Live coverage: Russian-American-British crew launches toward space station

Two NASA astronauts and an Italian flight engineer are sheltering in the space station’s Russian segment as mission control analyzes a possible leak of toxic ammonia coolant aboard the complex.

The Rosetta spacecraft neared its comet Saturday, targeting a close flyby within four miles of the tiny world’s jagged nucleus to gain new up-close views of the comet and taste the growing vaporous cloud surrounding it.

A Russian Soyuz rocket made a railroad journey Wednesday to its launch pad in Kazakhstan, two days before blastoff with a crew of three spaceflight veterans from the United States, Italy and Russia heading for the International Space Station.