Did a 27-year-old with perfect vision and admitted pickiness help prevent disaster on the space shuttle?

NASA may never know, but the manager of the shuttle program said inspections will be more thorough from now on, and a repair program is being launched.

The first of 11 tiny hairline cracks that grounded the entire shuttle fleet was spotted by David Strait, a sometime surfer with 20/20 vision who works for United Space Alliance, one of NASA's contractors.

Within the space agency there's talk of an award for the systems inspector, who caught the biggest potential hazard at the launch site since an engineer spied a 4-inch pin wedged against Discovery's fuel tank during a countdown in 2000.

If Strait had not spotted the fuel line crack inside space shuttle Atlantis that morning in June, "who knows how much longer it would have gone unnoticed -- or what could have happened," he said.

Engineers feared the cracks could grow, chip and possibly lead to a launch explosion.

NASA officials are still smarting over the fact that no one discovered them before. Shuttle program manager Ron Dittemore has already declared that workers will no longer rely solely on visual inspections.

On Friday, after getting the go-ahead from top NASA officials, Dittemore announced that welding repairs on the cracks will begin next week. The hope is that shuttle flights can resume in late September.

A crack was the last thing Strait expected to find as he began inspecting the fuel lines inside the tail of Atlantis on June 12, routine work before the three main engines can be installed.

As usual, he was using a flashlight to check for scratches on the sealing surfaces, a chore he had done several times before.

Barely 10 minutes into the job, he saw it, a crack three-tenths of an inch in one of the liners of the hydrogen-fuel pipe that feeds main engine No. 1. "I couldn't believe what I was seeing," he said.

He called over the two technicians working with him. Then main propulsion system engineers were summoned. Strait had to show the engineers where the crack was. "They wear glasses," he said, and couldn't find it themselves.

The next day the young inspector boarded a plane for Michigan to spend a long weekend back home in Evart. By the time he returned to Cape Canaveral, sensitive instruments had picked up two more cracks in Atlantis.

Similar cracks were later found in Discovery, Columbia and, finally, Endeavour. None is longer than three-tenths of an inch.

Engineers suspect manufacturing flaws dating to the beginning of the shuttle program in 1981. The cracks emanate from small holes that were stamped into the metal liners to ease the flow of fuel. These holes are rough around the edges and, with the vibration of the engines at liftoff, may have contributed to the cracking. Now, the holes will be polished and smoothed.

Strait theorizes the cracks may have worsened to the point of being spotted with the naked eye. Or it's possible the angle of his flashlight this time may have made a lucky difference.

"I think I'm a good inspector, as far as attention to detail," he said. "Kind of picky, I guess."

In the meantime, as the shuttle program struggles to get back on track, Strait finds himself in the unlikely role of hero.

The former airplane mechanic, who was hired at Kennedy Space Center three years ago, has been overwhelmed by all the kudos from co-workers and bosses.

When Atlantis finally blasts off this fall on a space station assembly mission, more than a month behind schedule, Strait may still be marveling over his discovery.

He notes that if he had gone on vacation a day earlier, the whole problem could have escaped attention. "It's weird how it all timed out like that," he said.