City Labs CEO Explores the Potential of Nuclear Micro-Power in Lunar Exploration

In our latest episode of Lexicon, we spoke with Peter Cabauy, CEO and founder of City Labs, about why power, rather than propulsion systems, may become the key technology for the next era of space exploration. Cabauy explained the extreme conditions on the Moon, particularly its 14-day-long nights and extremely cold temperatures, which pose significant challenges for long-term lunar missions, and why nuclear micro-power could be crucial for sustaining rovers, equipment, and future lunar bases.

Cabauy said, "The Moon is a very inhospitable environment. Your rover can only operate for 14 days because that's the length of the lunar day." Following that is the lunar night, another 14 days of darkness, with temperatures dropping below the level of liquid nitrogen. "We've all seen what happens when you put a flower in liquid nitrogen and hit it with a hammer; imagine how difficult it is to keep a rover alive in such an environment." He noted that this is where nuclear micro-power comes into play. Unlike traditional nuclear reactors, City Labs has developed a micro-power source that generates electricity and heat through the natural decay of tritium.

"The simplest analogy is a solar cell, but instead of receiving light, we are receiving beta radiation." Those electrons produce a small but continuous current. While the output is measured in nanowatts or microwatts rather than kilowatts, these systems do not require recharging and can operate for decades. "The real power lies in its continuity and ability to operate in extreme temperatures."

He emphasized that these devices are not meant to replace lithium batteries. "If you can use a lithium battery to get the job done, please do so. This is for situations where replacement is not an option." Instead, they are designed for environments where battery replacement is impossible, too costly, or life-threatening. For example, a pacemaker is one such case. "Do you really want to undergo additional surgery?"

Potential Applications of Nuclear Micro-Power

Cabauy believes that reliable long-term power will be one of the key technologies for humanity's permanent presence on the Moon. "Nuclear micro-power will facilitate the development of a lunar economy." He envisions a future where there is no reliance on copper cables stretching for miles or solar panels that fail during the lunar night, but rather thousands or millions of automated sensors distributed across the lunar surface. "You could deploy thousands of these devices into permanently shadowed craters." These sensors could provide navigation, communication, environmental monitoring, and scientific data, operating continuously in places where sunlight never reaches.

"Imagine millions of these tritium-driven little devices on the lunar surface; that’s the direction of the future." He also believes these devices could support future Mars missions, heliocentric spacecraft, and a new generation of microsatellites. "We are excited about a future that we cannot even imagine today."

One of Cabauy's childhood heroes was George Washington Carver, the scientist known for discovering hundreds of uses for peanuts. "George Washington Carver tried to find a thousand uses for peanuts," he said. "At City Labs, we are trying to find a thousand uses for tritium." This mindset shapes everything the company is currently pursuing. He explained that tritium is an ideal radioactive isotope because it is relatively harmless, has an existing regulatory framework, and a reliable supply chain. "We didn't choose tritium by accident."

Today, City Labs uses it to create beta voltaic batteries, heat sources, and future propulsion concepts.

Despite spending twenty years developing this technology, Cabauy believes the engineering challenges are only part of the story. "The engineering process is very difficult, but I think the regulatory challenges are equally daunting." The company's innovations focus not only on making the devices operational but also on making them safe enough to comply with existing regulatory frameworks. "We find ourselves engineering toward regulatory and commercial expansion." This work ultimately led to what he describes as a significant milestone. "We are crossing the threshold of nuclear space, becoming the first company able to commercialize the launch of nuclear devices."

Perhaps the most compelling part of the conversation was not about nuclear technology. Cabauy shared candid insights about the darkest times in the company's history. "It was a terrible year." He recalled the time in 2017 when City Labs was on the verge of shutting down. "I told my wife, 'I give up. I can't do this anymore.'" The following morning, he had a different realization. "I said, 'Okay... I can't give up. I just don't know how to proceed.'" The company even lacked the funds to close its facilities, leaving them with little choice but to keep going.

He noted that what changed was his mindset. "When opportunities arise, I just say yes." He stopped analyzing every decision like a physicist and returned to the curiosity of his childhood. "I decided to go back to that childhood inventor." Unexpectedly, people began to offer help. "I started to realize that help is not just about paying people to work." He said, "It's also about the vision of where we are going." This shift proved transformative. "People would proactively offer help." He said, "All I had to do was say yes." Soon after, contracts began to arrive from Lockheed Martin's space division and medical device manufacturers, setting City Labs on its current path of development.

Future Technological Developments

While lunar exploration dominated much of the discussion, Cabauy believes that nuclear micro-power will also find applications closer to home. He highlighted areas such as oil and gas drilling monitoring, industrial sensors, and next-generation medical implants. He is particularly excited about wireless pacemakers. "If you want to shrink it down to the size of a grain of rice, nuclear power might be the best option." He also pointed to research exploring micro tritium-powered light sources aimed at helping prevent diabetic retinopathy, potentially slowing vision loss for patients.

Looking ahead, Cabauy remains focused on the milestones City Labs is set to achieve, including the launch of its Bohr satellite demonstration mission. "We are ushering in this nuclear space age," he stated, but his ambitions extend beyond City Labs itself. "I want City Labs to lead the way in nuclear micro-power." He said, "But it's not just us. There are many others using this type of technology to find applications and use cases that our imagination today cannot foresee."

The Importance of Nuclear Micro-Power in Space Exploration

The development of nuclear micro-power technology is crucial for the exploration of the Moon and other extreme environments. As the demand for space exploration increases, traditional energy supply methods can no longer meet the requirements of long-term missions. Nuclear micro-power provides a durable and stable energy source that can operate in extreme temperatures, making it indispensable for future lunar bases and other planetary missions. Furthermore, the applications of this technology extend beyond space, reaching into medical and industrial fields, demonstrating its broad potential and significance.