A visionary concept proposes sending a spacecraft no bigger than a paperclip toward a nearby black hole at a fraction of light speed.
Powered by Earth-based lasers and built with ultra-light nanotechnology, the craft could make the journey in under a century, sending back data that might confirm — or challenge — Einstein’s theory of general relativity.
Paperclip-Sized Spacecraft Racing to a Black Hole
It may sound like something out of a sci-fi movie: a spacecraft no heavier than a paperclip, pushed forward by a laser beam and racing through space at light speed toward a black hole. Its goal would be to explore the very nature of space and time while putting the laws of physics to the test. Yet for astrophysicist and black hole specialist Cosimo Bambi, this vision is far from impossible.
In a paper published in the journal iScience, Bambi lays out a plan to turn such a deep-space mission into reality. If achieved, the journey could span a century and deliver data from nearby black holes that might transform what we know about general relativity and the fundamental rules of the universe.
“We don’t have the technology now,” says author Cosimo Bambi of Fudan University in China. “But in 20 or 30 years, we might.”
Two Key Challenges Ahead
This ambitious concept depends on overcoming two main hurdles—locating a black hole close enough to aim for and designing probes that can endure the entire trip.
Based on current knowledge of how stars evolve, there could be a black hole just 20 to 25 light-years away from Earth. However, spotting one is not simple, Bambi explains. Because black holes emit no light, they are effectively invisible to telescopes. Instead, scientists identify them by observing how they affect nearby stars or bend light passing close to them.
“There have been new techniques to discover black holes,” says Bambi. “I think it’s reasonable to expect we could find a nearby one within the next decade.”
Nanocrafts: The High-Speed Solution
Once the target is identified, the next hurdle is getting there. Traditional spacecraft, powered by chemical fuel, are too clunky and slow to make the journey. Bambi points to nanocrafts—gram-scale probes consisting of a microchip and light sail—as a possible solution. Earth-based lasers would blast the sail with photons, accelerating the craft to a third of the speed of light.
At that pace, the craft could reach a black hole 20 to 25 light-years away in about 70 years. The data it gathers would take another two decades to get back to Earth, making the total mission duration around 80 to 100 years.
Probing Physics at the Edge of Reality
Once the craft is near the black hole, researchers could run experiments to answer some of the most pressing questions in physics. Does a black hole truly have an event horizon, the boundary beyond which not even light can escape its gravitational pull? Do the rules of physics change near a black hole? Does Einstein’s theory of general relativity hold under the universe’s most extreme conditions?
Bambi notes that the lasers alone would cost around one trillion euros today, and the technology to create a nanocraft does not yet exist. But in 30 years, he says that costs may fall and technology may catch up to these bold ideas.
From Science Fiction to Proven Possibilities
“It may sound really crazy, and in a sense closer to science fiction,” says Bambi. “But people said we’d never detect gravitational waves because they’re too weak. We did—100 years later. People thought we’d never observe the shadows of black holes. Now, 50 years later, we have images of two.”
Reference: “An interstellar mission to test astrophysical black holes” by Cosimo Bambi, 7 August 2025, iScience.
DOI: 10.1016/j.isci.2025.113142
This work was supported by funding from the National Natural Science Foundation of China.
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5 Comments
While the proposed experiment may be decades away, it’s still possible to study general relativity here and now. In June I uploaded a fourth low budget, tabletop size, demonstration to my ad-free video channel (https://odysee.com/@charlesgshaver:d/5Gravity:c) to continue to prove the true nature of gravity; induced in all matter/objects by some still unidentified higher force (reverberations of the Big Bang?) to radiate in coherent pulsing angular lines of attractive force across the universe. For me it now begs this question: just how small can I make another low budget experiment that still demonstrates the true nature of gravity?
Why do folk draw black holes as whirpools? I thought that they were likely spherical lumps of very dense to singularly dense stuff surrounded by less dense stuff whirling around them. Rather like drawing gravity as a 2D grid distorted by a spherical object resting on it.
Because we lack a clear understanding of how a greater than 3 dimensional reality would be interpreted. We simply cannot comprehend what even one more dimension would be expressed. We’re not stupid; we just lack a point of reference.
Cool. Now somebody explain how this minute device is to transmit its wonderful information back to us here on Earth even if anybody remembers to listen after a couple of centuries of waiting. Probes that have barely left the solar system have enough trouble carrying out that task despite having large power supplies and large antennae.
One of the “nanocrafts” has a 10 m^2 sail (the one at distance from the BH/CO, as the one close will experience extreme tidal shear). Designing a gram-weight “nanocraft” with a relatively large sail is not specified in the cited paper. The author is not an engineer, he’s a theoretical physicist. The cited reference for the sail is a photonic lightsail, which presumably can be configured to also serve as an antenna for communication. “Breakthrough starshot” was supposed to be a platform to Alpha Centauri that exhibits these capabilities, with some differences. For that, the sail is 4 m^2, “possibly of composite graphene-based material” and “a laser communicator, utilizing the light sail as the primary reflector, would be capable of data rates of 2.6-15 baud per watt of transmitted power at the distance to Alpha Centauri, assuming a 30 m diameter receiving telescope on Earth.” Based on the latter estimate, I think the larger 10 m^2 sail may work, but a downlink calculation is required. Yes, cool idea, what are we waiting for?