Payload concept

The payload has two key functions

reduce disturbances of proof masses

measure changes in distance between proof masses

There are two main payload subsystems

disturbance reduction system contains gravitational reference sensor, control laws, and micronewton thrusters

Interferometry measurement systems consists of telescope, optics, laser, phase meter, phase noise correction and supporting structure

Other payload components - telescope mechanism, payload processor and Y-tube

Payload design features - 1 W Yb:YAG laser, 30 cm ULD telescope, composite Y-tube, thrusters have an I_sp of 10,000; 0 -100 microNewton thrust; ULE or Zerodur optical bench

Sensitive payload electronics are mounted behind the optical bench. Other payload electronics are mounted on top and bottom plates of the spacecraft.