Europe's Galileo satellite-navigation system has reached a key milestone after the first two operational spacecraft passed performance-verification tests.

Satellite operator Telespazio and the German Space Agency DLR have received and validated the functionality of encrypted signals that will enable provision of Galileo public regulated services. The tests supplemented work carried out by the European Space Agency in Redu, Belgium.

The Galileo mission is managed by Spaceopal, a joint venture between Telespazio and DLR-GfR, which runs Galileo control centres at Telespazio's Fucino Space Centre in Abruzzo, and in Oberpfaffenhofen, near Munich. Galileo is intended as an alternative to the Global Positioning System, in increasingly used satellite-assisted landings and as a source for area navigation.

The first two satellites were launched in October 2011 by a Soyuz vehicle from the European Space Agency's centre in Kourou, French Guiana, The in-orbit validation phase of the Galileo programme will be completed with the Soyuz launch of the next two satellites at the end of the summer.

A rapid launch plan aims to orbit 18 satellites by the end of 2014 for a functional service, and 26 satellites by the end of 2015 for near-global coverage. The full constellation of 27 spacecraft and three orbiting spares should be deployed by 2019.

From the second half of 2014, a requalified Ariane launcher, known as Ariane 5 ES Galileo, should be equipped with a four-satellite dispenser and be capable of delivering the spacecraft to orbital altitudes of 23,200km. The current ES launcher is used to launch ESA's Automated Transfer Vehicle to the International Space Station at about 380km.

Source: Flight International