London, UK – August 8, 2025
— In a bold proposal that sounds more like science fiction than modern astrophysics, a team of scientists is exploring the use of a revolutionary new technology—laser-propelled nanocraft—to conduct a century-long mission to test the fundamental laws of physics near a black hole. The ambitious project, led by astrophysicist Cosimo Bambi of Fudan University in China, aims to send a fleet of miniature, gram-scale spacecraft to a nearby black hole to directly probe the fabric of spacetime and definitively test Albert Einstein’s theory of general relativity in one of the universe’s most extreme environments.
The concept hinges on a technological leap that, while not yet a reality, is considered plausible within the next 20 to 30 years. The proposed nanocraft are tiny probes, no heavier than a paperclip, each consisting of a microchip with onboard sensors for navigation, data collection, and communication, along with a reflective light sail. The plan calls for a powerful, ground-based laser array to beam photons at the light sails, accelerating the probes to a significant fraction of the speed of light—potentially up to one-third. At this incredible velocity, a nanocraft could reach a black hole located 20 to 25 light-years away in about 70 years, a journey that would be impossible with current rocket technology.
The mission’s core objective is to answer some of the most profound questions in physics. While general relativity has been verified in numerous ways, from the bending of starlight to the detection of gravitational waves, it has never been tested in the immediate vicinity of a black hole’s event horizon. The event horizon is the theoretical boundary beyond which nothing, not even light, can escape the black hole’s gravitational pull. Scientists are keen to know if this boundary is as definitive and singular as Einstein’s theory predicts or if the rules of physics change near this cosmic extreme. One of the key experiments would involve one nanocraft orbiting a black hole while a second nanocraft observes it. The inner craft would send a steady electromagnetic signal back to its partner, and general relativity predicts that this signal would become increasingly “redshifted”—stretched to longer, lower-energy wavelengths—as the craft approaches the event horizon, eventually vanishing entirely. If the black hole is not a true black hole but a hypothetical object like a “fuzzball,” the signal might disappear abruptly rather than gradually.
The proposal comes at a time when technology is rapidly advancing, particularly in the areas of miniaturization and laser power. Projects like Breakthrough Starshot have already laid the conceptual groundwork for laser-propelled nanocraft, with the goal of sending probes to our nearest star system, Alpha Centauri. This new mission concept takes that idea a step further, proposing a longer journey to a far more scientifically compelling target. The mission’s timeline, from launch to the arrival of the first data, would span nearly a century, with the data itself taking another two decades to travel back to Earth. This makes it a multi-generational project, requiring a long-term commitment from the scientific community and funding bodies.
One of the major challenges, as noted by the report, is the astronomical cost. The proposed laser array, capable of generating the power needed to propel the nanocraft, could cost a trillion euros with today’s technology. However, Bambi notes that with the rapid pace of technological development, these costs could fall dramatically over the coming decades, making the project more feasible. The mission also hinges on finding a suitable black hole within the 20 to 25 light-year range, which is a difficult task as black holes are invisible by nature. Bambi remains optimistic, suggesting that a nearby black hole could be discovered within the next decade using advanced astronomical survey techniques.
Ultimately, this ambitious proposal represents a new frontier in the quest to understand the universe. By combining speculative but grounded technology with one of the most intriguing and mysterious objects in the cosmos, scientists hope to move beyond observational tests and perform direct, hands-on experiments in a realm where the laws of physics are pushed to their breaking point. If successful, this groundbreaking mission could not only confirm Einstein’s greatest theory but potentially lead to new discoveries that could completely alter our understanding of gravity, space, and time.
