High Precision Relative Position Sensing System for Formation Flying Spacecraft

Three candidate sensors under development
- Longitudinal Sensing: Precision Laser Ranger (PLR)
- Periodic laser pulses are reflected off a distant target.
- Heterodyne analysis of returning pulses enables high resolution ranging.
- Transverse Sensing = Transverse Alignment Sensor (TAS)
- Laser beam is focused onto distant laser position sensor.
- Analog sensor provides coordinates of spot on sensor.
- 3D PLR: Alternative approach to transverse sensing:
- Combine PLR with 3D target covered with retroreflective material.
- 6 degree of freedom sensing using PLR.
- May eliminate need for TAS.