STS-114 Post Mission Summary

Return to Flight and Space Station Re-supply Mission

The Shuttle Discovery rolled out to the Kennedy Space Center (KSC) launch pad 39B in June in preparation for a July 26, 2005, launch of STS-114.  Discovery lifted off at 10:39 AM EDT on a 12 day re-supply mission to the International Space Station.  A KSC landing was attempted on August 8 but both landing opportunities were waved off due to weather constraints.  Discovery and her crew landed at 8:12 AM EDT at Edwards Air Force Base in California on Tuesday, August 9, after both opportunities to Kennedy were waved off that day, again due to weather.  This 114^th Shuttle mission was the 31st  mission for Discovery, the seventeenth shuttle mission to the International Space Station, and was the first shuttle mission since the loss of Columbia in early 2003.

Launch Weather, July 26, 2005

Weak high pressure dominated the weather over central Florida.  Winds were forecast to be light and variable at the KSC Shuttle Landing Facility (SLF) at launch time with the sea breeze just forming along the coast.  Low clouds would be developing prior to launch, especially along the sea breeze and over Merritt Island with the Merritt Island convergence.  Isolated showers were forecast, mainly along the sea breeze front.  For the Transoceanic Abort Landing (TAL) sites, a moderate pressure gradient across Europe was forecast to cause winds to approach or exceed flight rule wind limits at Moron, Spain, and Istres, France.  There was a slight chance of thunderstorms at Zaragoza, Spain.  During the launch count SMG removed the chance of showers from the KSC forecast and removed the chance of thunderstorms from the Zaragoza forecast, allowing for an on time launch. 

Landing Wave-Off Weather, August 8, 2005

Only the KSC landing site was activated for the landing opportunities on August 8.  With a stationary surface and upper-level low over the panhandle of Florida, winds were forecast to be light southwesterly.  Due to heavy rain at KSC the previous day, August 7, shallow fog not restricting visibility was also forecast, along with a few low clouds, few mid clouds, and broken high clouds.

A weak short wave and weak mid level warm air advection triggered the development of mid clouds just south of the KSC Shuttle Landing Facility (SLF) early in the landing count.  Light showers began falling out of the mid clouds into the almost fully saturated layer of air at the surface.  Following the dissipation of the showers, low clouds began developing under the area where the rain had fallen, south of Patrick AFB northward to just west of the SLF.  SMG updated the KSC forecast to include a ceiling at one thousand feet, a no-go forecast.  The Flight Director waved off the first KSC opportunity.

The forecast for the second opportunity called for scattered low clouds and a slight chance of showers.  Although SMG removed the chance of showers from the forecast, the Flight Director could not get comfortable with the weather situation and waved off the second attempt.

Landing Weather, August 9, 2005

All three U.S. landing sites were activated on August 9.  Scattered low and mid clouds with broken high clouds were forecast for both KSC opportunities with a slight chance of showers, mainly out over the Gulf Stream.  An upper-level high over the southwestern U.S. dominated the weather picture for the western landing sites.  With the ongoing monsoonal conditions, thunderstorms were expected in southeastern California but not at Edwards for their two landing opportunities.  A slight chance of thunderstorms was forecast at White Sands for their two opportunities.

Early in the landing count showers and thunderstorms developed over the water east of KSC along an old outflow boundary.  Additional development began occurring offshore just east of Melbourne.  The forecast was updated to include showers and thunderstorms.  While the thunderstorms were moving away from the landing site, attached anvils remained close enough to the KSC SLF to violate weather flight rules.  Additionally, showers developed northeast of the SLF.  The Flight Director waved off the first KSC opportunity.

Additional thunderstorms developed before the second KSC landing opportunity with the proximity of their anvils violating weather flight rules.  The Flight Director then waved off the second KSC opportunity and targeted Edwards Air Force Base, California as the landing site. 

Discovery landed at Edwards on the next opportunity at 8:12 EDT (5:12 AM PDT), the third landing opportunity of the day, under mostly clear skies and light winds.

The Spaceflight Meteorology Group Lead Meteorologist was Karl Silverman working his 52^nd mission, 9^th as Lead.  Richard Lafosse was the Assistant Lead Meteorologist and Doris Hood was the Lead Techniques Development Unit Meteorologist.  For additional information about the Spaceflight Meteorology Group web site visit http://www.srh.noaa.gov/smg.

Submitted by:

Karl Silverman

STS-114 Lead Meteorologist

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