precision deployable shell-membrane antenna reflector for space applications

Paper number

IAC-08.C2.2.2

Author

Dr. Leri Datashvili, Technische Universität München, Germany

Coauthor

Prof. Horst Baier, Technische Universität München, Germany

Year

2008

Abstract

When a diameter of the antenna reflector needed in space orbit exceeds launcher shroud dimensions a large deployable reflector (LDR) technology must be applied. Analyses of future space mission requirements allow making a conclusion that the need of large deployable reflectors will be increased for the next years. There are a number of LDRs with flexible metal mesh reflecting surfaces (RS) which are already in use in space and have a diameter range up to 10-12m. All metal mesh reflectors are characterized with inherent systematic errors (so called pillow effect) decreasing the accuracy and RF performance of the RS.
Discussions of results of theoretical numerical and experimental investigations in a high precision LDR concept SMART (Shell Membrane Antenna Reflector Technology) with high growth potential, which can increase the applicable frequency range up to X/Ku bands is a focus of the paper. 
The concept of SMART is based on non-tensioned reflecting CFRS (carbon fibre reinforce silicone) surface together with a deployable backside structure consisting of thin foldable membranes deployed and tensioned in orbit. This concept leads to a high adaptability in reflector diameter (say from 4m up to 25 m) without changing the principle of the design. Interesting growth potential is also identified e.g. for possible active shape control to achieve even higher surface accuracy. This discussion of SMART is based on its design concept together with results from simulation models especially for in-orbit deformations and resulting RMS properties. Results from computer models will be complemented by experimental results obtained from scaled reflector models manufacturing peculiarities of which are also addressed in the paper. 
SMART scaled model has a diameter of about 2m. Folding/deployment tests confirmed high reliability and synchronization of the deployment. Another scaled model tests include the behaviour under quasi-zero-g conditions as obtained in a parabolic flight campaign with an Airbus aircraft. The surface accuracy achieved by manufacturing and integration is measured via precision photogrammetry under different laboratory conditions and also during aircraft parabolic flight. 
The presentation is amended with discussion of possible integration concepts for Earth observation and telecom satellites, as well as with an outlook for possible inclusion of active shape control technology.

Abstract document

IAC-08.C2.2.2.pdf

Manuscript document

IAC-08.C2.2.2.pdf (🔒 authorized access only).

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