Development of pico-satellite - onboard computer subsystem

• Main Author: Tan, Gary Han Soon.
• Other Authors: Ling Keck Voon
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electronic systems
• Online Access: http://hdl.handle.net/10356/40312
• Institution: Nanyang Technological University

This report gives an insight of the development of the Student Pico-Satellite Project, with main focus on the development of the Onboard Computer (OBC) Subsystem. The Pico-satellite used in this project is a product of Pumpkin Incorporated, the CubeSat Kit, and the microprocessor used in the Onboard Computer Subsystem is the Silicon Laboratories 8051 microcontroller, C8051F120. The objective of this project is to design the Overall Flight Operating Modes of the Onboard Computer Subsystem and develop a test software program for the Onboard Computer to illustrate the design. As the Onboard Computer Subsystem is responsible for the Command and Data Handling of the Pico-Satellite and the other subsystems, the design of the Overall Flight Operating Modes reflects the basic operations of the Pico-Satellite. From launch mode to the safe-hold modes of the Pico-Satellite, these modes describe the various predetermined states of the Pico-Satellite throughout the course of its mission flight. Moreover, the success to the Pico-Satellite’s mission is dependent on the design of the safe-hold modes which ensures a failsafe operating system. These operating modes will form the basic blocks of the Onboard Computer Subsystem’s operating software. The illustration of the Overall Flight Operating Modes is demonstrated through a simulation program, developed with the Keil micro Vision Integrated Development Environment (IDE) and the SALVO’s Real Time Operating System (RTOS), which performs the switching of the operating modes. Executed in real time scenario, the event-driven RTOS allows the OBC to handle multiple events with the multi-tasking capability while fully utilizing the limited resources available. This software program is then downloaded onto the hardware to demonstrate the processing capability of the Onboard Computer. Lastly, this report also highlights the challenges and problems encountered by the author in the course of the project and the steps taken to overcome those issues.