A network of eight tracking stations worldwide, operated by the European Space Agency. The stations provide links between satellites in orbit and the ground configuration control room (GCCR) in the operations control centre (OCC) at Darmstadt, Germany. One of the stations is mobile and can be transported anywhere in the world. The seven permanent ground stations are located at Kiruna, Sweden; Redu, Belgium; Maspalomas, Spain; Villafranca, Spain; Malindi, Kenya; Perth, Australia; and Kourou, French Guiana.