Today, vacuum tests for the spheres and the micro pumps were carried out to test the volume changing capabilities of SAM’s spheres. In the finished structure the volume change between two neighbouring spheres will result in a shape change of the entire structure. For today’s test two inflatable spheres were connected by a micro pump (Bartels Mikrotechnik GmbH) and tested first at ambient pressure and then in the vacuum chamber. It can be confirmed that the pumps worked in vacuum conditions, but the volume change was too slow (especially by considering the short micro gravity time of the sounding rocket experiment of roughly 140s). Further research will be focused on increasing the flow rate or maybe changing to more powerful pumps. Thanks to the Strathclyde students Thomas Perry and Paul Hammond for getting the micro pumps ready for today’s test.
Wednesday, 16 May 2012
Newsnight Scotland on BBC Iplayer (at around 14minutes):
Thursday, 10 May 2012
For the last couple of weeks, simulations on the deployment behaviour of the inflating spheres from the StrathSat-R REXUS cube satellites were carried out. LS-DYNA with an academic license of the University of Strathclyde was used for the deployment simulation. Two rows of 18 spheres were modelled with a constrained rigid cube satellite in the centre. To simulate the deployment from the cube, the flat spheres (two sheets of polymer joined together around their circumference) where pressed into the cube satellite first. After the spheres were stored, the residual air inflation deploys the entire structure. This “chaotic” storage followed by the residual air inflation can be seen in the attached clip. Current research is now focused on modelling different folding pattern in LS-DYNA and starting a code to program the shape change of the membrane.
Today, reporters from the BBC were at the University of Strathclyde to do a piece on Space Based Solar Power. The researchers's at Strathclyde are involved in the current NIAC (NASA Institute for Advanced Concepts) study on Space Power Satellites (SPS) called SPS-ALPHA with John C. Mankins from Artemis Innovation as a project lead. Space Based Solar Power is the promising concept of collecting the sun’s energy in space and then transmitting it via laser or microwaves to the ground. With this concept the energy can be harvested more efficiently without losing too much of the sun’s energy through the Earth’s atmosphere. These Space Power Satellites (SPS) are huge structures with diameters in the order of hundreds of meters. Large deployable structures become necessary to realise such an ambitious project. The smart structure of the Self-inflating Adaptive Membrane can be used as a reflector or concentrator to focus the Sun’s energy on the solar cells before transmitting it via microwaves or lasers to the ground. Further applications can be seen as all kinds of substructures for the SPS concept due to SAM’s adaptability. The piece will be aired probably on Monday (14th of May 2012) evening on BBC.