Optical pathlength stabilization between formation-flying air-bearing robots

Abstract

The Precision Formation Control project seeks to demonstrate experimentally the capability to perform optical pathlength stabilization of a visible-laser interferometer beam operating between two formation-flying robotic airbearing space-vehicle emulators in a terrestrial laboratory environment, as a precursor to future separated-spacecraft interferometer missions. The multi-tiered architecture utilizes laser sensors for inter-vehicle sensing, proportional pneumatic thrusters for vehicular control, and a piezo-actuated delay line for optical pathlength control. In the lab environment, relative stationkeeping between vehicles has been demonstrated to better than 9 μm in position and 11 μrad in rotation (1-σ). Simultaneously, the inter-vehicle optical pathlength has been stabilized to less than 190 nm, 1-σ.