Landers to large planetary bodies such as Mars typically use a secondary reconnaissance spacecraft to generate high-fidelity 3D terrain maps that are subsequently used for landing site selection and creating...

An algorithm was developed that determines the fuel-optimal spacecraft guidance trajectory that takes into account uncertainty, in order to guarantee that mission safety constraints are satisfied with the required probability. The algorithm uses convex optimization to solve for the...

A spacecraft guidance, navigation, and control (GN&C) system is needed to enable a spacecraft to descend to a surface, take a sample using a touch-and-go (TAG) sampling approach, and then safely ascend. At the time of this reporting, a flyable GN&C system that can accomplish...

GoView is a video-game-like software engine, written in the C and C++ computing languages, that enables real-time, three-dimensional (3D)-appearing visual representation of spacecraft and trajectories (1) from any perspective; (2) at any spatial scale from spacecraft to Solar-system...

A key enabling technology that leads to greater spacecraft autonomy is the capability to autonomously and optimally slew the spacecraft from and to different attitudes while operating under a number of celestial and dynamic constraints. The task of finding an attitude trajectory that...

A report discusses aspects of a ranging system in which the distance between the Earth and a spacecraft is determined from the difference between the phases of (1) modulation on a radio signal trans- mitted to the spacecraft and (2) a replica of the modulation transmitted back to Earth by a transponder on...

Two reports describe a Rayleigh-scattering attitude sensor (RSAS) - an optoelectronic instrument for determining the orientation of a spacecraft. An RSAS comprises a telescope/video-camera/image-digitizer combination that is mounted on the spacecraft and that captures images of the limb of...

A report describes a continuing program of development of flight software for the attitude-control system (ACS) and the command-and-data-handling (C&DH) system of a prototype standard spacecraft of the Small Explorer (SMEX)-Lite class. Both the C&DH and ACS parts of the software...

The Mission Planning Graphical Tool (MPGT) computer program provides a mouse-driven graphical representation of data on a spacecraft and its environment, for use in planning a space flight. MPGT is designed to be a generic software tool that can be configured to analyze any specified...

A collection of four documents contains information on various aspects of the flight software of the Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) spacecraft. The first document is part of a longer paper that presents design requirements for the software; the information in...

A report describes the ACS Design Tool - a Macintosh- and PC-based computer program for evaluating conceptual designs of a spacecraft attitude-control system (ACS) within a computation time of about 15 minutes. Services provided by the program include computation of ACS performance and...