Virgin Galactic returns to Spaceport America for exercises

Over and over again, Virgin Galactic's WhiteKnightTwo was put through the paces as the pilots, ground crew and mission control specialists checked off some of the numerous ground and air exercises scheduled this week as the team prepares for future commercial space flights.

A special cargo plane of sorts, the aircraft is designed to carry the company's rocket ship — called SpaceShipTwo — to high altitudes where it will detach and take paying tourists the rest of the way to the edge of space.

After years of development, Virgin Galactic appeared to be nearing the goal of turning ordinary civilians into astronauts when the first SpaceShipTwo broke apart on Oct. 31, 2014, during its fourth rocket-powered flight over the Mojave Desert, killing the pilot.