Satellites perform a delicate dance to maintain their orbit, by locking themselves to a speed just fast enough to counteract the downward pull of gravity.
To stop their orbit from decaying too much, satellites use small in-space thrusters, which broadly speaking, fall into two categories: chemical or electric. The former uses a combustible fuel source that gets accelerated through a nozzle, while the latter uses electrical energy to convert propellant into kinetic energy.
Now, New Zealand space startup Zenno Astronautics says it’s tested an entirely new type of thruster that, unlike either of those conventional technologies, uses superconducting magnets to maintain a satellite’s orbit and orientation. As Space.com reports, the magnets convert solar energy directly into momentum, effectively harnessing the Earth’s magnetic field itself.
“Energy is the one thing that is abundant in space, and you can use it to energize the magnet to create a magnetic acceleration device,” Zenno Astronautics CEO and founder Max Arshavsky told the site. “It gives you acceleration without fuel.”

