A groundbreaking study proposed a miniature spacecraft driven by a laser could travel to a nearby blackhole to test Einstein's theory of general relativity in one of the universe’s most extreme environments.
The technology has not been achieved yet, but can be developed in “20 or 30 years.”
The study also suggests that the weight of the paper clip will not be more than that of a paperclip.
Published in the journal iScience on August 7, 2025, the proposal suggests that the gram-scale nanocrafts, equipped with sensors and light sails, could be launched at speeds approaching one-third the speed of light using powerful ground-based lasers to reach a black hole.
Following a velocity of this intensity, a probe can reach a black hole 20 to 25 light-years away in approximately 60 to 75 years, with data taking another two decades to return to Earth.
The aim of the mission is to confirm the existence of an event horizon. The horizon is an invisible boundary that is predicted by general relativity beyond which nothing, not even light, can escape.
Einstein’s theory of general relativity suggests that existing black holes are regions of spacetime having the strongest gravity which makes everything unescapable. Objects like black holes are solutions to Einstein’s field equations that state gravity is a curvature of spacetime caused by mass and energy.
Another key concept that derived from Einstein's ideology is the Schwarzschild radius which describes the boundary of a black hole beyond which escape is impossible.
With this revolutionary breakthrough, it will be proved that if a black hole behaves as Einstein’s equation, a falling probe should gradually redshift and fade.
While, contrary to that, if a blackhole is a theoretical “fuzzball” (an alternative model without an event horizon), the signal could vanish abruptly, potentially revealing new physics.
The author and a cosmologist at Fudan University in China, Cosimo Bambi, stated: “We would obtain very valuable information about black holes and general relativity that might be difficult to get otherwise.”
Critics argue that building a spacecraft that can travel to a black hole appears like science fiction. But Bambi highlights that earlier discoveries like the detection of gravitational waves and first images of black holes prove that seemingly impossible discoveries can become reality.