WASHINGTON — Orbital Sciences Corp., one of two companies under contract with NASA to deliver cargo to the international space station, has rolled the core stage of its Antares rocket out to the launch pad for several days of fitting tests.

This post is only available to members.

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...