Gravitational modelling of the proof mass for ASTROD mission Original Research Article

In this paper we use gravitational modelling to study the requirement and design of the proof mass for the ASTROD (Astrodynamical Space Test of Relativity using Optical Device) mission. The gravitational interaction between a sphere and a cylinder is described by a 1-D integration for calculating the deviation acceleration of proof mass from the inertial orbit. It is found that the deviation acceleration is almost independent of the shape of proof mass for the combined configuration of proof mass with outer reference mass in ASTROD mission, while it depends on the dimensions of outer reference mass. The rotational-vibration period of proof mass due to the reference mass torque is calculated to be 2.4 days. Strategies for controlling the proof mass rotation is proposed. Requirements to keep the residual acceleration below 10−13 – 10−15m/s2√H z level are discussed.