The Air Force in December issued two contracts worth a combined $78 million for demonstrations of a Medium Class Stage III ICBM motor with technologies applicable to multiple future common strategic propulsion systems.

ATK [ATK] received $49.4 million Oct. 18 and Aerojet Rocketdyne, a division of GenCorp [GY], received nearly $29 million, according to the Defense Department. The contracts will begin development of a flight motor design that will be a direct replacement for the SR-73, which is the third stage motor on the Minuteman III ICBM. The Minuteman III’s first stage motor is a M55A while the second stage is a SR-19 motor. All three are ATK-refurbished motors, according to the Air Force.

The contract awards are part of the Air Force Nuclear Weapons Center Propulsion Application Program (PAP) out of Hill AFB, Utah. The primary objective of PAP, according to Aerojet Rocketdyne, is to provide a family of affordable, sustainable motors that can support a wide range of potential Air Force solutions, including modernizing or replacing Minuteman III.

Aerojet Rocketdyne said its contract also includes development, fabrication and demonstration and that a full-scale test of the motor, including thrust termination demonstration, is planned. Boeing [BA], the original developer of the Minuteman III, said in an email it did not bid for the Medium Class Stage III contracts because the contracts were focused on solid propulsion technologies. Northrop Grumman [NOC] said on Jan. 6 the company did not bid for the Medium Class Stage III contract, but that doesn’t mean it is out of the Minuteman III business. Northrop Grumman spokeswoman Michelle Bohlen said the company intends to compete for the remaining Future ICBM Sustainment and Acquisition Construct (FISAC) subsystem support contracts that are competitive awards. Northrop Grumman also intends to compete for the upcoming propulsion subsystem sustainment contract, Bohlen added. Northrop Grumman remains the ICBM prime contractor for Minuteman III operational sustainment through Sept. 30, 2015.

The Pentagon is on the cusp of a major nuclear weapons modernization effort including new ballistic missile submarines, long-range bombers, ICBMs and cruise missiles, as well as major life-extending refurbishments of current ICBMs, submarine-launched ballistic missiles and nearly all nuclear warheads. The Congressional Budget Office (CBO) in December issued a report estimating it will cost DoD $355 billion from 2014 to 2023 to operate, maintain and modernize the nuclear triad of air, sea and land-based nuclear delivery systems. CBO said this is $59 billion more than DoD requested in budget requests. The Air Force, which manages the air and land wings of the nuclear triad, did not respond to requests for comment by press time.

CBO said because most of these nuclear weapon modernization efforts are just beginning, it expects annual costs for nuclear forces to increase. From 2021 to 2023, CBO estimates nuclear costs averaging about $29 billion annually, roughly 60 percent higher than the $18 billion it said DoD requested for 2014. Annual costs are likely to continue to grow after 2023 as production begins on replacement systems, CBO said.

There are 500 Minuteman IIIs in active duty, according to the Air Force.