The Air Force has begun replacing the old solid fuel in 500 Minuteman-III missiles with new solid fuel, ensuring that the missiles can remain in service through 2020. The first 10 refueled missiles went on alert on 15 March; the last of the 500 will be refueled in 2008. Two other programs are replacing the guidance system and some key elements of the liquid-fueled upper stage.--Stephen V Cole
