In search of technology readiness level (TRL) 10

The NASA nine-level technology readiness level (TRL) system's top level is reached by a system being proven through use in a space mission. NASA, though, is not just an organization that seeks to develop unproven technologies. Future space activities require technologies more akin to an airliner than an Apollo Capsule. This paper considers the need for a higher TRL category indicating a proven technology demonstrated through extended operations, and it discusses its definition and sufficiency.