Engineering Simulation for Durable Spacecraft Components Design: A Case Study of Astrobotic Technology, Inc.

Astrobotic Technology, Inc. is a pioneering company in the lunar frontier, providing commercial payload delivery and robotic services through missions of increasing scope and capability. Their initial mission, Tranquility Trek™, aims to launch a robot to the Moon on a SpaceX Falcon 9 launch vehicle, win the Google Lunar X PRIZE, and return high-definition 3-D video and imagery. The company is committed to designing and refining lightweight aluminum and composite spacecraft to withstand the static acceleration and dynamic random vibration loads of launch while maintaining an acceptable level of safety.

Astrobotic Technology, Inc. faced a significant challenge in designing the structural components of the Tranquility Trek spacecraft. The components comprised of aluminum and lightweight composites, where carbon fiber was bonded to aluminum honeycomb to form a high-strength yet lightweight sandwich material. The layered construction and anisotropic properties of the sandwich required specialized pre-processing tools to accurately represent the fiber direction of every layer of carbon. Additionally, specialized post-processing tools were needed to predict sandwich failure. The company also had to consider random loads during launch. Astrobotic needed to test multiple spacecraft configurations under launch conditions to select and refine the best design in a cost-effective manner.

Astrobotic Technology, Inc. utilized ANSYS® Mechanical™, ANSYS DesignModeler™, and ANSYS Workbench™ to address their design challenges. Engineers imported CAD geometry into the ANSYS environment using a direct interface. The ANSYS DesignModeler tool pre-processed the model to prepare it for simulation. ANSYS Meshing provided automated discretization of the geometry while allowing user-defined refinement in regions of interest. To define the layered elements for laminate and sandwich layups, engineers used ANSYS Parametric Design Language (APDL) for ANSYS Mechanical software within the ANSYS Workbench environment. The team employed ANSYS Mechanical software within Workbench to define multiple analysis types (free vibration, static acceleration and random vibration) that all share the same geometry, material properties and connections. Using ANSYS Mechanical APDL capabilities within ANSYS Workbench, engineers compared the results against failure criteria to consider the layered construction of the materials and to identify regions of potential failure.

• The use of ANSYS tools provided Astrobotic with a streamlined and efficient design process. The ANSYS Workbench environment facilitated automated communications between the CAD software, pre-processor, solver, and post-processor, enabling quick and easy updates to solutions after changing design parameters. This automation significantly reduced the time and effort required to test different configurations of material layup definition. Furthermore, engineers could tweak and reshape components without the need to redefine mesh controls or loading. Although physical testing will still be conducted to validate spacecraft design, the use of simulation helped to reduce the number of costly prototypes and physical tests required.

• Astrobotic was able to quickly design and refine a lightweight aluminum and composite spacecraft.
• The ANSYS Workbench environment provided automated communications between the CAD software, pre-processor, solver and post-processor that allowed solutions to be updated quickly and easily after changing design parameters.
• Astrobotic gained the ability to test different configurations of material layup definition with minimal effort.