Cape Canavarel, Fla. ? A spacewalking astronaut accidentally let go of her tool bag Tuesday after a grease gun inside it exploded, and helplessly watched as the tote and everything inside floated away.

It was one of the largest items ever to be lost by a spacewalker and occurred during an unprecedented attempt to clean and lube a gummed-up joint at the international space station.

Heidemarie Stefanyshyn-Piper was just starting to work on the joint when the mishap occurred.

She said her grease gun exploded, getting the dark gray stuff all over a camera and her gloves. While she was wiping everything off, the white, backpack-size bag slipped out of her grip, and she lost all her tools.

“Oh, great,” she mumbled.