How Can These Satellites Move on Their Own?

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Most satellites require a propulsion system to move around in space, but apparently these satellites can move on their own! A constellation of small satellites recently demonstrated the ability to move around space without the benefit of a propulsion system.

According to nationaldefensemagazine.org, a subsidiary of Boeing that specializes in small satellites, showcased a host of capabilities on orbit with Red-Eye — a constellation comprising three 70-kilogram satellites. These small spacecrafts were built with the goal of advancing space-based small satellite technology needed for warfighters, such as on-board data processing, avionics, crosslink communications and more. 

Since these satellites were launched off the international space station and not off of solid ground, they were not given propulsion systems due to safety concerns. However, these satellites could be controlled using aerodynamic drag by adjusting the satellite’s solar arrays to move it through the small amount of atmosphere in low-Earth orbit. 

What is aerodynamic drag? aerodynamic drag is the force an object needs to overcome as it moves through the atmosphere at a certain velocity. Normally, this force causes objects to slow down over time. The low drag of a low-earth orbit, apparently, has enough force to manipulate the position of small satellites, causing them to move consistently with no need for a propulsion system. 

“With no propulsion at all and just by modulating our drag profile … they were able to drive them apart, pull them closer together, and really just control that spacing,” said Doug Hulse, the company’s Red-Eye program manager.

The position of these satellites could be manipulated by ground operators. For example, if two Red-Eye satellites needed to move closer together to perform a crosslink data transfer, a ground operator could reposition the satellites’ solar arrays in a way so the aerodynamic drag closes the distance between them. The company also created a ground-based automation system that allows the constellation to self-control its orbital spacing, Hulse said.