McDevitt’s propulsion system is deceptively simple. It combines rocket-fuel-grade hydrogen peroxide with a patented proprietary catalyst to create a chemical reaction that results in thrust channeled through tiny square nozzles incorporated into the small satellite. The system allows the satellites to be steered or stopped. The only byproduct of McDevitt’s tiny rocket motors is water vapor.

Except for this quote the article doesn’t provide much information about the design, probably because the builders didn’t reveal the details for proprietary reasons. They hope to launch a test satellite by 2018.