Some of their names harked back to a golden age of exploration. Others conveyed the promise of one to come. The space shuttles - Endeavour, Discovery, Atlantis, Challenger and Columbia - offered the prospect of a whole new approach to extra-terrestrial transport and exploration. After blast-off, they would perform much like normal aircraft, enabling astronauts to undertake weekly missions. So much for theory. When the final shuttle flight landed last week, the programme had, despite some successes, ultimately under-achieved. Worse, it had been such a financial drain that the United States' space programme is now at a virtual standstill.
The space shuttle should be viewed in terms of a continuum. In the wake of the moon landings, it was intended that, in relatively quick time, there would be shuttle flights, the establishment of a space station, a moon base and then manned flight to Mars, a planet thought billions of years ago to have had the conditions that shaped life on Earth. The shuttles duly played their part, building the International Space Station, a multinational space laboratory due for completion next year, and launching the Hubble Telescope. All told, the five shuttles completed 135 missions, orbiting the Earth 21,150 times, and carrying 355 people from 16 countries.
But those figures were nothing like as impressive as originally envisioned. Indeed, the shuttles proved a hugely expensive means of exploring space. When President Richard Nixon first approved the programme in 1971, it was estimated weekly flights would cost US$7 million. In fact, the last few flights cost more like $1 billion each. Equally, the shuttles proved far less safe and reliable than anticipated. The Challenger and Columbia disasters, in 1986 and 2003, respectively, further undermined the programme.
In sum, the space shuttles devoured about $200 billion. Nothing like this would have been spent if the National Aeronautics and Space Administration had continued to use rockets to carry its astronauts. Equally, we would surely be much closer to a flight to Mars if the shuttle programme had not proved so problematic and expensive. And we would not be witnessing the effective withdrawal of the US from space exploration.
That, however, was the thrust of a directive from President Barack Obama last year, which saw Nasa's budget slashed and its Constellation programme, which aimed to put a manned base on the moon by 2020, abandoned. Over the next few years, the few remaining American astronauts will have to hitch a ride on a Russian rocket if they wish to visit the International Space Station.
The President has indicated that he expects private companies to pick up some of the slack with space taxis. That may be so when a profit can be made from carrying wealthy individuals, but deep-space exploration and more mundane scientific research will surely not be part of the picture.
Nasa's whole future is hazy. President Obama has talked vaguely of a voyage to Mars by the mid-2030s, but there is a dearth of planning. It seems that only a discovery in some part of the universe that fires the imagination of Americans or perhaps a defence imperative would trigger a rebirth of enthusiasm. For now, the baton for space exploration has been handed to the Russians and the Chinese.
The tears shed by those at Cape Canaveral when the Atlantis landed late last Thursday (NZT) were for the end of a long-running project and the loss of thousands of jobs. They might also have been for the sidelining from space exploration of a nation that, more than any other, galvanised the global community. For those who thrilled to the exploits of the likes of Neil Armstrong and John Glenn, an awe-inspiring era has ended.