First we will mourn the brave and beautiful who fell out of the sky. Then, however, we will proceed to the usual post-catastrophe ritual: investigation and recrimination. We will search for the culprits. Some human agent will be hauled out to bear the blame. And we will search for the cause: flying foam, wing damage, insulating tiles, whatever -- we will find it. But we will miss the point.

The point is that the first 150 or so miles of space travel -- braving the gravitational well of Earth and shooting through the atmosphere -- is the most difficult and dangerous; the next million miles are comparatively easy. Yet going up and down that first 150 miles is the least glorious, least inspiring of all space adventures; it is the stuff beyond low-Earth orbit that speaks to our yearning as a restless, seeking species. Everyone notes how Columbia's flight was almost totally ignored until disaster struck, but it is hard to excite people about a space truck taking off every couple of months on service missions.

Here, then, is the heart of the problem: The shuttle does nothing but this most dangerous, yet most mundane, short-haul trip, over and over and over again -- until the odds catch up with it.

The risk of catastrophe for a commercial jet is 1 in 2 million. For a fighter jet, it is 1 in 20,000. NASA's best estimate for the shuttle was 1 in 240. Our experience now tells us that it is about 1 in 50.

That is a fantastic risk. It can be justified -- but only for fantastic journeys. The ultimate problem with the shuttle is not O-rings or loose tiles but a mission that makes no sense. The launches are magnificent and inspiring. But the mission is to endlessly traverse the most dangerous part of space -- the thin envelope of the atmosphere -- to get in and out of orbit without going anywhere beyond. Yet it is that very beyond -- the moon, the asteroids, Mars -- that is the whole point of leaving Earth in the first place.

We slip the bonds of Earth not to spend 20 years in orbit studying zero-gravity nausea, but to set foot on new worlds, learn their mysteries, establish our presence.

Why was Columbia up there in the first place? It was conducting scientific experiments. But almost all such experiments can be conducted by robot. Sending humans through takeoff so they can study spider behavior in weightlessness is crazy.

It is almost as crazy to risk lives to act as trucking agent for the space station, which was the mission of nearly every other shuttle flight for the past three years. It is hard to justify the space station in the first place. It is not a platform for further space travel. It produces very little science. It is basically a laboratory for the biology of weightlessness. That's about it. Yet the shuttle has become its slave, hauling up huge pieces of equipment and bringing up astronauts to do the construction work.

What an end. What a dead end. After millennia of dreaming of flight, the human race went from a standing start at Kitty Hawk to the moon in 66 years. And yet in the next 34 years, we've gone nowhere. We've gone backward. We've retreated from the moon and spent our time spinning around endlessly in low-Earth orbit.

The way to consecrate the memory of those noble souls on Columbia is not to mindlessly repeat the past 20 years but to rethink the whole enterprise. For now, we need to keep the shuttle going because we have no other way to get into space. And we'll need to support the space station for a few years, because we have no other program in place.

But that is not our destiny, nor our purpose. If we're going to risk that first 150 miles of terrible stress on body and machine to get into space, then let's do it to get to the next million miles -- to cruise the beauty and vacuum of interplanetary space to new worlds. Back to the moon. Establish a lunar base. And then on to Mars.

The Columbia tragedy will give voice to the troglodytes who want to give up manned space travel altogether. But the problem is not manned flight. The problem is this kind of manned flight, shuttling up and down at great risk and to little end.

Icarus fell because he flew too close to the sun. Columbia -- and the whole American manned space program today -- fell because it flies too close to the Earth, repeatedly, gratuitously braving the terrors of takeoff and reentry. It is time to once again raise our eyes and our horizons, and return to our original path, so inexplicably abandoned: to the moon and beyond.