An associate professor of aeronautics and astronautics at MIT has designed a penny-sized rocket thruster that could be used to power the smallest satellites in space. Paulo Lozano‘s device aims to replace current bulky satellite engines, which are heavy and require more fuel to power. Lozano’s system is a flat, compact alternative that is covered with 500 microscopic tips that, when stimulated with voltage, emit tiny beams of ions propelling the satellite forward.
“They’re so small that you can put several [thrusters] on a vehicle,” Lozano said in a statement, adding 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.” The microthruster was developed at MIT’s Space Propulsion Laboratory and Microsystems Technology Laboratory, and Lozano presented the new thruster array at the American Institute of Aeronautics and Astronautics’ recent Joint Propulsion Conference.
He suggested that the thruster can be used to power the nanosatellites or CubeSats that currently orbit the Earth. Each is slightly bigger than a Rubik’s cube, and weighs less than three pounds. They have become popular as they can be launched into space relatively easily, weigh very little, and can be carried into space in batches without the need for extra fuel.
The problem is that these small satellites lack propulsion systems, so once their mission is over they burn up in the lower atmosphere. However microthrusters would allow the satellites to operate in higher orbits and take much longer to degrade, thus creating less space clutter. Microthrusters would also solve this problem by allowing the CubeSats to act as galactic garbage collectors, pulling retired satellites down to degrade in Earth’s atmosphere.
Lozano’s microthruster design adds little to a satellite’s overall weight, as its microchip-esque design is composed of several layers of porous metal. Lozano says the entire systems works in the same way as a tree: “Water from the ground is pulled up a tree through a succession of smaller and smaller pores, first in the roots, then up the trunk, and finally through the leaves, where sunshine evaporates the water as gas. Lozano’s microthruster works by a similar capillary action: Each layer of metal contains smaller and smaller pores, which passively suck the ionic liquid up through the chip, to the tops of the metallic tips where it is then expelled.”
Nature-inspired, ultra-light weight thrusters for satellites? I love science!
Images: M. Scott Brauer of MIT