Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

Appendix F: Tether Boost Facility Design Final Report4 Technology Readiness Assessment4.1 AssessmentTechnology readiness of each MMOSTT subsystem was assessed using NASA's TRLscale, as shown in Table 1. TRL scores were developed for today's technology and fortwo future dates: 2005, the earliest feasible year in which MMOSTT could move to fullscaleengineering development, and 2010, a more likely date for beginning full-scaledevelopment following a more reasonably paced technology development program.Tables 2 through 5 show the scores for the subsystems of each MMOSTT element(control station, tether, grapple assembly, and payload accommodation assembly).Where TRL is predicted to increase over the 2001-2010 interval, the table includes areference to the planned or ongoing activity that will raise the technology level. Table 6shows TRL scores for some challenges that arise from integrating the elements into asingle system.Technology Readiness Levels (TRL)9 Actual system "flight proven" through successful mission operations.8 Actual System completed and "flight qualified" through test and demonstration.7 System prototype demonstration in an operational environment.6 System/subsystem model or prototype demonstration in a relevant environment.5 Component and/or breadboard validation in a relevant environment.4 Component and/or breadboard validation in a laboratory environment.3 Analytical and experimental critical function and/or characteristic proof-of-concept.2 Technology concept and/or application formulated.1 Basic principles observed and reported.Table 4.1. Definitions of NASA Technology Readiness LevelsMany subsystems or components of MMOSTT are easily within today's technology.Communications, computing hardware, most structures, and many of the sensors willrequire little or no improvement. TRLs for these subsystems range from 6 to 8. TRL 6means the technology is ready to be implemented in a component for the objectivesystem. TRL 8 means a working product exists that could be plugged directly into theobjective system with no development effort.Some subsystems of MMOSTT will face requirements that are similar in quality butmuch greater in quantity than today's systems. Examples are electric powermanagement, power conversion, and passive thermal control. Each of these musthandle many hundreds of kilowatts of power - an order of magnitude increase abovecurrent technology. TRLs for these subsystems are typically 4 or 5. The powerconversion system for the electrodynamic tether faces the additional challenge ofworking with unusually high voltage as well as high power.F-12