Joachim Block

Deployable Composite Booms for Various Gossamer Space Structures

Deployable structures are required to either enable orbit transfer of very large structure or to make the orbit transfer of medium and small size structures more affordable. Hereby, deployable booms are basic building blocks of such deployable structures. DLR is providing a concept for deployable booms that utilize very thin CFRP material and which can be stowed by coiling. The given paper introduces the concept of the CFRP booms and discusses the problems of their self deployment tendency. Furthermore, different mechanisms are presented that are able to control the deployment. Tests under artificial zero-g environment have been conducted to verify the applicability of the control concepts. Hence, the paper also gives insight in objectives, setup and the results of the experiment as well as a final evaluation of the concepts. Finally, an outlook on current and future projects that use the introduced booms or equivalent systems is given.

The NetLander geophysical network on the surface of Mars: General mission description and technical design status

Abstract Simultaneous measurements collected by a network of landers spread over the surface of Mars will provide a unique leap forward in our knowledge of Mars. This is the objective of the NetLander (for Network Lander) project developed by CNES (French Space Agency), FMI (Finnish Meteorological Institute), IfP (Institute fur Planetologie - Munster) in cooperation with a number of institutes in Europe and in the United States. The NetLander mission will deploy four identical landers on the surface of Mars. Each lander includes a scientific payload with instrumentation aimed at studying the interior of Mars, the atmosphere, the sub-surface, as well as the ionospheric structure and geodesy. The European NetLander mission will be launched in 2007 with the orbiter developed by CNES in the framework of the French Mars exploration program. After a cruise phase lasting several months, the NetLander probes will be separated from the orbiter and targeted to their landing sites. NetLander has successfully completed the phase A study. Its Entry, Descent and Landing System uses a front-shield, parachutes and air-bags. On the surface of Mars, NetLander will use solar arrays and batteries for its power supply. Particular attention is paid to the definition of this power supply system, which should provide enough energy throughout the mission, with a duration objective of one Martian year. Telecommunications will be possible via data relay satellites in orbit around Mars.

Deployment verification of large CFRP helical high-gain antenna for AIS signals

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 presented1,2. 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 15th 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.