To do this, heat balances are set up and are calculated numerically. This delivers the time dependent temperature distribution. Extensive investigations resulted in the following design. The skin will consist of a sandwich panel, which has a honeycomb core and surface plates. Both will probably consist of a fiber material.
Sandwich panels combine low weight with high stiffness.
For the solar cells that are mounted on the skin, the stiffness is very important, because the satellite will experience strong vibrations during the launch. On the inner surface the sandwich panel will be coated with gold. As gold has a very low absorptance, most of the radiation inside the satellite will be reflected. Therefore the skin is insulated from the interior of the satellite and local temperature differences on the skin will not affect the temperature of the electronic devices. The heat sources produce the high heating power only in the transmission mode, which lasts for 15 minutes.