Scaled Composites, founded by renowned aircraft designer Burt Rutan, historically has kept the timing of important test flights under wraps partly to prevent crowds from gathering at the Mojave airport, and partly to avoid putting undue pressure on project managers to launch or take off.
Last month, Mr. Whitesides said in an interview that after the test flights are completed, Virgin Galactic would like to retain "some kind of relationship" with Scaled Composites, but he didn't provide specifics.