• VEHICLE: Discovery/OV-103
• LOCATION: Pad 39B
• TARGET KSC LAUNCH DATE/TIME: December 19 at 7:50 p.m. EST
• TARGET KSC LANDING DATE/TIME: December 27 at about 5:24 p.m. EST
• LAUNCH WINDOW: 42 minutes
• MISSION DURATION: 7 days, 21 hours, 34 minutes; with 3 EVAs
• CREW: Brown, Kelly, Smith, Foale, Grunsfeld, Nicollier, Clervoy
• ORBITAL ALTITUDE and INCLINATION: 317 nautical miles/28.45 degrees

Work in progress: Today, Shuttle managers decided to proceed with the STS-103 launch countdown and loading Discovery's external tank. The tanking activity began at 10:30 a.m. today and will take approximately 3 hours to complete.

The countdown clock will enter a planned 2-hour built-in hold at the T-3 hour mark at 2 p.m. The clock will resume at 4 p.m. and enter the next planned built-in hold at the T-20 minute mark at 6:40 p.m. for 10 minutes. The final planned hold will come at the T-9 minute mark at 7:01 p.m. for 40 minutes. The clock will resume at 7:41 p.m. for an on-time launch at 7:50 p.m. The launch window closes today at 8:32 p.m.

Tonight's weather forecast calls for improved conditions as the weak frontal boundary continues to drift north away from Central Florida. There is an 80 percent chance for acceptable weather conditions tonight. Clouds will be scattered at 3,000 feet, 8,000 feet, and 25,000 feet; visibility will be 7 miles; winds out of the southeast at 10 knots; temperature at 65 degrees F; and there is a slight chance of a low cloud ceiling.

Although the Kennedy Space Center is the prime end-of-mission landing site, Shuttle managers carefully reviewed turnaround-processing operations at Edwards Air Force Base, CA, should landing be diverted. There are several landing opportunities in both Florida and California on the planned landing on Dec. 27. Historical weather data indicates both sites have a high probability of favorable weather this time of year at the planned landing time.