Regulatory-Compliant Tritium Mini-RHU: A Scalable Alternative for Next Gen. Space Power

City Labs proposes a Tritium Mini-Radioisotope Heater Unit (Mini-RHU) utilizing advanced tritium metal hydride technology to provide scalable, long-duration thermal energy for dynamic power conversion systems. The Tritium Mini-RHU is a compact, cost-effective alternative to traditional Pu-238-based Radioisotope Power Systems (RPS), offering thermal power ranging from milliwatts to hundreds of watts and beyond. Leveraging City Labs' expertise in tritium betavoltaics and metal hydride storage, the Mini-RHU uses titanium tritide as a heat source. Tritium’s advantages include minimal shielding requirements, long half-life, commercial availability, and low regulatory overhead. Following NSPM-20 guidelines, tritium RHUs will provide a streamlined regulatory framework for space launches. City Labs' state-of-the-art facility, capable of safely handling and loading tritium, positions the company to support future missions. The Mini-RHU’s modular design enables scalable power generation and meets NASA’s needs for high-efficiency, autonomous power systems in harsh space environments. Unlike Pu-238, tritium is readily available, significantly reducing both costs and regulatory complexities. City Labs’ facility is capable of managing tritium under high pressures and temperatures. Furthermore, City Labs is actively pursuing FAA payload approval for a 2026 launch of betavoltaic devices containing up to 20 kCi of tritium, reinforcing its commitment to safely integrating tritium-based technologies in space missions. This project’s intended deliverable, the 1,000 Ci Mini-RHU can be bundled to provide scalable power while reducing regulatory barriers, streamline mission planning, and provide a cost-effective, reliable power solution for lunar and deep-space exploration. It directly supports NASA's goals for long-duration lunar operations and high-power energy generation, advancing the integration of tritium-based RHUs into NASA’s RPS program.

City Labs’ Mini-RHU offers a cost-effective, scalable, and NASA-friendly thermal energy solution, providing a promising alternative to traditional Pu-238-based Radioisotope Heater Units (RHUs) for deep-space exploration. By utilizing commercially available tritium, the Mini-RHU significantly reduces procurement costs and simplifies regulatory compliance, making it an ideal choice for NASA’s demanding missions. The Mini-RHU is designed to meet NASA’s requirements, especially for deep-space missions to comets, asteroids, icy moons, and planetary atmospheres where solar power is impractical. It is also well-suited for CubeSats, small spacecraft, and lunar or planetary robotic missions, offering reliable thermal power for battery operation, long-term power generation, and survival in extreme environments, such as during lunar night. Additionally, the Mini-RHU can power Radioisotope Power Systems (RPS) in shadowed or dust-affected areas, supporting NASA’s exploration goals on planetary surfaces. What distinguishes the Mini-RHU is its scalable power due to its modular design and the benign nature of tritium, which eliminates many of the regulatory and logistical complexities associated with Pu-238 RHUs. This simplifies shipping and handling under off-the-shelf Type A packages, dramatically reducing both costs and compliance burdens for NASA missions. Furthermore, City Labs is proactively working with regulatory bodies, including undergoing the NSPM-20 approval process, to ensure seamless integration into NASA's space exploration efforts. The Mini-RHU offers NASA a reliable, cost-efficient, and adaptable power source for the future of space exploration. The Mini-RHU, developed by City Labs, presents a cost-effective, scalable, and regulatory-friendly alternative to traditional Pu-238-based radioisotope heater units (RHUs). Leveraging commercially available tritium, it addresses key challenges in space exploration and national security applications by offering lower costs, reduced regulatory hurdles, and increased accessibility. In non-NASA markets, the Mini-RHU shows significant potential. In defense and intelligence sectors, it can power reconnaissance missions, low-light picosatellites, and sensor systems, offering an affordable, long-duration power source for harsh environments. Commercial applications include powering CubeSats, petroleum monitoring systems, and other extreme-condition research platforms, where temperature-independent energy is crucial. Key benefits include the affordability of tritium, scalability for various power levels, and simplified logistics, as tritium can be shipped with fewer regulatory constraints compared to Pu-238. Additionally, City Labs' partnerships with aerospace and defense giants like Lockheed Martin and Raytheon enhance its credibility and market reach. The Mini-RHU’s potential is demonstrated in projected revenue streams, including $50-$75M in the defense sector over the next decade, and growing sales in both commercial and NASA markets. With strong industry partnerships, ongoing regulatory engagement, and a planned Series B investment round, City Labs is well-positioned to meet the demand for reliable, low-power solutions for both space exploration and defense applications.

This is a mature technology (TRL 7+) — the realistic path in is usually NASA's Technology Transfer Program: licensing an existing NASA patent, or a Space Act Agreement to use NASA facilities/expertise directly. NASA also runs a startup licensing program with no upfront fee for companies formed to commercialize a specific NASA technology.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.