Update: Spacewalks Still On Track

The loss in space today of a briefcase-sized tool bag shouldn't prevent Endeavour astronauts from completing their remaining three spacewalks, NASA officials said this evening.

The so-called "crew lock" bag - which measured about 20 inches tall and a hand width wide, and weighed about 30 pounds on the ground - should have been tethered within a larger bag but was not, for reasons that aren't known.

"All it takes is one small mistake for a tether just not to be hooked up quite correctly or to slip off where it's supposed to be engaged, and that's what happened here, it appears," said John Ray, lead spacewalk officer for the mission.

Video showed the bag float away after lead spacewalker Heidemarie Stefanyshyn-Piper set it down for a moment. She was trying to clean up tools that were covered in grease because a grease gun had leaked - an event that is also being investigated.

The bag held a set of equipment including two grease guns, one with a straight nozzle and one with a J-hook nozzle. Also lost were a caddy containing six terrycloth wipes, a large trash bag for disposing of used wipes, a scraper and a box for disposing of scraped-up debris "pancakes."

The astronatus started a two-year effort to repair a damaged joint that rotates the station's starboard solar wings like paddle wheels so they continuously track the sun.

Ray said backup equipment is available for all of the tools except the grease guns, and several options are being considered for how to proceed without them.

The shuttle carries two similar guns for repairs of wing leading edges if damage from space junk is discovered after the orbiter undocks from the station.

Ray said those guns could possibly be adapted for applying grease, but maintaining redundancy for the wing repairs must be considered. The quantities of grease required to complete the remaining tasks is also being reviewed.

Or, the spacewalkers could proceed by using just one set of grease guns, as they did today with success. Stefanyshyn-Piper and Steve Bowen shared the grease guns, a scraper and a large trash bag.

"We've got several options, and we're confident that we'll be able to still get our primary tasks completed on the future (spacewalks), and overall very happy with the way things went today," said Ray.

Two more spacewalks are planned Thursday and Saturday on the starboard Solar Alpha Rotary Joint, or SARJ. The station's port rotary joint would be lubricated in a fourth spacewalk Monday.

Ginger Kerrick, the lead space station flight officer, said the lost tool bag was being tracked and would not endanger the station or shuttle as it orbited.

As of about 9:30 p.m., the bag was about 4,000 meters in front of the station and 200 meters below it.

"It is definitely moving away with every orbit," Kerrick said. "(We have) no concern whatsoever for recontact at this moment, with the data we have," she said.

Overall, Ray and Kerrick said they were extremely happy with the day's work, which put activities both inside and outside the station ahead of schedule.

Unloading and installation of racks that are being unloaded from the Leonardo cargo van has moved so quickly that planners are scrambling to decide what to schedule Wednesday.

"We've been having a hard time keeping up with them," Kerrick said.

Racks fastened in place inside the station today included a second toilet, two sleep stations, a second kitchen, two Water Recovery System racks and a Combustion Integration Rack used for science experiments.

The saved time means it may not be necessary to extend the 15-day mission a day, which was under consideration primarily so samples could be taken from a water recycling system.

If the system works properly, it will distill and acid-treat urine, sweat and other wastewater and turn it into drinking water. NASA wants samples from a new potable water dispenser to be taken home for testing, but thought they would need an extra day to acquire them.