Rosetta Lander Software Simulator

Paper number

IAC-06-D1.P.1.11

Author

Dr. Sandor Szalai, SGF Ltd, Hungary

Coauthor

Mr. Andras Balazs, SGF Ltd, Hungary

Coauthor

Mr. Attila Baksa, KFKI Institute for Particle and Nuclear Physics, Hungary

Coauthor

Mr. Gabor Troznai, KFKI Research Institute for Particle and Nuclear Physics, Hungary

Year

2006

Abstract

Rosetta is one of the most challenging missions of ESA. The complications of sending a small spacecraft halfway across the Solar System and making a soft landing on a small comet are immense. The time of the cruise phase to reach the comet is about 10 years. To preserve the knowledge on the lander system is a very important task. For this purpose has been developed a Lander Software Simulator (LSS). It consists of the real Command and Data Management Subsystem (fault tolerant computer) and simulators of experiments and subsystems (including radio channel). The simulation is realized in two levels: signal level simulation and logical level simulation. The signal level simulators content an embedded processor, which are controlled by PC. PCs execute the logical level of simulation. Experiment simulation realized on XML language. The XML simulation language has action, parameter, condition and loop. The complicated subsystem simulation can be realized on C++ language, supported with hardware close handling library. Simulation of a Lander Unit actually means:
1.	Manipulation of HK data of a Subsystem/Experiment according to the dynamic model of simulation
2.	Generation of science data according to the dynamic model of simulation
3.	Setting/resetting dedicated HW signals (Separation, Touch-down, PSS alarm) according to changes in mission phases, operational conditions
The LSS may provide the benefits:
1.	As a verification tool/help for/in mission planning
2.	As a mean for feasibility studies for various mission sequences (i.e. energy balance, mass-memory usage)
3.	As a mean for studying some off-nominal scenarios, of which realization on GRM is circumstantial or impossible
4.	As a training/exercising tool for Lander operation
In order to make possible a "full-scale" simulation LSS is extended with a Lander Environment Model (LEM). LEM is in charge of thermal modeling of the Lander and simulating flight dynamics, including the spacecraft orbit and the Solar Arrays illumination with respect to the landing site and orientation of the Lander on the comet. The simulator software of LSS is running on a multi-computer system with an LSS server in the centre. The simulation of units is distributed on four computers equalizing their loads. Data and parameters between models of subsystems and experiments as well as LEM are exchanged through a common Simulation Data Pool in LSS server. Two copies of LSS are used in DLR and MPS Germany.
 

Abstract document

IAC-06-D1.P.1.11.pdf

Manuscript document

IAC-06-D1.P.1.11.pdf (🔒 authorized access only).

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