U.S. Air Force General Lori Robinson, Commander of the North American Aerospace Defense Command and U.S. Northern Command speaks during the NORAD 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD photo by Lewis Carlyle)

Royal Canadian Air Force’s Snowbirds aerial demonstration team perform a flyover during the North American Aerospace Defense Command’s 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD photo by Lewis Carlyle)

Royal Canadian Air Force’s Snowbirds aerial demonstration team perform a flyover during the North American Aerospace Defense Command’s 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD photo by Lewis Carlyle)

U.S. and Canadian military aircraft assigned to the North American Aerospace Defense Command mission perform a flyover during the command’s 60th Anniversary Ceremony at Peterson Air Force Base, Colorado, May 12, 2018. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD photo by Lewis Carlyle)

Canadian Chief of the Defence Staff, General Jonathan H. Vance speaks during the NORAD 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD photo by Lewis Carlyle)

Members of the North American Aerospace Defense Command and U.S. Northern Command and invited guests salute during the singing of the Canadian and U.S. National Anthems during the unveiling ceremony for a memorial cairn outside the NORAD and USNORTHCOM headquarters building on Peterson Air Force Base, Colorado, May 11. The cairn honors the Canadian service men and women who passed away while serving at NORAD in Colorado Springs. The placement and dedication of the cairn was conducted in conjunction with the 60th Anniversary of NORAD and the U.S. Canadian binational NORAD agreement. (DoD Photo By N&NC Public Affairs)

U.S. Air Force General Lori Robinson, Commander of the North American Aerospace Defense Command and U.S. Northern Command and Canadian Lt. Gen. Pierre St-Amand, the NORAD Deputy Commander pause for a photo during the unveiling ceremony for a memorial cairn outside the NORAD and USNORTHCOM headquarters building on Peterson Air Force Base, Colorado, May 11. The cairn honors the Canadian service men and women who passed away while serving at NORAD in Colorado Springs. The placement and dedication of the cairn was conducted in conjunction with the 60th Anniversary of NORAD and the U.S. Canadian binational NORAD agreement. (DoD Photo By N&NC Public Affairs)

U.S. Air Force General Lori Robinson, Commander of the North American Aerospace Defense Command and U.S. Northern Command and Canadian Lt. Gen. Pierre St-Amand, the NORAD Deputy Commander salute during the playing of the Last Post and missing-man formation flyover by the Royal Canadian Air Force’s Snowbirds aerial demonstration team on Peterson Air Force Base, Colorado, May 11. The ceremony was part of the placement and dedication of a cairn to honor the Canadian service men and women who passed away while serving NORAD. The placement of the cairn was conducted in conjunction with the 60th Anniversary of NORAD and the U.S. Canadian binational NORAD agreement. (DoD Photo By N&NC Public Affairs)

(From left to right) The Honorable Cory Gardner, U.S. Senator for Colorado, Gen. Lori J. Robinson, commander of the North American Aerospace Defense Command and U.S. Northern Command, and Gen. Jonathan Nance, Chief of the Defence Staff of the Canadian Armed Forces, pause for a photo during the NORAD 60th Anniversary Ball in Colorado Springs, Colo., May 11, 2018. The NORAD 60th Anniversary Ball commemorates 60 years of binational cooperation between the U.S. and Canada for the defense of North America. Established in 1958, NORAD is the world's only binational military command. (DoD photo by Staff Sgt. Emily Kenney, USAF)

The Honorable Seamus O’Reagan, the Canadian minister of Veteran’s Affairs, speaks to guests at the NORAD 60th Anniversary Ball in Colorado Springs, Colorado, May 11, 2018. The NORAD 60th Anniversary Ball commemorates 60 years of binational cooperation between the U.S. and Canada for the defense of North America. Established in 1958, NORAD is the world's only binational military command. (DoD photo by Staff Sgt. Emily Kenney, USAF)

General Lori J. Robinson, commander of North American Aerospace Defense Command and U.S. Northern Command, speaks during the NORAD 60th Anniversary Ball in Colorado Springs, Colorado, May 11, 2018. The NORAD 60th Anniversary Ball commemorates 60 years of binational cooperation between the U.S. and Canada for the defense of North America. Established in 1958, NORAD is the world's only binational military command. (DoD photo by Staff Sgt. Emily Kenney, USAF)

Royal Canadian Air Force’s Snowbirds aerial demonstration team perform a flyover during the North American Aerospace Defense Command’s 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD Photo By: Jhomil Bansil)

Vice Chairman of the Joint Chiefs of Staff, U.S. Air Force General Paul J. Selva speaks during the NORAD 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD Photo By: Jhomil Bansil)

Distinguished guests attend the North American Aerospace Defense Command’s 60th Anniversary Ceremony on Peterson Air Force Base Colorado, May 12. The ceremony and static display of various NORAD aircraft was the culmination of a three-day event, which included a media tour of Cheyenne Mountain Air Force Station, the dedication of a cairn outside the commands’ headquarters building memorializing the Canadians who have passed away while serving NORAD, and a fly over in missing-man formation performed by the Royal Canadian Air Force’s Snowbirds aerial demonstration team. (DoD Photo By: Jhomil Bansil)