Inexpensive, Rubik’s cube-sized satellites are finding roles in aerospace — there are currently two dozen of them orbiting Earth. But the so-called CubeSats need will small thrusters to prevent them spinning passively in orbit and burning up as they reenter the atmosphere. Researcher and MIT professor Paulo Lozano has a possible solution: microthrusters consisting of several layers of porous metal, with the bottom layer containing a reservoir of free-floating ions in a liquid. The top layer has 500 evenly spaced raised tips. The entire device is gold plated. Applying a voltage and creating an electric field between the reservoir and tips which sends beams of ions streaming from the tips. Researchers could adjust the thrust generated by two thruster in parallel from 0 to about 0.01 lb (50 N) by applying 250 mA and varying voltage from 900 to 1,100 V.
Attaching several such microthrusters to a CubeSat would extend its useful life by giving it a means of staying high enough above Earth to remain in orbit. The microthrusters’ light weight and small size would incur a minimal penalty in extra fuel for lifting CubeSats into orbit. The small thrusters could also take CubeSats out of orbit by pushing them down into the atmosphere. This would eliminate CubeSats as collision hazards to other satellites and spacecraft.