Sensors on the Space Shuttle Discovery have captured a number of problems with the external fuel tank. Beginning on Friday (5/20), problems with the tank's pressurization system were detected. NASA is taking no chances and intends to swap out the external tank and solid rocket boosters for a tank and booster set which had originally been scheduled to fly with Atlantis on its next mission. These changes, which will begin tomorrow, may force NASA to scrap the planned July launch of Discovery.
Breaking News - 05/24/05:
NASA says flight is still scheduled for July despite problems.