(Editor's note: This story was originally published on June 24, 2002.)
CAPE CANAVERAL, Fla. — Concern about small cracks recently found in the plumbing of the shuttle fleet's main propulsion system forced NASA on Monday to delay Columbia's next launch "a few weeks."
Six cracks measuring one-tenth to three-tenths of an inch (2.5 to 7.6 millimeters) were detected inside sister ships Atlantis and Discovery.
Their presence prompted NASA officials to order inspections of Columbia's plumbing, an operation that requires removal of the orbiter's three main engines.
The spaceplane, now in its hangar at the Kennedy Space Center, was essentially ready to be moved to the Vehicle Assembly Building, all set to go for a targeted July 19 liftoff.
But all launch preparations were put on hold Monday as engineers tried to figure out what they have found, why the cracks are there in the first place and what it all means for the shuttle program .
"These cracks may pose a safety concern and we have teams at work investigating all aspects of the situation," said Ron Dittemore, NASA's shuttle program manager. "This is a very complex issue and it is early in the analysis. Right now there are more questions than answers.
Even if no problems are discovered on Columbia, the process of removing, inspecting, re-installing and testing the orbiter's trio of Rocketdyne powerplants will take a couple of weeks, officials said.
As a result, Columbia's 16-day science mission featuring Israel's first astronaut likely won't get off the ground until August.
The cracks were found on metal liners that fit inside the engine plumbing and helps supercold propellant move past accordion-shaped bellows, which are built into the pipes to make them flexible.
The liners don't hold pressure so a cracked liner doesn't mean any liquid hydrogen or liquid oxygen is leaking, said NASA spokesman James Hartsfield.
But there is concern that any debris from a crack could work its way into a firing engine, which could lead to disaster.
The cracks are not in the propellant lines themselves, Hartsfield said.
A dozen liners inside Atlantis and Discovery were inspected visually, with magnifying glasses and with a process that detects disturbances in the flow of gas over the liner's surface.
Three cracks were found on a single liner in each orbiter.
Endeavour's plumbing also will be inspected after the vehicle returns to Florida from Edwards Air Force Base in California, where it landed Wednesday following a successful mission to the International Space Station.
Follow SPACE.com on Twitter @Spacedotcom. We're also on Facebook & Google+.
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.
