US builds ‘spacecraft speedometer’ to enhance satellite navigation without GPS

Los Alamos National Laboratory and the U.S. Air Force Academy have created a "spacecraft speedometer" to measure satellites' velocity without GPS. The device uses two plasma sensors to detect charged particles, calculating speed by comparing front and back particle hits. This technology could enhance space traffic management and orbit sustainability as satellite numbers increase. The speedometer can also measure the local space environment and function without GPS, making it valuable near other planets or during space weather events.