Tactically Responsive Space: An Emerging New Deterrence Tool

Commentary by John Plumb

Published October 31, 2024

This series-featuring scholars from the Aerospace Security Project, non-resident experts, and the broader space community-explores key space trends, challenges, and policy issues that will confront the next administration as well as offers recommendations for how to navigate them.

The specter of a potential Russian on-orbit, antisatellite nuclear weapon demands a new way of thinking about how space might be used by an adversary and an assessment of the ability of the U.S. Department of Defense to quickly respond to new threats on orbit.

In order to establish slow relative velocities useful for characterization, a satellite needs to be nearly coplanar with the potential threat and also close in altitude. In geostationary orbit (GEO), it is straightforward for one spacecraft-for example, a Geosynchronous Space Situational Awareness Program (GSSAP) satellite-to establish a low velocity relative to any other satellite in GEO, by operating the spacecraft slightly above or below geostationary altitude. But GEO is unique: the orbit is so useful that many different satellites-hundreds-are built to be placed in that orbit. This means one GSSAP satellite or other spacecraft, already in GEO, has the ability to characterize multiple existing and future satellites in that orbit.

Unlike in GEO, there is very little chance that any single satellite already in medium Earth orbit (MEO) or low Earth orbit (LEO) today is in an orbit that allows them to sufficiently characterize a new potential threat that has not yet been launched. That chance goes down even more if a potential adversary intentionally chooses a unique orbit designed to avoid U.S. or other satellites.

The Department of Defense needs the ability to rapidly respond to and characterize new potential threats on orbit. The most promising possibility today is the Tactically Responsive Space (TacRS) program. Since 2021, this program-originally called Tactically Responsive Launch-has been slowly but steadily progressing on a two-year launch cadence. The 2023 mission, titled VICTUS NOX, involved a satellite and a launch vehicle being rapidly mated, fueled, and launched to an orbit that was not known to the operators until the day before the launch. The successful test demonstrated that the concept is possible. In 2025 the Department of Defense intends to conduct a new, more complicated TacRS mission. That mission, titled VICTUS HAZE, will involve the rapid launch of two separate satellites on two separate rockets. VICTUS HAZE will continue to develop both the ability to rapidly launch a satellite into a previously unspecified orbit and rapidly provide operational capability from that satellite as soon as possible after it is inserted into orbit. Using two rockets and two satellites allows for more testing and more learning, which is exactly what is required for this problem set in today's security environment.

With continued investment, TacRS will provide a unique opportunity to develop a new and needed tool for integrated deterrence. But to truly serve as a deterrent, the Department of Defense will need to signal an intent to continue tests like VICTUS HAZE and VICTUS NOX, ideally eventually converging from a two-year cadence to an annual one. Establishing an annual cadence will send strong market signals to the commercial sector, encouraging further innovation and further investment by private capital. It will drive the Space Force's test program to be more agile, requiring it to rapidly absorb and incorporate lessons learned into year-over-year improvements. And it will send a clear message to potential adversaries that the United States will continue exercising this new deterrence tool until-and after-it becomes routine, and therefore credible.

Fully matured, the TacRS program will ensure that no matter what orbit a new threat object may utilize, the United States will be able to respond quickly, professionally, and precisely.

John Plumb is the former assistant secretary of defense for space policy at the U.S. Department of Defense in Washington, D.C.

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