Force said that they will "proceed with an aggressive and effective sole-source negotiation" in reference to Northrop's bid. On 8 September 2020, the Department of the Air Force awarded Northrop Grumman a $13.3 billion contract to develop the GBSD intercontinental ballistic missile. Work on the GBSD missiles will be done in Roy and Promontory, Utah; Huntsville and Montgomery, Alabama; Colorado Springs, Colorado; Bellevue, Nebraska; San Diego and Woodland Hills, California; Vandenberg Space Force Base, California; Chandler, Arizona; Annapolis Junction, Maryland; and other locations. In April 2022, the GBSD's official designation was announced: The LGM-35A Sentinel. Warhead In March 2019, the W87 Mod 1 (W87-1) thermonuclear warhead was selected for GBSD, replacing the W78 warhead currently used on the Minuteman III. It is planned for GBSD to deploy in 2028, with W87-0 warheads initially being fitted to the system and W87-1 warheads being fitted from 2030 onward. This affords the Air Force a small amount of flexibility if the W87-1 is delayed. Testing GBSD testing would occur mainly at Hill Air Force Base, Utah, and at Vandenberg Space Force Base (VSFB), California, with missile launches from VSFB over the Pacific Ocean. Additional testing would be conducted at U.S. Army Dugway Proving Ground, Utah, U.S. Army Garrison–Kwajalein Atoll and within the territorial waters of the Republic of the Marshall Islands. On 7 July 2022, a Minotaur II+ rocket launched from Vandenberg TP-01 for a suborbital reentry vehicle (Mk21A reentry vehicle belonging to AFNWC) demonstration mission for the future LGM-35A Sentinel intercontinental ballistic missile. The rocket exploded 11 seconds after launch. Debate Pro Supporters of the GBSD include the Heritage Foundation, Secretary of Defense Lloyd Austin, former Secretary of Defense Ash Carter and members of Congress in the "ICBM Coalition." They argue that the current ICBMs, first introduced in the 1970s, have had their life extended long enough and need to be replaced with a modular system in which components are easier to replace or update. In defending the importance of land-based missiles, supporters say they are the least expensive leg of the nuclear triad because they do not necessitate large maintenance crews or incur expensive refueling costs, like nuclear-powered submarines. Additionally, they argue land-based missiles are visible reminders that the US can strike back in the event of a nuclear attack, thus making them essential to nuclear deterrence. In its annual 2021 Threat Assessment, the US Intelligence community said China was planning