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Once Cygnus is loaded with supplies, the spacecraft, along with its rocket thrusters is mated to the Antares launch vehicle in an assembly building at Wallops Island. Here, the two vehicles are joined for the first time and technicians run an initial systems check of the entire assembly. They are held together with frangible rings that readily break free for staging after launch. When this is finished, the combined spacecraft will be rolled out to the launch pad. Photo: Orbital Sciences Corp.