Penny-sized thrusters developed to propel nanosats

Washington -  Scientists have developed a penny-sized rocket thruster that could soon power the movement of tiny satellites or nanosats in orbit.

The device, designed by Paulo Lozano, associate professor of aeronautics and astronautics at Massachusetts Institute of Technology (MIT), bears little resemblance to today's bulky satellite engines, which are laden with valves, pipes and heavy propellant tanks.

Instead, Lozano's design is a flat, compact square - much like a computer chip - covered with 500 microscopic tips that, when stimulated with voltage, emit tiny beams of ions.

Together, the array of spiky tips creates a small puff of charged particles that can help propel a shoebox-sized satellite forward, according to an MIT statement.

"They're so small that you can put several (thrusters) on a vehicle," Lozano says. He adds that a small satellite outfitted with several microthrusters could "not only move to change its orbit, but do other interesting things - like turn and roll."

Today, more than two dozen small satellites, called CubeSats, popularly referred to nanosatellites, including India's own Jugnu, orbit Earth. Each is slightly bigger than a Rubik's cube, and weighs less than 1.5 kg.

But these nanosats lack propulsion systems, and once in space, are usually left to passively spin in orbits close to Earth. After a mission concludes, the satellites burn up in the lower atmosphere.

"These satellites could stay in space forever as trash," says Lozano, who is associate director of the Space Propulsion Lab.

"This trash could collide with other satellites... You could basically stop the Space Age with just a handful of collisions."

Engineering propulsion systems for small satellites could solve the problem of space junk: CubeSats could propel down to lower orbits to burn up, or even act as galactic garbage collectors, pulling retired satellites down to degrade in Earth's atmosphere.

Lozano and his group presented their new thruster array at the American Institute of Aeronautics and Astronautics' recent Joint Propulsion Conference.