Thruster module

摘要

The thruster module described in this paper provides a low but controlled acceleration in a mission which would normally be labelled "microgravity". The first mission was Cryofenix, where tanks containing liquid hydrogen were used in the experiment. The experiment utilizing the low acceleration is using liquids and requires a precise acceleration profile throughout the mission. Acceleration obtained by payload rotation is not feasible due to that the transversal forces required to change the acceleration will cause undesired liquid turbulence. In order to satisfy the experiment requirements a thruster module was developed by SSC for the Cryofenix mission funded by CNES. The Cryofenix mission had a payload weight of 380 kg and an apogee of about 260 km. The module produces a controlled thrust in flight direction by means of a cold gas system. The thrust can be varied up to 40 Newton, causing a controlled acceleration up to 10 mg. The total impulse is about 5800 Newton-seconds. The thrust profile is under closed loop control, which means that it is flexible to changes, as long as basic restrictions such as maximum thrust and gas consumption are kept within design limits.