Boeing announced Wednesday it has received a $138-million award from the U.S. Air Force to build three more Global Positioning System satellites under the GPS Block IIF contract. The award – an exercised option – brings to 12 the number of Block IIF satellites Boeing is building under the military's NAVSTAR GPS joint program office.

Boeing expects the first satellite, known as SV-1, will be ready for delivery in 2007, the company said in a news release.

"The award of this follow-on contract to Boeing reaffirms an enduring partnership between the Air Force and Boeing, a partnership that began more than three decades ago," said Col. Wesley Ballenger, commander of the NAVSTAR GPS Joint Program Office at the Space and Missile Systems Center in Los Angeles.

"Starting with the first GPS Block I demonstration satellites and continuing through more than 40 operational systems, Boeing has been a long-standing contributor to the operation and sustainment of the GPS on-orbit constellation," Ballenger added.

The GPS system currently comprises 24 orbiting satellites. GPS provides two levels of service: a standard positioning service for general public business and recreational use, and an encoded service primarily intended for use by the U.S. Department of Defense.

GPS IIF satellites will provide enhanced navigation support for both military and civilian users and will include a new dedicated L-5 signal approved by the government for civilian aviation.

In addition to building 12 Block IIF satellites, Boeing also is under contract to support the GPS ground segment. Total value of the contract is approximately $800 million.