Optical Filter Wheel Assemblies

Moog’s design of Filter Wheel Assemblies is unique in concept and has been used successfully on several space missions. The design is based on integrating the motor rotor with the optical disk thus providing an optimized solution with high torque in the most compact volume and with lower mass. The more conventional design of filter wheels driven by external motors has the design limitation of only two optical disks in a FWA with two motors on opposite sides. The Moog design is not limited by the number of optical disks, as each optical disk is the motor rotor driven by its own stator assembly. A good example is the Selectable Optical Filter Assembly (SOFA) on the Hubble Space Telescope which consists of 12 separate rotor/stator motor combinations. Each rotor assembly carries 4 filters and one open aperture, providing 48 total filters and many possible filter combinations which is impossible to achieve through conventional FWA designs.


Featured Products

Selectable Optical Filter Assembly (SOFA)

The Selectable Optical Filter Assembly (SOFA) was designed specifically for the Hubble Space Telescope (HST) Wide Field Planetary Camera. The design is a unique concept and has subsequently been used on several other missions, such as Cassini.


HST Fine Guidance Filter Wheel Assembly

The Fine Guidance Systems FWA is located in the optical path. The FWA assembly consists of a wheel bearing five filters with 2.0 inch diameter clear aperture.


CASSINI Narrow Field and Wide Field Filter Wheel Assembly

The Cassini Narrow Field FWA housed 24 filters on two disks each having 12 filters with 1.15 inch diameter clear aperture. The Wide Field FWA housed 18 filters on two disks each bearing 9 filters with 1.55 inch diameter clear aperture.


Sandia's AFT Telescope Cryogenic Filter Wheel Assembly

The Advanced Flight Telescope (AFT) cooled and un-cooled FWA assemblies housed six (6) optical filters with a 1.60 inch diameter clear aperture on a single disk.


Hayabusa I and II Filter Wheel Assembly

The Hayabusa filter wheel containing eight (8) optical filters is driven in the center by a Moog M8 Rotary Actuator. The actuator is a stepper motor driven mechanism with zerobacklash Harmonic Drive transmission.