Europe’s next two Galileo satellites have received technical clearance for their launch this Friday. They are currently resting in place atop their Soyuz launcher.
Yesterday saw the three-stage Soyuz ST-B launcher moved horizontally to the launch pad on the 600-meter long railway. It was then lifted into the vertical position to await the attachment of the Upper Composite — the combination of twin Galileo satellites, the dispenser holding them in place, the Fregat-MT upper stage and the protective fairing.
Meanwhile, the satellites themselves underwent their formal Launch Readiness Review, after which the Upper Composite joined the Soyuz at the launch pad to be mated to the Soyuz that evening using the mobile gantry. The Soyuz and Upper Composite will undergo a full launch dress rehearsal in the remaining days before the 18:15:00 GMT (20:15:00 CEST) launch on October 12, including preparations for fueling the vehicle, which will begin four and a half hours before liftoff.
This follow-up launch marks a major step for Europe’s own satellite navigation system. Four is the minimum number of satellites needed to achieve a navigational fix on the ground, with one satellite each to measure latitude, longitude, altitude and provide a time reference. So once this second pair of satellites has been commissioned and tested, the quartet will form a completely operational mini-constellation that will be used to validate the Galileo system.
The performance of the satellites in space together with the worldwide ground infrastructure serving to maintain Galileo’s service accuracy will be assessed in depth, to prepare the way for the launch of further satellites and then deliver initial services by mid-decade and finally build up to full operational capability.
These two new satellites are also the first to carry search and rescue antennas to pinpoint aircraft and ships in distress as part of the international Cospas–Sarsat system.