Contract and launch issues are again dogging Europe's Galileo satellite navigation system, which is unlikely to begin operation by its latest 2013 target date.

The timetable for Europe's alternative to the US GPS system is suffering as industry contracts are to be awarded almost a year later than planned. And, it has emerged, the constellation's two-year launching timetable could take much longer, as the Arianespace EADS Astrium-built Ariane 5 launcher will only be able to deploy three spacecraft per launch, not six as originally planned.

The European Commission says that it hopes to conclude contracts in the period around the end 2009 and the start of 2010, but in September 2008 it announced that Galileo's six work packages' contracts would be awarded from the first to the third quarters of this year.

Italian space agency commissioner Enrico Saggese says that a reason for the delay is that "the content of the contracts is changing. We are not happy about this."

Under the original deployment plan, after four in-orbit validation spacecraft are launched by Starsem-provided Soyuz rockets, the Ariane 5 and more Soyuz launchers would lift off with 20 satellites to make up the 24 needed for global coverage. The remaining 20 had been due to be launched with four Soyuz rockets carrying eight satellites and two Ariane 5s launching 12 spacecraft, all over two years.

But with Ariane 5's Galileo satellite dispenser only able to deploy three spacecraft, the plan will demand more Ariane launches and increased funding. If only Soyuz rockets were used, the programme would need eight launches, not six, for the 20 satellites that with the validation units make up the full global coverage.

Then another four rockets would be needed to complete the planned constellation of 30 spacecraft, including in-orbit spares that could be activated in case of failure.

Asked whether Ariane 5 would be dropped, the EC says: "We are in the process of negotiating with Arianespace the launch contract and it is too early to draw any conclusions."

Source: Flight International