Engineering topics
Cangahuala, L. Alberto
Publications and source records attributed to Cangahuala, L. Alberto.
Small Body Landing Accuracy Using In-Situ Navigation
Spacecraft landings on small bodies (asteroids and comets) can require target accuracies too stringent to be met using ground-based navigation alone, especially if specific landing site requirements must be met for safety or to meet science goals. In-situ optical observations coupled with onboard navigation processing can meet the tighter accuracy requirements to enable such missions. Recent developments in deep space navigation capability include a self-contained autonomous navigation system (used in flight on three missions) and a landmark tracking system (used experimentally on the Japanese Hayabusa mission). The merging of these two technologies forms a methodology to perform autonomous onboard navigation around small bodies. This paper presents an overview of these systems, as well as the results from Monte Carlo studies to quantify the achievable landing accuracies by using these methods. Sensitivity of the results to variations in spacecraft maneuver execution error, attitude control accuracy and unmodeled forces are examined. Cases for two bodies, a small asteroid and on a mid-size comet, are presented.
Augmentations to the polyhedral gravity model to facilitate small body navigations
One of the challenges in modeling low-altitude mission scenarios at small bodies is the need to minimize the computation time penalty for more detailed shape models, especially when the scale of the detail is on the order of the spacecraft trajectory. This paper describes variants of the polyhedral model and their relative performance.
Argos: A System to Monitor Ulysses Nutation and Thruster Firings from
The predicted return of the solar-induced nutation of the spin-stabilized Ulysses.