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U.S. Air Force Col. Marcie Lewis, incoming 21st Medical Group commander, accepts the guidon from U.S. Space Force Col. Kenneth Klock, Space Base Delta 1 commander, during the 21st MDG change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. The passing of the guidon represents a formal transfer of authority and responsibility from an outgoing commander to an incoming one. (U.S. Space Force photo by Tiana Williams)

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260717-X-IF173-6612

U.S. Air Force Col. Marcie Lewis, incoming 21st Medical Group commander, renders her first salute to a formation of Airmen during the 21st MDG change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. The first salute symbolizes the commander's assumption of leadership and commitment to the Guardians and Airmen of the unit. (U.S. Space Force photo by Tiana Williams)

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260717-X-IF173-1104

U.S. Air Force Col. Marcie Lewis, incoming 21st Medical Group commander, gives remarks during the 21st MDG change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. Lewis assumed responsibility for leading the 21st MDG, providing medical, dental, and ancillary care to more than 36,000 beneficiaries across Peterson SFB, Schriever SFB, and Cheyenne Mountain Space Force Station. (U.S. Space Force photo by Tiana Williams)

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260717-X-IF173-1043

U.S. Space Force Col. Kenneth Klock, Space Base Delta 1 commander, gives remarks during the 21st Medical Group change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. Klock presided over the ceremony, marking the official transfer of command of the 21st MDG from U.S. Air Force Col. Gloria Walski to U.S. Air Force Col. Marcie Lewis. (U.S. Space Force photo by Tiana Williams)

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260717-X-IF173-1009

U.S. Air Force Col. Gloria Walski surrenders the guidon to U.S. Space Force Col. Kenneth Klock, Space Base Delta 1 commander, during the 21st Medical Group change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. The passing of the guidon represents a formal transfer of authority and responsibility from an outgoing commander to an incoming one. (U.S. Space Force photo by Tiana Williams)

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21 MDG Change of Command

Published July 24, 2026
By Tianna Williams
Space Base Delta 1 Public Affairs

PETERSON SPACE FORCE BASE, Colo. -- U.S. Air Force Col. Marcie Lewis, incoming 21st Medical Group commander, accepts the guidon from U.S. Space Force Col. Kenneth Klock, Space Base Delta 1 commander, during the 21st MDG change of command ceremony at Peterson Space Force Base, Colorado, July 17, 2026. The passing of the guidon represents a formal transfer of authority and responsibility from an outgoing commander to an incoming one. (U.S. Space Force photo by Tiana Williams)

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