Small satellites are becoming increasingly popular tools for Earth-imaging, communications, and other applications. But they have major control issues: Once in space, they can’t accurately point cameras or change orbit, and they usually crash and burn within a few months.
What these satellites lack is a viable propulsion system. Accion Systems has developed a commercial electrospray propulsion system, their first is about the size of a pack of gum, made of tiny chips that provide thrust for small satellites. Among other advantages, Accion’s module can be manufactured for significantly less than today’s alternatives.
This technology could enable low-cost satellites, such as those known as “CubeSats,” to become more viable for various commercial and research applications, including advanced imaging and communications, where numerous satellites could provide global coverage.
Electric propulsion (EP) provides momentum for propelling spacecraft (in space, not for launch) by converting electrical energy into kinetic energy. Charged particles are electromagnetically accelerated within the propulsion device, and the opposite momentum reaction forces the spacecraft in the other direction. This is in contrast to chemical propulsion, which utilizes the exchange from chemical energy to kinetic.
Highly efficient use of propellant. EP systems provide more thrust per unit propellant compared to chemical systems. For the same mission, an EP system can use up to 1000 times less propellant by mass.
In January, Accion tested a miniature version of MAX-1, called MIN-0, inside a vacuum chamber at MIT. The team measured the emitted current of the released ions after applying certain levels of voltage. From that experiment, and others, they conclude the MAX-1 can provide about 100 micronewtons of force per square meter.
This is enough thrust, for example, to stabilize a CubeSat launched from the International Space Station, and to compensate for atmospheric drag, “which is the force that pulls [small satellites] into the atmosphere prematurely, where they burn up,” Brikner says.
However, with dozens of small satellites being launched annually, Lozano adds, the system could also help control how long they stay in space, so they don’t become floating space junk.