Hold Me Closer, Tiny Thruster
August 17, 2012

MIT Microthrusters Could Help Propel CubeSats

Michael Harper for redOrbit.com — Your Universe Online

Some MIT engineers have taken the old cliche “Good things come in small packages” to heart, creating a rocket thruster no larger than an American penny or postage stamp. These thrusters, which operate on jets of ion beams, could soon power some of the tiniest satellites in space.

These “micro thrusters” were created by Paulo Lozano, an associate professor of aeronautics and astronautics at MIT.

According to the MIT website, these tiny thrusters are a far cry from the common idea of rocket engines. Rather than loaded down with pipes, tanks and valves, these thrusters more closely resemble a tiny computer chip. Each chip-like thruster is covered in 500 microscopic tips which emit ion beams when energy is channeled to them. When charged, these tips then puff out small clouds of charged particles which can propel an object the size of a shoebox.

They´re so small that you can put several [thrusters] on a vehicle,” Lozano says about his micro-thrusters, according to the MIT website.

These thrusters can multi-task as well, says Lozano, turning and rolling the satellites as well as propelling them forward.

As more universities become interested in sending their own tiny satellites into space for their own research, the need for smaller engines has become even more important.

As it stands, more than 2 dozen of these small satellites are currently orbiting around the Earth. These satellites, called CubeSats, are only slightly larger than a Rubik´s cube and weigh around 3 pounds. In fact, compared to other, more “traditional” satellites, these CubeSats are often referred to as “nanosatellites.” Cheap to assemble and not entirely difficult to catapult into space, they have become the choice of many universities and other researchers. Several of these CubeSats can be placed on one rocket booster and shot into space, but since they lack any other kind of propulsion, they are left to orbit freely once they break through the Earth´s atmosphere.

When their purpose is served, these satellites simply fall to Earth and burn up in Earth´s lower atmosphere.

According to Lozano, if these CubeSats were launched higher into space, they´d be more likely to last longer. As such, and without any propulsion, these CubeSats could end up cluttering the void and contributing to the existing detritus. As more of these tiny satellites are launched, this could end up being a costly problem.

“These satellites could stay in space forever as trash,” says Lozano.

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

Thus, Lozano´s micro thrusters could alleviate this problem, allowing those on Earth to pilot and direct these CubeSats, either moving them out of the way or sending them to their doom in the Earth´s lower atmosphere.

Additionally, Lozano´s small thrusters leave enough room on these satellites for communication equipment and other electronics without adding much in the way of overall weight.

As you might expect, the micro thrusters aren´t very bulky and only consists of several layers of thin, porous metal. The top layer contains the 500 spiked tips and the bottom layer contains a small reservoir of liquid of free-floating ions which is key to the thrusters´ performance. According to Lozano, these engines are so small, they´re manufactured using the same tools used to build microchips and other electronics equipment.

The ability to flip, turn and rotate these thrusters only serves to make them even more useful on CubeSats.

“Just like solar panels you can aim at the sun, you can point the thrusters in any direction you want, and then thrust,” Lozano says. “That gives you a lot of flexibility. That´s pretty cool.”