Live coverage: International crew lands in Kazakhstan

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.

With one last task to carry out, a space station Cygnus cargo ship loaded with trash and no-longer-needed equipment fell back to Earth Wednesday, hitting the discernible atmosphere 60 miles or so above the Pacific Ocean at nearly 5 miles per second.

A modified Russian missile built for nuclear war blasted off on a peaceful mission Friday, targeting placement of a European Earth observation satellite in orbit to measure atmospheric chemistry and global air quality. Liftoff from the Plesetsk Cosmodrome in northern Russia occurred at 0927 GMT (5:27 a.m. EDT).