Galileo satellite fleet apparently reduced

Galileo satellite fleet apparently reduced

Order for final six birds put on indefinite hold

Indications have emerged of possible delays or cuts to the European Galileo satellite navigation system. Orders for several satellites, expected to be placed this year, have been placed on indefinite hold.

Galileo at present has only Galileo In-Orbit Validation Element (GIOVE) test sats in orbit, intended to prove the technology and keep hold of the system's spectrum slots. Plans had called for 28 operational spacecraft to be deployed in addition, but it now appears that Galileo may operate for some time with only 26. This is two more than necessary for global coverage, but more satellites would offer better performance to users.

Flight International reported yesterday that Fritz Merkle, COO of German satellite builder OHB System, says that the initial Galileo constellation will consist of four satellites previously ordered and expected to be launched in 2010, plus a further batch of 22, ordered this month by the European Commission. It had been expected that the EC would order the further 26 required for a total of 30 at this point.

Galileo planners had always intended to deploy more than the bare minimum 24 spacecraft required for global coverage. The system is intended to match or exceed the performance offered by America's Global Positioning System (GPS) constellation, and GPS users have in recent years benefited from a strong fleet of more than 30 operational satellites.

While Galileo will use more modern technology than the older GPS spacecraft, the US will also gradually replace its sats with superior technology - though it has lately been asserted by the US Government Accountability Office that mismanagement and lack of funds for GPS will see the American constellation's performance decline seriously in coming years.

Flight quotes the EC as saying that "We are ordering in two batches. The first batch will contain 22 and the second one, six. A decision still needs to be taken when we will order the second batch."

The second batch would apparently include two spares to be kept on the ground until needed, leaving 28 in orbit. However it would appear that until something changes, Galileo will have just 26 satellites - with global coverage being threatened in the event of more than one mishap or loss.

There was great difficulty assembling funds for Galileo, with planned industrial participation failing to materialise and extra public funds clawed back from unspent farm subsidies - most of which would normally have returned to the treasuries of the EU's main paymasters, Britain, Germany and the Netherlands.

The Brussels contract postponement could lead one to speculate that costs have escalated on Galileo, and that in fact the last four birds won't be ordered until more cash can be found - which, based on the byzantine negotiations thus far, could take a long time. As Flight notes, officially speaking Galileo is still projected to cost the same as it was years ago - which if true would be quite unusual for a multinational high-tech space project, especially one so riven by porkbarrel politics.

Regardless of that, it would appear that neither Galileo nor GPS will be operating at full potential for at least part of the coming decade - though neither seems likely to fall below global coverage. Ordinary civilian users needn't fear any major consequences, however; the two systems are designed to work together, and it will be possible to buy receivers which use both at once.

With a combined fleet of 50+ to draw on, a combo GPS/Galileo receiver should work just fine, no matter if either system alone is looking a bit spotty. �