The technology for mass production of solar sails for flights to other stars has been presented.

In shipping, one of the most difficult and expensive things was the production of a ship’s sail. It must be both light and durable, which fully applies to solar sails for interstellar travel. Researchers from the Netherlands and the USA have managed to develop a technology for producing a lightweight and most affordable solar sail for interstellar travel – its cost promises to be 9000 times less than its analogues. Is the path to Alpha Centauri open?

Image source: Delft University

The Breakthrough Initiatives program, organized by the Milners and inspired by Stephen Hawking, took up the issue of interstellar flights on solar sails more or less thoroughly. It was assumed that under the pressure of laser radiation, one-gram probes would be launched towards Alpha Centauri with one-gram sails with an area of ​​16 m2. This should be a proof of concept for interstellar travel of 20 years at 20% of the speed of light. And if there are no special problems with 1-gram probes, then there are no sails with the required characteristics and an acceptable price as a class.

A number of scientific teams have since been working on the issue of creating the lightest solar sails. NASA even allocated a grant for one of the most promising developments in this direction. An international group of scientists from the Netherlands and the USA recently contributed to this program. The scientific preprint website arXiv.org published an article about an experimental photonic crystal that could form the basis of a light sail for interstellar travel.

From silicon nitride, scientists created a crystalline structure (plate) with a thickness of only 200 nm with sides of 60 × 60 mm. The idea was, firstly, to make the material as light as possible and, secondly, to provide it with the most favorable conditions for the perception of light pressure. To reduce weight, millions of nanometer holes were created in the plate, which simultaneously solved the second problem – they refracted the light falling on them in the most optimal way. In fact, scientists have created a photonic crystal on a macroscale and substantiated how to create such structures of a meter and larger size.

According to the researchers, the cost of producing each square meter of such light sail material would be 9,000 times lower than alternative proposals. It is interesting to note that the pattern of holes that turns the material into a photonic crystal was optimized using a neural network (machine learning).

«This mission requires light sail materials that challenge the fundamentals of nanotechnology, requiring innovations in optics, materials science and structural engineering, the team said in the paper. “This research highlights the potential of neural topology optimization to create innovative and economically viable light sail designs critical to space exploration through next-generation space programs.”