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Space Shuttle: Difference between revisions
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→Main Propulsion System
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As of June 2015, the MPS is modeled in a good amount of detail, including most of the relevant valve settings, hydraulic and electric lockup, power failures on the engine controllers and the propellant dump sequence. The in-sim checklists provide instructions on how to execute the propellant dump and how to safe the engines for orbital operations. | As of June 2015, the MPS is modeled in a good amount of detail, including most of the relevant valve settings, hydraulic and electric lockup, power failures on the engine controllers and the propellant dump sequence. The in-sim checklists provide instructions on how to execute the propellant dump and how to safe the engines for orbital operations. | ||
=== Mechanical Systems === | |||
The Shuttle uses electromechanical actuators to move components which do not require hydraulic power. This includes the ET umbilical doors and the payload bay door. Each actuator contains two separate motors for redundancy, and transition time for any motion doubles if a motor is non-functional. The movement of these components is not time-critical, and hence usually slow - the complete payload bay door opening sequence takes about four minutes at normal speed to execute, twice that for actuator failures. | |||
The ET umbilical doors are open at launch to allow the oxidizer and fuel feedlines to enter the orbiter, and they need to be closed after reaching orbit for the thermal protection during entry to be efficient. The payload bay doors are closed during ascent and entry and only opened in orbit. This is crucial, as the freon cooling loop radiators are located on the inside of the payload bay doors, i.e. the Shuttle can not remain indefinitely in orbit without opening the payload bay. | |||
Opening or closing mechanical components usually involves unlatching, moving and possibly re-latching the components. | |||
As of June 2015, the normal operation of ET umbilical door and payload bay door is implemented, but no actuator failures. The sequences can be driven from the GUI in automatic mode, but there is in principle support to drive them in manual mode as well as described in the Shuttle Crew Operations Manual. | |||
== Avionics and guidance systems == | == Avionics and guidance systems == | ||