An anonymous reader quotes Newsweek:
A hypothetical spacecraft made from an extremely thin layer of a synthetic foam could technically make it to our closest neighboring star Proxima Centauri in just 185 years, scientists have said. If Voyager were to make the same journey, it would take around 73,000 years, according to NASA.
In a study that is due to be published in the journal Astronomy & Astrophysics, René Heller from the Max Planck Institute for Solar System Research, Germany, and colleagues, propose the spacecraft as a precursor to interstellar travel — beyond our own solar system. They estimate a prototype would cost around $1 million, while the launch of an interplanetary mission would be around $10 million.
The spacecraft would be made from aerographite. This is a carbon-based foam that is around 15,000 times more lightweight than aluminium. It is versatile and light enough that it could be used to create solar sails — “which harness energy from the sun for propulsion, a process called solar photon pressure… In most cases, photons would have little impact on an object. But if the target is an ultralight material, such as aerographite, then the target can actually be pushed to significant speed,” he said.
“We found out that a thin layer of aerographite, with a thickness of about 1 millimeter (0.04 inches), can be pushed to speeds that are sufficiently high to let it escape the solar system. Once it has gained an initial push from the solar radiation pressure, it will simply float through space….”
Heller said these spacecraft could travel far faster than any probe ever sent by humans before.