Live coverage: Ariane 5 lifts off on its first Galileo launch

Two astronauts ventured outside the International Space Station Friday for the first of four spacewalks to repair a $2 billion cosmic ray detector, breezing through work to prep the device for invasive surgery to splice in new coolant pumps and extend the instrument’s life probing the composition of the universe.

Rolling out for its first liftoff of the year, an Ariane 5 rocket journeyed out of a launcher assembly building Thursday and rode railroad tracks to its launch pad in French Guiana with two European communications satellites.

Firing off a launch pad on the fringes of the Amazon rainforest, a European Vega rocket climbed into space Tuesday night and deployed a new optical surveillance craft for the Italian military and a French-Israeli environmental satellite to monitor vegetation, snow cover and coastal waterways.