NASA’s new James Webb Space Telescope, the largest telescope ever launched into space by any agency, is already looking to the future. NASA is exploring the possibility to create liquid lenses that could make a giant telescope 100 times larger than the Webb.
NASA has published a new article on their website stating that they are exploring fluid materials and new ways to build giant telescopes.

The agency states that a bigger telescope is better. Larger telescopes can collect more light, which allows astronomers to see farther into space and distant objects in greater detail.

What if a telescope could be made 10x larger than it was before? Or even 100x bigger than it was before? This started out as a theoretical question and has evolved into a series experiments to find out if fluids could be used to make lenses in microgravity.

Space-based experiments with liquid lenses

The current experiments are being stored on the ISS U.S. National Labin (USOS), International Space Station (ISS). They await the arrival of astronauts aboard Axiom Mission 1 (a private crew mission) that will send four people to Axiom Mission 1 for an eight-day stay.

Eytan Stibbe (mission specialist 2 in Israel) will carry out the experiments as part his research portfolio.

Although liquids are not as useful as optical lenses in Earth’s gravity, they can focus light in microgravity.

NASA states that all liquids possess an elastic force that holds them together at the surface. This force is known as surface tension. It is what allows insects to glide over water without sinking, and it gives water droplets their shapes. When water droplets are sufficiently small (2 mm or less), the surface tension overcomes gravity, and they remain perfectly spherical. Droplets that grow in size will sink under their own weight.

“But in space, blobs water and other liquids (after wobbling around) eventually assume an ideal spherical form.”

Stibbe’s experiments will examine whether it is possible to make high-precision mirrors and lenses in space by using liquids.

“We thought we would take advantage of how liquids behave in microgravity to construct large-scale telescopes and space-manufactured optical parts that can be used for many purposes,” said Edward Balaban (principal investigator of NASA’s Fluidic Telescope Experiment) at NASA’s Ames Research Center. “In microgravity liquids can take on shapes that are useful to make lenses and mirrors. If we make them in space, it could be used for telescopes that are significantly larger than what was thought possible.”

Previous Tests on Earth that were successful

Scientists previously tried the idea of liquid lense on Earth by creating a weightless environment using water.

Dr. Valeri Frumkin of Technion-Israel Institute of Technology explains to NASA that she used a liquid that could be solidified to inject lenses into circular frames submerged under water. The natural choice for lens material is polymers. They are used in nail salons to make acrylic nails and in adhesives such as superglue.

“The trick is to ensure that the water we inject has exactly the same density as our polymer to counter gravity and simulate weightlessness.

These solid lenses were created using liquid and had an “outstanding” surface that was comparable to or better than what could be achieved with the most advanced polishing techniques in optical lens manufacturing. They took only a fraction of time to make than traditional lenses.

Moran Bercovici, Technion’s mechanical engineering professor, says that this method “allows us to completely skip mechanical processes like grinding or polishing.” “The natural physics and fluids do all the work.

After successful ground experiments, the researchers tested their experiment on ZeroG parabolic plane flights. They were able to temporarily create liquid lenses in the desired shapes, but the plane stopped diving. Gravity destroyed the lenses.

Giant Space Telescopes: Opening the Doors

Stibbe will add an extra step to cure the liquid into a lens that retains its shape after the experiment is completed in permanent microgravity aboard International Space Station. After the lenses have been created using liquid polymers, and then hardened with UV light or temperature they will be sent back home to NASA scientists at Ames for analysis.

“We expect that this approach will create perfectly-shaped and smooth surfaces: these surfaces are the best to turn into mirrors,” Vivek Dwivedi, FLUTE scientist at NASA’s Goddard Space Flight Center.

Balaban says, “If our station experiment succeeds, it will mark the first time that an optical component has been made in space.” It feels like you are making history.

If everything goes according to plan, liquid transport on multiple missions into space could be combined to make enormous space telescopes. These could be impossible to launch from Earth because they would be too large.

James Webb Space Telescope will capture the best-quality images of space that humans have ever seen. But it could be replaced by “liquid lens” telescopes, which are 100 times larger and capture photos of space we can only dream about.