If all goes well this morning at the Kennedy Space Center - it might not given the weather forecast - Atlantis will head into space on the final mission of the U.S. space shuttle program. The flight caps 30 years of space travel that has been marked by tragedy, triumph and the advancement of science.

The last flight, the 135th since the program began, is in many ways mundane. The four crew members will deliver several tons of supplies and spare parts to the International Space Station. Still, there is much sentiment attached to Atlantis' mission. It concludes a remarkable chapter in the history of the United States and space travel.

There have been major triumphs since the first shuttle soared into space in 1981. The shuttles and their crews have launched satellites and space probes, helped build and maintain the International Space Station and repaired the Hubble Space Telescope more than 400 miles about the Earth. Shuttle astronauts walked in space more than 160 times. They played major roles in developing technologies and materials that prompted significant advances in everything from medicine to the suits competitive swimmers wear.

It's not all been triumph, though.

Fourteen men and women died aboard Challenger and Columbia in accidents that seared the soul of the nation. The deaths were a reminder that exploring the unknown is always dangerous. As routine as space travel became, there was never a guarantee that the other 355 astronauts who have flown other shuttle missions would return safely. That they did is testament to their own skill and to the exacting standards continually developed and employed by the U.S. shuttle program.

The end of the space shuttle program, of course, is not going unnoticed. Larger than usual crowds - about a million people - are expected to watch the last launch from sites near the space center. If weather or technical issues postpone today's liftoff, managers will try again on Saturday or Sunday. Atlantis is scheduled to return to the center on July 20. That landing will be the official end of the U.S. shuttle program. It shouldn't be the end of the nation's involvement in space.

Commercial companies are scheduled to deliver supplies to the space station in coming years. What will happen to the National Aeronautics and Space Administration - the backbone of U.S. involvement in space - and its programs is uncertain. Its budget has been reduced considerably in recent years and additional cuts in funding are possible. Imposing them would be a mistake.

The United States has been a leader in space exploration since President John F. Kennedy dared the nation to reach for the stars. It should not surrender that position. Rather, it should assume a major role in the next stage of mankind's journey into space - travel to Mars and beyond.