard state propagation is more often the mode of state knowledge maintenance, since the ability to determine position and velocity using such observations is limited. An overview of Shuttle nevigation is presented.