In 2010, when Mr Obama outlined his ideas, he spoke, somewhat vaguely, of a manned trip to a near-Earth asteroid, to be followed at some unspecified date in the 2030s by the ultimate space-cadet dream a manned mission to Mars.

ECONOMIST: The space shuttle

And, for those space-cadets who still dream of a manned mission to the planet, there is also the Mars radiation environment experiment.

ECONOMIST: Mars Odyssey

The heroes of Mr Morton's book are the astronomers who yearn to solve Mars's scientific puzzles, the science-fiction writers who project their politics on to Mars's blank canvas, and the space-flight enthusiasts who dream of Martian colonies.

ECONOMIST: Mars

The company's ultimate goal is to re-create the science-fiction dream of making access to space the province of individuals, not governments.

ECONOMIST: On a rotor-blade and a prayer | The

Is it your dream to see the space shuttle lift off -- in person?

CNN: The Internet: the final frontier for space watchers

There was a time when projects like Space X were the reserve of dream and fantasy, and this next vehicle -- for now at least -- also sits in that category.

ENGADGET: Alt-week 7.21.12: Outer space, flying hotels and federal trolls