CAPE 1
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By October 2005, the University of Louisiana at Lafayette plans to launch its first earth orbiting satellite, CAPE 1 (Cajun Advanced Picosatellite Experiment). The purpose of this satellite is to gather data while orbiting in space and transmit this data to the ground station on the UL at Lafayette campus. The team of engineering students will run experiments and maintain the satellite while in orbit.
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[edit] 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.
[edit] Payload characteristic
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.
[edit] Power
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.
[edit] Comunication
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.
