How to Raise the TRL of Your Space Technology

A practical guide to knowing where you stand and what evidence gets you to the next level

Most teams building space hardware describe their maturity as a number. TRL 4. TRL 6. It appears on slides, in proposals, in investor decks.

The number is rarely theirs to assign.

A Technology Readiness Level is a rating an independent team gives you after reviewing your evidence. The federal reference on how that works is the U.S. Government Accountability Office's Technology Readiness Assessment Guide (GAO-20-48G, 2020), and reading it changes how you plan a test campaign. It tells you exactly what an assessor will ask for at each level.

This guide condenses that into three things: how to find out where you actually stand, what evidence moves you up, and what to document while you still can.

Figure 1. The nine Technology Readiness Levels, from basic principles observed (TRL 1) through a system proven in mission operations (TRL 9). Suggested image: NASA TRL "thermometer" diagram, available from NASA public affairs imagery.

1. What a TRL actually measures

GAO defines a five-step assessment process: prepare the plan and select the team, identify the critical technologies, assess them, prepare the report, and use the findings.

Three features of that process matter to you as a developer.

The assessors are independent. GAO specifies that assessment team members are independent and objective. They are evaluating artifacts, not narrative. GAO is explicit about why: optimism is pervasive in acquisition programs, and both program managers and contractors have incentives to overstate maturity, particularly before contract award.

The rating is assigned per technology, not per system. Assessments target critical technologies, the specific elements that are new or novel and that drive cost, schedule, or performance risk. A system is not "at TRL 6." Each critical technology within it has a level, and the immature one governs your risk.

Every level has a named evidence requirement. GAO's guide includes a table of the supporting information a hardware assessor expects at each TRL. This is the most useful page in the document, because it converts a vague target into a document checklist.

2. Know where you are standing

Before planning anything, establish your honest current level. Work down this list and stop at the first question you cannot answer with a document.

Adapted from GAO-20-48G, Table 4.

If you have to guess your level, you are below it.

3. TRL 4 to 6 is the bridge, and it is where programs stall

The Department of Energy's TRL definitions, reproduced in GAO's Appendix IV, describe levels 4 through 6 as the bridge from scientific research to engineering. It is a useful framing. Below TRL 4 you are proving physics. Above TRL 6 you are qualifying a design. In between, you are proving that real hardware survives a real environment.

For space systems, this bridge carries additional weight, because of a caveat GAO states plainly: technologies should normally be demonstrated in an operational environment before integration, typically at TRL 7, but in special cases such as the space environment it would be impractical to test in the operational environment, so TRL 6 can be acceptable.

The consequence is easy to underestimate. For most space hardware, the ground-based demonstration is not a rehearsal for the real test. It substantially is the test of record. Everything riding on TRL 6 is riding on how faithfully your test environment represents space.

4. For surface systems, the test medium is part of the environment

If your technology touches a planetary surface, regolith is not a backdrop. It is the active agent: the material being excavated, drilled, sorted, sintered, chemically reduced, driven over, sealed against, or worn down by.

Which means the material in your test bed is a component of your relevant environment, and an assessor can challenge it.

Work backwards from your failure mode to the property that drives it:

5. The documentation package

Assemble these alongside your performance data. Items 6 and 7 are the ones teams skip and the ones GAO's evidence table names directly.

1. Critical technology definition. What the element is, why it is critical, and at what level it is testable.

2. Derived relevant environment. Which conditions are risk drivers for this technology, and why, tied to failure modes.

3. Test article description. Configuration, fidelity relative to flight, and how performance, weight, and volume compare to targets.

4. Test environment description. Facility, conditions achieved, and instrumentation, in enough detail that a reader can judge representativeness.

5. Test medium identity and traceability. For surface systems: material name, producer, lot or batch, and the measured properties of the material you received, not the datasheet values. Include as-tested conditions such as compaction method, bulk density, moisture and drying history, and particle size distribution as loaded, since handling changes it.

6. Gap analysis. An explicit, property-by-property statement of how the test environment differed from the operational environment.

7. Interpretation. What the results imply for performance in the real environment given those gaps, and in which direction the error is likely to run.

8. Sufficiency evidence. Number of repetitions and the statistical basis for the claim. GAO distinguishes adequate performance from sufficiency, which requires enough consistent repetitions to be meaningful.

9. Problem log. Anomalies encountered, their causes, and the resulting changes to the test plan.

6. How to start

A practical sequence for the next quarter:

1. List your critical technologies. Use your work breakdown structure. Flag what is new or novel and what drives cost, schedule, or performance risk.

2. Rate each one honestly against the table in Section 2. Record the document that justifies each rating. Gaps in that column are your real backlog.

3. Write the derived relevant environment for your lowest-rated critical technology. One paragraph per risk driver, each tied to a failure mode. This is a one-day exercise that reshapes the test plan.

4. Identify your test-medium requirements from that document. For surface systems, that means naming the specific regolith properties your test material must reproduce, and accepting that more than one material may be required.

5. Characterize what you actually receive, by cited standard methods, before it goes into the test bed.

6. Run the campaign, then write the gap analysis and interpretation while the test is fresh. Reconstructing it a year later for a proposal deadline is how teams lose evidence they already paid for.

Step 4 is where most surface-system programs discover they have been planning around whatever material was already in the lab.

If you are at that step, we can help. We produce characterized planetary regolith simulants across mare, highlands, and specialty formulations, with the property data your assessment package will need. Tell us the failure mode you are testing against and we will help you work out which materials your relevant environment actually calls for.

References

• U.S. Government Accountability Office, Technology Readiness Assessment Guide: Best Practices for Evaluating the Readiness of Technology for Use in Acquisition Programs and Projects, GAO-20-48G, January 2020.

• Slabic, A., Gruener, J. E., Kovtun, R. N., Rickman, D. L., Sibille, L., Oravec, H. A., Edmunson, J., and Keprta, S., Lunar Regolith Simulant User's Guide, Revision A, NASA/TM-20240011783, October 2024.

• Schrader, C. M., and Rickman, D. L., Overview of Figure of Merit Analyses of Simulants and the Fit-to-Use Matrix, NASA Technical Reports Server.

• Heiken, G., Vaniman, D., and French, B. M. (eds.), Lunar Sourcebook: A User's Guide to the Moon, Cambridge University Press, 1991.