The the Ground Based Strategic Deterrent engineering and manufacturing development programme has passed a baseline review. (Photo: Northrop Grumman) Completion of the Integrated Baseline Review puts the Ground Based Strategic Deterrent on track for IOC by 2029, says lead contractor Northrop Grumman. Northrop Grumman announced on 7 April that it has passed a ‘critical milestone’ by completing the Integrated Baseline Review (IBR) for the Ground Based Strategic Deterrent (GBSD) engineering and manufacturing development (EMD) programme. The review sets a benchmark for performance measurement of GBSD and keeps the programme on track for IOC with the USAF by 2029, the company added. Using the W87 mod 1 thermonuclear warhead, GBSD will replace the LGM-30G Minuteman III intercontinental ballistic missile (ICBM).