The FLUTE (Fluidic Telescope) project, a joint development between NASA and the Technion University, aims to build 50-meter-diameter telescopes with liquid mirrors. This new technology demonstrates that liquid surfaces could replace the glass-mirror telescopes currently used for deep-space observations.

At the heart of the project is the ability of liquids to form perfectly spherical shapes in microgravity due to surface tension. This natural formation offers a new method for producing high-quality optical mirrors.

FLUTE could usher in a new era in space observations

The FLUTE concept envisions using a 50-meter liquid mirror in space, many times larger than even the largest telescopes built to date. Compared to the James Webb Space Telescope’s 6.5-meter mirror, FLUTE’s optical diameter would be approximately eight times larger.

However, the question of how a liquid surface would behave when the telescope is reoriented has long been a subject of debate. Theoretical analyses and laboratory experiments conducted in new studies have shown that liquid mirrors are only affected by such movements at the micrometer level, and that the distortions propagate very slowly to the central region.

Research has revealed that these systems must have limited directional changes, defined as a “maneuvering budget.” It has been determined that small, multi-directional maneuvers should be preferred over large, single movements.

It has been emphasized that these small movements produce less distortion and are easier to correct optically. These behaviors were tested by creating controlled distortions on liquid films in laboratory experiments using non-contact electromagnetic forces, confirming the accuracy of the developed models.

The greatest advantage of liquid mirrors over traditional telescopes is not limited to size. This technology also offers flexibility. Mirrors developed using the FLUTE concept can change shape according to observation missions, automatically correct optical errors, and even self-repair after micrometeor impacts. These features could significantly simplify both cost and maintenance in future space missions.

Despite all these advances, transporting and long-term controlling liquids in space remains a technical challenge. However, analyses and experiments indicate that such telescopes can operate effectively for decades.