DARPA Otter Program Contract Won By Redwire

By: Jordan Buck, 2024-06-17

For VLEO (very low Earth orbit), the DARPA Otter program is seeking a spacecraft powered by electric propulsion. This type of “air breathing” technology would be designed to operate between 90 and 250 kilometers, with the potential of operations up to 450 kilometers. Redwire has won the prime integrator contract to deliver SabreSat, which is Redwire’s intelligence, surveillance, and reconnaissance satellite, to use this novel propulsion technology. Subcontracts for Electric Propulsion Laboratory Inc. and Phase Four have also been proposed to develop their respective electric “air breathing” propulsion systems. Redwire will be providing the SabreSat bus and performing final design and integration for the mission.

From a cybersecurity perspective, the spacecraft being in VLEO means that any hack effort to control the propulsion system or deny service may result in swift mission demise due to imminent atmosphere reentry. There is less margin for error and less time for ground segment responses in the event of control interruption. Additionally, due to SabreSat’s proximity to Earth, more than likely relay satellites are going to be needed for communications. This will probably look like bouncing signals off of antennae in the GEO neighborhood. If the relay system itself is targeted, then a threat actor may have control of what happens during the relay or be able to redirect communications entirely. Moreover, while not a novel idea, having the propulsion system developed under a different company and at a different location poses cyber risks. There are more hands and eyes involved to transfer data between organizations, meaning a larger surface area to go after. There may also be different levels of security that can provide stepping stones such as to attack the most vulnerable targets in order to gain access to more protected targets. One last consideration is that due to being below LEO orbits, VLEO satellites could have the capability to intercept, interfere, or block communications with higher orbiting satellites. While unlikely and difficult to achieve, a man-in-the-middle attack is technically possible at VLEO altitudes. Nation state threat actors may choose to pursue this option to develop VLEO constellations partly by this reasoning.