Happy NASA officials yesterday pronounced the shuttle Columbia a "tight ship" again after it passed an elaborate fueling test, ending the long hunt for hydrogen leaks that sabotaged shuttle launch attempts throughout the summer.

"Maybe things are turning around," said a smiling Robert L. Crippen, head of the shuttle program.

Early this month, the shuttle Discovery -- the one orbiter in the three-ship fleet that has not sprung excessive hydrogen leaks -- successfully deployed a probe to the sun after a hiatus in shuttle launches of more than 5 1/2 months.

Last week, after repairs to its leaky plumbing, the orbiter Atlantis passed a fueling test similar to Columbia's. NASA yesterday gave it the go-ahead for a Nov. 9 launch.

Atlantis is to carry aloft five astronauts with a secret military payload that experts say is a 22,000-pound photo-reconnaissance satellite destined to monitor the Persian Gulf region. The mission, delayed since July by the hydrogen leak problem, will be the last completely secret flight for the shuttle fleet, according to the Air Force.

Columbia's 10-day astronomy mission, postponed four times since May, could be rescheduled for launch as early as the first week of December if there are no other problems, Crippen said.

"There was a sense of victory . . . a sense of relief that this problem is behind us," said launch director Robert Seick, describing the mood in the launch control center at Kennedy Space Center yesterday as Columbia's fueling test ran its course. The vehicle showed no more than the low level of hydrogen leakage that is expected routinely.

He and Crippen praised the special team of "leak hunters" headed by propulsion expert Robert Schwinghamer, a top engineering official at Marshall Space Flight Center in Huntsville, Ala. The team was assembled late last month, after previous efforts to find all the leaks had failed, and told to stay at Cape Canaveral until the problem was solved.

"The results today prove that they did the job right," Crippen said. "I just gave them permission. . . to go home."

During the test, supercold hydrogen was pumped through the orbiter's fuel system at up to 8,300 gallons per minute and temperatures of minus 423 degrees Fahrenheit.

The fueling test was the most heavily instrumented in shuttle history, with 10 remote control television cameras placed inside Columbia's aft engine compartment to spot the source of any leaks.

But the Schwinghamer team had found them all, locating and fixing "at least three different significant leaks" including two crushed seals "that were very hard to isolate," Crippen said.

Investigators have concluded that Columbia's leak problems began early this year when technicians took the fuel plumbing apart in order to clean a kind of sandpaper grit out of the lines. The leak paths were created when the technicians put the parts back together imperfectly, they said.

The leakage in Atlantis was apparently caused by microscopic glass beads that drifted into key shuttle plumbing as it sat on the shelf at a California contractor's factory. NASA has approved a new test facility at Marshall to check similar components for leaks in the future, engineers said, and other leak tests are also being reviewed.

William Lenoir, who heads NASA's office of space flight, has acknowledged that NASA might have found the leaks sooner and prevented some of the summer's embarrassments if it had followed the Schwinghamer approach from the start, pursuing an exhaustive investigation instead of gambling on a single line of inquiry that focused each time on the most suspect hardware.

"There's been a lot learned this summer," an engineer said.