Launch commit criteria

Launch commit criteria are the measurements obtained during the countdown and launch of a space vehicle which relate to any safety issue and the general success of the launch, as opposed to supplemental data. [ [http://science.ksc.nasa.gov/shuttle/countdown/launch-team.html The Space Shuttle Launch Team ] ]

Shuttle criteria

Temperature

Prior to external tank propellant loading, tanking will not begin if the 24 hour average temperature has been below 41 degrees.

After tanking begins, the countdown shall not be continued nor the Shuttle launched if:

a.) the temperature exceeds 99 degrees for more than 30 consecutive minutes.

b.) the temperature is lower than the prescribed minimum value for longer than 30 minutes unless sun angle, wind, temperature and relative humidity conditions permit recovery. The minimum temperature limit in degrees F. is specified by the table below and is a function of the five minute average of temperature, wind and humidity. The table becomes applicable when the observed temperature reaches 48 degrees. In no case may the Space Shuttle be launched if the temperature is 35 degrees or colder.

Wind

Tanking will not begin if the wind is observed or forecast to exceed 42 knots for the next three hour period.

For launch the wind constraints at the launch pad will vary slightly for each mission. The peak wind speed allowable is 34 knots. However, when the wind direction is between 100 degrees and 260 degrees, the peak speed varies and may be as low as 20 knots.

Precipitation

None at the launch pad or within the flight path. [ http://www-pao.ksc.nasa.gov/kscpao/release/1997/98-97.htm]

References