The Air Force released a notice today stating it will award a prime contract to develop the Ground Based Strategic Deterrent's Mk21A re-entry vehicle no later than the fourth quarter of fiscal year 2023 -- slightly earlier than previously anticipated. The Mk21A re-entry vehicle will be capable of delivering warheads from the future GBSD intercontinental ballistic missiles that are slated to replace the military's decades-old Minuteman III ICBMs starting in the late 2020s. Lockheed Martin is the only company with...