The Galileo Project
Why Europe wants its own satellite navigation program.
- By Craig Mellow
- Air & Space magazine, April 2013
Artist's conception of a Galileo validation satellite in orbit. If successful, Galileo will be the world's third global satellite navigation system.
ESA
(Page 3 of 5)
Galileo’s main difference from GPS is an orbital altitude 3,000 kilometers (1,864 miles) higher, which in turn points the satellites at a sharper angle back toward Earth: 56 degrees instead of 52. This will yield two benefits, project director Marco Falcone says: better coverage in “urban canyons,” where surrounding buildings can interfere with the GPS signal, and in the polar regions that European and other companies will increasingly be tapping for oil and other resources.
Galileo also aims to improve on GPS with a new kind of onboard clock powered by hydrogen laser technology. Very reliable clocks are essential: A deviation of one nanosecond—one-billionth of a second—per day translates to a 30-centimeter (12-inch) mistake in location, Falcone says. Galileo’s new clock will make the system more accurate than the current generation of GPS, which has a “worst case” margin of error of 7.8 meters (compared with Galileo’s four).
So far, the hydrogen laser clocks are working perfectly on the test satellites. That may be because funders threw politics aside to engage super-clockmaker Spectratime, whose Swiss facilities are outside the EU entirely. (Its parent company, Orolia, is French.) “The clocks were seen as quite high-risk, but they have turned out to be the least of the problems,” says Richard Peckham, a British executive with satellite maker Astrium.
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The backroom struggle over a Galileo partnership—the public-private idea being backed by the capitalist-oriented north (Britain, Germany, and the Netherlands) but opposed by the Social Democratic south (France, Italy, and Spain)—was resolved by an unlikely party: the U.S. Department of Defense. Europe’s leaders were still struggling for consensus at the time of the terrorist attacks of September 11, 2001. Washington’s attitude abruptly hardened toward anything conceivably related to security, including a rival satellite network in the hands of its allies.
In December 2001, all 15 EU military ministries received a letter from Paul Wolfowitz, U.S. deputy secretary of defense, urging them to reconsider Galileo. The European network, he argued, could end up hogging spectrum that the U.S. military wanted for future GPS applications. That would “significantly complicate our ability to ensure availability of critical military GPS services in a time of crisis or conflict,” he wrote.
Wolfowitz went on to impugn the competence of mere civilians to mess with strategic satellite navigation technology. “I do not believe the current civil forum being used by the EC provides the proper venue to fully assess the security implications,” he wrote.
His missive backfired badly, rallying Europe around Galileo rather than scaring it off. French President Jacques Chirac, the continent’s most vocal critic of America’s post-9/11 policy, personally took up the cudgels for Galileo. The program, Chirac said, was essential to keep united Europe from becoming a “vassal” of the United States. It meant, he said, “we would not have to accept subjugation in space matters.”
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