April 21 (UPI) -- Northrop Grumman was awarded a $2.3 billion contract for the propulsion system maintenance of the Minuteman III missile system, the Pentagon announced.
The contract, which runs through 2040, calls for "sustaining engineering support and program management support services for the Intercontinental Ballistic Missile [ICBM] propulsion subsystem," according to a Tuesday night contract announcement.
It follows announcement of a $13.3 billion contract between Northrop Grumman and the Air Force, in December 2020, for the engineering and manufacturing development phase of the ICBM system meant to replace the aging Minuteman III.
Known as the LGM-30, the Minuteman III is the United States' only land-based ICBM in service, and is an element of Air Force Global Strike Command.
It entered service in 1970, and is based on Minuteman I and II missiles which date to 1962.
"The primary focus shall be to identify aging mechanism[s], anomalous behavior, and ensure any modifications or changes tot he system which shall maintain and/or improve system-level performance," the Defense Department announcement said in part.
The U.S. Air Force's Ground Based Strategic Deterrent, or GBSD, is under development to replacement for the aging LGM-30 Minuteman III ICBM.
GBSD represents the modernization of the ground-based leg of the nuclear triad.
Earlier this month, Northrop Grumman Corporation announced the successful completion of an the Integrated Baseline Review for the GBSD engineering and manufacturing development program.
The milestone established a performance measurement baseline to keep the program on track for initial operational capability by 2029, according to Northrop Grumman.
The GBSD involves the modernization of the United States' ground-based missile system, involving both the upgrades to the Minuteman III and the development of its replacement.
A test-firing of a Minuteman III missile from Vandenberg Air Force Base, Calif. landing 4,200 miles away at the Kwajalein Atoll in the Marshall Islands, in February 2021.