Pierre Demuysere, Guillaume Houchard, Silvio Akitani Fo-Me Comlan
DOI Number XXX-YYY-ZZZ
Conference Number HiSST-2022-0313
The Space Rider is a European mini-shuttle project lead by ESA and destined to bring payloads into orbit for a duration of up to two months and return them back safely to Earth. It consists out of two major element: the Re-Entry Module (RM) developed by TAS-I and the AVUM Orbital Module (AOM) derived from the AVIO VEGA 4th stage. SABCA is responsible for the design of the Aerodynamic Surface Control System (ASCS) on the RM and the Thrust Vector Control System (TVCS) of the AOM. Both of these systems consist out of:
– two Electro-Mechanical Actuators (EMA);
– an Actuators Control Unit (EMACU) containing all the power and control electronics; – two battery packs for the power generation; and
– all the necessary cables and harnesses.
For the ASCS, two mechanical levers transfer the displacement of the actuators to the flaps. The ASCS system design has been validated in-flight during the IXV mission. SABCA has taken, in the development of these systems, a “modified off-the-shelf” approach. The TVC of the ZEFIRO stages of Vega has been adapted for the ASCS, while the TVC of the AOM is derived from the AVUM stage of Vega. The changes are linked to the new mission profile. The main drivers were the long exposure to space radiative environment and the need for reusability. This approach allows leveraging on existing qualified products, and therefore reducing development cost and duration. After the ASCS EMA control mission, the EMACU will also be used to control the winch parafoil motor in order to ensure the precision landing. All the functions and components were thoroughly analysed and, when necessary, adapted to ensure that the system as a whole complies with the reliability figure necessary for such a multi-flight mission with long stays on orbit. Lessons learnt of IXV mission and VEGA production experience were also useful : years of tests on VEGA engineering equipment gave, before starting Space Rider development, a good idea of the limits of this equipment and of its potential to reusability. The reusability analysis has been deeply conducted in order to avoid dismounting of equipment between flights. The reusability analysis highlights the most important tests to be perform in order to insure a good reliability for the next mission. The CDR has validated the adaptations needed to ensure that the equipment meets the new constraints in terms of reusability and radiation, and the additional tests to qualify it. These tests are mainly linked to performance (extended duty cycle) and vibration at subsystem (ASCS) level which are not covered by the qualification on VEGA or IXV program