NASA is getting closer to building the powerful telescopes needed to find Earth-like planets beyond our solar system, thanks to a surprising new material that does something unusual—it shrinks when it gets hot and expands when it cools.
This strange behavior is called negative thermal expansion, and it could be the key to building the ultra-stable telescopes of the future.
Finding habitable planets—worlds that might support life—is one of NASA’s biggest goals. To do this, scientists study the light that comes from distant planets or passes through their atmospheres.
But spotting these planets is extremely difficult because the stars they orbit are up to a billion times brighter.
Future telescopes like the Habitable Worlds Observatory will need to block out that bright starlight and focus only on the faint glow of the planets.
That kind of precision requires an incredibly stable telescope, much more stable than anything that exists today—including NASA’s James Webb Space Telescope.
Even tiny changes in temperature can cause the parts of a telescope to expand or shrink, throwing off its accuracy. Materials like aluminum or titanium expand when heated, which is a big problem in space, where temperatures can change quickly.
That’s where a company called ALLVAR comes in. They’ve created a new alloy—called ALLVAR Alloy 30—that does the opposite of most materials.
It gets smaller when it’s heated and bigger when it’s cooled. When used together with traditional materials that expand, this new alloy helps cancel out the size changes caused by temperature shifts.
NASA worked with ALLVAR to test how well this material works in real telescope parts. They built a special structure called a hexapod that uses six arms to hold two mirrors apart.
These arms combined materials that normally expand with the new alloy that shrinks. The result? A structure so stable that its movements were measured in picometers—tiny units about one-tenth the width of an atom.
Tests at the University of Florida and NASA’s Marshall Space Flight Center showed the design met almost all the stability goals needed for the next-generation space telescope. It held up well even during a 28-degree temperature swing, with only tiny changes in the shape of the mirror—less than 5 nanometers.
This amazing alloy isn’t just useful for telescopes. It’s also being used in NASA projects like the Lunar Surface Electromagnetics Experiment-Night, a device heading to the Moon, and in parts of the Roman Space Telescope’s heat transfer system. It can even help in everyday Earth-based uses, like preventing bolts from loosening or improving medical imaging tools.
ALLVAR is now developing more advanced versions of this alloy, including ones with custom expansion properties or even zero expansion. This could help solve problems in everything from nuclear power to quantum computers.
Thanks to this tiny but mighty material, we’re one step closer to answering the big question: Are we alone in the universe?
Source: NASA.
