Rocket propulsion technology has progressed far beyond the first weaponized rockets of the Chinese and Mongolian empires. They were really nothing more than rocket-powered arrows and spears but they set the foundations for our exploration of space. Liquid propellant, ion engines and solar sails have all been featured in the media as we strive for more efficient methods of space travel. However, a team of researchers has taken the next leap with a palm-sized thruster system that could boost future tiny spacecraft across the gulf of space.
Palm-sized thrusters are quite different from the huge rockets we are used to. An example would be the Saturn V rocket that carried the Apollo astronauts to the moon. That rocket stood three hundred and sixty feet tall. The new ion thrusters are designed for maneuvering and propelling cubesats and small satellites once they are in space rather than propelling rockets from the surface of the Earth.
The research team is led by Daniel Perez Grande who is the CEO and Co-Founder of IENAI Spain. They have called their palm-sized thruster “ATHENA,” which stands for the Adaptable, THruster based on Electrospray powered NAnotechnology. The technology has been developed for the European Space Agency. Next will be a design stage and, if all goes to plan, a prototype will be available by the end of 2024.
The ATHENA technology relies upon something known as an electrospray which has previously been used in mass spectrometry but has now found its way into spacecraft propulsion. Each thruster has seven emitter arrays that are etched onto silicon wafers. Each array houses 500 pinhole emitters. Electrically charged particles from a conductive salt are sprayed out of the arrays. They are propelled via an electrostatic field to produce the maximum amount of thrust, which can be of the order of about twelve miles per second. This concept is very similar to the ion propulsion systems already in use but the new engine is a much smaller scale.
Like its ion and liquid propellant precursors, the thruster is highly adjustable and can be reconfigured in flight. The thrusters are also eco-friendly because the propellant is a non-toxic liquid and requires no pressurized storage tanks. The small size of the thrusters allows them to be grouped together in any required configuration with a total of six required to fit the face of a typical four inch cubesat and can be clustered together on satellites and probes of up to one-hundred-and-ten-pound mass. The researchers are hoping they can develop the technology further to work on craft up to six hundred and sixty pounds.
Like most other areas of technology, space technology is getting smaller and smaller. In order to achieve this though, the propulsion systems also have to shrink, and this is potentially a more challenging task. ATEHNA appears to be a promising development, but ESA and their partners are working on two other thruster systems based upon electrospray technology. All of these seem to be bringing promising results.