Photos: Atlas 5 rocket aims for International Space Station

A Northrop Grumman Antares rocket rolled out of its hangar Monday night, riding a self-propelled transporter for a mile-long trip to launch pad 0A on Wallops Island, Virginia, for a predawn liftoff Thursday with a Cygnus supply ship heading for the International Space Station.

A powerful European Ariane 5 rocket blasted off from French Guiana late Friday and boosted a pair of satellites into space for a seven-year plunge into the inner solar system, a voyage requiring seven planetary flybys to slow down enough in the sun’s gravitational clutches to slip into orbit around hellish Mercury.

Japanese officials halted a countdown Monday at the Tanegashima Space Center when teams overseeing preparations for launch of an H-2A rocket detected a nitrogen gas leak, prompting the return of the launcher and its Japanese government payload to a nearby assembly building for repairs.