One giant leap of faith by pioneer Bush
After the Soviets put the first man in space in 1961, President John Kennedy pledged to send a man to the moon by the end of the Sixties.
Many doubted it could be done, but on 20 July 1969, Neil Armstrong stepped down from the lunar lander Eagle with the words: "That's one small step for man, one giant leap for mankind."
Five more manned missions to the moon followed. Apollo 14 saw Alan Shepard play golf on the moon, while the lunar rover made its debut on Apollo 15.
But as the expense of manned space flight soared, so public interest declined. By the time Nasa ended the Apollo programme in 1972, 12 men had been to the moon. Nasa decided to concentrate on a reusable spaceship, starting with the shuttle Columbia in 1981.
The shuttle ushered in an era of routine space flights, carrying men and women of all ages and nationalities into orbit, including British-born astronaut Michael Foale.
But after the success of missions like the Hubble telescope, the shuttle programme was halted in January 1986 when the Challenger exploded after lift-off, killing all seven crew.
Grounded for two years, the shuttle found new life in the Nineties, taking sections of the International Space Station into orbit. Then last year disaster struck again when Columbia was torn to pieces on re-entry, killing all seven astronauts.
The tragedy could have doomed manned exploration of space. Instead President Bush has decided to make a leap of faith as dramatic as Kennedy's.