Live at KSC: Sensor data in; De-tanking has begun

Live: Refresh this page for periodic updates and the latest still images from NASA TV's Public channel (left) and a live video feed at Kennedy Space Center's launch pad 39A. (right). Click on the left image for live NASA TV coverage of the spacewalk at the International Space Station. Click on the right image for live NASA TV coverage of the shuttle tanking test at KSC.

The troubleshooting team has given the green light to begin removing 500,000 gallons of liquid Oxygen and liquid Hydrogen from the shuttle's external tank.

"We are beginning to drain the external tank, taking data as we go," said NASA spokesman George Diller.

"A second sensor has failed," said Diller. "We're collecting data on sensor No. 3,(which worked intermittently before it failed)."

Sensor No. 1 failed completely earlier this morning. Sensor No. 2 worked intermittently, while sensor No. 4 had no sign of failure.

Engineers believe they have enough electronic data from morning tests to determine why three of four low-fuel sensors failed during tests. The suspect sensors have failed and scrubbed launch attempts on Dec. 6 and 9.

"We did get the kind of data we need to get to the bottom of this problem. It's very good quality data," said Diller. "I think they're gradually converging on what's wrong from the data they've gotten today."

Atlantis is scheduled to launch Jan. 10 for a mission to the International Space Station.

NASA commentary ended about 1:20 p.m.

However, watch The Flame Trench for coverage as Shuttle program manager Wayne Hale discusses the test at a briefing no earlier than 4:30 p.m. EST.

NASA's Mission Management Team will meet Wednesday to discuss the data collected during today's test.