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The Spaceflight Meteorology Group

Postflight Mission Summary for STS-99


The Space Shuttle Endeavor soared high over the Southeast U.S. to a beautiful twilight landing at the Kennedy Space Center on February 22, 2000. The first attempt to land at KSC had been thwarted by no-go weather. Though clouds remained scattered below 8000 feet, crosswinds exceeded the 15 knot limit at the deorbit burn time. NASA waived off the first landing opportunity due to high crosswinds. For the second landing opportunity, meteorologists at the NWS Spaceflight Meteorology Group (SMG) in Mission Control Houston closely monitored the winds and scattered to broken clouds northeast and southeast of KSC. NASA Shuttle Training Aircraft (STA) pilot Charlie Precourt relayed crucial weather reconnaissance reports back to Houston. When he and SMG gave a "weather–go" to the flight director, Endeavor was cleared to land. It glided past a few clouds below 10000 feet and landed with crosswinds of 12 knots from the northeast, within the 15 knot limit. Commander Kevin Kregel reported smooth conditions for the 1823 EDT (2323 UTC) landing.

No-go weather was forecast for the next two days at both the Edwards, California and KSC landing sites. Therefore, White Sands, New Mexico was being considered as a potential landing site if Endeavor had not landed on the 22nd.

This highly successful mapping mission completed 181 orbits of the Earth on its 11 day mission. The primary Payload SRTM (Shuttle Radar Topography) sent back spectacularly detailed pictures of most of the populated portion of the earth. The secondary payload EarthKam allowed students to take many pictures of the Earth.

Endeavor had launched on February 11th at 12:44 EDT (1744 UTC). Launch weather also presented a challenge with clouds at 4000 feet, staying just scattered enough (4/8 coverage); crosswinds were just under the 15 knot limit for Return To Launch Site (RTLS) at KSC.

The SMG Lead Forecaster for STS-99 was Steve Sokol, working his 86th mission and the 16th as Mission Lead. Wayne Baggett was the Assistant Lead and Mark Keehn was the Techniques Development Unit (TDU) Meteorologist.

The SMG web site is

Submitted by:
Steve Sokol
STS-99 Lead Meteorologist

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Page last modified: 1 May 2003