A Seattle-area startup called Portal Space Systems is emerging from stealth to share its vision for a type of satellite that’s apparently never been put into space before: a spacecraft that uses the heat of the sun to spark its thrusters.
The technology, known as solar thermal propulsion, could be put to its first in-space test as early as next year.
“I’m not aware of anybody that has flown any system with solar thermal propulsion, in the U.S., or foreign for that matter,” Portal co-founder and CEO Jeff Thornburg told me. “I mean, it could have happened, but maybe no one’s aware of it.”
Bothell, Wash.-based Portal says it has already been awarded more than $3 million by the Defense Department and the U.S. Space Force to support the development of its Supernova satellite bus. In space industry parlance, a bus is the basic spacecraft infrastructure that supports a satellite’s payloads.
Supernova-based satellites would be equipped with a solar concentrator apparatus that focuses the sun’s rays on a heat exchanger. “It’s a very simple system,” Thornburg said. “You pass your monopropellant through a hot heat exchanger, and out comes thrust.”
The technology has the potential to give satellites much more mobility in orbit — which could smooth the way for applications ranging from rounding up orbital debris to responding to international crises.
