Session
Weekend Session I: Advanced Technologies Research & Academia 1
Location
Utah State University, Logan, UT
Abstract
As the volume of space-borne data increases, laser communication techniques are being considered to achieve a fast transmission rate and high link security or privacy. The very-high-speed intersatellite link system using an infrared optical terminal and nanosatellite (VISION) mission comprises two 6U formation-flying nanosatellites, and its main objective is to achieve a Gbps-level inter-satellite data-transfer capacity by applying laser communication technology in free space. A pointing, acquisition, and tracking (PAT) system is required to establish and maintain a stable laser crosslink. In the CubeSat platform, the PAT system relies on a satellite attitude determination and control system (ADCS) for body pointing, owing to its low size, weight, and power (SWaP) constraints. Precise orbit/attitude determination and control techniques primarily determine the availability of a coarse pointing system before entering a fast-steering mirror (FSM) feedback loop system with a laser communication terminal (LCT). This study focused on developing a software orbit-attitude integrated simulator to analyze the performance of the PAT system in the VISION mission scenario. An orbit-attitude integrated simulator was designed to test and validate the PAT sequence of the bus initialization stage (BIS) and coarse PAT stage (CPS) with short-wave infrared camera (CAM) feedback. By applying the characteristics of the CubeSat, absolute and relative navigation systems, star trackers, and control hardware, numerical assessments were conducted to evaluate the body pointing performance during the PAT sequence caused by internal or external disturbances in the VISION mission scenario. The simulation results give a total body pointing error of 46.94 arcsec (3σ), indicating that the attitude control system combined with the developed navigation model satisfies the total body pointing error budget within 90 arcsec (3σ) in the PAT system.
Performance Analysis of a Pointing, Acquisition, and Tracking System for the VISION Laser Crosslink Mission
Utah State University, Logan, UT
As the volume of space-borne data increases, laser communication techniques are being considered to achieve a fast transmission rate and high link security or privacy. The very-high-speed intersatellite link system using an infrared optical terminal and nanosatellite (VISION) mission comprises two 6U formation-flying nanosatellites, and its main objective is to achieve a Gbps-level inter-satellite data-transfer capacity by applying laser communication technology in free space. A pointing, acquisition, and tracking (PAT) system is required to establish and maintain a stable laser crosslink. In the CubeSat platform, the PAT system relies on a satellite attitude determination and control system (ADCS) for body pointing, owing to its low size, weight, and power (SWaP) constraints. Precise orbit/attitude determination and control techniques primarily determine the availability of a coarse pointing system before entering a fast-steering mirror (FSM) feedback loop system with a laser communication terminal (LCT). This study focused on developing a software orbit-attitude integrated simulator to analyze the performance of the PAT system in the VISION mission scenario. An orbit-attitude integrated simulator was designed to test and validate the PAT sequence of the bus initialization stage (BIS) and coarse PAT stage (CPS) with short-wave infrared camera (CAM) feedback. By applying the characteristics of the CubeSat, absolute and relative navigation systems, star trackers, and control hardware, numerical assessments were conducted to evaluate the body pointing performance during the PAT sequence caused by internal or external disturbances in the VISION mission scenario. The simulation results give a total body pointing error of 46.94 arcsec (3σ), indicating that the attitude control system combined with the developed navigation model satisfies the total body pointing error budget within 90 arcsec (3σ) in the PAT system.
