A Boeing-Lockheed joint venture's launch of a new Vulcan rocket this week inaugurated a formidable rival to Elon Musk's SpaceX, a milestone long sought by the U.S. government as it seeks to build a list of launch suppliers for its satellites. Boeing and Lockheed Martin's United Launch Alliance sent Vulcan into space for the first time on Monday, a first step toward reclaiming market share from SpaceX, whose reusable Falcon 9 rocket for years has been the main option for countries to get their satellites into space. "This launch puts ULA in the front-runner position to challenge SpaceX's de facto monopoly over launch," said Caleb Henry, a space analyst at Quilty Analytics.