This study explores parking orbit selection for an aerocapture-entry system at Mars and assesses the impact on vehicle design. For dual-heat-pulse trajectories, there is a tradeoff between energy dissipated during aerocapture and energy dissipated during entry. This study explores that tradeoff and the effects on the total entry system mass. The effect of non-virgin thermal protection system during entry, descent, and landing is considered. The analysis finds that the mass from the thermal protection system does not vary significantly depending on orbit selection. The larger driver of entry system mass is the propellant needed to stabilize the parking orbit. This leads to longer period parking orbits having less entry system mass.