High-Accuracy 200 mm Siderostat

The proposed innovations are major improvements to existing fine-steering mirror (FSM) actuator and sensor technology for NASA applications such as ST-3 and SIM. Mass of the FSM mechanism is reduced by up to 25%. Simultaneous improvements in power consumption and lateral load capability are also featured. The first innovation involves the use of LHDC's efficient CS actuator technology for FSM actuation. Innovation #2 is the incorporation of advanced sensors having increased accuracy. The result is reduced mass, acceleration, and power as well as the improved accuracy of interferometric and optical encoder sensors without compromise to mirror surface figure quality. Benefits for JPL's ST-3 program include: improved global and small-range accuracy, lower cost than previous FSM, lower mass for lower launch costs and a simpler support structure. Line-of-sight stabilization can be done with only a few mW of actuator power and it can be launched without a mechanical caging mechanism for increased reliability. Additional benefits for other space-based applications include: extended travel, chopping or dither functions can be performed at higher frequencies and larger amplitudes with lower power for improved images.