Pituffik Space Base
Pituffik Space Base, formerly Thule Air Base, is a United States Space Force base located on the northwest coast of Greenland in the Kingdom of Denmark under a defense agreement between Denmark and the United States. As of 2025, about 150 United States service members are permanently stationed there, after the United States significantly reduced its presence from 6,000 personnel during the Cold War.
Denmark was a founding member of NATO in 1949, and the 1951 Greenland Defense Agreement has allowed the United States to operate the base under a NATO framework, as long as both Denmark and the United States remain NATO members. Under the agreement, the United States has exclusive jurisdiction over its facilities at the base, but with the Danish flag being required to be flown over the base alongside the American flag and the Danes having the right to station a consulting liason officer at the base. The 1951 agreement was modified in 2004 to require that the Greenlandic flag also be flown over the base and giving the Greenlandic government the right to appoint a liaison officer for the base. Danish Prime Minister Mette Frederiksen has referred to this recently. If the Americans want to expand their military presence beyond that, they only must consult and inform the authorities in Nuuk and Copenhagen.
Trump won the US presidential election on 5 November 2024. On 23 December 2024, he
renewed his interest in Greenland and claimed that ‘ownership and control of Greenland’ was an ‘absolute necessity’ for the US – ‘for reasons of national security’.
Therefore, a new parliament was elected ahead of schedule in Greenland on 11 March 2025.
In response to the Greenland crisis, Colonel Susannah Meyers, U.S. Space Force, the highest-ranking U.S. officer in Greenland and the base commander, said Trump's threats against Greenland were "not reflective of Pituffik Space Base". She was relieved of her command.
It is the northernmost Department of Defense installation, north of the Arctic Circle and from the North Pole. Pituffik's Arctic environment includes icebergs in North Star Bay, two islands, a polar ice sheet, and Wolstenholme Fjord. The base is home to a substantial portion of the global network of missile warning sensors of Space Delta 4, and space surveillance and space control sensors of Space Delta 2, providing space awareness and advanced missile detection capabilities to North American Aerospace Defense Command, the United States Space Force, and joint partners.
Pituffik Space Base is also home to the 821st Space Base Group and is responsible for space base support within the Pituffik Defense Area for the multinational "Team Pituffik" population. The base hosts the 12th Space Warning Squadron, which operates a Ballistic Missile Early Warning System designed to detect and track ICBMs launched against North America. The base is also host to Detachment 1 of the 23rd Space Operations Squadron, part of the Space Delta 6's global satellite control network. The airfield's runway handles more than 3,000 US and international flights per year. The base is also home to the northernmost deep water port in the world.
History
Location and original population
In 1818, Sir John Ross's expedition made first contact with nomadic Inughuit in the area. James Saunders's expedition aboard HMS North Star was marooned in North Star Bay in 1849–50 and named landmarks. In 1910 explorer Knud Rasmussen established a missionary and trading post there. He called the site "Thule" after classical ultima Thule; the Inuit called it Umanaq or Uummannaq, and the site is commonly called "Dundas" today. Whaling captain, explorer, and ethnologist George Comer discovered a midden, dubbed Comer's Midden, at Umanaq in 1916, and an archaeological excavation subsequently revealed a village of the proto-Inuit who came to be called the Thule people. The United States abandoned its territorial claims in the area in 1917 in connection with the purchase of the Virgin Islands. Denmark assumed control of the village in 1937.A cluster of huts known as Pituffik stood on the wide plain where the base was built in 1951; a main base street was named Pituffik Boulevard. The population was forcibly relocated to Thule. Later in 1953, the USAF planned to construct an air defense site near that village, and in order to limit contact with soldiers, the Danish government again relocated 130 inhabitants of "Old Thule", settling them north in a newly constructed village also named Thule.
In a Danish Supreme Court judgment of 28 November 2003, the move was considered an expropriative intervention. During the proceedings, the Danish government recognized that the movement was a serious interference and an unlawful act against the local population. The Thule tribe was awarded damages of 500,000 kroner, and the individual members of the tribe who had been exposed to the transfer were granted compensation of 15,000 or 25,000 kroner each. A Danish radio station continued to operate at Dundas, and the abandoned houses remained. The USAF used that site only for about a decade, and it has since returned to civilian use.
Knud Rasmussen was the first to recognize the Pituffik Plain as ideal for an airport. USAAF Colonel Bernt Balchen, who built Sondrestrom Air Base, knew Rasmussen and his idea. Balchen led a flight of two Consolidated PBY Catalina flying boats to Thule on 24 August 1942 and then sent a report advocating an air base to USAAF chief Henry "Hap" Arnold. However, the 1951 air base site is a few kilometers inland from the original 1946 airstrip and across the bay from the historical Thule settlement; an ice road connects it. The joint Danish-American defense area, designated by treaty, also occupies considerable inland territory in addition to the air base itself.
World War II
After the German occupation of Denmark on 9 April 1940, Henrik Kauffmann, Danish Ambassador to the United States, agreed "In the name of the king" with the United States, authorizing the United States to defend the Danish colonies on Greenland from German aggression. This agreement faced Kauffmann with a charge of high treason by the protectorate Government. Beginning in the summer of 1941, the United States Coast Guard and the War Department established weather and radio stations at Narsarsuaq Airport, Sondrestrom Air Base, Ikateq, and Gronnedal. In 1943 the Army Air Forces set up weather stations Scoresbysund on the east coast around the southern tip of Greenland, and Thule to be operated by Danish personnel. Many other sites were set up, but BW-6, isolated in the far North, was then of very minor importance.Joint weather station
After liberation, Denmark ratified the Kauffmann treaty but began efforts to take over US installations. Nonetheless, in the summer of 1946, the radio and weather station was enhanced with a gravel airstrip and an upper-air observatory. This was part of an American-Canadian initiative to construct joint weather stations in the High Arctic. This station was under joint US-Danish operation. The location changed from the Thule civilian village to mainland Pituffik. From 1946 to 1951, the airstrip played an important role in Arctic resupply, aerial mapping, research, and search-and-rescue.The treaty's ratification in 1951 did not change much, except that the Danish national flag must be side by side with the US national flag on the base.
Thule Air Base
In 1949, Denmark joined the North Atlantic Treaty Organization and abandoned its attempt to remove the United States bases. By the outbreak of the Korean War next year, the USAF embarked on a global program of base-building in which Thule would be considered the crown jewel owing to its location across the Pole from the Soviet Union, as well as its merit of being the northernmost port to be reliably resupplied by ship. Thule became a key point in American nuclear retaliation strategy. Strategic Air Command bombers flying over the Arctic presented less risk of early warning than using bases in the United Kingdom. Defensively, Thule could serve as a base for intercepting bomber attacks along the northeastern approaches to Canada and the United States.A board of Air Force officers headed by Gordon P. Saville recommended pursuing a base at Thule in November 1950. It was subsequently supported by the Joint Chiefs of Staff and approved by President Truman. To replace the agreement entered into during World War II between the US and Denmark, a new agreement concerning Greenland was ratified on 27 April 1951. At the request of NATO, the agreement became a part of the NATO defense program. The pact specified that the two nations would arrange for the use of facilities in Greenland by NATO forces in defense of the NATO area known as the Greenland Defense Area.
Thule Air Base was constructed in secret under the code name Operation Blue Jay, but the project was made public in September 1952. Construction for Thule Air Base began in 1951 and was completed in 1953. The construction of Thule is said to have been comparable in scale to the enormous effort required to build the Panama Canal. The United States Navy transported the bulk of men, supplies, and equipment from the naval shipyards in Norfolk, Virginia. On 6 June 1951, an armada of 120 ships sailed from Naval Station Norfolk. On board were 12,000 men and 300,000 tons of cargo. They arrived at Thule on 9 July 1951. Construction, aided by continuous daylight in summer, took place around the clock. The workers lived on board the ships until quarters were built. Once they moved into the quarters, the ships returned home.
On 16 June 1951, the base was accidentally discovered by French cultural anthropologist and geographer Jean Malaurie and his Inuit friend Kutikitsoq, on their way back from the geomagnetic North Pole.
Strategic Air Command
Originally established as a Strategic Air Command installation, Thule periodically served as a dispersal base for B-36 Peacemaker and B-47 Stratojet aircraft during the 1950s. It also provided an ideal site to test the operability and maintainability of these weapon systems in extreme cold weather. Similar operations were also conducted with B-52 Stratofortress aircraft in the 1950s and 1960s.In 1954, the Globecom Tower, a tower for military radio communication, was built at Northmountain. At the time of its completion, it was the third tallest human-made structure on earth and the tallest structure north of the Arctic Circle in the Western hemisphere.
In the winter of 1956–1957, three KC-97 tankers and alternately one of two RB-47H aircraft made polar flights to inspect Soviet defenses. Five KC-97s were prepared for flight with engines running in temperatures of to ensure three could achieve airborne status. After a two-hour head start, a B-47 would catch up with them at the northeast coastline of Greenland where two would offload fuel to top off the B-47's tanks. The B-47 would then fly seven hours of reconnaissance, while the tankers would return to Thule, refuel, and three would again fly to rendezvous with the returning B-47 at northeast Greenland. The B-47 averaged ten hours and in the air, unless unpredictable weather closed Thule. In that case, the three tankers and the B-47 had to additionally fly to one of three equidistant alternates: England, Alaska, or Labrador. This sometimes occurred in moonless, 24-hour Arctic darkness, December through February. These flights demonstrated the capabilities of the US Strategic Air Command to Soviet Anti-Air Defense.
In 1959, the airbase was the main staging point for the construction of Camp Century, some from the base. Carved into the ice, and powered by a nuclear reactor, PM-2A Camp Century was officially a scientific research base, but in reality was the site of the top secret Project Iceworm. The camp operated from 1959 until 1967.
In the late 1950s, the DEW 1 to 4 were built as "weather stations". Thule Air Base would act as a supply station for the DYE bases.
Other nearby installations built at the time that received support from Thule Air Base included the Cape Atholl, Camp TUTO, Sites 1 and 2, Pingarssuit Mountain , Thule Site J, North and South Mountains, and a research rocket firing site. It also was essential in the construction and resupply of High Arctic weather stations, including CFS Alert and Station Nord.