Following routine film analysis of external tank separation during the STS-106 launch, engineers noted a 2 ¼ - inch protrusion of the aft attach bolt following tank separation. At separation, a frangible nut inside the orbiter releases the 14-inch bolt which is supposed to fully retract into the external tank's bolt housing. On STS-106, that bolt did not fully retract.

Engineers are evaluating the cause of this occurrence and what impact a bolt protrusion would have on the STS-92 flight if any. Following the engineering evaluation, Shuttle managers will gather tomorrow morning to address the issue and discuss launch options.

Engineers are also evaluating an issue with a valve inside Discovery's main propulsion system that controls the flow rate of propellant and mitigates vibrations in the aft compartment. During a routine test today, the valve operated sluggishly. Engineers will evaluate whether this condition is acceptable for flight and report back to Shuttle management. When additional information is available, another status report will be issued.

Weather forecasters indicate a 20 percent chance of weather violation for a Friday launch attempt. The official forecast calls for clouds to be scattered from 3,000 feet to 7, 000 feet and at 25,000 to 30,000 feet; visibility at 7 miles; launch pad winds from the south east at 8 gusting to 10 knots; temperature at 77 degrees F; and relative humidity at 85 percent. The primary concern is the chance of showers. The 24-hour delay forecast indicates a 60 percent chance of weather violation.