John Plumb speaks on Aug. 28, 2024, at a GovExec Space Project event in Washington, D.C. Samuel Robbins / Defense One
US falling dangerously behind China on GPS development: Pentagon’s former space-policy leader
The Pentagon needs other position-navigation-timing systems if it loses connection to GPS satellites.
The United States isn’t working quickly enough to replace its aging and vulnerable GPS system, according to the Pentagon’s former space policy chief.
“We are falling behind. We aren't modernizing constellation signals fast enough,” John Plumb said Wednesday at a GovExec Space Project event.
China is developing a comprehensive and modernized position-navigation-timing architecture that integrates space and ground layers, Plumb said, while the Pentagon relies on about two dozen satellites to guide its planes, ships, and weapons.
“One of the things the [Defense] department is worried about is: you have 24 GPS satellites, roughly, providing all these signals for the whole planet, both commercial [and] civil signals, but also for the military. That's 24 [anti-satellite] missiles that remove that completely,” said Plumb, who served for two years as the first-ever assistant defense secretary for space policy until he stepped down in May.
The Pentagon has been trying to find technologies that can provide alternatives to GPS satellites. Advances in quantum technology and other systems that use on-board sensors to locate themselves without a constellation of satellites could be promising, but the U.S. isn’t fielding them fast enough, Plumb said.
The right path, Plumb said, is a kind of mosaic GPS architecture that involves space-based systems and other versions of timing systems on Earth.
“It's just a question of, why are we so slow at it?” he said.
The U.S. still needs a modern GPS system to serve as the “backbone,” but the military also needs other position and timing systems available if a weapon loses that signal, Plumb said.
“The question is—are there other versions of timing systems available as well? So these are all good questions. But the fact is, timing signals decay, the farther away they are from the distributed system, so how do you keep your timing signals, which are kind of absolutely essential to our current systems?” Plumb said.
The President’s National Space-based PNT Advisory Board has recently issued some “stark warnings” about the low attention given to developing PNT, Plumb said, so the problem is starting to gain some traction.