Terminal Velocity Aerospace, LLC (TVA) proposes to improve utilization of the International Space Station (ISS) by providing a system for on-demand return of experiment samples to Earth. TVA is presently developing a small reentry device (RED) capable of returning small payloads from space, with initial prototype development funded by a separate contract. The device, named RED-4U, is sized to accommodate a payload mass and volume equivalent to four CubeSats, commonly referred to as units or "U." The payload accommodations and concept of operations for RED-4U are currently generically defined, but are readily suitable to the ISS small payload return mission. In the proposed Phase I R&D effort, TVA proposes to (1) design, fabricate, and demonstrate RED-4U payload accommodations specifically for high-frequency sample return from ISS; and (2) detail the concept of operations for RED-4U use on ISS.