Sprint (missile)

The Sprint was a two-stage, solid-fuel anti-ballistic missile built for the United States Army and carrying a W66 enhanced-radiation thermonuclear warhead. It was designed as the last layer of a missile defense, intended to meet incoming reentry vehicles low in the atmosphere, below roughly 60 kilometres, where thickening air stripped away decoys and the warhead had only seconds left to reach its target. To manage that, the missile accelerated at about 100 g and reached Mach 10 within five seconds, and its skin glowed white from heat. It was the centerpiece of the Nike-X concept and was later folded into the Sentinel and Safeguard programs. Safeguard stayed operational only for a few months, from October 1975 to early 1976, before congressional opposition and cost ended it. A follow-on Sprint II was studied for defending Minuteman missile fields but work stopped as United States policy on missile defense changed.