Work to upgrade the early warning station at RAF Fylingdales in North Yorkshire will be carried out by Boeing, the Pentagon in Washington has announced.
The Fylingdales base has been on the North York Moors since 1963
The base on the North York Moors is being revamped as part of the United States government's Son of Star Wars anti-missile system.
Boeing's work includes installing faster computers, new communication links and modern graphic displays.
Boeing has also been awarded a contract for 15 ground-based interceptor missiles as part of the defence system which is due to become operational next year.
Altogether the work is worth $823m to Boeing.
The work to upgrade RAF Fylingdales can go ahead quickly as officials at the North York Moors National Park Authority have decided it does not need planning permission.
Concern has been raised about possible health risks from the base and the local primary care trust is carrying out a study to see if there are more cancers near Fylingdales than in other parts of the country.
The Ministry of Defence says radiation from Fylingdales is within safe limits.