AURORA, Colo.--On Feb. 13, the U.S. Air Force broke ground on a prototype silo for the Northrop Grumman [NOC] LGM-35A Sentinel future ICBM at the company's Promontory, Utah, site, officials said here on Wednesday at the Air & Space Forces Association's warfare symposium. The prototype is to allow engineers to test and refine modern construction techniques, validating the new silo design before work begins in the missile fields, the Air Force has said. In the last year, the service determined…
