After resisting working with satellite navigation systems developed by foreign countries for a decade, the U.S. space policy President Obama signed on Monday opens the distinct possibility of using non-U.S. systems to back up and strengthen GPS.
The policy embraces global cooperation, Obama said. "No longer are we racing against an adversary," he noted. "In fact, one of our central goals is to promote peaceful cooperation and collaboration in space, which not only will ward off conflict, but will help to expand our capacity to operate in orbit and beyond."
The new policy said the United States must continue to maintain its global lead in the operation of satellite navigation systems, adding, "Foreign positioning, navigation and timing services may be used to augment and strengthen the resiliency of GPS."
Ray Williamson, executive director of the Secure World Foundation, a nonprofit in Superior, Colo., that works on global space issues, said the language is a significant policy shift for Washington, and called it "a big deal." Only a few years ago the United States tried to dissuade the European Union from developing its navigational system Galileo, a planned constellation of 27 satellites that was scheduled to begin operating in 2014.
But the policy shift recognizes the reality that the United States no longer has an exclusive on satellite navigation, said Elliot Pulham, chief executive officer of the nonprofit Space Foundation in Colorado Springs, Colo.
Russia has invested in its GLONASS navigational system, which it started in 1976, and expects to have 30 satellites in orbit next year. China launched the fourth satellite this month for its planned 35-satellite Compass system, and India announced last month it plans to develop a 24-satellite system.
If these systems are completed, it will result in more than 100 satellites in orbit, which could provide a backup to the United States' 24-satellite GPS system in case one of those satellites goes dark, Pulham said. Satellite navigation receivers, which could pick up signals from more than one of the systems, would have greater precision and better reliability than GPS-only receivers, he added.
Laura Grego, senior staff scientist for the global security program at the Union of Concerned Scientists, said the new policy is aimed at ensuring all receivers can accept signals from multiple systems.
Jeffrey Auerbach, adviser on global navigation satellite systems affairs at the Office of Space and Advanced Technology in the State Department, said in a speech this month at the International Satellite Navigation Forum in Moscow that the United States wants to make sure the systems are compatible.
Interoperabilty, Auerbach said, will provide end users with better capabilities and service than they could get from only one system.