Bye-bye, grease gun.

An astronaut cleaning a solar rotary joint on the International Space Station lost her 30-pound tool bag yesterday, sending two grease guns, a scraper, a garbage bag and wipes into the cosmos, NASA reports.

"Oh, great," said astronaut Heidemarie Stefanyshyn-Piper as the bag drifted away. "You see it?"

The slip-up occurred about midway into the nearly seven -hour spacewalk. Piper was about to lubricate the rotary joint, which is clogged with metal shavings, when the gun squirted grease into her tool bag. As she was cleaning out the bag, it drifted away. She and astronaut Steve Bowen shared a second set of tools for the rest of the spacewalk.

NASA is tracking the bag, which is now space litter, spokesman Bill Jeffs told today. "There's no concern for re-contact with the station. It continues to move away from the station with each orbit. It will eventually drop out of orbit and burn up on re-entry."

The bag is expected to re-enter Earth's atmosphere in about six months, Jeffs said.

This isn’t the first time an astronaut has lost an item during a spacewalk, Jeffs added, and they routinely get rid of items in space. A wrench and other tools lost during previous walks have already re-entered Earth's atmosphere and burned up, he said. "It's not frequent, but it's not uncommon that spacewalkers lose some tools and drop some equipment," he said.

Also yesterday, astronauts moved a second toilet into the station. Today they'll install additional sleeping quarters. The bedrooms and the new commode are part of an expansion of the space station that will double its capacity from three to six astronauts at a time.

Stefanyshyn-Piper will take a second spacewalk tomorrow with astronaut Shane Kimbrough, when they'll continue cleaning the rotary joint, sharing the spare grease gun, Jeffs said.

Endeavour docked at the International Space Statio with robotic Canadarm2 in the foreground/NASA