NASA officials are reviewing the schedule of spacewalks for the shuttle Endeavour mission to the space station, after a critical tool bag floated into space. VOA's Brian Wagner says officials hope the loss will not affect planned repair work on the station.

STS-126 mission specialists Heide Stefanyshyn-Piper (l) and Steve Bowen participate in interviews with the Associated Press, KMSP-TV in Minneapolis and WCVB-TV in Boston, 19 Nov 2008

The loss happened Tuesday during the first of four planned spacewalks for the Endeavour's mission to the International Space Station.

Astronauts Steve Bowen and Heide Stefanyshyn-Piper were outside the orbiter to clean and lubricate a troublesome joint on a wing of solar panels for the station. Then Stefanyshyn-Piper noticed grease was leaking from one of several guns in the tool bag she was carrying.

"Every time I put my hand in the bag to try to clean one piece, I found more areas with grease," she said. "In the process of the cleaning, the bag came loose and floated away. It was definitely disheartening to see it float away."

The bag should have been tethered to the astronaut, and Stefanyshyn-Piper said she is trying to figure out how it came loose. She and Bowen finished the seven-hour space walk successfully, however, by sharing tools from Bowen's bag.

Speaking with reporters Wednesday, Stefanyshyn-Piper said the grease guns and other tools were not very special, but in space it is impossible to find replacements.

"We are just going to have to rearrange what we do," she said. "It means we are not be as efficient as if we had two sets of guns. That is the big thing, we do not have replacements of the grease guns."

Astronauts have been talking with NASA officials on the ground to adjust plans for the three remaining space walks, which were to involve two astronauts performing repairs outside the orbiter at the same time. The next spacewalk is set for Thursday for additional repairs and preparation for the installation of a new truss to the space station.

Crew members also have been busy transferring supplies and equipment from the shuttle into the station. Endeavour is delivering a number of new facilities, including additional sleeping quarters, a second toilet and an exercise machine to the station.

The upgrades are part of a plan to double the number of astronauts living at the station to six by next year.