EAPSI: Orientation control of a solar sail spacecraft

Pimienta-Penalver Adonis R, Buffalo NY

Investigators

Abstract

Because they require no conventional propulsion system, solar sail spacecraft are at the forefront of sustainable technology in space. The recent successful deployment of the JAXA IKAROS solar sail has renewed interest in this type of spacecraft to fulfill a certain class of missions once thought to be impractical due to large propellant requirements. Of all the possible types of solar sail configurations, the heliogyro has the most understood control strategy and is the easiest to deploy. This structure, akin to a dutch windmill, uses long, thin, flexible blades rotating about a central spacecraft body in order to propel itself using solar radiation pressure (solar wind). The objective of this project is to investigate the appropriate control architecture to maneuver the attitude (orientation) of such a spacecraft while guaranteeing the stability of the structure. This research will be conducted in collaboration with Dr. Jer-Nan Juang, an expert on solar sail technology at the National Cheng Kung University in Taiwan. As a consequence of their flexibility and size, heliogyro sails require persistent control attention at the root of each blade in order to maintain stability and achieve changes in attitude. The proposer will design an adaptive control scheme robust to random vibrations and changes in the response of the blades due to the highly-coupled non-linear nature of the system. The development of the control algorithm will implement concepts of estimation and system identification to approximate the system parameters and adapt to uncertainties in real time. Furthermore, the project will require devising a model to capture the system's dynamic response; creating blade pitch actuation routines to reproduce attitude-changing maneuvers; implementing a realistic model of solar radiation pressure; and investigating optimal sensor placement along the blades in order to maximize observability. This NSF EAPSI award is funded in collaboration with the National Science Council of Taiwan.