Design and Additive Manufacturing of a Mechanical Chassis for Small Satellite Launch Vehicle Inertial Navigation Package

Abstract

The demand for a small satellite launch vehicle for ISRO has been ever increasing due to growing launch requirements from the rising number of industrial and academic players who are venturing into design and fabrication of smaller satellites for their specific applications. Therefore, a new lightweight navigation system needs to be designed for catering to the requirements of a low weight small satellite launch vehicle. The major mechanical component of a navigation package is the cluster (chassis) which is used for mounting gyroscopes and accelerometers required for providing information about the position and attitude of the launch vehicle. The cluster adds a good percentage to the total mass of the package. As a first step towards proving the technical feasibility of AM route, the CNC machinable cluster was 3D printed along with test coupons, and their structural and thermal characteristics were studied. Then, improvements were made on the cluster to increase one of the normal mode frequencies using design for additive manufacturing philosophy. This modification also helped to reduce the mass, which was made possible with the flexibilities offered by additive manufacturing in terms of manufacturing constraints. The modal analysis carried out on the modified cluster proved the improvement in performance of the cluster. The modified cluster was successfully 3D printed, followed by testing to meet all geometric and performance requirements.