The move casts doubts on the European Unions claim that the ý£2.3 billion ($4 billion) project can pay for itself.

The Cornells team efforts, including the codes and methods used to extract them, were described in this months issue of GPS World which means that anyone with a navigation device that uses pseudo random number (PRN) codes could access Galileo for no charge.

However, the European Commission suggests that the Cornell effort to crack the code is irrelevant, as the final codes for the system would be different from that in the prototype, and would in any case be made available at the appropriate time.

The Cornell team applied a computer algorithm to the signal coming from the GIOVE-A (Galileo In-Orbit Validation Element-A) satellite to extract the codes that keep the public from accessing that signal.

GIOVE-A is the prototype satellite for the planned 30-satellite network that the European Union, European Space Agency, and private investors, including, controversially, a company closely linked with the Chinese state, plan to launch by 2010 to compete with the U.S. Global Positioning System network. Because GPS satellites, which were put into orbit by the Department of Defense, are funded by U.S. taxpayers, the signal is free -- consumers need only purchase a receiver. The backers of Galileo, however, planned to charge a fee for the PRN codes.

Since Galileo and GPS will share frequency bandwidths, Europe and the U.S. signed an agreement whereby some of Galileo's PRN codes must be "open source." Nevertheless, after broadcasting its first signals this January, none of GIOVE-A's codes had been made public.

The Cornell team requested access to the codes but were refused, so they decided to try and pull the codes off the air, using powerful antennae and huge amounts of signaling power. They succeeded in April and published the codes on the Internet. Galileo responded by publishing the PRN codes, but they weren't the codes currently used by the GIOVE-A satellite. Furthermore, the same publication labeled the open source codes as intellectual property, claiming a license is required for any commercial receiver.

This means, the Cornell team suggests, they were trying to make money out of open source code, an accusation the Galileo backers deny.

According to Cornell lawyers, their efforts were perfectly legal: Creative intellectual property such as music or literature is protected by law, but codes for a navigational system are fair game.