Return To Flight T- 08:00:00

Image courtesy NASA/KSC

The Rotating Service Structure (RSS) was rolled away from Discovery at 3:38 p.m. on Monday. The giant enveloping appendage is used to install payloads into an orbiter's cargo bay and provide protection from inclement weather. With the RSS now out of the way, propellant loading is set to begin after midnight Tuesday morning with the pumping of more than 500,000 gallons of liquid oxygen and hydrogen into the vehicle's orange External Tank.

Launch of Space Shuttle Discovery on NASA's Return to Flight mission is still on track for Tuesday at 10:39 a.m., NASA Test Director Pete Nickolenko announced during a morning briefing at Kennedy Space Center in Florida.

According to International Space Station Mission Manager Scott Higginbotham, the hardware in Discovery's payload bay is ready for mission STS-114.

"We are still concerned that right around the launch time, the sea breeze will be developing, and some off-shore activity could bring in some anvil clouds and some showers or cumulous clouds in the area of the launch pad or the [Shuttle Landing Facility]," said Shuttle Weather Officer Kathy Winters. The chance of Kennedy weather cooperating for the launch remains at 60 percent.

Wayne Hale gave a show-and-tell presentation of a fuel sensor and described how they're used in the External Tank. "We have completed all of our ambient temperature checks. We have run every test we could think of and so far no repeat."

Hale went on to say "If the problem recurs and under very closely defined circumstances in sensor #2 or sensor #4 then we will do some more tests and if we are comfortable that we have a good understanding then we can go fly...We are ready to go launch Tuesday morning."

Senior NASA managers met Sunday at Kennedy Space Center for a launch readiness meeting. Discussions focused on recent problems related to a liquid hydrogen low-level fuel sensor inside the external fuel tank, which prompted postponement of the Shuttle’s launch on July 13. Since then, engineers have been working around-the-clock on troubleshooting the sensor system issue.

During the countdown, managers will monitor for recurrence of the problem. If any new sensor-related issues occur, engineers would stop the countdown to reassess the situation.

During their 12-day mission to the International Space Station, Commander Eileen Collins and her six fellow astronauts will test new techniques and equipment designed to make Space Shuttles safer. They also will deliver supplies and make repairs to the Space Station.

Godspeed, Discovery