When does deeptech become venture-backable?

It started with a conversation about space dirt.

Specifically, molten regolith electrolysis - a nifty process that extracts oxygen from lunar soil. I’ve become really interested in in-situ resource mobilization (or ISRM for short) - and had been messaging with a research in this space.

ISRM is building stuff out of the stuff we find on the planets we send rockets to - and unlocks inter-planetary travel (you’ll need fuel for the return leg, oxygen for the astronaut once she gets there, etc.).

In the chat, the researcher asked me at what TRL deeptech needs to be to be considered ‘venture backable’.

If you’re a scientist tinkering at the edge of physics, chemistry, or the final frontier, it can be hard to tell when your invention stops being an academic novelty and starts looking like a venture deck.

The answer often lies in a slightly nerdy but surprisingly useful metric: Technology Readiness Levels (TRLs). Born out of NASA, the TRL framework charts the maturity of a technology from TRL 1 (basic research) to TRL 9 (fully operational in the real world). And for venture capitalists - especially those in deeptech - these levels function like a map, helping them decide when to write a check.

I’ve tried to pull together my notes on this to map TRL levels to investment stages. Here's the rough lay of the land.

At TRL 1–3, you're in the land of curiosity-driven research and grant funding. The tech might be novel, but it's still unproven and risky - catnip for government labs, not VCs. By TRL 4, you’ve validated the core technology in a lab setting. TRL 5 is a prototype working in a relevant environment. TRL 6? Now you’re talking - early deployment, systems integration, and real traction. That’s when VCs start to pay attention.

TRL 4–6 seems like the sweet spot for venture. At this stage, the science has crossed the valley of death - somewhat, at least partially - investors can begin to see a path to commercialization. The tech works, the market’s big, and the founding team is convincing. That’s when term sheets (can) start flying.

Some investors are explicit about this. Prime Movers Lab, for instance, has a whole essay dedicated to TRLs and why TRL 4–6 is where the magic happens. Cottonwood Technology Fund targets TRL 4 and above, especially for industrial spinouts that need patient capital and a hands-on partner. Oxford Science Enterprises, the venture arm aligned with the University of Oxford, regularly backs companies emerging from TRL 3–5 zones and shepherds them toward market readiness. Edale Group, a UK-based investment advisory firm, maps TRLs to corresponding funding sources - I used that as a source to develop the graphic above.

Of course, different sectors tweak the TRL lens. AI-native biotech or materials simulation companies might attract funding earlier, because their defensibility comes from data and algorithms more than physical hardware. On the flip side, moonshot fields like direct air capture or space manufacturing often need to stretch into TRL 5 or 6 before venture gets comfortable - ideally with some juicy non-dilutive capital (shoutout to Innovate UK, EIC Accelerator, and the like) de-risking the journey.

The takeaway?

If you're a scientist with a world-changing idea, it's not just about whether your technology could work - it's about proving it does, in the right environment, with enough fidelity to convince outsiders it’s more than a lab curiosity. That transition - lab bench to prototype - is where venture starts listening.

And for the deeptech-curious among us, get in touch - I’m particularly interested in the UK and the EU’s competitive positioning with respect to novel deeptech, and will help founders and scientists however I can.

I love deeptech. To the moon and back.