|Abstract:||Using aerocapture to insert into an elliptic parking orbit prior to entry, descent, and landing is being explored for human Mars missions. These aerocapture-entry trajectories have advantages over a direct entry, but the advantages come at the cost of additional entry system mass. The goal of this research is to identify the parking orbit which minimizes entry system mass and to compare that to the entry system mass for a direct entry. The impact of a higher efficiency propulsion system, a higher entry velocity, and a reusable thermal protection system on aerocapture-entry system mass requirements is explored. Results indicate that the thermal protection system thickness does not vary significantly with parking orbit selection while shorter period orbits require more propellant for maneuvers. This result is not sensitive to changes in propulsion system efficiency, entry velocity, or heat shield material. Additionally, results show that aerocapture-entry architectures incur a TPS mass penalty up to 27% relative to direct entry, depending on vehicle. In addition, direct entry avoids needing propellant for in-space maneuvers between aerocapture and entry which ranges from 1.5% to 4.5% depending on orbit.