Exploring beyond our solar system requires traveling enormous distances. The nearest star system to ours — Alpha Centauri — is 4.37 light years away, or 25 trillion miles; and distant star systems will take hundreds or thousands of years to reach, even in the best of circumstances. So scientists who want to send unmanned probes to another star system must create some innovative technologies that can outlive them.
UConn researcher in the School of Engineering Seok-Woo Lee, who recently received an Early Career Faculty grant from NASA, is working on one such technology. In collaboration with researchers at Iowa State University and Ames Laboratory and Colorado State University, he has developed a shape memory material (called ThCr2Si2-type intermetallic compounds) that can help in deep space travel by changing shape at low temperatures. Shape memory materials can be deformed, but return to their original shape when exposed to a specific temperature, usually at high heats. Lee’s material, a solution-grown crystal, works at colder temperatures.
Once a vessel leaves our solar system, the temperature drops below 50 kelvins, which will cause the shape memory material to deform and activate an actuator, which in turn will power down the vessel. With minimal gravity in deep space, the vessel will continue in a set direction for hundreds of years, slowly making its way to its target while depowered. If the vessel arrives at a new solar system, even the very distant heat at the edges of a star’s reach will activate the shape memory material, which would return to its original shape.
The shape change would push the actuator, which would power up the vessel and allow it to begin recording and transmitting data back to Earth — long after the scientists who launched the vessel are gone. —JOSH GARVEY