A compact--some would say subcompact--model of the space station that NASA has been trying for seven years to get Congress to approve is on its way to the Hill. An earlier debate over whether the station was too big will now ask whether it is too small.
The answer to the first question was clearly yes, at least for the present state of space technology. Carrying parts of the station into space for assembly would have required nearly as many space shuttle flights as the fleet has flown since 1981. Partly because of the shuttle's limited load capacity, the assembly schedule would have meant starting repairs on parts of the orbiting laboratory before it was even finished.
The answer about the compact version is less clear. The new design is based on advice from many quarters, including that of a White House commission appointed last year to plot NASA's future in space. The panel advised NASA to stop trying to keep so many programs in the air at once and concentrate on doing a few things very well.
Applying that specifically to the space station, the commission said it should be smaller, cost less and be designed for fewer missions.
By trimming the size of the space station, NASA could cut the number of shuttle flights required to lift construction materials into orbit. That, in turn, would reduce crew size--perhaps cutting it by half--and the number of experiments. It is not clear whether the Augustine commission's notion of using the station to study Earth the way unmanned space probes study other planets could survive in a smaller model.
One mission that might even be the sole survivor would test the effect of weightlessness on human beings for the 18 months or more that it would take to get a manned spacecraft to Mars if it were to leave in a generation or so. The Mars mission has always seemed to us the next logical leap into the unknown for Earthlings. Knowing whether they could survive the leap is essential to further planning for it. Another mission is research on whether perfect crystals could be created free of Earth's gravity or metals forged in ways that cannot be duplicated on Earth.
Some scientists doubt that the smaller station justifies the expense. Congress must ask whether it should commit $2 billion to designs now, with the federal budget so tight. These questions need answers.
There is no pressure to rush. Outer space will beckon for a long time to come. And humans are not likely ever to quell the wanderlust that a dark sky full of stars provokes.