The rise of SpaceX as the dominant force for U.S. rocket launches has meant that NASA's role is now evolving. To find out what this means for the future of the space agency, WSJ's George Downs sat down with NASA Deputy Administrator Pam Melroy. Photo Illustration: George Downs

SpaceX's soaring revenue helped it eke out a small profit in the first three months of the year after two annual losses, according to documents that offer a rare view into the financials of Elon Musk's rocket company.