LOCKING MECHANISM FOR IXV RE-ENTRY DEMONSTRATOR FLAP CONTROL SYSTEM

The atmospheric re-entry domain is considered as a cornerstone of a wide range of space applications encompassing the planetary exploration, the sample return, the future launchers, the space planes, the crew and the cargo transportation. The IXV (Intermediate eXperimental Vehicle), as shown by Fig. 1 is an “intermediate” element of a European roadmap for in-flight technology verification; the objective is to prepare future ambitious system developments with limited risks for Europe. Figure 1: IXV vehicle (ESA program) The aerospace company SABCA, located at Brussels, Belgium, is in charge of the development and manufacturing of the Flap Control System (FpCS) of the IXV vehicle, under Thales Alenia Space Italy (TAS-I)’s responsibility. The Flap Control System (FpCS), as shown by Fig. 2, consists of: 2 electro-mechanical actuators (EMA’s) 1 EMA control unit (EMACU) 2 levers, interfacing with the structure and the flap rod a battery set a cables harness. Each FpCS actuator is equipped with a locking mechanism, that holds the flaps in a fixed position during the launch phase, the orbital flight and the last part of the descent (with the parachutes), the IXV flaps being actuated by the FpCS during the re-entry phase itself; the locking mechanism holds the flaps position when the FpCS is unpowered. For this application, the locking mechanism consists in a passive static brake. The design of the brake was made by Thales Avionics Electrical Motors (TAEM); at the beginning of the study, two concepts were compared: friction disc brake teeth brake. During the project design phase, teeth brake breadboard tests have been performed. The FpCS qualification is scheduled by 2012-2013, and the IXV flight by 2013. Figure 2: IXV flap control system Battery set EMA control unit (EMACU) Electromechanical actuator (EMA) and lever (2*)