Technology readiness level

|TRL|NASA usage[4]|European Union[5]| |---|---|---| |1|Basic principles observed and reported|Basic principles observed| |2|Technology concept and/or application formulated|Technology concept formulated| |3|Analytical and experimental critical function and/or characteristic proof-of concept|Experimental proof of concept| |4|Component and/or breadboard validation in laboratory environment|Technology validated in lab| |5|Component and/or breadboard validation in relevant environment|Technology validated in relevant environment (industrially relevant environment in the case of key enabling technologies)| |6|System/subsystem model or prototype demonstration in a relevant environment (ground or space)|Technology demonstrated in relevant environment (industrially relevant environment in the case of key enabling technologies)| |7|System prototype demonstration in a space environment|System prototype demonstration in operational environment| |8|Actual system completed and "flight qualified" through test and demonstration (ground or space)|System complete and qualified| |9|Actual system "flight proven" through successful mission operations|Actual system proven in operational environment (competitive manufacturing in the case of key enabling technologies; or in space)|