Kellye Burns, right, a space test engineer, hands a material sample to Eric D'Ambro, a test operations engineer, that will be tested in a Space Asset Resilience thermal vacuum chamber, Aug. 3, 2020, at Arnold Air Force Base, Tenn. Materials and space systems can be subjected to the natural and induced threat sources, such as protons, electrons, solar, atomic oxygen, thruster ions, material outgassing and spacecraft charging.(U.S. Air Force photo by Jill Pickett)