Structural Design of a NPS CubeSat Launcher

To encourage student interest in space and education Stanford University and CalPoly developed the CubeSat. These picosatellites weigh about one kg and can be developed and built by students. NPS is designing CubeSats and a structure to deploy them in orbit as part of its emphasis on hands-on education This technical report deals with the development of a CubeSat Launcher (NPSCuL). NPSCuL will carry up to ten P-PODs built and flight qualified by CalPoly. It will be launched into orbit and deploy multiple CubeSats. Several designs have been developed including finite element models each with a variable number of elements and shell wall thicknesses and tested to loads of 15 g. The simulation results show that the aluminum structures need to have a minimum shell thickness of 15 mm to handle the maximum expected stress. Different bolt patterns for the connection between the structure and the base plate were analyzed. A circular bolt pattern is preferred because the stress is distributed more evenly over the bolts but the shell thickness was modified based on the results from the frequency analysis.