• Home
  • Current congress
  • Public Website
  • My papers
  • root
  • browse
  • IAC-07
  • C1
  • 8
  • paper
  • ESOC Precise Flight Dynamics Emulation for the GOCE Mission

    Paper number

    IAC-07-C1.8.03

    Author

    Mr. Stefano Pessina, Terma GmbH at ESA/ESOC, Germany

    Coauthor

    Mr. Livio Tucci, Terma GmbH at ESA/ESOC, Germany

    Coauthor

    Mrs. Susanne Kasten-Coors, European Space Agency/ESOC, Germany

    Coauthor

    Mr. Michael L. Flegel, Terma GmbH at ESA/ESOC, Germany

    Year

    2007

    Abstract
    The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) will measure the Earth's gravity field, flying at a very low altitude (around 270 km). The GOCE Drag Free Attitude Control (DFAC) provides knowledge and control of orbit and attitude. In particular, the DFAC allows a drag free control of the satellite when the payload gradiometer is measuring, by means of ion propulsion force.
    \\\\Within the Flight Dynamics (FD) Division of the European Space Operations Centre (ESOC), a GOCE emulator has been developed by the FD Test \& Validation group (T\&V). During operations preparation, the emulator is used to test the FD Command Generation and Attitude Monitoring systems and to train the whole FD team. In operations the emulator validates FD commands and it is valuable in analysing DFAC performance and investigating contingencies.
    \\\\The FD emulator has to reproduce the functionality of the DFAC on-board software (S/W) in a very representative way, also modelling with high fidelity closed-loop S/C dynamics, space environment, sensors and actuators. Telemetry data have to be generated in real-time, according to ground stations visibility and foreseen space-to-ground interfaces also in response to ground telecommands or injected failures.
    In addition to the emulators' development of previous missions, accurate orbit propagation is performed, to precisely model in closed loop the effects of aerodynamic drag and corrective ion propulsion forces.
    \\\\T\&V approach for emulator development consists of a model-based design, allowing rapid-spiral prototyping and system decomposition. The target of a highly representative system is constrained by limited development resources and it has recently become more and more difficult to achieve, because of a general increased complexity in S/C design. This is driving T\&V to integrate, when feasible, the real flight S/W (instead of re-implementing a functional model) and to make maximum use of externally developed simulation models (when available and fulfilling FD accuracy requirements). In GOCE particular case, the above mentioned baseline has been fully followed: the provided S/W has been adapted and integrated into the FD multi-mission emulator infrastructure, creating also appropriate communication interfaces between unit models and the flight S/W.
    \\\\In this paper, after an outline of the requirements for the FD GOCE emulator, the design and implementation approaches will be presented, their advantages and the models' details will be described. Examples will be given about the operational applications of the emulator for FD system validation and team training, during launch preparation.
    Abstract document

    IAC-07-C1.8.03.pdf

    Manuscript document

    IAC-07-C1.8.03.pdf (🔒 authorized access only).

    To get the manuscript, please contact IAF Secretariat.