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Space Shuttle: Difference between revisions
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→Auxiliary Power Unit and Hydraulics System
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When not in use, electrically powered hydraulic circulation pumps keep the hydraulic fluid moving such as to equalize temperatures in the components. | When not in use, electrically powered hydraulic circulation pumps keep the hydraulic fluid moving such as to equalize temperatures in the components. | ||
As of June 2015, the APU and hydraulic system is modeled with a fair amount of detail and operated from a dedicated menu. APUs need to be started as part of the pre-launch checklist - refer to Help/Aircraft Checklists for the detailed procedure. <b>If the hydraulic system is not available during ascent, this will result in loss of the vehicle after SRB separation as there is no control over the Shuttle if the SSMEs can not be gimbaled.</b> | In case of a hydraulic failure, Priority Rate Limiting (PRL) for the airfoils is used to allocate the remaining power as efficiently as possible. Usually the elevons move with 20 deg/s and the rudder with 14 deg/s, however in the case of multiple hydraulic failures, these numbers are reduced to 13.9 deg/s for elevons and 7 deg/s for the rudder. The orbiter is still fully controllable in this case, but not as responsive to agressive maneuvers. | ||
As of June 2015, the APU and hydraulic system is modeled with a fair amount of detail and operated from a dedicated menu. APUs need to be started as part of the pre-launch checklist - refer to Help/Aircraft Checklists for the detailed procedure. <b>If the hydraulic system is not available during ascent, this will result in loss of the vehicle after SRB separation as there is no control over the Shuttle if the SSMEs can not be gimbaled.</b> Also PRL for all airfoils is fully supported. | |||
Operation of the water spray boilers is realistically integrated into the heat transfer model of the Shuttle (see below), including the failure of overheating APUs. | Operation of the water spray boilers is realistically integrated into the heat transfer model of the Shuttle (see below), including the failure of overheating APUs. | ||