Project Iceworm was the code name for a top-secret United States Army program during the Cold War to build a network of mobile nuclear missile launch sites under the Greenland ice sheet. The ultimate objective of placing medium-range missiles under the ice — close enough to strike targets within the Soviet Union — was kept secret from the Danish government. To study the feasibility of working under the ice, a highly publicized "cover" project, known as Camp Century, was launched in 1960. However, unsteady ice conditions within the ice sheet caused the project to be canceled in 1966.