New approach for separation study in Vega launcher: Vega stages separation tool models development and multibody separation dynamic simulations for Vega payload fairing jettisoning
- Paper number
IAC-06-C1.3.09
- Author
Dr. Ing. Vincenzo Mirra, ELV S.p.A., Italy
- Coauthor
Mr. Gonzalo Saavedra, SENER Ingeneria y Sistemas, S.A., Spain
- Coauthor
Mr. Rafael Rebolo Gomez, SENER Ingeneria y Sistemas, S.A., Spain
- Coauthor
Mr. Daniele Barbagallo, European Space Agency/ESRIN, Italy
- Year
2006
- Abstract
The stages separation of a launcher during its ascent phase is a very significant problem in the Multybody Dynamics that represents an essential feasibility aspect to be studied. These transient flight phases are in principle not fully reproducible on ground dealing with the need of reliable simulations. The risk of collision among separated bodies has to be assessed to assure the design compliance with the reliability/safety requirements for the launcher and the payload. In the frame of the ESA Programme contracted by ELV for the VEGA Launcher Development, the stages separation analyses including the multybody fairing jettison have been addressed developing an advanced separation simulation tool by a new model based approach. In this context, SENER and ELV have developed a 6DoF model taking into account the parameters affecting the separation dynamic (mass, centre of gravity, inertia, structural dynamics, angular rate, separation energy and pyrotechnic ignition delay). This paper firstly describes the VEGA stages multybody model developed by SENER in SimulinkÒ environment. This tool aims to evaluate the collision risk during the separation and the influence of each parameter to the separation clearance, also including features for uncertainties and dispersions on the different parameters, providing the possibility to perform MonteCarlo analyses. Further, the paper focuses on the main applications and achievements performed by ELV/SENER team on the VEGA separation studies. In particular the analysis of the VEGA fairing jettisoning dynamics is described to present a complex multybody separation problem to assess the collision risk for the three bodies involved in the disengagement phase. The effects of the structures flexibility on the separation dynamics have been also simulated in terms of structures ‘breathing’ motion by following both the deterministic approach and the MonteCarlo test based statistics to prove the safe fairing jettisoning of the two halves with a suitable clearance respect to Launcher and Payload. The simulation environment modelling includes aerodynamics, gravity and propulsive forces during the VEGA ascent flight; the geometry and the disengagement criteria in terms of launcher and payload forbidden volumes; the separation pyrotechnics dynamics by non-linear springs acting on the fairing halves contact surface.
- Abstract document