A Practical, Affordable Cryogenic Propellant Depot Based on ULA's Flight Experience

TLDR

Human exploration aims to return to the Moon and reach Mars, requiring robust lunar infrastructure and overcoming Ares I/V performance limits, so orbital refueling from propellant depots offers a cost‑effective, reliable solution. The paper proposes a propellant depot option that supports orbital refueling for exploration, national security, science, and other space missions. The depot is launched by a single EELV medium‑class rocket, uses flight‑proven cryogenic storage with emerging technologies, and includes propellant management, flight experience, and refueling options that integrate with exploration architecture.

Abstract

Mankind is embarking on the next step in the journey of human exploration. We are returning to the moon and eventually moving to Mars and beyond. The current Exploration architecture seeks a balance between the need for a robust infrastructure on the lunar surface, and the performance limitations of Ares I and V. The ability to refuel or top-off propellant tanks from orbital propellant depots offers NASA the opportunity to cost effectively and reliably satisfy these opposing requirements. The ability to cache large orbital quantities of propellant is also an enabling capability for missions to Mars and beyond. This paper describes an option for a propellant depot that enables orbital refueling supporting Exploration, national security, science and other space endeavors. This proposed concept is launched using a single EELV medium class rocket and thus does not require any orbital assembly. The propellant depot provides cryogenic propellant storage that utilizes flight proven technologies augmented with technologies currently under development. The propellant depot system, propellant management, flight experience, and key technologies are also discussed. Options for refueling the propellant depot along with an overview of Exploration architecture impacts are also presented.