Kissimmee, Fla. – SabreSat, Redwire Space’s satellite for very low Earth orbit, looks more like a dart than a traditional spacecraft.
“As you think about aerodynamics, you want the dart to be skinny and long, not stubby and fat,” Spence Wise, Redwire senior vice president for missions and platforms, told SpaceNews.
Redwire is designing SabreSat for government intelligence, surveillance and reconnaissance missions.
“You wouldn’t want to bring one of those multimillion dollar payloads into VLEO just to have it deorbit,” Wise said. “So we’re building a persistent platform capable of delivering on the customer’s needs for exquisite payloads.”
VLEO Advantages
In recent years, companies have worked to establish constellations at altitudes ranging from 250 to 400 kilometers to gather high-resolution Earth imagery and to provide low-latency communications.
Redwire sees advantages for national security satellites to operate at VLEO altitudes from 90 to 350 kilometers.
“Getting twice as close gives you a 400 percent improvement in your sensor performance for electro-optical, infrared and all sorts of applications that the U.S. government is interested in,” Wise said.
Flying above uncrewed aerial vehicles and below proliferated low-Earth orbit constellations offers resiliency too, said Dean Bellamy Redwire executive vice president for national security space.
If collisions occur or antisatellite weapons strike targets in traditional low-Earth orbits, VLEO satellites would not be affected.
“We call it the orbital drone. It offers a new capability,” Bellamy said.
SabreSat and SkimSat
Redwire CEO Peter Cannito announced SabreSat during a March earnings call. At the time, he cited the importance for Redwire of moving up the value chain from supplying components to delivering spacecraft.
SabreSat benefits from expertise in Redwire’s European arm. The former QinetiQ Space, acquired by Redwire in 2022, is working with Thales Alenia Space on SkimSat, a VLEO platform for Earth-observation applications funded by the European Space Agency.
SkimSat and SabreSat rely on electric propulsion to compensate for drag in VLEO.
“We’re currently working on the design phase for our VLEO platform on the European front,” Juan Pablo Ramos, Redwire Space business development manager, said in April at the 39th Space Symposium in Colorado Springs. “We are focusing on sustaining operations in VLEO as long as possible.”
Air-Breathing Option
In addition to standard electric thrusters, Redwire is offering customers an air-breathing option for SabreSat.
“Depending on the duration of the mission, we have the ability to scoop atomic oxygen and nitrogen to utilize in our electric thrusters,” Wise said. Solar panels provide additional power.
SabreSat is designed with bulkheads. When customers need more payload capacity than a 200-kilogram SabreSat provides, Redwire adds bulkheads to the center of the satellite, maintaining the dart-like shape. Extending the satellite’s length also increases available power. Solar arrays mounted on the edges scale with the length, Wise said.
Digital Engineering
Through digital engineering, Redwire is exploring SabreSat configurations for various altitudes.
“We created a plugin that allows us to model the drag of sparse gas as you travel through the thermosphere,” Wise said.
At certain altitudes, “we can collect more atomic oxygen and nitrogen than we would actually expel,” Wise said, “which means that in theory, you can entirely maneuver without regret, make various maneuvers, orbit changes and so forth.”
Because SabreSat relies on electric thrusters, the maneuvers will take time. “But it is a unique capability,” Wise said.
