Technology Readiness Levels (TRLs) is a systematic metric/measurement system that supports assessments of the maturity of a particular technology and the consistent comparison of maturity between different types of technology. The TRL approach has been used on-and-off in NASA space technology planning for many years and was recently incorporated in the NASA Management Instruction (NMI 7100) addressing integrated technology planning at NASA. However, to be most useful the general model must include:

(a) ‘basic’ research in new technologies and concepts (targeting identified goals, but not necessary specific systems),

(b) focused technology development addressing specific technologies for one or more potential identified applications,

(c) technology development and demonstration for each specific application before the beginning of full system development of that application,

(d) system development (through first unit fabrication), and

(e) system ‘launch’ and operations.