'Metajets' could allow future spaceships to be propelled by nothing but light

Forget rocket fuel. Researchers at Texas A&M University say the key to reaching another star system might be light itself.

Their team has successfully levitated and steered tiny microscopic devices using only laser beams, no motors, no fuel, no physical contact. The secret lies in specially engineered "metasurfaces," ultrathin materials patterned at the nanoscale that redirect incoming light, generating force in multiple directions simultaneously.

The real ambition here is interstellar travel. Alpha Centauri, our nearest neighboring star system, sits 4.37 light-years away. At today's rocket speeds, getting there would take tens of thousands of years. With laser propulsion accelerating a lightweight craft to roughly 20% the speed of light, that journey shrinks to around 20 years.

There are enormous hurdles ahead. The current prototypes are smaller than a human hair. But researchers say the force scales with laser power, not device size, leaving the door open to something far bigger.