ESA GNC Conference Papers Repository

Selex Galileo is the leader in Europe for Earth Sensors development and manufacturing, with more than three hundreds IRES (InfraRed Earth Sensor) equipments successfully flown. Further unit cost reduction and improvement in procurement time and exportability have been achieved with the latest IRES-N2 version. Following the AOCS (Attitude and Orbit Control System) system architecture evolution, with the introduction of the Star Sensor as attitude instrument on the telecommunication satellites and with the Earth Sensor as backup unit, Selex Galileo has started, in the frame of an European Space Agency (ESA) contract, the development of a new Earth Sensor based on concepts that allow a significant cost reduction, while maintaining a good range of functionalities, possibly with some reduced performance. The new architecture permits to have an Earth Sensor suitable for support/back-up unit for the Star Sensor on GEO applications or, with coarse performances, for safe-mode purposes on LEO satellites, by means of a modular design with very low impact for GEO/LEO employments (change only of the optics). The most interesting characteristics, that the new Earth Sensor design will be able to match, are: low cost, simplicity, modularity, small size, reduced mass and power consumption. Furthermore, the use of consolidated technologies will lead to a high reliable product for both GEO/LEO environments and available on the market within a couple of years. A Market Survey, carried out by Selex Galileo in the frame of the same ESA contract, has contributed to clarify the market requirements and to assess the actual matching with the new Earth Sensor preliminary design. This paper will present the design concept, the architecture and the expected performance of the new Earth Sensor, as well as the results of the breadboarding activities performed on two configurations characterised by the employment of two different sensing technologies: the first one with pyroelectrics and the second one with thermopile detectors. In addition, the conclusions of the market survey will be reported to highlight the application scenario for this product. A follow-on of this development is foreseen in the near future in order to define the detailed design of the most promising sensor configuration, based on pyrolectric detectors.