The Spaceflight Meteorology Group
Postflight Mission Summary for STS-99
SPACE SHUTTLE ENDEAVOR COMPLETES FIRST MISSION OF THE NEW MILENNIUM
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 http://www.srh.noaa.gov/smg.
Submitted by:
Steve Sokol
STS-99 Lead Meteorologist
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www.nws.noaa.gov 
