NEST - Next-Generation Equipment for Satellite Testing

The Power Subsystem Special Check-Out Equipment (SCOE) is a central component of the Electrical Ground Support Equipment. It provides power and control signals to the satellite during assembly, testing and launch preparation until just a few seconds prior to lift-off. The activity aims at reducing the manufacturing complexity of the overall Power SCOE system emphasising standardised components (leading to reduced costs and improved reliability) and making the system operator’s user interface more intuitive (leading to easier operations procedures and to a high acceptance by the test engineers).

Short Description

The approach started with an in-depth analysis of the present system architecture in the areas of hardware architecture, control architecture and user interface, comparing a variety of alternatives in a comprehensive manner. The alternatives are carefully assessed, thus identifying possible areas of improvement. Feedback and advice has been obtained from external experts and customers on the envisaged changes.

The outcome is an improved detailed hardware design and manufacturing documentation, a prototype consisting of central modules controlled by the newly embedded controller, and an improved Power SCOE application software together with a fully functional Power SCOE SW prototype with simulation of non- existent hardware.

The most important requirements for the power SCOE can be summarized as follows:

  • Flight hardware safety: The safety of the flight hardware, even in the presence of a HW or SW failure in the SCOE or operator error, is of utmost importance. Hence, it requires primary protection in the power supplies themselves as well as secondary protection features that are implemented in the SCOE HW, and the SCOE SW is only used for configuration and monitoring purposes.
  • Operating Modes: To allow an efficient use of the SCOE hardware during all stages of spacecraft assembly, integration and validation, the SCOE operators need to be able to control the SCOE elements both in a low-level, ad-hoc mode for troubleshooting as well as in a (configuration-) controlled mode for verification and regression testing of the complete onboard system. Therefore the SCOE software can be operated in two major modes: local and remote. Remote commands are sent via the CCS communication interface while local commands are controlled over the GUI.
  • Power SCOE Self Test and Validation: In order to verify the operational status of the Power SCOE equipment and functions, a self test facility shall be provided that can be activated at any time to verify the operability of the SCOE instruments and devices and therefore shall consist mainly of internal self test calls in order not to disturb the momentary S/C interface configuration and state.
  • Launch site switchover between Nom/Red Rack (COMMUTATION): Commutation between Nominal/redundant rack must be performed for different interfaces of the SCOE.

Project Partners


Siemens AG Österreich, Siemens IT Solutions and Services PSE, Aerospace Industry Solutions - Wolfgang Mader

Contact Address

Siemens AG Österreich - Siemens IT Solutions and Services PSE, Aerospace Industry Solutions

Wolfgang Mader
Gudrunstrasse 11
A-1101 Vienna
Tel.: +43 (517) 07 42654
Fax: +43 (517) 07 52902
Mobile: +43 (676) 77 95 022