Discovery Launch Scrubbed NASA has scrubbed the launch of Discovery because of a problem with a fuel tank sensor designed to protect the Shuttle's engines by shutting them down if fuel runs low. http://www.nasa.gov/externalflash/rtf_front/index.html Post-Scrub Press Briefing NASA managers are currently meeting to evaluate the sensor issue. More information will be released at a press conference scheduled for no earlier than 4:30 p.m. EDT this afternoon from Kennedy Space Center, Fla. The press conference will be broadcast on NASA TV. Today's Return to Flight launch of Space Shuttle Discovery has been postponed due to an issue with a low-level fuel cutoff sensor onboard the vehicle. The sensor protects an orbiter's main engines by triggering them to shut down in the event fuel runs unexpectedly low. Eileen Collins is the commander for the Return to Flight mission and leads an international crew of six astronauts. Discovery is set for a 12-day flight to deliver equipment and supplies to the International Space Station. The STS-114 mission comes after a two and a half year initiative to reinforce the orbiters and improve the safety of the Space Shuttle fleet.