>[!summary] This wheel is optimized for torque and for radiation hardness. It can give performance equivalent to a 0.4 Nms CMG with 22.5 deg/sec gimbal rate at much reduced mass and complexity. Designed for high-agility remote sensing or science microsatellites. > 🔗 Official Page: https://www.rocketlabusa.com/space-systems/satellite-components/reaction-wheels/ 📋 Data Sheet: [[RW4-0.4-Datasheet-v3.0.pdf]] ![[Pasted image 20250108214057.png]] ## Specs | Parameter | Value | | ------------------------------------- | -------------------------------------------------------------------------- | | Momentum (Nominal) | ±0.2 Nms (light rotor) or ±0.4 Nms (heavy rotor) | | Torque | ±100 mNm (see torque-box) | | Control Mode | Speed or Torque | | Command/Telemetry | Redundant RS-485 | | Mechanical Dimensions | 105 mm x 103 mm x 46 mm | | Mass | 0.6 kg max (0.2 Nms) or 0.75 kg max (0.4 Nms) | | Imbalance (Static) | 2 g·mm (average) | | Imbalance (Dynamic) | 30 g·mm² (average) | | Supply Voltage | 24 V to 34 V (nominal 28 V) | | Power (28 V Vacuum, 0.2 Nms) | 2.8 W steady state<br>112 W @ 0.2 Nms +100 mNm torque | | Power (28 V Vacuum, 0.4 Nms) | 3.5 W steady state<br>118 W @ 0.2 Nms +100 mNm torque | | Environment (Thermal) | −30°C to +85°C (operating) | | Environment (Vibration) | 20.16 gRMS (Random Vibration) | | Environment (Radiation) | 50 krad (board level)<br>Up to 50 MeV·cm²/mg on most active parts | | Flight Heritage (As of August 2 2024) | 28 units on orbit across 2 generations, with cumulated 19 years since 2023 |