Official Signing President Donald J. Trump, joined by Acting Defense Secretary Patrick M. Shanahan, left, and Air Force Gen. Paul J. Selva, vice chairman of the Joint Chiefs of Staff, far left, signs the Space Policy Directive 4 in the Oval Office at the White House, Feb. 19, 2019. SHARE: Download: Full Size (1.75 MB) Tags: Shanahan, Donald J. Trump, President, Vice Chairman, Selva, Space Force, Acting Defense Secretary Credit: Tia Dufour VIRIN: 190219-D-HG842-0472.JPG Photo Gallery