The Spaceflight Meteorology Group
Postflight Mission Summary for STS-90
May 13, 1998
Space Shuttle Columbia landed at the Shuttle Landing Facility (SLF), Florida at 16:09
UTC, on Sunday, May 3, 1998, after almost sixteen days in orbit with the Nuero Lab as the
Weather for launch day on April 17 was favorable over the CONUS sites with high
pressure dominating weather over Florida and California. Strong subsidence aloft
suppressed cloudiness over Florida.
The TAL sites were a different story as a strong low which developed in the Bay of
Biscay on April 16th moved rapidly northeastward into the North Sea. The associated
frontal boundary brought generally unstable and windy conditions to Zaragoza and Moron,
Spain and Ben Guerir, Morocco as northwesterly flow persisted. All three sites were
observed and forecast to be NO GO due to low ceilings. Crosswinds were also a
factor at the Spanish sites and precipitation was expected at Zaragoza for the TAL abort
time. Late in the count conditions began improving such that Ben Guerir and Moron were
given a GO. Only Zaragoza was observed NO GO at launch time, but
conditions there improved such that it was observed GO at what would have been
the TAL abort time.
Following a one day delay due to hardware problems on the orbiter, Columbia lifted off
at the opening of the two and one half hour launch window at 18:19:00 UTC, April 17. With
some high level moisture present, pileus clouds were observed briefly around the vehicle
as it lifted through the 30 000 foot level.
Toward the end of the Nuero Lab mission, mission managers met to decide whether to
extend the mission by one day. SMG meteorologists expressed concern about possible
deteriorating weather in Florida and California should a one day extension occur. NASA
opted not to extend the mission.
Touchdown of Columbia occurred at the Shuttle Landing Facility (SLF), KSC, Florida at
16:09 UTC, May 3, after almost sixteen days in orbit. Even with the pristine weather at
the SLF, mission controllers and SMG forecasters discussed the possibility of a reduced
crosswind restriction of 10 knots due to the possible problem in cooling an on-board
Auxiliary Power Unit (APU). However, the Flight Control Team held the cross wind limit at
15 knots, which is the standard End Of Mission (EOM) crosswind limit.
SMG forecasters held to a forecast of FEW clouds and unrestricted visibilities with
west winds of generally 8 to 12 knots. The final touchdown observation reported FEW clouds
at 7 000 feet, unrestricted visibilities, and surface winds of 230 04 P 11 knots.
Lead Meteorologist for STS-90 was Dan Bellue. Steve Sokol was the Assistant Lead, and
Doris Rotzoll worked as the Lead Techniques Development Unit (TDU) Meteorologist.
Submitted by: Dan G. Bellue Frank C. Brody