Deep Space Navigation of Distributed Small Spacecraft using Variable Celestial Sources

This program will develop an innovative Hybrid Navigation (HYNAV) system using multiple energy band observations of variable celestial sources. The concept creates photon measurements across each source observed in unique energy bands where signals are most beneficial, and blends the diverse signals into a single spacecraft position and velocity solution. Previous work by ASTER Labs has demonstrated concept feasibility of X-ray navigation (XNAV) and gamma-ray navigation (GLINT) as stand-alone architectures. The HYNAV instrument unifies the two individual concepts while adding radio observations into an operational prototype hardware instrument and software package. The advantage of the blended approach is it exploits both the periodic nature of the faint, stable radio and X-ray pulsars with the aperiodic, transient nature of bright, chaotic fast radio and gamma-ray bursts. Thus, the operational system would be capable of frequent measurement updates and continuous accurate absolute or relative navigation. The baseline instrument is designed for small spacecraft (lt; 180 kg) class vehicles, including larger CubeSats, facilitated by emerging detector materials capabilities, with near-all-sky detection configurations, very good energy resolution, lower energy thresholds for high photon counts, and precise onboard photon timing. Benefits include increased deep space autonomy and formation flight for distributed small spacecraft, while decreasing the burden on the DSN. Phase I will evaluate HYNAV feasibility for relevant NASA applications. System requirements will be developed based upon identified and characterized sources assembled into a catalogue. The instrument hardware design will be coupled with blended data processing navigation algorithms that fuse measurements in a single filter. ASTER Labsrsquo; XPRESS software and a filter simulation will assess absolute and relative navigation performance under target mission scenarios.nbsp;