The Modular Propellant Transfer System: An Element w/Line & On-Orbit Replaceable Features for the L3Harris SpaceCrane Family of LARS Transfer Vehicles

The AR SpaceCrane Transfer Vehicle (LARS-TV) four classes are a family of single stage, re-useable, mission flexible, Lunar Ascend and Return to Surface Transfer Vehicles or LARS-TVs, known as the SpaceCrane-VL, -LL, -ML & -HL Lander/Hopper vehicles. This family of vehicle classes are being designed specifically “from the ground up” as an agile, mission flexible architecture with both “on-orbit serviceable” and “on-surface serviceable” modular sub-system elements to facilitate lunar surface extreme engineering projects and to adequately support a robustly developing long term lunar infrastructure that enables both government sponsored, and/or cooperatively internationally led, and/or commercial lunar industrialization. All class of vehicles are designed to function as an integral part of a lunar transportation architecture. Each class of SpaceCrane vehicle is designed to ascend to Low Lunar Orbit (LLO) or to the Lunar Gateway and return to the lunar surface, accomplish extended lunar surface flight operations (hops), have Gateway or on-orbital and lunar surface refueling capability, and be easily serviced through their design and their use of component line replaceable units (LRU) and on-orbit replaceable units (ORU). This paper will provide a detailed description of the Modular Propellant Transfer System (MPTS) found on the family of SpaceCrane vehicles. An in-depth physical description of the MPTS as a common architectural element incorporated into all four classes of the SpaceCrane vehicle will be offered. The various sub-systems, major assemblies, major components and features that comprise each MPTS and the commonality of these elements across each of the SpaceCrane family will be discussed. The various sub-systems, major components and features will be related to the LRU & ORU functionality that they enable. This paper will also include a complete evaluation of, and mass allocation for, each of the components & sub-systems that are comprised within the MPTS. This evaluation will include all critical trades, assumptions and associated rationale. Furthermore, this paper will include continued discussion of how the MPTS element helps enable a new orbital and surface operations capability concept. Finally, a description of how the MPTS element and overall vehicle architectures would be adapted for use in a Mars lander and surface vehicle architecture, will be included. This paper is the fourth in a continuing series of AIAA papers describing aspects of the GEN-3 LARS-TV, SpaceCrane family of vehicles.