The structure enables us to use moving parts such as deployable in our CubeSat, provides us with rails for deploying our CubeSat from the launch vehicle, as well as it ensures that our CubeSat will endure harsh space conditions and such tests as mechanical shock, vibration, thermal-vacuum cycling, bakeout and potentially others.
The structure mostly consists of the CubeSat’s aluminum frame with rails, which are a part of the CubeSat to deployer mechanical interface. The rails are needed because the CubeSat is firstly put into a deployer and then the deployer is mounted onto a launch vehicle (rocket). When a launch vehicle reaches the orbit, CubeSat is deployed by being pushed out from the deployer with a spring.
Spring separation mechanism:
When a CubeSat is the size of 1U (1 Unit = 10x10x10 cm), it is put inside of a deployer with several other CubeSats. Therefore, our CubeSat will most likely have a spring separation mechanism, to separate it from other CubeSats during deployment.
RBF and kill switches:
The CubeSat has to be cut off from power for the duration of launch. That is why the RBF (Remove Before Flight) pin is used to disconnect CubeSat’s systems from any electrical current sources. During the deployment, the power is turned back on by kill switches on CubeSat’s rails.
Structure consists also of the deployment systems, including solar panels and antennas. Deplorables shall wait to deploy a minimum of 30 minutes after CubeSat’s kill switches are activated. Usually to deploy the solar panels, burn wires are used. When an electric current is passed through the burn wire, it heats up and burns through the tether holding the solar panels in place. This causes the panels to spring open.
Materials used in a cubesat must be chosen very carefully. For example, if a material has a too high melting point, it might not entirely burn in the atmosphere, fall on Earth, and create a potential danger to people.
In addition, materials have to endure in the harsh space conditions. There are some unwanted processes such as outgassing or cold welding, but there are also methods to deal with them. For example, all metals can be anodized in order to oppose cold welding. Typically, Aluminum 7075, 6061, 6082, 5005, and/or 5052 are used for the main CubeSat structure.