High Agility Demonstration with a New Actuator System by Small Satellite BIROS

Kurzfassung

The small satellite BIROS is one part of the DLR FIREBIRD mission and shall be launched in 2015. The satellite bus based on the successfully flying TET-1bus developed by Astro- und Feinwerktechnik Adlershof GmbH in cooperation with the DLR. The TET-1 satellite was successfully launched on June 22nd 2012 from Baikonur and is also part of the FIREBIRD mission. Both satellites are equipped with an identical main payload. This is an infrared camera system for Earth observation, especially hot spot detection. As part of the DLR FIREBIRD mission both satellites shall be used in a constellation. Additionally BIROS shall demonstrate new technologies as secondary payloads; one of this is the demonstration of a highly agile small satellite without using of control momentum gyros. In future the agility shall support the earth observation missions, for example to observe larger areas within one orbit. To enlarge for example the swath width parallel image stripes on ground shall be requested. Therefore fast slew maneuvers for re-orientating the satellite are necessary. The objective of the agility demonstration by BIROS is a slew maneuver of 30° within 10s and subsequent continuation of the mission operation – the earth observation. So it is possible to take up to five parallel stripes within one orbit. The different demonstrated slew maneuvers of BIROS are according to the maneuvers of the satellite WORLDVIEW-2 which is used as “reference” but the agile slew maneuvers shall be done with the new actuator wheel developed by the DLR - the high torque. Principally this actuator based on the reaction wheel concept but is especially designed for high torques. At first this paper shall give a short overview of the small satellite BIROS especially the attitude control system. Then the objective and realization of the agility demonstration shall be presented. The different slew maneuvers and the requirements shall be presented and the new actuators as well as their effects on the BIROS attitude control system shall be described. Additionally some simulation and test results as well as test strategies shall be shown.