SPUDNIK-1
COMMAND & CONTROL DESIGN
ATTITUDE DETERMINATION
The attitude determination system is made up of two different components: sun sensors and an inertial measurement unit (IMU). The sun sensors do just what you would think, making use of photodiodes they can detect the intensity and angle of the sun. With four of these sensors placed at the top of the CubeSat (green rectangles to the right) they can work together to determine where the satellite is in relation to the sun. The IMU component contains what is called a 3-axis magnetometer. It can detect the satellite's position relative to the magnetic poles here on Earth.
ATTITUDE CONTROL
The attitude control system is also made up of two different components: reaction wheels and magnetorquers. The reaction wheel is basically just a tiny metal wheel that is attached to an even tinier motor. These motors while small are very powerful and cause the reaction wheel to spin at such a speed that it can make the CubeSat rotate in space. Magnetorquers are essentially small metal rods wrapped in a copper wire. These rods can create their own magnetic field which can then align with the Earth's magnetic field. Much like the reaction wheels, these magnetorquers while tiny are very powerful and can rotate the satellite to the correct position in a zero-gravity environment. There will be one of each of these components on all three axes of rotation to control the CubeSat's movement in all directions.
POSITION SENSING
Tracking the position of something in space is no light task, and so SpudNik-1's position sensing system is powered by a very advanced GPS chip. This chip can operate at the satellite's altitude of 400km while also allowing it to move at up to 7.8km/s. That's really fast. This chip can also handle the extreme temperature conditions of space and can operate between -40°C and 80°C. It's also tiny, which is a requirement for practically all component's in a CubeSat application.