The Spaceflight Meteorology Group

Postflight Mission Summary for STS-87

January 7, 1998

...Columbia’s "Thanksgiving" Mission Launches and Lands On-time at KSC...

Space Shuttle Columbia lifted off on time November 19, 1997 at 1946 UTC. The only weather concern was cirrus anvils from thunderstorms in the central gulf being carried over central Florida by strong westerly upper level winds. Although SMG’s Return To Launch Site(RTLS) forecast remained GO throughout the launch count, the 45 WS Launch weather evaluation went "Red" or NO-GO for launch 3 hours prior to launch due to an anvil Launch Commit Criteria violation and did not go "Green" or GO until 45 minutes before launch.

Columbia’s crew spent nearly sixteen days in space conducting experiments and space walks in support of the future international space station. The crew also spent Thanksgiving on board the shuttle and received a call from President Clinton who wished them continued success in space.

For landing day on December 5, timing the clearing of low clouds at KSC behind the cold front was the main forecast challenge. The National Center for Environmental Prediction (NCEP) Medium Range Forecast (MRF) model provided outstanding guidance in forecasting this cold front moving across Florida. The consistency of consecutive model runs, coupled with the NCEP MRF Ensemble forecasts, gave SMG confidence in the frontal timing and low- cloud-clearing scenario as early as six days before landing. This enabled SMG to accurately forecast a GO for landing several days in advance.

The cold front pushed through the KSC area about eight hours before landing, as advertised by both the MRF and other short range NCEP models. The low clouds cleared the KSC area about two hours before landing, or about one hour before the deorbit burn. Skies remained mostly clear for the landing.

Columbia touched down on time at the KSC Shuttle Landing Facility on December 5, 1997 at 1221 UTC. This was the twelfth consecutive mission to end with a landing at the Kennedy Space Center and the nineteenth in the last twenty flights.

The lead forecaster for STS-87 was Richard Lafosse. Assistant lead/TAL site forecaster was Tim Garner. The lead Techniques Development Unit meteorologist was Mark Keehn.

Submitted by:

Richard Lafosse STS-87 Lead Forecaster