Satellites Now Uses Water as Propellant

IAS Prelims 2023

A new type of micropropulsion system for miniature satellites called CubeSats uses an innovative design of tiny nozzles that release precise bursts of water vapor to maneuver the spacecraft.

Scientists have developed a new micropropulsion system that uses ultra-purified water.

The new system, called a Film-Evaporation MEMS Tunable Array, or FEMTA thruster, uses capillaries small enough to harness the microscopic properties of water.

Because the capillaries are only about 10 micrometers in diameter, the surface tension of the fluid keeps it from flowing out, even in the vacuum of space.

Activating small heaters located near the ends of the capillaries creates water vapor and provides thrust.

In this way, the capillaries become valves that can be turned on and off by activating the heaters. The technology is similar to an inkjet printer, which uses heaters to push out droplets of ink.

The FEMTA technology is a micro-electromechanical system, or a MEMS, which are tiny machines that contain components measured on the scale of microns, or millionths of a meter. The thruster demonstrated a thrust-to-power ratio of 230 micronewtons per watt for impulses lasting 80 seconds.