The AML Space Group team is composed of three PhD and three Master students from the University of Patras in Greece. The group aims to gain greater insight in space manufacturing by experimenting on ultra-violet polymerizing materials and composites in microgravity.
Behaviour of Polymers in Microgravity
|University||University of Patras, Greece|
Prof. Vasileios Kostopoulos
University of Patras, Greece
Deployables are the future of space structures. Consequently, there is a need for extensive research in the field of deployable structures with intended use in solar panels, satellite antennas, spaces trusses and space station habitats in space or settlements. Deployable structures can be separated into two large categories: mechanically-actuated and pneumatically-actuated, each having its own benefits, disadvantages, and risks.
Mechanically-actuated deployable structures use motors for deployment. While having the benefit of high stiffness, the risk of a motor malfunction or failure could be catastrophic for the deployable. On the other hand, pneumatically-actuated structures which expand with the help of a fluid (usually a gas) are easier and at lower risk at deployment. They can also have more complex geometries and can be packed more easily and into lower volume. However, their greatest disadvantage is their low degree in stiffness and damage tolerance. The lower stiffness could be countered with the use of a thicker shell for the inflatable structure. The damage tolerance, however, would require the structure to retain a significant proportion of its initial stiffness, even in the case of internal pressure loss, which could occur due to a micrometeorite or space debris impact, and which could puncture the outer shell.
The team aims to solve this problem by testing the deployment of pre-impregnated polymer fiber fabrics into space and polymerizing them. This will create a lightweight, high-stiffness, thin-shelled structure in space. Such structures could easily tolerate a pressure loss and/or an impact scenario and still retain a significant proportion of their initial stiffness, shape, and strength, solving the most important impediment of inflatable structures.
Conducting two basic experiments, the team aims to realise the first step in this research by testing the behaviour of various polymer resins in a microgravity environment. In the first experiment, uncured carbon fiber-reinforced polymer tubes will be stowed before flight and then deployed and cured during the microgravity duration of the parabolic flights using UV light. In the second experiment, small uncured polymeric samples will also be cured during the microgravity intervals of the parabolic flights. Identical experiments will be performed on Earth with the same equipment at 1g gravity acceleration, so as to compare the mechanical properties and microstructure between these two different gravity accelerations.
The team's experiment report is available here.