Three Startups Reinventing Critical Infrastructure

What It Covers

Three a16z portfolio companies—Ulysses (autonomous ocean robots), Mariana Minerals (technology-enabled critical mineral extraction), and Radiant (portable nuclear microreactors)—address gaps in underwater infrastructure, domestic mineral supply chains, and off-grid energy. Each founder outlines the technical, geopolitical, and regulatory obstacles blocking progress in their respective sectors.

Key Questions Answered

• •Ocean infrastructure defense: Protecting subsea cables and offshore assets requires a layered system: cheap distributed sensor nodes for detection, autonomous underwater vehicles like Ulysses' Mako for intervention, and autonomous surface vehicles like Leviathan for recharging and data relay. Current prime contractor alternatives cost millions per unit with no integrated recovery system, making scalable deployment economically unviable for most operators.
• •US-China undersea parity window: China produces hundreds of autonomous underwater vehicles annually—comparable to US output—unlike aerial drones where China produces tens of millions versus US single-digit millions. This near-parity makes the undersea domain the one area where the US can still establish decisive military advantage, particularly as China deploys an Indo-Pacific underwater sensor network and 18,000-kilometer-range autonomous submarines.
• •Mining's "death spiral" for tech startups: Point-solution technology vendors face a structural trap in mining: operators run pilots willingly but build only one major facility every five years, so unless a startup's pilot precedes that specific build cycle by exactly five years, commercial deployment is delayed another cycle. Vertical integration—owning the entire process from permitting through refining—is the only viable path to controlling deployment timing.
• •Refinery commissioning gap: Western companies take two to four years to commission a minerals refinery to full throughput spec; Chinese operators achieve the same in roughly six months. The gap stems from latency in process feedback loops—large projects aggregate field data on three-week cycles—and from managing high-latency chemical circuits where a single process change takes 24–48 hours to cascade through 20 interconnected unit operations.
• •Government demand-side support as capital unlock: Trillions in infrastructure capital avoids mining due to commodity price uncertainty. Off-take agreements with price floors—modeled on the recent DOD deal with MP Materials that included equity participation—can convert that dry powder into active investment. Reducing the NEPA permitting trigger that activates when federal funds enter state-permitted projects would further lower the cost of accessing government capital.
• •Radiant's microreactor product model: Radiant targets off-grid customers paying above $6.50 per gallon diesel equivalent—markets including Hawaii (80% diesel-powered), Northern Europe ($7–9/gallon average), and remote industrial sites. Each one-megawatt trailer-mounted reactor deploys within 48 hours of arrival, runs five years (equivalent to 2 million gallons of diesel), and is produced at a Tennessee facility targeting one unit per week at scale.