Technology Readiness Level (TRL)

The ESA Science Technology Development Route

Instruments and spacecraft sub-systems are classified according to a "Technology Readiness Level" (TRL) on a scale of 1 to 9. Levels 1 to 4 relate to creative, innovative technologies before or during mission assessment phase. Levels 5 to 9 relate to existing technologies and to missions in definition phase.

ESA Technology Readiness Level Summary
TRL	Level Description
1	Basic principles observed and reported
2	Technology concept and/or application formulated
3	Analytical & experimental critical function and/or characteristic proof-of-concept
4	Component and/or breadboard validation in laboratory environment
5	Component and/or breadboard validation in relevant environment
6	System/subsystem model or prototype demonstration in a relevant environment (ground or space)
7	System prototype demonstration in a space environment
8	Actual system completed and "flight qualified" through test and demonstration (ground or space)
9	Actual system "flight proven" through successful mission operations

If the TRL is too low, then a mission risks being jeopardized by delays or cost over-runs. It is a responsibility of the Future Missions Preparation Office to promote the technology readiness at a very early stage in order to make new missions feasible.

Last Update: 08 March 2012