>[!summary] Rocket Lab's largest wheel, suitable for 100 kg Earth-observation missions. There are currently 52 units on-orbit on 13 spacecraft, with the first launch in June 2016. > 🔗 Official Page: https://www.rocketlabusa.com/space-systems/satellite-components/reaction-wheels/ 📋 Data Sheet: [[RW4-1.0-Datasheet-v3.1.pdf]] ![[Pasted image 20250108213835.png]] ## Specs | Parameter | Value | | ----------------------------------- | ----------------------------------------------------------------------- | | Momentum (Nominal) | ±1.0 Nms | | Torque | ±100 mNm (see torque-box) | | Control Mode | Speed or Torque | | Command/Telemetry | Redundant RS-485 | | Mechanical Dimensions | 148 mm x 146 mm x 45 mm | | Mass | 1.4 kg max | | Imbalance (Static) | < 4 g·mm (average 2 g·mm) | | Imbalance (Dynamic) | < 80 g·mm² (average 25 g·mm²) | | Supply Voltage | 24 V to 34 V (nominal 28 V) | | Power (Steady State) | Max 5 W (at 28 V in vacuum) | | Power (Peak) | 99 W at max torque | | Environment (Thermal) | −30° C to +85° C (operating) | | Environment (Vibration) | 20.0 gRMS (Random Vibration) | | Radiation (TID) | 50 krad (board level) | | Radiation (Heavy Ion) | Up to 50 MeV·cm²/mg on most active parts | | Flight Heritage (as of Jan 31 2025) | 136 units on orbit across 2 generations; 590 years cumulated since 2016 |