Repairs Will Ground Shuttle Fleet Until at Least Sept. 28

NASA will begin repairs to cracked fuel lines on its grounded fleet of space shuttles next week and may be able to launch a mission as early as Sept. 28, the U.S. space agency said Friday.

But the wait will be even longer for Israel’s first astronaut, Ilan Ramon, who had been scheduled for a 16-day science mission in mid-July along with six U.S. astronauts on the shuttle Columbia.

Because two missions to the international space station have been given priority, Ramon’s flight will not lift off before Nov. 29, and it could launch as late as January, NASA said.

The four shuttles in the U.S. fleet have been confined to hangars since late June, when the first tiny cracks were discovered in fuel lines that deliver highly explosive liquid hydrogen to the engines.

The cause of the 12 cracks found so far, which are so small they cannot be seen in detail without magnifying them about 100 times, remains a mystery.

“We’re not at the point yet where we’ve determined the root cause,” shuttle program manager Ron Dittemore said at a news briefing.

Dittemore said a combination of welding and polishing should make the stamped metal fuel lines stronger than when they were new, and NASA should not have to worry about more cracks for at least three to five years.

NASA considered, but ultimately rejected, continuing to fly the shuttles without repairing the cracks.

In all likelihood, the cracks had been there for years, since shortly after each shuttle went into service, NASA officials said. The oldest, Columbia, first flew in 1981.

The fissures are not growing at all or are growing very slowly, and they have not threatened astronauts on past missions, Dittemore said.

“We looked at great length at flying [with the cracks], but in the end determined there were too many unknowns associated with that,” he said.

Dittemore had high praise for the technician who spotted the cracks, David Straight. “With this particular finding, he’s a star and deserves a medal.”