Use of New Developments of Attitude Control Sensors for the Micro-Satellite Flying Laptop

Paper number

IAC-06-D1.P.2.07

Author

Mrs. Viola Wolter, Steinbeis Transferzentrum Raumfahrt, Germany

Coauthor

Mr. Matthias Waidmann, University of Stuttgart, Germany

Coauthor

Mr. Dominik Saile, University of Stuttgart, Germany

Coauthor

Mr. Christian Waidmann, University of Stuttgart, Germany

Coauthor

Mr. Georg Grillmayer, University of Stuttgart, Germany

Year

2006

Abstract

Currently the Institute of Space Systems (IRS) at the University of Stuttgart is in the implementation phase of its first micro-satellite Flying Laptop. Within the scope of the small satellite program of the IRS the Flying Laptop is the first satellite in a consecutive series of small spacecraft. The Flying Laptop with it's primary mission objectives being technology demonstration is developed and built by faculty, PhD/master students and in cooperation with the industry.
This paper provides an outline of the used attitude control hardware sensors and actuators. Several new developments are conducted and will be flown for the first time. 

The Flying Laptop will use a Field Programmable Gate Array (FPGA) as on-board computer. A Vertex II-Pro from Xilinx will be integrated into a custom tailored system. The interfaces for the sensors and actuators are tested on a simple Spartan IIE development board. Currently the EM models of the reaction wheel, magnetometer, GPS, star tracker, magnetic torquer, sun sensor and rate gyro are connected to the development board and communication as well as simple simulations are executed.
The timing and parallel structure of a FPGA allow a dependable and precise attitude control of the satellite. All sensors or actuators of a kind can be addressed simultaneously, e.g. all 4 momentum wheels can be commanded at once while at the same time requesting data from the rate gyros. 
For the programming of the interfaces Celoxica's Handle-C compiler is used. It allows high-level  programming with the use of PAL (platform abstraction layer) libraries as well as low-level programming for timing and communication with non-serial components, for example the IBIS bus for the rate sensors. The software interfaces are combined in a library. The programmed functions provide services for the attitude control system, prepare telemetry from the new GPS and Star Tracker for the TM logger, and report hardware states and errors to the FDIR.

Abstract document

IAC-06-D1.P.2.07.pdf

Manuscript document

IAC-06-D1.P.2.07.pdf (🔒 authorized access only).

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