The Mars 2020 mission is a future rover designed to investigate key questions about the habitability of Mars. The sampling subsystem will use a coring drill to collect samples for potential return to Earth in the future. The design of the hardware and control algorithms for the coring drill is based heavily on development testing. Results from testing of prototype hardware is used to refine the design. We use techniques from design of experiments to develop our test plans, and use multiple regression and other modeling techniques to understand the factors that best explain the coring process. Ultimately, the goal is to create the best quality cores given the mission resources. This approach to experimental design and test data analysis helps us to improve the quality of the samples we collect.