The Spaceflight Meteorology Group

Postflight Mission Summary for STS-80

January 10, 1997

The Space Shuttle Columbia touched down at the NASA Shuttle Landing Facility (SLF) in Florida on December 7 at 1149 UTC. This marked another record for mission duration in the Shuttle program. From launch to wheel stop on landing the mission lasted 17 days 15 hours 54 minutes. Weather was a primary factor in delaying the landing until the third landing day.

Columbia lifted on STS-80 on November 19 at 1956 UTC from the Kennedy Space Center. Launch had been scheduled for November 14, but forecasts of unacceptable weather on launch day and scheduling conflicts with the planned Atlas rocket launch caused NASA mission managers to reschedule the launch day to the 19th. Weather was a primary reason for choosing November 19 as the launch date. Launch weather was GO as well as weather at the potential abort landing sites in the US and at the Transoceanic Abort Landing sites in Spain and Morocco with the exception of Moron where cloud ceilings were below limits.

Forecasting the weather for landing proved to be a challenging task. The weather forecast remained GO up until moments before the de-orbit burn. Surface weather observations received via digital voice and telephone communications, along with Doppler radar detection of clouds, led SMG forecasters to amend the landing weather forecast to NO GO just minutes from the de-orbit burn based upon a threat of a low cloud ceiling. The NASA Flight Director at the Mission Control Center decided to “waive-off” Columbia for another landing attempt approximately one hour later. Reconnaissance reports from the astronaut piloted Shuttle Training aircraft flying around the SLF also noted an increase in low level clouds. A cloud ceiling was subsequently observed at the SLF at just seven minutes after the possible de-orbit burn time. Surrounding surface weather observations and extrapolation of low cloud trends available on the first few visible images from the GOES-8 geosynchronous weather satellite raised the possibility of low cloud ceilings for the second landing opportunity. The NASA Flight Director at the Johnson Space Center again decided to waive off this time until the following day.

Weather forced another day in orbit for the crew of Columbia on December 6. Fog was forecast to envelop the SLF for the first landing opportunity near sunrise. Visibility in fog at the SLF dropped to 1/8 mile at what would have been the first landing opportunity. Some hope remained that fog would clear off in time for the second landing opportunity at the SLF. Weather was observed NOGO at the de-orbit time so Columbia was again waived off. The fog cleared off only 29 minutes after the second landing opportunity at KSC. High winds and turbulence were forecast at Edwards Air Force Base both at the surface and aloft so the NASA Flight Director waived the Shuttle off until the following day.

Weather at KSC for the December 7 landing initially looked to be problematic. Winds at Edwards Air Force Base were, however, expected to be lighter than on December 6 and within Flight Rule limits. Fog was again anticipated for the first landing opportunity just minutes before sunrise with low cloud ceilings and showers possible for the second opportunity for a Florida landing. Data from the instrumented 500ft tower, the KSC area wind tower network, rawinsondes, and cloud cover observed on satellite imagery led to SMG’s decision to remove the potential for fog and stratus from the landing weather forecast. Finally, satellite imagery, pilot reports, and lightning strike location reports were consulted to ascertain the age and opacity of a detached thunderstorm anvil which was moving in from the Gulf of Mexico into central Florida. Flight Rules require that optically opaque detached anvils less than three hours old be avoided by 20 miles to mitigate the risk of triggered lightning. Columbia and its record setting crew touched down on the first landing opportunity of the day at 1149 UTC marking the completion of the 80th Space Shuttle mission.

Tim Garner was Lead forecaster for the ascent and entry phases of STS-80. The Assistant Lead/TAL site forecaster was Karl Silverman. Cara Heist and Tim Oram acted as Lead Techniques Development Unit Meteorologists.

Submitted by: Tim Garner