NASA officials announced on Tuesday that the 6-hour, 56-minute spacewalk performed by astronauts Dan Tani and Peggy Whitson ended 11:46 a.m. EST. The main objective was to identify the malfunctions on the International Space Station’s Beta Gimbal Assemblies (BGAs) for starboard solar wings and Solar Alpha Rotary Joint (SARJ).

Approximately two weeks ago, chairman of the NASA space station management team Kirk Shireman announced problems to the primary and backup power sources that slowed down their activity. The Tuesday spacewalk was expected to reveal physical damage, but there were no evidence of space debris or meteorite hit.

After inspecting the BGA for 45 minutes and disconnecting two of the cables, the astronauts declared the cables not responsible for the malfunctions and reconnected them afterwards.

The SARJ inspection showed various degrees of contamination, which included metal shavings debris and “dusting” in the race ring, but nothing that hasn’t been previously seen.

Ginger Kerrick, the station spacewalk director, said in a televised conference that the problem could be inside the rotary mechanism of the joint, and that a plan is being developed in order to fix the problem. NASA representatives added that the main priority is to find the cause of what is damaging the mechanism and that they did not wish to use the spare backup yet.

At the same time, at the Kennedy Space Center in Florida, the external fuel tank of Atlantis was filled with cold liquid hydrogen and liquid oxygen in order to identify the source that caused the malfunctioning of the fuel gauge sensors, which already delayed the shuttle’s launch two times.

Three of the four hydrogen sensors failed during the test, but the problem has been linked to a metal and glass connector through which wiring from inside the tank joined with circuits at the back of the shuttle.

Engineers can’t pronounce yet on whether the cause of the malfunction is due to the cold hydrogen or if it can be fixed without returning the shuttle to the hangar, but they announced they will come up with a plan within the next few days.

Until further notice, the date for the next launch attempt of the Atlantis remains January 10, 2008.