Space shuttle Atlantis, seen here on Sept. 4 as it entered the secured area around the launch pad at Kennedy Space Center in Cape Canaveral, Fla., is scheduled to launch Oct. 10. (John Raoux/Associated Press)

The October launch date of NASA's shuttle flight to the Hubble Space Telescope is in jeopardy because of a problem with insulation on the replacement batteries for the telescope.

The telescope equipment was supposed to be loaded onto the shuttle Atlantis on Friday, with no time to spare for an Oct. 10 liftoff. That loading operation will be delayed at least 24 hours, NASA spokesman Allard Beutel said Wednesday.

Engineers discovered that crucial insulation on the batteries was accidentally knocked off and blown around by the humidity-purging system.

"Obviously, it has the potential to delay our target launch date," Beutel said.

Shuttle managers want to see how long the cleanup will take before discussing any new launch date, Beutel said. As of Wednesday night, it did not appear as though the batteries or anything else had been contaminated by the insulation, he said.

The insulation came loose and was blown around the plastic bag that encloses the batteries by a gas-purging system that keeps the telescope parts clean. The incident occurred in the building where payloads are serviced.

Atlantis is to carry seven astronauts on NASA's last repair mission for the popular Hubble telescope.