The American people shouldn't overreact to the news that NASA has grounded all future shuttle flights because of the large chunk of foam that broke off Discovery's fuel tank during its launch Tuesday morning. There should be no groundswell in favor of a major scaleback in the U.S. space program; the program's accomplishments since its primitive efforts of the 1950s greatly outnumber its failures, although, admittedly, several of those failures have been tragic in terms of loss of human life.

Everyone involved in the space program acknowledges the dangers and risks involved, despite all of the expertise and technology employed on behalf of safe, problem-free missions. From the program's beginnings, Americans accepted the possibility of setbacks, and now should be no exception.

As the Columbia (2003) and Challenger (1986) space shuttle disasters, as well as the Apollo spacecraft flash fire (1967) attest, something can go wrong even when the most fine-tuned precautions geared toward safety are employed. Those who have bravely volunteered for service as astronauts acknowledge the full scope of possibilities, good and bad, but recognize the importance of the program moving forward.

Tuesday's 114th shuttle liftoff came only after a 2½-year self-examination on NASA's part, plus extensive safety modifications to the spacecraft. In all, nearly 50 safety improvements were made to the shuttle in the wake of the Columbia tragedy.

NASA's quick acknowledgment of the seriousness of Discovery's launch problem and the space agency's decision that there would be no more shuttle flights until the problem is completely addressed should be viewed hopefully and optimistically by the American people.

President George W. Bush's plan for NASA to return astronauts to the moon by 2020 and eventually to Mars should not become sidetracked by the latest development. Neither should the technological prowess and the confidence that has been a big mark of the space program and the space agency for so long.

Successful completion of Discovery's mission and the combined efforts of hundreds of engineers and scientists in evaluating even the most minute details of the current journey will eventually allow NASA to emerge from the somber mood in which it became embedded Wednesday based on its Discovery launch findings.

The suggestion by some that a national debate about the future of the space program is warranted is part of a narrow vision that ignores the big picture surrounding the space program, including not-yet-imagined scientific and medical achievements.

"Until we're ready, we won't go fly again," said Bill Parsons, shuttle program manager.

That was the right message for now, but it is not the right message for the long run.

Shuttle flights must eventually resume, paving the way for introduction of the new generation of spacecraft NASA plans to introduce for flights after the current shuttle fleet is retired in 2010.