Last night saw the final launch of an Atlas rocket with American designed-main engines. The Atlas ICBM was a mainstay of the U.S. nuclear deterent in the early 1960s. Of course ICBMs also make good rockets for putting things into space: John Glenn, the first American to orbit the planet, went up on top of an Atlas. And Atlas boosters fitted with powerful Centaur upper stages have launched a series of significant space probes since the 1960s.