Update: Heat Shields Look Good

Photo analysis of Endeavour's heat shields indicates they are in good condition, so mission managers have ruled out the need for a more intensive inspection on Wednesday.

That gives Endeavour preliminary clearance for a safe landing, but another round of pictures will be taken of the shuttle's reinforced carbon wings and nose after it undocks from the International Space Station on Thanksgiving.

Analysts then will be looking for signs that micrometeoroids or other space debris could have damaged the vehicle.

Not having to do a so-called "focused inspection" Wednesday frees up more than 10 hours for some astronauts that could be used to hook up a new water recycling system and collect samples for analysis.

Managers are also considering a one-day extension to the planned 15-day mission, a decision that may not come until Friday.

Meanwhile, NASA officials say Endeavour astronauts are close to opening the hatch to the Leonardo cargo module that was connected to the station earlier today with a robotic arm.

The crew is working more than an hour ahead of schedule, which could speed up the unpacking of two racks containing critical water recycling equipment to Tuesday, managers said during a briefing this afternoon at Johnson Space Center in Houston.

A new resistive weight training machine will also be unloaded Tuesday, to complement an aging treadmill already on the station.

In all, roughly 14,500 pounds of equipment will be unloaded from the Italian-made container.

Also in progress on the station are preparations for Tuesday's spacewalk. Heidemarie Stefanyshyn-Piper and Steve Bowen - shown at left - moved their spacesuits into the Quest Airlock, where they will camp out tonight at a lower air pressure.

That will reduce the amount of time they need to breathe pure oxygen before the spacewalk, which will purge nitrogen from their bodies and reduce the risk of decompression sickness while working in the vacuum of space.

A second mission briefing is scheduled at 6 p.m. You can watch it live here by clicking the NASA TV picture at the top of the page.