SUBMITTED BY ARTHUR N1ORC - AMSAT A/C #31468

*Launch Day Arrives, Tanking Completed*

/ Sept. 8, 6:15 a.m. EDT (1015 UTC)/ The launch team has reported that an ECO sensor on the hydrogen side of the external tank has failed. At this time the team is pressing forward with launch preparations. Mission Management Team members are meeting at this to determine if they will consider launching with three working sensors or if it will be necessary to de-tank and come back tomorrow.

At Launch Pad 39B, the three-hour process for loading of Space Shuttle Atlantis' orange external tank with 500,000 gallons of liquid oxygen and hydrogen was completed at 5:46 a.m EDT this morning. The "topping off" of propellants into the tank will continue until liftoff. All systems onboard the space shuttle are functioning normally and we continue to press toward a scheduled launch time at 11:41 a.m. this morning.

Throughout the morning, the STS-115 astronauts will prepare for launch in the Operations and Checkout Building's crew quarters before taking the 20-minute ride to the launch pad about 7:50 a.m. this morning aboard the Astrovan.

Launch weather remains at 70 percent "go" for launch, with the primary concern for rain within 20 miles of the Shuttle Landing Facility. No other issues are being addressed by the launch team at this time.

Follow along with the countdown: + NASA's Launch Blog http://www.nasa.gov/mission_pages/shuttle/launch/sts-115/launch-vlcc.html + NASA TV http://www.nasa.gov/multimedia/nasatv/index.html