International Space Station Assembly 5A.1
STS-102, the 103rd Shuttle mission, lifted-off from Pad 39B of the Kennedy Space Center (KSC), Florida on March 8, 2001 at 1142 UTC. The Shuttle Discovery was launched into a 51.6° orbit inclination at an altitude of 173 nautical miles. Discovery remained in orbit for almost 13 days while the shuttle crew delivered and installed the Leonardo cargo module and performed the first ISS crew exchange to the International Space Station.
High Pressure over the Southeastern US provided clear skies and light winds at the Shuttle Landing Facility in the early pre-dawn hours on Thursday March 8. Temperatures in the 40's, however, caused some concern for forecasters at the 45th Weather Squadron dealing with Launch Commit Criteria (LCC). With winds at the 60 foot launch pad blowing at 8 to 12 kts and relative humidity near 75 percent, the temperature constraints governing LCC remained within limits during the launch count. Pad temperature at lift-off was 44 degrees.
Weather at Zaragosa and Moron in Spain proved more troublesome due to a strong low pressure system approaching the British Isles and another system well offshore. The prime Transoceanic Abort Landing (TAL) site was Ben Guerir, Morocco. Low cloud ceilings and precipitation within 20 nautical miles precluded the use of Moron, Spain as a TAL weather alternate. Crosswind concerns reduced Zaragosa, Spain to the status from a TAL option to an Augmented Contingency Landing Site (ACLS). Fog formed at Ben Guerir, Morocco late in the launch count, but visibilities improved about 40 minutes prior to launch providing acceptable weather at Ben Guerir. As a result, Discovery launched on time at 11:42 GMT.
An intense low pressure system over south Alabama threatened to delay the landing of Discovery on the night of March 20. Strong crosswinds, bands of low clouds, and rainshowers approaching from the west resulted in a "NO GO" forecast and a wave-off of the 1st KSC landing opportunity. By the second opportunity deorbit decision, conditions improved significantly resulting in a "GO" forecast and a decision to deorbit to KSC. Winds, however, began increasing shortly after the deorbit burn and at touchdown were reported at 9 kts with 10 minute peaks to 16 kts. Discovery coasted to a smooth landing at 0731 UTC.
One second post-landing wind data revealed winds averaged just under 10 kts from main gear toudchdown til nose gear touchdown, and did not exceed 12 kts between MGTD and NGTD. However, the 10-minute peak crosswind for landing time was 15 kts.
Other mission information is available at SMG's website under the link for the Spaceflight Meteorology Group (SMG) or from NASA Public Affairs Office or at http://spaceflight.nasa.gov/shuttle/.
SMG Lead Meteorologist Wayne Baggett worked his 10th mission as Lead. Karl Silverman was the Assistant Lead and Mark Keehn was the Lead Techniques Development Unit Meteorologist.
G. Wayne Baggett
STS-102 Lead Meteorologist