The Air Force says the first radar site in a new system to track satellites and space junk will be built on Kwajalein Island in the Republic of the Marshall Islands.
The Air Force Space Command, based at Peterson Air Force Base, said Tuesday construction on the new radar station is expected to start in 2013 and take four years, including testing.
No cost estimate was immediately available.
The radar station will be part of the Space Fence system to track objects in Earth orbit and watch for potential collisions and other hazards.
The Air Force monitors about 1,000 active satellites and 20,000 pieces of debris in orbit around the Earth.