October 12nd, 2012

Second launch of twin Galileo satellites

Europe’s own satellite navigation system will come a step nearer today, with the second launch of twin Galileo satellites. Bradford deliverd Coarse Sun Sensors (128) and Fine Sun Sensors (16) for the Galileo Satellites.

Click on the descriptions below the photos to see where the sun sensors are located.

Bradford Fine Sun Sensor

Bradford Coarse Sun Sensor
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 perform a timing check. A successful launch would put four Galileo IOV spacecraft in orbit, the minimum number needed to provide enough signals to achieve a position fix on the ground. The two satellites are also the first to carry search and rescue antennas to help locate aircraft and ships in distress as part of the international COSPAS–SARSAT system.

The two Galileo In-Orbit Validation satellites are protected during their launch by Soyuz by a launch fairing. Once the Soyuz has passed most of the way through the atmosphere, this fairing can then be ejected.

The Galileo satellite navigation system will consist of a total of 30 spacecraft in three planes in medium Earth orbit, which will each be occupied by nine satellites, and with three spares satellites distributed on the three orbital planes. Galileo is the first joint program to be shared between the European Space Agency and the European Union.

The pair of in-orbit validation (IOV) spacecraft have been enclosed within their protective fairing and moved to join the Soyuz rocket on the launch pad at the European spaceport in Kourou, French Guiana. Live streaming will begin at 17:48 GMT (19:48 CEST) for about 1 hour. From launch to final deployment, when the dispenser releases the satellites sideways in opposite directions, takes three hours and 44 minutes. Live coverage resumes at 21:25 GMT (23:25 CEST). Watch the launch on the ESA website.