In the aftermath of the breakup of the space shuttle Columbia an important debate on the purpose and future of the U.S. human-space-flight program is under way, though perhaps not as forthrightly as it should be. The issue at stake is not space exploration in itself but the necessity of launching manned (versus robotic) vehicles. Because articles of faith are involved, the arguments tend to be manipulative and hyperbolic. If the debate is to be productive, that needs to change.
The proponents of manned space flight—particularly at NASA—are in an unenviably defensive position. They argue weakly for the operational flexibility provided by astronauts in space, and trot out the story of the Hubble Space Telescope's in-orbit repair, as if this single success might justify two decades of shuttle flights; they advertise the applied scientific benefits of performing laboratory-style experiments in orbit, though they cannot point to much of significance that has arisen from them; and finally, bizarrely, they argue that only the excitement of a human-space-flight program can persuade the American public to foot the bill for the robotic efforts—a self-indicting logic if ever there was one. When all else fails, they fall back on the now empty idea that the shuttle program is a matter of national prestige—or on the still emptier claim, made obliquely by the NASA administrator Sean O'Keefe last spring, that a retreat from human space flight would be akin to a return to the Stone Age for all humankind.
That sort of talk allows the opponents of human space flight to play the role of the rationalists. They question the effect on the national psyche of successive accidents, debunk NASA's orbital science, and describe the ultra-expensive International Space Station as hardly more than an artificial destination for an ill-conceived spaceship with nowhere else to go. They are right about all that. While they are at it, they juxtapose the human-space-flight budget (currently about $6 billion annually) with underfunded research on Earth (for example, in oceanography and clean energy), and they point to the history of absurd cost overruns in both the shuttle and the space-station programs; NASA's manipulation of budget figures; and its well-demonstrated managerial incompetence. Again, these are all valid arguments. But the critics here are not merely noting the problems in human space flight; they are setting up a straw man—the shuttle— in order to knock a much larger thing down. An honest national debate would demand more.
Such a debate would almost certainly lead to the conclusion that the United States has for thirty years followed human-space-flight policies that are directionless and deeply flawed, and that those policies must now be radically changed, with whatever regret about the historical costs. Chances are that such a change would involve maintaining the space station in its current, unfinished state, and doing so in the least expensive way, with cargoes and minimal crews launched atop subsidized Russian rockets—after laws that currently prohibit such subsidies are repealed. But it would also involve permanently grounding the shuttle fleet, and shutting down much of the associated NASA infrastructure. The savings would be large and immediate.
This would not mean, however, that the opponents of human space flight had won. Indeed, it may be that a pause to regroup is precisely what a vigorous human-space-flight program now needs. One thing for sure is that the American public is more sophisticated than the space community has given it credit for. In the event of a grounding the public might well be presented with a question now asked only of insiders—not whether there are immediate benefits to be gleaned from a human presence in space but, more fundamentally, whether we are to be a two-planet species. If upon due consideration the public's answer is "yes," as it probably should be, the solutions will be centuries in coming. Compared with the scale of such an ambition, a pause of a few decades now to rethink and rebuild will seem like nothing at all.