A Historic Launch for a Tiny Satellite
Miami-based company City Labs has successfully sent its BOHR satellite into orbit aboard a SpaceX Falcon 9 rocket. The satellite, roughly the size of a softball, is the world's first commercial spacecraft to test a nuclear power source in space. BOHR—short
for Betavoltaic Orbital High-Reliability—is designed as a pathfinder mission. While the satellite's main operations still rely on conventional solar panels, its key purpose is to validate a tiny, dedicated payload: a NanoTritium™ battery. This test marks a significant milestone, demonstrating that compact, privately-developed nuclear power systems are ready for deployment and have cleared a rigorous regulatory pathway with the US Federal Aviation Administration.
How Tritium Power Works
Unlike traditional nuclear reactors that use heat from fission, the BOHR satellite uses a non-thermal process called betavoltaics. The power source uses tritium, a radioactive isotope of hydrogen. As tritium naturally decays, it releases a steady stream of beta particles (essentially high-energy electrons). These particles strike a semiconductor material inside the battery, which converts their energy directly into a small but continuous electrical current. Think of it less like a powerful reactor and more like a battery that never needs to be recharged. With a half-life of 12.3 years, tritium can provide a predictable, low-level power output for more than two decades, making it ideal for long-duration missions.
The Advantage Over Solar
For decades, solar panels have been the default power source for most satellites. However, they have a critical weakness: they need sunlight. This limits missions in several ways. Satellites in Earth's shadow go dark, long lunar nights can last for two weeks, and deep-space probes venturing far from the sun receive too little light to operate effectively. Betavoltaic technology offers a solution. City Labs' NanoTritium™ batteries are unaffected by darkness or extreme temperatures. While they produce very low power—in the range of nanowatts to microwatts—it is constant and reliable for over 20 years. This makes them perfect for powering critical, always-on systems like sensors, backup communication devices, or autonomous electronics where replacing a battery is impossible.
Unlocking the Future of Space Exploration
The success of the BOHR mission opens the door to a new class of spacecraft and exploration possibilities. As NASA's Artemis program aims to establish a long-term presence on the Moon, there is a growing demand for power sources that can survive in permanently shadowed craters where water ice may be located. Tritium batteries could power the rovers and sensors needed for this exploration. Beyond the Moon, these long-life power sources are essential for deep-space probes that need to operate for decades on their journey to the outer planets and beyond. By providing a continuous trickle of energy, they can keep vital systems alive, gathering and transmitting data from the furthest reaches of our solar system. City Labs' technology is pitched as the first commercial answer to these long-standing challenges.
Safety, Regulation, and Next Steps
The idea of nuclear material in space may raise safety concerns, but tritium is considered relatively benign. The beta particles it emits cannot penetrate human skin and are easily contained. City Labs also stores the tritium in a solid metal hydride form, which prevents the risk of gas leakage. The BOHR mission's approval established a clear regulatory framework for future commercial nuclear payloads, a significant achievement in itself. While the current technology provides only microwatts of power, City Labs and NASA are already working on scaling it up to milliwatt levels, which could power more complex microelectronics. This successful orbital test is the crucial first step, proving the technology is not just viable in a lab but also in the harsh environment of space.
