Nuclear weapons have been prohibited in space for nearly 60 years, since the signing of the 1967 Outer Space Treaty. This international agreement bans the placement of nuclear weapons or other weapons of mass destruction in orbit. Recently, a feasibility study led by MIT physicist Areg Danagoulian has proposed a new method to ensure compliance with this treaty. The idea involves using a satellite equipped with a sensor that can detect the presence of nuclear materials on other spacecraft. This sensor would use high-energy protons trapped by Earth's magnetic field to identify radioactive elements like uranium inside a nuclear warhead. The method relies on detecting a burst of neutrons that occur when these protons interact with such materials. The consequences of a nuclear explosion in space are particularly severe. Unlike on Earth, where nuclear tests can be detected through seismic activity and radioactive fallout, a nuclear warhead hidden within a satellite could go unnoticed for decades. A detonation in orbit could damage or destroy thousands of satellites used for communication, research, and military purposes, creating a dangerous field of debris. Historical examples include the 1962 U.S. high-altitude nuclear test, Starfish Prime, which damaged or destroyed eight satellites and left radiation in orbit for nearly five years. The Soviet Union also conducted similar tests as part of Project K, which caused disruptions on the ground. For much of the treaty’s history, verifying compliance has been a challenge. While the effects of a nuclear detonation in space are well understood, the lack of a reliable detection system has left a gap in enforcement. Recent concerns have increased, including claims by U.S. officials in 2024 that Russia was developing a nuclear anti-satellite weapon, a claim Russia denied. The Russian satellite Kosmos-2553, launched into a radiation-heavy orbit, raised questions about its purpose and potential capabilities. Implementing a detection system faces both technical and diplomatic hurdles. Keeping satellites close enough to observe another for an extended time could be perceived as a threat or an act of espionage. Moreover, the country whose satellite is being inspected would need to agree to the inspection, raising questions about international norms and cooperation. Experts stress that while the technology is promising, the policy and diplomatic challenges are often more complex and difficult to resolve. The risk of a nuclear attack in space has grown with the increasing number of satellites in orbit. Today, more than 48,000 objects are tracked in space, compared to just 24 satellites in 1962. Many of these satellites are not designed to withstand the radiation from a nuclear blast. A high-altitude nuclear explosion could disable nearly all unhardened satellites, potentially causing up to $500 billion in direct damage and a total economic impact of up to $3 trillion. As reliance on space-based systems continues to grow, the threat of a nuclear attack in space has become an increasingly pressing concern.