NASA is commemorating the heady days in the 1960s when the United States was committing enormous resources, both financial and technological, to its space program, with a celebration this week of the 40th anniversary of the first Apollo flight.

That mission four decades ago involved orbiting the moon, but not landing on the lunar surface. Apollo 8 blasted off Dec. 21, 1968, and circumnavigated the moon on Christmas Eve, Dec. 24, returning to a safe splash-down on Earth three days later.

That flight by Apollo 8 astronauts Frank Borman, Jim Lovell and Bill Anders, launched atop a huge Saturn V rocket, blazed a trail for the first mission to land on the lunar surface, the Apollo 11 voyage half a year later, when astronaut Neil Armstrong in 1969 took “one small step for [a] man, one giant leap for mankind.”

That was the ultimate triumph in a U.S. space race against the Soviet Union, which had electrified the world in the prior decade by orbiting the first satellite, Sputnik, and later sending the first man into space.

Those times of limitless possibilities for NASA and its never-before-attempted missions stand in contrast to the outlook today, where NASA isn’t being even partially refunded for the billions of dollars it had to spend on returning to space after the Space Shuttle Columbia disaster. The U.S. space agency also faces half a decade in which it won’t have any spaceship system to transport U.S. astronauts even to low Earth orbit, much less the moon. Rather, in a note of irony, the United States for half a decade will have to depend for human transport on the Russians, until the next-generation Orion-Ares American spaceship system flies its first manned mission in 2015.