Thomas Sinn

Design and development of deployable Self-inflating Adaptive Membrane

Space structures nowadays are often designed to serve just one objective during their mission life, examples include truss structures that are used as support structures, solar sails for propulsion or antennas for communication. Each and every single one of these structures is optimized to serve just their distinct purpose and are more or less useless for the rest of the mission and therefore dead weight. By developing a smart structure that can change its shape and therefore adapt to different mission requirements in a single structure, the flexibility of the spacecraft can be increased by greatly decreasing the mass of the entire system. This paper will introduce such an adaptive structure called the Self-inflating Adaptive Membrane (SAM) concept which is being developed at the Advanced Space Concepts Laboratory of the University of Strathclyde. An idea presented in this paper is to adapt these basic changeable elements from nature’s heliotropism. Heliotropism describes a movement of a plant towards the sun during a day; the movement is initiated by turgor pressure change between adjacent cells. The shape change of the global structure can be significant by adding up these local changes induced by local elements, for example the cell’s length. To imitate the turgor pressure change between the motor cells in plants to space structures, piezoelectric micro pumps are added between two neighboring cells. A passive inflation technique is used for deploying the membrane at its destination in space. The trapped air in the spheres will inflate the spheres when subjected to vacuum, therefore no pump or secondary active deployment methods are needed. The paper will present the idea behind the adaption of nature’s heliotropism principle to space structures. The feasibility of the residual air inflation method is verified by LS-DYNA simulations and prototype bench tests under vacuum conditions. Additionally, manufacturing techniques and folding patterns are presented to optimize the actual bench test structure and to minimize the required storage volume. It is shown that through a bio-inspired concept, a high ratio of adaptability of the membrane can be obtained. The paper concludes with the design of a technology demonstrator for a sounding rocket experiment to be launched in March 2013 from the Swedish launch side Esrange.

Multibody dynamics for biologically inspired smart space structure

Structures in space are often just serving a single purpose. By developing a structure which is able to change it properties and adapt to changing environmental conditions, the costs of space missions can be decreased significantly. The design and simulation of such a structure is presented in this paper. The developed structure consists of an array of interconnected cells which are each able to alter their volume due to internal pressure change. By coordinated cell actuation in a specific pattern, the global structure can be deformed to obtain a desired shape. A multibody code was developed which constantly solves the equation of motion with inputs from internal actuation and external perturbation forces. During the inflation and actuation of the structure, the entities of the mass matrix and the stiffness matrix are changed due to changing properties of the cells within the array based on their state and displacement. This paper outlines the principles behind the developed code and gives examples in two dimensional and three dimensional space.

Simulation and control of a space web deployed by centrifugal forces in a sounding rocket experiment

A deployable space web is a flexible structure that can act as a lightweight platform for construction of large structures in space. In order to save space and energy for small deployable structure ...

The wideband ionospheric sounder cubesat experiment (WISCER)

This paper describes a preliminary design study to assess the possibility of flying a wideband ionospheric sounder cubesat experiment (WISCER). WISCER comprises a wideband (~100 MHz) beacon on a low cost cubesat designed to measure and evaluate the ionospheric channel in anticipation of the development of operational, space-based, low frequency (i.e. around 450MHz) synthetic aperture radar (SAR) systems.