Ground Based Strategic Deterrent
The Ground Based Strategic Deterrent ( GBSD ) is a US land-based intercontinental ballistic missile system in the early stages of development , slated to replace all 450 Minuteman III missiles in service with the United States Air Force from 2029 onward . 
<triplet> Minuteman III <subj> intercontinental ballistic missile <obj> subclass of <subj> United States Air Force <obj> operator