NASA officials signed a memorandum of understanding Tuesday with a U.S. company, Virgin Galactic, LLC, to explore the potential for collaborations on the development of space suits, heat shields for spaceships, hybrid rocket motors and hypersonic vehicles capable of traveling five or more times the speed of sound. Seated from left are: NASA Deputy Administrator Shana Dale, Alex Tai, chief operating officer for Virgin Galactic LLC, and S. Pete Worden, director of NASA Ames Research Center, Moffett Field, Calif.