A Soyuz rocket launched two Galileo satellites into orbit on
Friday, marking a crucial step for Europe’s planned navigation
system, operator Arianespace announced. The launch took place at
the Kourou space base in French Guiana, at 3:15pm (6:15pm GMT).
Three and three-quarter hours later, the 700kg satellites were
placed into orbit. The new satellites add to the first two in
the Galileo navigation system, which were launched on Oct. 21,
last year. Together they create a “mini-constellation.” Four is
the minimum number of satellites needed to gain a navigational
fix on the ground, using signals from the satellite to get a
position for latitude, longitude, altitude and a time reference.
Galileo will ultimately consist of 30 satellites, six more than
the US Global Positioning System. By 2015, 18 satellites should
be in place, which is sufficient for launching services to the
public, followed by the rest in 2020, according to the European
Space Agency. It is claimed that the system will be accurate to
within one