During the T-9 minute built in hold, engineers concluded evaluations of four superficial cracks in the thermal foam on the lower side of Endeavour's external tank. They determined that the cracks were too shallow to cause ice or debris concerns. Shuttle engineers successfully repeated a pressure leak test of the orbiter's crew compartment that initially showed a slight variance in the pressure and confirmed the orbiter's readiness to proceed toward launch. Also, a meter that was giving intermittent pressure readings from Endeavour's main propulsion system was exonerated as alternate sensors confirmed good data. Finally, managers determined that a fluctuating reading from Endeavour's hydraulic system was a normal condition. Following a decision to resume the countdown no further issues were worked through liftoff.

The two solid rocket booster recovery ships, Freedom Star and Liberty Star, deployed into the Atlantic Ocean yesterday and are currently on station with the STS-99 boosters. Depending upon weather conditions during recovery operations, the ships are expected to arrive at Hangar AF Sunday at 8 a.m. and 10 a.m. Preliminary inspections will commence on Sunday and booster disassembly begins Monday.