TRL9 (also known as TRL6)
Technology readiness is a slippery metric. How ready is anything to perform? Well, it depends. And because the definition of ‘ready’ is as subjective as it gets, we are always ready (pun intended?) to game it as we see fit.
Traditional space has used Technology Readiness Levels (TRL) as a way of discretizing maturity levels of different parts and components of a space system in a more or less standardized way. There is extensive documentation and even standards to describe what each level entails. But as it usually happens with classifications:
a. Most of the value lies in the gray areas
b. Most classifications are open for human interpretation
The European Space Agency classifies technology readiness using the next levels:
As it happens, employing a framework that originated in another context to a newer/different context is a common—and questionable—practice. TRL levels come from ‘traditional space’ (another arbitrary classification) where technical readiness evolves strictly on the ground and where launch marks the entry of the system into the real environment; i.e., the transition between engineering and operations. By that time, the engineering heavy work is practically completed and you basically check that what your thorough design and verification lifecycle stages showed while on the ground—while connected to a variety of synthetic simulation environments—still holds when you pass the Kármán line.
NewSpace challenged that mindset. In NewSpace, launch is not anymore THE gate of technological readiness, and spacecraft can still be developed and tested while in orbit, by frequent software patches. Strange? Not really. Time to market being a strong driver, and with satellites concept-of-operations (CONOPS) getting closer to a sysadmin task more than classic space operations, companies aim for launching as soon as they can, accepting they will flesh out their software and other matters—calibrations, etc—later. “Let’s launch first and we’ll see” kind of a paradigm. Rockets being the exception: you can’t afford such approach.
Seeing the graph above, many NewSpace companies are objectively at TRL6 (“full-scale instance of the design in its relevant environment”) when they launch. And most likely TRL2 (at the most) in aspects such as Management, Product and Quality Assurance, Materials and Processes, EEE components, Dependability and Safety.
Still, upon getting into orbit, a miraculous jump of three TRL levels typically happens: because the thing is now in orbit, it automagically becomes TRL9. A remarkable, quasi-instantaneous leap from caterpillar to butterfly.
But true TRL9, that is, being *flight proven*, means making sure your design is performing consistently across thermal and power cycles. TRL9 means that the software is mature for nominal operations (bug are found and solved, the main functionality is developed). TRL9 means that enough data has been collected to assess that the spacecraft behaves according to the technical performance measures expected. TRL9 means that the system has executed through all of its internal states, including safe and/or emergency modes, and managed to get out of it in one piece. TRL9, in conclusion, is a hard-to-win medal: getting into orbit only marks the start of the marathon.