NASA is targeting Tuesday, July 26 as the earliest possible date to launch the Space Shuttle Discovery on the Return to Flight mission (STS-114). The determination was made during Monday's meeting of the Mission Management Team (MMT) at Kennedy.

The MMT reviewed efforts by teams of engineers. The engineers are working through a troubleshooting plan to address an issue with a liquid hydrogen low-level fuel sensor circuit. The sensor circuit failed a routine pre-launch check during the countdown July 13, delaying Discovery's first launch attempt.

NASA is still working to launch Discovery by the end of the July window that extends to the 31st. A dozen teams, with hundreds of engineers across the country, are expected to complete their battery of tests by Wednesday. While they have not isolated a cause of the sensor circuit failure, they have eliminated a number of possibilities. If the remaining tests are inconclusive, NASA could reload the External Tank with super-cooled propellants to see how the sensor circuit behaves. The tanking could be done as a test or as part of an actual launch countdown.

Commander Eileen Collins and her six Discovery crew mates come out of quarantine today for one day off. They resume quarantine and training later this week.

For the latest information about STS-114 on the Web, visit:

http://www.nasa.gov/returntoflight