The Skydome floor, which formerly had a two-level display area, will become one level, allowing easier access for the cars and providing more display room.

The board members reserved the option to go back later and fill the hole. They also asked for more information on humidity levels in the display area and its effect on the cars as well as temperature control and its affect on utility costs.

Jason Polk, assistant professor of geosciences at nearby Western Kentucky University and a sinkhole expert, told museum officials the sinkhole has two cave "branches" running from the Skydome, both starting about 50 ft down. Mineral deposits in an arm of one cave indicate dry conditions and that the cave has existed for thousands of years, he said.

That information might cause modifications in the repair plans.

The museum is not disclosing repair costs, spokeswoman Katie Frassinelli says.

The board members discussed several options for the repairs, making their choice after learning that year-to-year attendance is up almost 60% and revenue from admissions, shop and food sales and memberships is up 65%. About 150,000 people each year pay the $10 admission fee for the museum.

"We have to look at creative ways to generate interest in the museum," Wendell Strode, its executive director, said. "It would be so much easier to just be a regular automotive museum with our Corvettes on display, but we have to think outside the box."

The delay in starting the repairs is partially due to the museum's 20th-anniversary celebration on Aug. 27-30 and the opening of the neighboring National Corvette Museum Motorsports Park, which will draw thousands of Corvette owners and enthusiasts on Aug. 28.