Command and Data Handling
Lead:
Ben Kempke (Computer Engineering)
Members:
Matthew Chase (Electrical Engineering)
Noah Klugman (Computer Engineering)
Jonathan Las Fargeas (Aerospace Engineering)
Adam Willis (Computer Engingeering)
Subystem Overview
The Command and Data Handling (C&DH) subystem has primary control over the operations of the satellite. In order to accomplish this the C&DH team designed a custom flight computer and has programmed the flight computer to communicate to and control all other subsystems. Another objective of the C&DH is to write and maintain ground station software to communicate with the satellite.
Computer
The selected flight computer is the Stamp9G20 from Taskit. This is a computer on module device, meaning it contains all the vital parts of a computer on a single circuit board. The Stamp9G20 has 400MHz ARM9 core, 54M of SDRAM, 128 of NAND Flash, and an extensive set of connectivity ports. Running a real-time Linux operating system, the Stamp9G20 is extensible for future missions. Initial tests show succesful operation even in thermal vacuum conditions.
Software
A driving factor in the selection of a flight computer was ease of programming and scalability. All software can be written in C/C++ and tested on development work stations before being applied to the embedded flight computer. To control the camera and compress the images the software will use open source code which is already available. Each command will be executed in its own address space, providing a safer operational environment for the entire mission.
Ground Station
The ground station will be able to autonomously receive data from M-Cubed throughout the day, reducing the human oversight required. S3FL is working closely with the University of Michigan Amateur Radio Club (ARC) on this task. The ARC has expressed great interest in sharing resources with other student groups such as S3FL and has a declaration of intent to expand its space communication capabilities. The ARC’s facilities will be utilized for the duration of the mission and include a dedicated ground computer, IC-910H transmitter, a tracking 13.1 dBi circularly polarized Yagi antenna, preamps, and supporting cabling. This equipment will be adequate for M-Cubed’s purposes and prevent further expenses.
COVE Board
Although JPL is in charge of the complete fabrication of the COVE board, the students of M-Cubed are responsible for its integration with the rest of the structure. This includes writing all software necessary for the operation of both COVE and M-Cubed. This task falls on the C&DH team as they write the entirity of the COVE software, once it has arrived at the University of Michigan.
