BY ROGER SIMON

For a complete list of articles included in Fallen Stars, a special newsstand issue of U.S. News, please click here.

It seems as if we cannot catch a break. It feels as if our luck has run out. It appears that to live in the land of the free, you really do have to dwell in the home of the brave. September 11. Iraq. North Korea. And, now, Columbia. Murder, terror, dread, and loss. The four horsemen of our daily apocalypse.

But we are at risk because we will not change. After September 11, we did not trim our sails; instead, we spread our wings. We could have cut back on our high-risk adventures, the things that make us look bad when they go wrong and give our enemies comfort. (In Baghdad, after the explosion over Texas, they were calling the Columbia disaster "God's retribution on Americans.") We could easily have ended our space program and shifted the money into national defense. But where others might have hunkered down, we continued to soar. We continued to be out there, pushing the boundaries.

Why do we do it? Because we can. To be an American is to dare. We will sometimes fail because failure is part of being human. But our failures do not define us. Our daring does. We do not shirk from our duties nor turn from our destiny. As Theodore Roosevelt said: "Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to take rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows not victory nor defeat."

We do not live in the gray twilight. We live in the world's spotlight, where our every success and every failure can be seen.

The seven who lost their lives Saturday were not heroes in this country while they lived or superstars or even household names. The space shuttle, the most complicated machine ever constructed, was little thought about anymore. Few knew it had taken off; few knew it was about to land. Today, the technology that captivates us is the technology that entertains us: MP3 players, DVD burners, TiVO. There are still those, however, who see technology as the machinery of pure science. Practical applications can come from shuttle missions, and NASA has to emphasize those applications to justify the huge cost. But on board Columbia for 16 days, the astronauts–even the term seems dated–were carrying out scientific experiments that might never bear fruit or perhaps add only a minute particle to the sum total of human knowledge. Which is one reason we did not know the crew. They were scientists; they were dreamers of the dream. They flew, they explored simply for knowledge, simply to push the boundary.

"As difficult a situation as this is, we are moving forward," Ron Dittemore, the shuttle program manager, said hours after the Columbia exploded. "We are preserving data. We are beginning thorough and complete investigations. We are mobilizing our forces, our engineers, our technicians, our safety and quality, our best experts to try and understand what went wrong."

And while there may be plenty of blame handed out in the future, the immediate goals were clear: Mobilize. Understand. Move forward. How very American. Hours after the crash, something else that was very American took place: CBS switched from disaster coverage to the Bob Hope Chrysler Golf Classic. ABC carried snowmobile racing. Relentlessly, even remorselessly, life in America was already moving on.

Still, there were those who found it harder to let go. In Titusville, Fla., 8 miles from where the shuttle was to have landed, those waiting for the sonic boom of its return heard only silence. "I didn't hear the boom," said Dorothy Geiser, 74, who has lived in Titusville for 33 years. "It brought me to my knees. I always wait for the boom and give a prayer that they are on their way back, ready to land. I didn't hear the boom, and I was in disbelief."

We are getting good at disbelief, adept at shock, perhaps more inured to pain. Americans, it is said, are different from others because we actually expect things to turn out all right. We believe that happiness will be the norm and tragedy the interruption. And we do not like looking back, fearful that it will keep us from moving forward. "The only limit to our realization of tomorrow," Franklin Roosevelt said in his last, undelivered speech, "will be our doubts of today."

We fear, we grieve, we sometimes feel as if we are at the breaking point. But we do not break, and we do not doubt. We are a nation with its face perpetually turned toward the light, not the darkness. And if these days our sunny optimism has been replaced with grim resolve, the resolve will see us through until the sun shines brightly once again.