Shuttle launch pushed to at least October

(CNN) -- The next space shuttle launch will occur no earlier than October 2, NASA mission managers announced this week.

The shuttle fleet has been grounded since June 21, when cracks were discovered in the fuel lines on the shuttle Atlantis and subsequently all the other orbiters.

NASA decided on a strategy to repair the cracks and announced that the next launch would come no earlier than September 28.

But ground crews then found cracks in the bearings on the crawlers that carry the shuttle from the Vehicle Assembly Building to the launch pad.

"Currently, engineers are evaluating cracks on bearings in the jacking, equalization and leveling, or JEL, cylinders on transporter No. 2," NASA said in a written statement Thursday.

NASA has ordered 64 new bearings to be delivered on September 2 for the four 10,000-pound shock absorbers on each of the two crawlers.

The delays have cost NASA between $10 million and $15 million dollars in overtime plus the cost of replacement parts.