Space antennas with a helical geometry are an advantageous choice for many applications, for instance if the transmission of electromagnetic waves with a circular polarization is intended, or if signals from terrestrial objects shall be received with a high angular resolution. In all these cases the desired electromagnetic properties of a helical geometry can be combined with the mechanical advantage that the antenna acts as a compression spring, provided that its core structure has the necessary high spring stiffness but can nevertheless easily be compressed. Such an antenna has been developed by DLR Institutes in Bremen and Braunschweig together with some industrial partners for a small satellite named AISat which shall be able to pursue the position of individual ships in critical sea areas in order to improve the security of seafare trade. The development was very challenging since the antenna must expand from a stowed stack length of only 10 centimeters to a total length of 4 meters. Only a special carbonfiber core under the conductive coating and a system of stabilizing cords led to a satisfying solution. Both the self-deployment and the self-stabilization function of this innovative antenna concept have been successfully tested and verified under zero-gconditions in the course of a parabolic flight campaign. It could be convincingly demonstrated that the helical antenna can really achieve its desired contour in weightlessness within some seconds and maintain the required stability. Beyond the current application for the AISat satellite it is therefore a quite promising concept for future satellites.
In this paper the development of the structural design of a deployable helical antenna made from fiber composite material as well as its deployment verification in Zero-G environment will presented 1,2. In the introduction the advantages of helical antennas will be pointed out and a potential field of application, the receiving of AIS (Automatic Identification System) signals from maritime vessels, will be presented. The next chapter deals with the antenna design where especially manufacturing aspects will be addressed. The test setup for deployment tests in weightlessness will be explained and the results recorded during the 15 th parabolic flight campaign (PFC) of DLR (German Aerospace Center) in March 2010 will be shown. During this campaign the deployment of 4 different helix antennas was tested as well as reaction forces and the dynamical behavior were recorded. An outlook is given on the subsequent finite element (FE) nonlinear numerical analysis. The aim of these calculations is to correlate analysis and test results, to use the correlated models for further improvements of antenna parameters, and to enhance predictions of the antenna behavior and its effect on the satellites attitude control during and after deployment.-TABLE OF CONTENTS 1. INTRODUCTION .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.