The Northrop Grumman [NOC] LGM-35A Sentinel ICBM, which has a significantly larger design than its predecessor 1960s-era Minuteman missile series, is to have new silos, U.S. Air Force leaders told community leaders during program town halls in Kimball, Neb., and Pine Bluffs, Wyo., on Apr. 1 and 2.
The Minuteman “silos are already really old so if we use them for Sentinel, they are going to be over a century old,” Col. James Rodriguez, Sentinel program infrastructure and deployment division director, said on Apr. 1. “There were a number of other issues that were driving costs to be quite large, and it was becoming prolifically expensive to try to renovate them, so sometimes it is just cheaper to build something new.”
Air Force leaders have previously not given a straight answer when asked whether Sentinel would need new silos and have downplayed the significance of new silo construction.
The provision of multiple warheads, countermeasures, and increased range to hit China means the Sentinel design is significantly larger than that of the current Boeing [BA] Minuteman III.
In February, Sen. Angus King (I-Maine), the ranking member of the Senate Armed Services Committee’s strategic forces panel, said that he believed that the Air Force would have to build new silos to house Sentinel (Defense Daily, Feb. 26).
The Air Force fielded 450 Minuteman siloes between 1962 and 1967, of which 50 are decommissioned but may be brought back for future testing. Experts have said that placing Sentinel in Minuteman silos may lead to several degrees of tilt in such silos.
Sen. Kevin Cramer (R-N.D.) suggested this month that the Air Force may be able to re-use some Minuteman III silos for Sentinel and that the Air Force is increasingly discussing possible concurrent upgrades to house Sentinel at the three ICBM missile wings under Malmstrom AFB, Mont., F.E. Warren AFB, Wyo., and Minot AFB, N.D. (Defense Daily, Apr. 1).
“To the degree that it’s possible yet to modify the design of Sentinel to utilize existing silos, it would be a tremendous opportunity,” he said. “We’ll see. Some of them [silos] are gonna have to be [replaced]. Some of them are full of water.”
The Air Force plan has been to conduct sequential upgrades at the bases with Minot being the third and final base.
The first operational Minuteman fielded on Oct. 27, 1962 at Malmstrom during the Cuban Missile Crisis.
Air Force Global Strike Command (AFGSC) had planned to “renovate all 450 existing [Minuteman] launch facilities in the missile fields to like-new condition.”
In addition to the Apr. 1 and 2 public discussions in Kimball, Neb., and Pine Bluffs, Wyo., the Air Force held another Sentinel town hall, as scheduled, on March 31 in Raymer, Colo., but the latter’s remoteness led to a lower turnout and no press at the event, Glenn Robertson, a spokesman for the 90th Missile Wing at F.E. Warren, wrote in an email response to questions.
AFGSC said that more than 200 residents attended the three town halls.
For the town halls, “there were no transcripts or video…to ensure participation of the local public without fear of recording them,” Robertson wrote in an email.
Air Force Maj. Gen. Colin Connor, who heads the Sentinel Site Activation Task Force in his position as director of ICBM Modernization at Air Force Global Strike Command at Barksdale AFB, La., told the Pine Bluffs town hall that the Air Force plans to begin digging up the old, Hardened Intersite Cable System (HICS) copper wires for Minuteman III in 2027 to replace them with fiber optic cables for Sentinel by 2030.
Section 1638 of the fiscal 2023 National Defense Authorization Act created AFGSC’s Site Activation Task Force to provide the Sentinel program with missileers’ insights.
On Jan. 18 last year, the Air Force said that it notified Congress that Sentinel had breached Nunn-McCurdy guidelines, primarily due to construction design changes, and then DoD acquisition chief William LaPlante ordered a root-cause analysis. The latter led last summer to the DoD decision to continue the program, due to its stated importance to strategic deterrence, but also to the rescinding of the Sentinel Milestone B engineering and manufacturing development (EMD) go-ahead from 2020 (Defense Daily, July 8, 2024).
Last summer, the Air Force pegged Sentinel cost at $140.9 billion, 81 percent higher than the September 2020 estimate when the program was approved for EMD–a rise that DoD said has less to do with the missile than the command-and-control segment, including silos, launch centers, “and the process, duration, staffing, and facilities to execute the conversion from Minuteman III to Sentinel.”
Initial operational capability for Sentinel will now likely be years past the Air Force’s initial goal of May 2029.
Air Force plans have called for a Sentinel launch center for at least 24 of the missile alert facilities and for 3,100 miles of new utility corridor for Sentinel.
The civil works for Sentinel may also include hardening silos to account for improved accuracy of Russian and Chinese nuclear missiles.