It is easy - and probably right - to be cynical about President Bush's call for a return to the moon by 2020, and a mission to put people on the surface of Mars at some undisclosed date. There's no prior evidence that Bush is a space visionary - while governor of Texas he never even visited the Johnson Space Centre, Nasa's vast human space flight citadel in Houston. The space plans were rolled out in the middle of January, but having failed to strike a chord, merited no mention in the state of the union address the following week. A White House source talked to the Washington Post of a "Kennedy moment," but to most observers it was just more irresponsible spending wrapped in specious rhetoric. In some ways, Bush's announcement was pretty much the opposite of Kennedy's original decision to go to the moon. But in others, it is peculiarly similar, and could mark the beginning of the end for America's humans-in-space programme.
The first thing to understand about the original Kennedy moment - the 1961 call to put a man on the moon before the decade was over - is that it was entirely a creature of its geopolitical circumstances. While Bush may conceivably believe that space exploration is "a subject that's mighty important to the country and to the world," as he told the audience at Nasa HQ when announcing his new "vision," Kennedy did not. "I'm not that interested in space," Kennedy told his Nasa administrator, James Webb, in a private meeting when Webb came to him pleading for the wherewithal to make the space programme something broader than a blinkered rush for the moon. Kennedy cared about space only as a means to an end. "We're talking about these fantastic expenditures which wreck our budget," he told Webb "because we hope to beat the Soviets." Other means would have been welcome, had they been available. "If you had a scientific spectacular on this earth that would be more useful," Kennedy complained to his Apollo-sceptic science adviser Jerome Weisner, "say desalting the ocean - or something as dramatic and convincing as space, then we would do it." In the absence of huge sexy desalination plants, the president was stuck with huge sexy rockets. But the record suggests that he used them without obvious enthusiasm for anything other than a cold war victory.
Thus the first big difference between Kennedy-to-the-moon and Bush-to-the-moon is that Kennedy's programme had a well conceived and serious purpose, while for the most part Bush just has a second-hand version of that purpose. A lack of purpose for the programme does not mean that Bush had no reasons for announcing it. It allowed him to reassure those who worry about such things that America will not fall behind anyone else. The proposed schedule for a return to the moon is untaxing and unspecific, but it should do a good job of making sure that, at any given time, Nasa will be closer to putting people on to the surface of the moon than the Chinese. And the announcement allowed the president to reassure the two aerospace giants, Boeing and Lockheed Martin, that money will continue to flow through the space programme into their bank accounts after the space station is completed in a few years.
And since, unlike Kennedy, President Bush doesn't care about wrecking the budget, there's not much downside to the scheme. A sharp increase in Nasa's budget at a time when overall federal R&D money is stagnating will irritate a lot of scientists - but scientists are not a strong lobby. The job losses that come with retiring the shuttle (in 2010, when the space station is completed) and abandoning the space station (around 2016) take place well beyond Bush's hoped-for second term. Both of the big new developments - the previously announced Jupiter Icy Moons Orbiter (Jimo), a vast nuclear-powered robot probe which dwarfs in ambition any previous planetary mission, and the Crew Exploration Vehicle (CEV), a new system of space capsules - are not due to fly until after 2010, and thus cannot embarrass him in office by blowing up or being delayed. The only change that has effect in the next presidential term is the proposed increase in Nasa's budget (up a couple of billion by 2008) and a redistribution of money and priorities within the space agency. Replacing plans for an Orbital Space Plane (OSP) which may or may not have ended up having wings with plans for a definitely wingless CEV will have little immediate impact outside Nasa.
In the long run, though, the clipping of the OSP's incipient wings is the key to the Bush plan's potentially revolutionary - and incidentally Kennedy-esque - nature. It opens the possibility of a space programme that breaks with the model of space exploration that has dominated planning for 50 years - often called the von Braun paradigm. In the von Braun paradigm the great task of the space age was the creation of a permanent infrastructure with which to do more and more otherworldly things. This infrastructure would be a pyramid, the base and bulk of which had to increase significantly whenever the top got even a little higher. You build a system for getting to orbit; then you use it to build a space station; then you use the space station to build spacecraft that will go further. To see the idea in its pomp, look at von Braun's 1952 blueprint for a Mars mission. A fleet of 46 space shuttles undertakes 1,000 missions in order to construct ten Mars ships in orbit. Once this flotilla reaches its destination, three craft go down to the surface; two later return to Mars orbit. Seven of the Mars ships return to earth.
Apollo was a dramatic rejection of the von Braun paradigm. It had no need of space stations and the on-orbit assembly of spacecraft. This allowed the Soviets to be beaten - but because it left almost no infrastructure after achieving its goal, it left Nasa pretty much defeated too.
The space agency returned to the von Braun paradigm out of both expedience and conviction. The expedience was that the development of a space shuttle with which to get into low earth orbit was all the Nixon White House was willing to pay for. The conviction was that the purpose of the space programme was to build an ever better space programme. After the shuttle was up and flying, President Reagan was pleased to sign on for the next step, a space station for the shuttle to visit and provision. The space station would be a centre for research and also a place where new spaceships would be assembled and launched, once a future president had been found to back the next great building phase.
The interesting thing about the Bush plan is that it ditches all this. The shuttle is to be retired after it has lifted the last pieces of the space station to orbit, and there is no provision for anything to replace it. The immense technical difficulty of building a spacecraft capable of reaching orbit and, trickier, returning again and again only makes sense if there is a reason to make lots of trips to low earth orbit. Under the new dispensation there isn't. People going to the space station will do so first in disposable Russian Soyuz capsules and later, when they are ready, in the new CEVs, which will probably be largely disposable themselves. Not that this will go on for long; the space station, having been given a fig leaf of purpose as a place to study how humans cope with long periods in weightlessness, will be abandoned as soon as is seemly. There is no longer any sense that it could be a base from which to launch future missions.
Missions to the moon will probably be put together in orbit as needed. The Bush plan requires no build-up of space-based infrastructure, and no permanently attended facilities beyond the earth. It just consists of missions, first to the moon, then, eventually, to Mars. Some lunar landers may be reusable, some of the missions to the moon may overlap with each other, and some may stay there for some time, but there's no commitment to a permanent moonbase, and nor should there be. Building a permanent base requires a great deal more effort than landing individual missions, and offers few obvious advantages. The moon is worth some exploration - not least because there is likely to be a treasure trove of rock samples from the earliest history of the earth - but it is of almost no practical utility.
The future Bush has outlined marks the end of the era in which the goal of spaceflight is to become routine. It is a future in which space travel is about events - missions to places, landings in unexplored territory, that sort of thing. It is a future where the possibility of humans actually doing interesting things elsewhere is rather higher than it was. In this, it really is rather like Apollo, and rather refreshing. But it is Apollo without the sense of urgency, without the purpose. It is a future in which space missions become sporadic and, given their cost, rare. Indeed, it could be a future in which missions eventually cease altogether, as people come to ask whether the moon missions are worth it. With no permanent infrastructure that needs servicing, it could turn out to be quite easy simply to mount fewer missions until eventually you find yourself mounting none at all. The Bush vision makes it possible to imagine shutting down the whole shebang simply by offering a future with a lot less long-lasting shebang to shut down.
This is not a problem. A humans-in-space programme that could be more easily cancelled would be more appealing than the one we have today. It would be one that had to justify itself in terms of its present objectives, rather than in terms of building a railroad to nowhere. And such justification may be possible. There is something exciting about exploring the universe, as well as something rewarding. It may be that there is a low and fitful level of human exploration of the moon, Mars and nearby asteroids that can keep justifying itself, that can adjust its scope to budgetary realities, that can amaze people on an occasional basis.
But it is worth remembering that an Apollo-without-a-purpose programme has been tried before - in the form of the six Apollo missions flown after the goal of beating the Russians had been achieved by Apollo 11. With the exception of Apollo 13, the missions produced ever more scientific knowledge while becoming ever less newsworthy. The programme was quickly cancelled; the last three moon ships never flew.