The early warning radar at an Air Force station about 70 miles southwest of Fairbanks will get an upgrade.
The Department of Defense has announced Raytheon Co. has been awarded the contract, worth up to $125 million.
The Clear Air Force Base's radar originally went online in October 1961, looking for satellites and incoming missiles. A newer system began being used in 2000.
Officials say this is part of a $400 million upgrade to Clear, including integrating the radar with the nation's missile defense system.
The radar from the Alaska base sends missile tracking data to bases in Colorado.