An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.

An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.

An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.

An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.

An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.

An artist's portrayal of the Northrop Grumman LGM-35A Sentinel ICBM. (Northrop Grumman)

The Northrop Grumman LGM-35A Sentinel intercontinental ballistic missile (ICBM) is “struggling” with “unknown unknowns”, Secretary of the Air Force Frank Kendall told a crowd at the Center for a New American Security (CNAS) on 13 November.

“Sentinel is one of the most large, complex programmes I've ever seen,” Kendall said. “It's probably the biggest thing in some ways that the air force has ever taken on, because it's a vast real estate development [and] civil engineering programme, a fairly vast communications command-and-control programme, as well as of course, the missile itself.

“Sentinel, I think is quite honestly struggling a little bit,” Kendall continued. “There are unknown unknowns that are surfacing that are affecting the programme, and that the department is going to have to work its way through.”

The programme requires extensive modifications to the missile silos that currently house the LGM-30G Minuteman, in addition to the communications systems that connect remote silos to command centres.