Function of Component

Reaction wheels (sometimes operated as, and referred to as, momentum wheels) are typically the primary actuators on any spacecraft without propulsion methods [1]. As it is an actuator, it is found in the actuator section of the ADCS Architecture. They typically contain a rotating flywheel connected to an electric motor which, when its rotational speed is changed, causes the spacecraft to rotate in the opposite direction due to the conservation of angular momentum. For more information, refer to Reaction Wheels.

Key Parameters

Explain all the parameters used in making a selection

• Torque
  • The reaction wheel’s torque performance is its ability to rotate a spacecraft around its center of mass.
  • Good reaction wheel torque performance may be in the range of 0.1 - 10 mNm.
• Momentum storing
  • The reaction wheel’s momentum storing performance is its ability to provide a satellite with a large amount of stored angular momentum. This allows the spacecraft to be more resilient to external disturbance torques as any applied torques result in generally smaller angular motion about a perpendicular axis rather than a larger angular motion about the applied axis.
  • Good reaction wheel momentum storing performance may be on the order of 10s of mNms
• Quantity
  • The reaction wheel's quantity refers to whether the reaction wheel is sold as an individual wheel or as a set of four, interconnected reaction wheels.
  • Good reaction wheel quantity may consist of a set of four reaction wheels as it tends to be more cost-effective and easier to implement.
• Price
  • Reaction wheels are typically one of the most expensive components in a CubeSat.
  • A good reaction wheel price may simply be as cost-effective as possible.
• Size
  • Size in this context refers to the overall volume of the device as well as each individual major axis dimension.
  • Ideally, the device should be as compact as possible, less than 100 mm for its length, width, and height.
• Weight
  • Weight in this context refers to the overall weight of the device.
  • Since the entire spacecraft for the 2023 cycle needs to be within 4kg, the device should not take up a significant portion of that weight.
• Input Voltage
  • Input voltage in this context refers to the amount of supplied voltage that the device requires.
  • For the 2023 cycle spacecraft, the input voltage should be between 1 and 5 V, depending on its current draw.
• Input Power
  • Input power in this context refers to the amount of supplied power that the device requires.
  • For the 2023 cycle spacecraft, the input power must be less than 5W.

Selection Criteria

• Torque
  • More than 0.1022 mNm
• Momentum Storing
  • As high as possible
• Quantity
  • Ideally comes as a set of 4
• Price
  • As low as possible
• Size
  • Length less than 100 mm
  • Width less than 100 mm
  • Diameter (if applicable) less than 100 mm
  • Height less than 100 mm
• Weight
  • Less than 1 kg
• Input Voltage
  • Between 1 and 5 V