Command and Data Handling Subsystem for a Satellite without Energy Storage: Delfi-C3

Paper number

IAC-07-B4.3.06

Author

Mr. Jasper Bouwmeester, Delft University of Technology, The Netherlands

Coauthor

Mr. Rouzbeh Amini, Delft University of Technology, The Netherlands

Coauthor

Mr. Rob Hamann, Technical University of Delft (TUDelft), The Netherlands

Year

2007

Abstract

The basis for a satellite’s command and data handling subsystem (CDHS) are the nominal mission operations. However, in case of failures, a satellite should still be able to perform as much operations as possible, by circumventing or dealing with such failures. An important factor for the reliability of a satellite is its dependency on continues power supply for its CDHS operations. How can the continuity of the operations be guaranteed with discontinues power supply?

The CDHS design of Delfi-C3 will serve as a case study. Delfi-C3 is a student nano-satellite from Delft University of Technology. It is designed without energy storage (i.e. batteries), which is very uncommon for spacecraft. The consequence for the command and data handling subsystem are severe. Not only will the power go down when the satellite enters an eclipse, but also a failing solar panel will introduce brown-outs of the satellite in a periodic manner, depending on its rotational speed. For the Delfi-C3 this would mean that in the worst case scenario the operational periods are about 30 seconds. This shines an interesting light on the CDHS design, which should be able to cope with these short periods of operation and still be able to reach and perform mission operations. Non-volatile memory is used to save intermediate states for longer operations, like deployment. The time from power-up to the successful transmission of a payload data packet should be within this short period. 

This paper discusses the impacts of the lack of onboard energy storage for the CDHS design and the differences in the design compared to satellites which do have an onboard energy storage or source. It also discusses whether this new approach can be useful for all satellites, independent of the availability of energy storage.  

Abstract document

IAC-07-B4.3.06.pdf

Manuscript document

IAC-07-B4.3.06.pdf (🔒 authorized access only).

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