Spacecraft Speedometer: Enabling Precision Orbit Determination for Satellite Traffic Management in the GPS-Denied Regime

The Spacecraft Speedometer, developed by Los Alamos National Laboratory and the United States Air Force Academy, is a compact, low-power, and cost-effective instrument designed to provide real-time spacecraft speed in GPS-denied environments. As global satellite traffic increases and the number of objects in low-Earth orbit (LEO) exceeds 10,000, precise orbit determination has become a critical necessity for space traffic management and collision avoidance. The Spacecraft Speedometer enables autonomous orbit estimation by comparing ion fluxes in the ram and wake directions as a spacecraft traverses the ionosphere. When combined with advanced data processing and correction algorithms, the system matches GPS-based speed measurements to an average absolute accuracy of 9.7% on held out test orbits. This technology addresses fundamental gaps in orbit prediction during space weather events and enables autonomous maneuvering and constellation safety in a congested and increasingly volatile orbital environment.