HOUSTON - In a somber ceremony yesterday, President Bush told the families and colleagues of the seven astronauts lost aboard the space shuttle Columbia that the crew had perished in a great cause that the nation would continue to pursue.
Speaking to thousands beneath a brilliant Texas sky at the Johnson Space Center, Bush said the astronauts would be enshrined forever in the nation's memory.
"To leave behind Earth and air and gravity is an ancient dream of humanity. For these seven, it was a dream fulfilled," Bush said. "Each of these astronauts had the daring and discipline required of their calling. Each of them knew that great endeavors are inseparable from great risks. And each of them accepted those risks willingly, even joyfully, in the cause of discovery."
The memorial marked a break from the National Aeronautics and Space Administration's search for the cause of the shuttle's disintegration over East Texas on Saturday morning, 16 minutes before it was to land at Cape Canaveral, Fla.
Regular business came to a halt at the sprawling space center for the morning as many of the area's 16,600 government and private-sector employees connected with NASA streamed onto the center's broad central lawn for the ceremony.
The event drew dozens of dignitaries from across the country. Senators and House members sat quietly behind rows of the lost astronauts' friends and relatives.
For current and former astronauts, who turned out in large numbers - including former Sen. John Glenn, the first American to orbit Earth, and Neil Armstrong, the first to walk on the moon - it was a reunion of sorts, as they exchanged greetings with fellow explorers they hadn't seen in years.
For many in attendance, the memorial had an unwanted familiarity, recalling ceremonies to mark the explosion of the space shuttle Challenger in 1986. One NASA employee walked into the ceremony gripping the same small American flag she had carried 17 years ago.
Bush assured his audience that the second catastrophic loss of a shuttle and crew in two decades would not weaken the country's commitment to space travel.
"This cause of exploration and discovery is not an option we choose; it is a desire written in the human heart," he said. "We are that part of creation which seeks to understand all creation. We find the best among us, send them forth into unmapped darkness and pray they will return."
Bush and Navy Capt. Kent V. Rominger, chief of the astronaut corps, offered short tributes to the shuttle crew, which, Rominger said, was one of the most closely knit in NASA history.
They joked about Capt. David M. Brown, the crew's lone bachelor, and his insatiable quest for food. They quoted Lt. Col. Michael Anderson, who told his minister shortly before the mission that "if this thing doesn't come out right, don't worry about me, I'm just going higher."
NASA Administrator Sean O'Keefe recalled the awe of Kalpana Chawla, who in the mission's final days summoned her fellow crew members to see Earth, at sunset, reflected in her retina.
"It is this image, of the crew joyfully joined to see the view of the planet reflected in their friend's eye, that we will treasure forever," O'Keefe said.
The remembrances visibly affected the astronauts' family members, who were arrayed on both sides of the president and first lady in the front row.
Laura Husband, the teen-age daughter of the shuttle commander, Col. Rick D. Husband, buried her head in her mother's shoulder. One of Anderson's two daughters kneaded a large white teddy bear. The sons of Col. Ilan Ramon, the first Israeli in space, patted the shoulder of their younger sister, Noaa.
Bush spoke directly to the 12 children of the astronauts, "who miss Mom and Dad so much," telling them that "you need to know they love you and that love will always be with you. They were proud of you, and you can be proud of them the rest of your life."
O'Keefe, who has been at NASA's helm for less than a year, directed his words at the thousands of NASA employees fanned out behind the families, telling them that they owe it to the seven astronauts to forge on with a cause that began with "two bicycle-makers in Ohio," the Wright brothers.
"We have a tremendous duty to find the cause, correct what went wrong, and make sure it never happens again," he said. "We hope our unceasing efforts will provide a fitting tribute to the Columbia Seven."
Interspersed with hymns sung by the Navy Band's Sea Chanters, the ceremony closed with seven tolls of a ship's bell. Moments later, four fighter jets streaked across a sky that was, for a day, startlingly free of Houston's haze. The sudden salute left Lani McCool, widow of shuttle pilot William C. McCool, gaping in amazement in her seat beside Laura Bush.
Before the ceremony, several U.S. senators said NASA retains the support of Congress. Some aerospace experts have begun to question in recent days whether manned space flights are still worth their human and financial toll, however.
The budget Bush sent to Congress this week includes $15.5 billion for NASA, a 3.1 percent increase.
"The space program represents America's technical prowess, a reflection of our vision as a people, that we are by nature explorers and adventurers," said Sen. Bill Nelson, a Florida Democrat and former astronaut. "We never want to give that up."
Nelson described his horror at seeing the shuttle disintegrate Saturday, saying it reminded him of his thoughts during his 1986 mission aboard Columbia.
"On the ascent, you realize you are holding on for dear life. So many parts have to be working perfectly. ... If you have the slightest error, it will cause catastrophe," he said. "What do you do if you know there's going to be a disaster? There's nothing you can do. You close your eyes."
Sen. Mary L. Landrieu, a Louisiana Democrat, said she strongly supports NASA but hinted that it might be time to reassess its mission.
"The shuttle program may change in terms of its intensity and concentration," she said. "We will continue to explore space and move on to the next generation of shuttle."
Bush's statements of support for the shuttle program reassured NASA employees. One administrator, who wouldn't give her name for fear of retribution from her supervisors, said that having support for the manned space program "so profoundly stated" by officials at a memorial reduced the likelihood that it would be cut back.