Rocket Science: TRL

I thought it might be useful, as an irregular feature here, to drop in a little “rocket science” information for readers who might not be familiar with what goes on within the aerospace industry.

Since a discussion at work on Technology Readiness Levels (TRLs) prompted the idea, let’s start there.

Technology Readiness Level (TRL) is a rubric or scale against which the maturity of a given technology can be assessed. It is a systematic means for comparing various technology options, one which is intended to be objective (but sometimes ends up being fudged a bit, in favor of a preferred option).

TRL is rated on a scale of 1-9:

1. Basic principles observed and reported
2. Technology concept and/or application formulated
3. Analytical and 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

For example: metallic honeycomb thermal protection systems designed for the windward surfaces of X-33/RLV might merit a TRL of 6 (multiple panels were tested together in simulated flight environments). Had X-33 flown, this technology might have reached TRL 8, and with multiple flights, it could have attained TRL 9.

The TRL system involves some subjectivity, in terms of where to draw the box around what is a system vs. a subsystem, or what is actually a “relevant environment”, but generally permits realistic assessment of whether a technology being considered requires further development, and some indication of how much development might be involved.

More detailed information on TRLs can be found here.