From Launch Complex 39 at the Kennedy Space Center in Florida, this is Shuttle Launch Control at T-3 hours and holding.
We are now in the final six hours of the countdown for the launch of Atlantis on mission STS-115,
the first mission since Return to Flight to resume construction of the International Space Station.
The countdown is being controlled from Firing Room 4 in the Launch Control Center and we are
currently on schedule for a liftoff at 11:40 a.m. Eastern time this morning.
STS-115 is planned to last approximately 10 days, 19 hours and 30 minutes,
with a landing at the Kennedy Space Center Shuttle Landing Facility on Tuesday, Sept. 19, at 7:10 a.m.
This is the 116th launch of the Space Shuttle Program, the 27th launch of
Space Shuttle Atlantis and the 19th flight to the International Space Station.
There are six astronauts aboard Atlantis who will shortly be en route to the space station on the first day of this 11-day mission.
Aboard will be the P3/P4 truss segment, the, and the second set of solar arrays and batteries to provide power to the station.
The integrated truss in the payload bay is over 45 feet long and weighs nearly 35,000 pounds. The astronauts, a six-member crew,
consist of Mission Commander Brent Jett, Pilot Chris Ferguson, Mission Specialists Joe Tanner,
Dan Burbank, Heidi Stefanyshyn-Piper and Steve MacLean from the Canadian Space Agency.
This morning, our tanking operations began at 2:49 a.m. and the fuel cell that we've been watching
carefully over the last couple of days as part of our engineering evaluation is working just fine this morning so far.
We are working a problem with a low-level eco-sensor, hydrogen eco-sensor, cut-off sensor that,
on the hydrogen side of the tank that has failed wet. And at this point,
we're continuing our countdown operations as per plan while this is under discussion.
It will get more discussion by the mission management team later on this morning. There are a couple of options.
One is, depending on how the engineering analysis turns out and the discussion of the mission management team,
we may pick the option of choosing to launch with three eco-sensors instead of the four.
Or the other option is to detank, come back tomorrow and, when we retank, see what that sensor does the next time around.
So that will be a developing story during the morning, but nothing at this point that is going to
constrain any of the activities as far as tanking and inspections at the pad,
or the crew activities that will be coming up in terms of getting it ready to go to the pad and boarding Atlantis.
We have two hours, 11 minutes, 11 seconds remaining in this built-in hold. At T-3 hours and holding, this is Shuttle Launch Control.