Station Commander Peggy Whitson and Flight Engineer Dan Tani will perform the 100th spacewalk in support of International Space Station assembly on Tuesday, Dec. 18. They will inspect the starboard Solar Alpha Rotary Joint (SARJ) and the Beta Gimbal Assembly (BGA). The SARJ and BGA have been temporarily locked in place while the solar arrays still produce power.

Whitson and Tani completed a procedure review on Friday and held a tagup with the lead spacewalk officer on the ground.

Kirk Shireman, station program deputy manager called the spacewalk a "fact-finding mission." The spacewalkers will report back to ground controllers what they find and return a trundle assembly back inside the station. Specialists on the ground will use the results to determine how to restore the starboard solar array's sun-tracking capability.

HOUSTON - Many people will travel for the holidays, but no one will be farther from home than the astronauts aboard the International Space Station. With that in mind, NASA invites the public to send personal holiday greetings to the orbiting crew.

NASA astronaut Peggy Whitson, the first female to command the station, and her crewmates are circling Earth at 17,500 mph, orbiting 16 times each day. Whitson and Flight Engineer Yuri Malenchenko, a Russian cosmonaut, have been on the station since Oct. 12. Flight Engineer Dan Tani, a U.S. astronaut, joined them Oct. 25. Together, they make up the 16th resident crew of the orbiting outpost.

Dec. 9 -9:30 a.m. EST
The launch of space shuttle Atlantis has been rescheduled for no earlier than Jan. 2, 2008. The postponement will give engineers time to evaluate false readings from the engine cutoff sensor system that measures liquid hydrogen in the external tank.

Of the four engine cutoff sensors, ECO sensor number three gave false readings during Sunday's launch attempt. The sensor system is one of several that protect the shuttle's main engines by triggering their shut down if fuel runs unexpectedly low.

Atlantis' scheduled launch on Thursday was delayed after two of the four engine cutoff, or ECO, sensors in the shuttle's external fuel tank gave false readings. A third sensor failed after the tank was drained of fuel.

Dec. 6, 10 a.m. EST: During tanking, two of four LH2 Engine Cutoff (ECO) sensors failed to respond appropriately, which is a Launch Commit Violation. The requirement to proceed calls for 3 of 4. The launch was scrubbed at 9:56 a.m. EST on the recommendation of Launch Director Doug Lyons.

Mission Management Team Chairman LeRoy Cain concurred following a short briefing on the issue. The ice inspection team will proceed with an abbreviated vehicle inspection prior to offloading the LO2 and LH2 and recycle for a launch attempt tomorrow, at 4:09 p.m.

A press briefing is tentative scheduled for 3 p.m. An update is forthcoming on NASA TV.

The launch team at NASA's Kennedy Space Center in Florida began the countdown Monday night for the launch of mission STS-122. Space shuttle Atlantis is scheduled to lift off at 4:31 p.m. EST on Thursday to begin an 11-day mission to the International Space Station.

"All of our systems are in good shape," said assistant launch director Charlie Blackwell-Thompson.

The weather forecast calls for an 80 percent chance of acceptable weather at launch time, weather officer Kathy Winters said.

"We're very optimistic about it," Winters said.

The seven astronauts who will perform the mission arrived at Kennedy at about 12:30 p.m. EST on Monday to begin their final preparations for the mission. Atlantis has a 10-minute window to launch so it can catch up with the International Space Station.

Columbus , the laboratory built by the European Space Agency (ESA), is now packed inside space shuttle Atlantis' payload bay. It is the culmination of years of design and engineering work aimed at creating Europe's primary component for the International Space Station (ISS). At 23 feet long and 15 feet in diameter, the cylindrical segment is designed to host specialized experiments examining how humans react to microgravity and the effect of space on various fluids and objects such as crystals. Two Amateur Radio on the International Space Station (ARISS) antennas have been installed on the nadir side of Columbus. NASA is currently planning on a launch date of Thursday, December 6 for Atlantis.

According to ARRL ARISS Program Manager Rosalie White, K1STO, a record number of Amateur Radio on the International Space Station school contacts have been made during 2007 -- 74, to be exact. This is nearly twice the highest number of school contacts the astronauts and the ARISS Team handled in previous years. "Though the ARISS Team's expectations are a little lower for being able to achieve this level of contact activity in 2008, this is a good time to file an application and begin making preparations for your school to have an ARISS contact," White said.

The 2007 Amateur Radio activity was led by the energetic participation of astronauts Sunita Williams, KD5PLB, and Clay Anderson, KD5PLA. They have significantly reduced the backlog of schools waiting for a contact. The ARISS Team plans to award a Certificate of Appreciation to Anderson. The astronaut set a new record for ARISS school contacts. White said, "A successful ARISS contact with a school in Quebec was the 39th contact made by Expedition 15 crew members, surpassing the record set by the Expedition 12 crew for the most contacts made during an International Space Station expedition."

Spacewalkers Peggy Whitson and Dan Tani completed Saturday's spacewalk at 11:54 a.m. EST. The 7 hour and 4 minute excursion started an hour and 10 minutes early. They completed their main tasks well ahead of the timeline then moved on to perform some get-ahead work.

+ Read more about Saturday's spacewalk at http://www.nasa.gov/mission_pages/station/expeditions/expedition16/eva_1...

The two spacewalkers moved the 300-pound, 18.5 foot Loop B fluid tray from the station's main truss to the port side of Destiny and completed fluid and electrical connections.

Tani did an inspection of a Solar Alpha Rotary Joint that had previously shown increased power consumption and vibration while rotating as it followed the Sun. Whitson deployed and mated cables to be used as part of the Station to Shuttle Power Transfer System, or SSPTS. A portable foot restraint was also installed on Node 2 for upcoming spacewalks when the European Columbus laboratory is installed on the STS-122 mission.

A 6-hour, 30-minute spacewalk by International Space Station Commander Peggy Whitson and Flight Engineer Dan Tani will continue the external outfitting of the Harmony node in its new position in front of the U.S laboratory Destiny.

The spacewalk is scheduled to begin at 6 a.m. EST Saturday from the U.S. airlock Quest. As was the case in the Nov. 20 spacewalk, Whitson, the lead spacewalker, will wear the suit with the red stripes while Tani will be in the suit with the barber-pole stripes.

After leaving the airlock and setting up tools and equipment, Whitson will remove, vent and stow an ammonia jumper, part of a temporary cooling loop. Removing it allows connection of the hookup of the permanent Loop B ammonia cooling loop on a second fluid tray on the station's exterior.

The research capacity of the International Space Station is set to double during a December NASA mission that is a milestone for European spaceflight.

The European Space Agency's Columbus laboratory packed inside space shuttle Atlantis' payload bay is the culmination of years of design and engineering work aimed at creating Europe's primary component for the space station.

At 23 feet long and 15 feet in diameter, the cylindrical segment is designed to host specialized experiments examining how humans react to microgravity and the effect of space on various fluids and objects such as crystals.