The loss of a toolbag, which floated away into space from the space shuttle Endeavour Wednesday, has forced changes in plans to remaining spacewalks during the ship's visit to the International Space Station.

The briefcase-sized tool bag drifted away from astronaut Heidemarie Stefanyshyn-Piper on Tuesday as she cleaned and lubed a gummed-up joint on a wing of solar panels on the space station.

She and fellow crewman Stephen Bowen were midway through the first of four spacewalks when the toolkit was lost.

NASA officials said the toolkit was not properly tethered and slipped away.

"What it boils down to is all it takes is one small mistake for a tether not to be hooked up quite correctly or to slip off, and that's what happened here," said lead spacewalk officer John Ray.

Flight controllers are considering having the two astronauts share Bowen's pair of grease guns for the three remaining spacewalks on Thursday, Saturday and Monday.

© 2008 Newsroom.