ADCS is the subsystem of a satellite that determines where the satellite is pointing (attitude determination) and controls that orientation (attitude control). The ADCS ensure that the satellite is correctly oriented in space relative to the Earth, the Sun, a constellation or another specific target, using a combination of sensors to measure orientation and actuators to adjust it. ADCS is required for most space missions because many functions desired in satellites depend on attitude within an accuracy limit. For example:

• Communication: Directional antennas need to point toward the ground station to transmit and receive data efficiently.
• Power generation: To maximize power generation, the solar panel faces need to be turned orthogonal to the incoming solar rays.
• Payload operations: Cameras, scientific instruments, or sensors must point at specific targets (Earth, stars, or space phenomena).
• Stability: Without ADCS, a space vehicle may tumble uncontrollably due to disturbances such as Earth’s magnetic field, gravity gradients and solar radiation pressure.

A typical CubeSat ADCS uses a combination of sensors and actuators that work together. Below is a short summary of the ADCS solutions and components we are utilizing or may utilize in the future.

Sensors (for attitude determination):

• Magnetometers: Measure Earth’s magnetic field and help estimate satellite
• Sun sensors: Detect the direction of the Sun relative to the
• Gyroscopes: Measure angular velocity and help track rotation over short time Actuators (for attitude control):
• Reaction wheels: Small spinning wheels that change the satellite’s orientation by using the conservation of angular momentum. They allow precise pointing and smooth
• Magnetorquers: Electromagnetic rods that interact with Earth’s magnetic field to generate torque. They are mainly used for de-tumbling and reaction wheel de-

How they work together:

• Sensors collect data about the satellite’s current
• The onboard computer processes this data using estimation
• Control algorithms decide what torque to
• Reaction wheels provide fine pointing

 

• Magnetorquers assist with coarse control and help unload excess momentum from the reaction wheels.

 

Tasks & Responsibilities	a)     Design the attitude determination sensor configuration. b)     Select the attitude determination sensor suite. c)     Design and manufacture the magnetorquers. d)     Design reaction wheel assemblies, or select from commercial options. e)     Design ADCS algorithms. f)      Test and evaluate the ADCS system in collaboration with the PA Subteam.
Roles	Mechanical Engineers, Control Engineers, Physicists