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 IMAGE: Download Image: Full Size (1.75 MB) Tags: Shanahan, Donald J. Trump, President, Vice Chairman, Selva, Space Force, Acting Defense Secretary Photo By: Tia Dufour VIRIN: 190219-D-HG842-0472.JPG Photo Gallery