Attitude Determination and Control System
The ADCS team has chosen to use a completely passive stabilization system in order to conserve power and reduce complexity. Attitude is controlled by passive magnetic stabilization using permanent magnets and hysteresis rods. The permanent magnets will align the satellite with Earth's magnetic field. The antennas will also act as the satellite's spin mechanism. The antennas will be coated with highly reflective tape on one side and black anodized on the other. This surface difference will create a torque on the satellite and induce a spin. In order to control the rate of spin, hysteresis rods will be placed on the satellite. These rods will be mounted perpendicular to the spacecraft's Z-axis. As the rods rotate they generate eddy current and a torque in the opposite direction of the satellite's spin.
Communications
The communications subsystem will consist of a TNC, Transceiver, RF Amplifier and Antennas. The CAPE team is designing all the pieces of the communications subsystem. A PIC Microcontroller will act as the TNC, which will create and decode the AX.25 protocol which contains the team's data. The Transceiver being used is the Chipcon CC1020, which was chosen because of its extremely small size, low power, and low cost. The CC1020 will give the CAPE team tehe ability to communicate with the satellite.
Payload
Our payload consists of what we want our satellite to do while it is in space. After several discussions, we have decided on some things to be certain. The first section of our payload will be a series of diagnostic tests which include checking temperature of different sides of the satellite as well as temperature of certain devices. We will monitor other things such as battery power consumption and solar power collection. Outside of the standard statistical information we will try to embark on some other ambitious goals. In light of Denmark's failed picosatellite, which contained a camera that took pictures of it, we hope to capture an image of the satellite while it is in space and transmit that image back down to earth. This will be a great opportunity to share our satellite success with everyone who wants to see it.
As everyone in knows, our coast lines in the Gulf of Mexico are becoming eroded by saltwater intrusion. Our wetlands suffer the most, and our state prides itself on wildlife in fresh water conditions. In conjunction with a professor in the EE department, we will be developing a data exchange system on the satellite which will interface several terrestrial transmission towers. These 'floating' towers will pick up information from hundreds of sensors in the gulf water and transmit the data as the satellite passes over. We hope to have this entire system setup and tested before our launch.
Our software team will be programming our satellite to perform the operations mentioned above. This will involve knowing assembly language as well as 'C' code in order to program the PIC microcontrollers we have on board.
Power
The power team will be responsible for power management and power distribution. Dual Junction Solar Cell's will be used to generate power. The power generated will then be stored in lithium-ion batteries. The lithium ion batteries will be reserved for usage during the eclipse periods of the satellite orbit. The batteries will also be used when subsystems require more power then the solar cell's can provide. A power management system will be implemented to control the amount of power provided to each individual subsystem.
