Redwire Corporation, a company based in Jacksonville, has secured a DARPA Phase 2 contract, valued at $44 million, to continue its work on the Otter Very Low Earth Orbit (VLEO) mission. This mission focuses on the development and in-orbit demonstration of an air-breathing electric propulsion (ABEP) system designed to sustain spacecraft operation in VLEO.

What Is VLEO And Why Go There?

Very Low Earth Orbit, which spans altitudes between roughly 90 and 450 kilometers (~56 to ~280 miles), presents a challenging environment for satellites due to significant atmospheric drag. This drag typically requires satellites operating in this region to carry a considerable amount of propellant for frequent orbit maintenance, limiting their operational lifespan. Shorter lifespans ultimately translates to “more expensive” and by creating satellites that last longer, Redwire plans to offer better value to its customers.

“VLEO represents an exciting new frontier for defense, intelligence, and communications missions. Through our work with DARPA, we are accelerating the development of cutting-edge capabilities that will define the future of this domain,” said Tom Campbell, President, Space Missions at Redwire in a press release. “With Otter and our SabreSat platform, we are delivering higher-performance missions at lower altitudes: improving sensor perception and proximity to targets of interest, increasing revisit, reducing latency, and redefining mission resilience.”

The Otter program aims to overcome this limitation by utilizing ABEP electric propulsion technology. This system is designed to harvest the low-density air present in the upper atmosphere, which is then ionized and accelerated to generate thrust. This approach provides a virtually unlimited propellant supply, theoretically enabling smaller, lighter satellites to remain in VLEO for extended periods without relying on stored fuel.

Redwire’s Proposed Solution

Redwire’s spacecraft for the Otter mission is built on its proprietary SabreSat Orbital Drone platform. The final stage of this project involves manufacturing and delivering the spacecraft for launch, followed by an orbital flight demonstration lasting over one year. During this test, the mission will characterize the performance of the air-breathing electric propulsion system and collect data for comparison with ground-test results, helping refine future VLEO satellite designs.

Operating closer to Earth offers several potential advantages for applications such as communications, intelligence, and surveillance. These benefits include lower latency for data transmission, improved sensor perception due to closer proximity to targets, and higher-resolution Earth observation. Furthermore, debris at VLEO altitudes is naturally cleared relatively quickly by atmospheric drag, reducing the long-term risk of space debris accumulation.

The Otter program is a multi-year effort that seeks to transition this novel propulsion technology from concept to operational capability, setting a precedent for persistent, long-duration missions in this orbital regime.

No launch date or launch provider were provided. This is a technology that ultimately could lead to many satellites in operation, so it is well worth keeping an eye on.