Future space telescopes may have bigger, lighter and cheaper mirrors, all thanks to a newly developed method. An article published in the journal Applied Optics describes new flexible mirrors that can be packed into a spacecraft, reducing bulk during the flight to orbit.
During the development of the manufacturing process for the new mirrors, the researchers obtained prototypes so flexible and thin that they can be described as a “membrane”. To demonstrate the technology, they produced parabolic mirrors 30 cm in diameter.
Production is done with a chemical vapor over a rotating liquid inside a vacuum chamber. The steam is thermally split into monomeric molecules that deposit on the surfaces of the vacuum chamber and then combine to form a polymer.
This process itself is not new, as it is based on a basic principle that uses gravity itself to form an object in a parabolic shape, but it is the first time that it has been used to create membrane mirrors for telescopes.
When the polymer is thick enough, a layer of reflective metal — such as aluminum — is applied over it on top and the liquid is washed away. In addition to being light and flexible, allowing it to bend to fit spacecraft, the mirror can be “fixed” after being unfolded when in orbit.
The technology, however, is still in its early stages, although it has already been validated through successful prototypes. Now, the researchers want to improve the technique to know the limits of the correction capacity after deploying the mirror in space.
They also plan to create a larger chamber to increase the size of the prototypes and produce them one meter in diameter. Thus, it will be possible to better study the structure of the surface on larger scales and the “packaging” processes that can be used in spacecraft.
Source: OPTICAL
