Meteorological Support for Space Operations Review and Recommendations (1988) / Chapter Skim
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1 Sensitivity of the Space Program to Weather Elements
1 Sensitivity of the Space Program to Weather Elements
Pages 9-19
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From page 9... ...
At 36.5 seconds into the flight, and again at 52 seconds, major atmospheric electrical disturbances occurred that were subsequently attributed to vehicle-triggered lightning. Temporary Thrum tions of normal operations included the loss of attitude reference by the inertial platform in the spacecraft, illumination of many warning lights and alarms in the crew compartment, disconnection of the electronic circuitry to three fuel cells, loss of communication, and disturbances to the timing system, clocks, and other instrumentation.
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From page 10... ...
Space vehicle encounters with adverse weather conditions have been quite limited over the Midyear history of the space program, owing to a judicious selection of launch days, landing sites that usually favor benign weather environments, and the relatively short periods of tone when the flight is in the weather-bearing layers of the atmosphere. The accumulated "exposure" time, amounting to a few minutes during each launch and up to an hour on manned reentry and landing, makes the total base of weather experience a few days at most.
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From page 11... ...
The Apollo 12 and Atias-Centaur accidents have clearly demonstrated the vulnerability of spacecraft electronics to triggered lightning. A similar experience by NASA astronauts flying a NASA T-38A on February 24, 1987, in wintertime stratiform clouds near Los Alam~tos Army Aviation Facility, California, shows that triggered lightning is pervasive.
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From page 12... ...
WEATHER FACTORS IMPORTANT FOR SPACE OPERATIONS Weather elements influence all phases of space operations, from mission planning through actual launch, booster rocket recovery (in the case of the Space ShuttIe) , and landing.
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From page 13... ...
could cause the vehicle to deviate from course or break apart. Aerodynamic loads, from wind shears comparable to the largest previously encountered during launch and from vehicle response maneuvers, may have contributed to the final failure of the O-ring seals.~*
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From page 14... ...
More obvious weather threats such as thunderstorm-related wind shears and lightning present an even greater risk to the spacecraft during the landing phase. :Rescue and Recovery at Sea Booster rockets from the Space Shuttle normally fall into the sea and are recovered by ship.
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From page 15... ...
Unfortunately, it appeared] to the pane} that there is only crude quantitative data regarding the risk posed by some weather hazards, such as the values of cloud electric fields that are capable of pros ducing spacecraft-triggered lightning.
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From page 16... ...
Most of the data needed for an effective climatology of this type do not yet exist and require obtaining data sets from new sensors. Among the data needed are the types and sizes of precipitation elements in various kinds of clouds, the electrical fields within and near detached anvils and a variety of other cloud types, the electric fields that are required to produce triggered lightning, and the magnitude of wind variations on a variety of time scales.
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From page 17... ...
The dashed plot represents the cumulative number of lightning flashes detected over the Eastern Test Range (ETR) using the field mill network (Launch Pad Lightning Warning System (LPLWS)
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From page 18... ...
wedges of high wind speeds with strong vertical shears, such as illustrated in Figure 2, are typically associated with disturbed weather and may not have been adequately represented in a sample biased toward warm, fair weather occasions. An accelerated launch schedule will tend to require launches on some les~than-perfect occasions, and the present jimsphere pairs underestimate the wind shear hazard on those types of days.
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From page 19... ...
It ~ especially critical that the data base include cases of clear skies immediately following cold front passage, where strong turbulent jet streaks axe often found. The jm~phere-pan data base should be expanded, e~eciaDy ding the winter season, and shown be supplemented by wind profiler data.
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