The examples and perspective in this article may not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (March 2015) (Learn how and when to remove this message)
|
Launch commit criteria are the criteria which must be met in order for the countdown and launch of a Space Shuttle or other launch vehicle to continue. These criteria relate to safety[citation needed] issues and the general success of the launch, as opposed to supplemental data.[1]
Launch commit criteria for Atlas V launches are similar to those used for the Atlas V launch of the Mars Science Laboratory[2]
NASA has identified the Falcon 9 vehicle cannot be launched under the following conditions.[3]
The following should delay launch:
Unique for Crew Dragon launches of the Falcon 9:[4]
The weather conditions[5] NASA required during countdown and launch were specified for "prior to loading external tank propellant" and "after loading propellant has begun". Weather forecasts were provided by the 45th Weather Squadron at nearby Patrick Air Force Base with concerns such as thunderstorms, winds, low cloud ceilings, or anvil clouds noted in the report.
Tanking was not to begin if the 24-hour average temperature had been below 41 °F (5 °C), the wind was observed or forecast to exceed 42 knots (78 km/h; 48 mph) for the next three-hour period, or there was a forecast to be greater than a 20% chance of lightning within five nautical miles of the launch pad during the first hour of tanking.
After tanking began, the countdown must not be continued, nor the Shuttle launched, if any of the following weather criteria were exceeded:[6]
Once propellant loading had begun, the countdown was to be stopped if the temperature remained above 99 °F (37 °C) for more than 30 consecutive minutes. The minimum temperature the countdown may proceed at was determined by a table of temperatures determined by wind speed and relative humidity ranging from 36 °F (2 °C) (high humidity, high winds) to 48 °F (9 °C) (low humidity, low winds). In no case was the space shuttle to be launched if the temperature was 35 °F (2 °C) degrees or colder.
For launch the wind constraints at the launch pad varied slightly for each mission. The peak wind speed allowable was 34 knots (63 km/h; 39 mph). However, when the wind direction was between 100 degrees and 260 degrees, the peak speed varies and may be as low as 20 knots (37 km/h; 23 mph).
None was allowed to exist at the launch pad or within the flight path.