The various software modules that are designed to implement the Docking and Undocking Procedures are described below.
This module is responsible for broadcasting standard AutoDock 1.0 broadcast channel. The broadcast gives detailed information of the capabilities of the Docking Station. It includes the frequency band on which the initial docking request can be accepted. This broadcast helps the Spacecrafts in sensing the Docking Station.
Spaceship Object Manager
The Spaceship object manager manages all the Spaceship object entities. The manager creates a Spaceship object when the docking request is received from a new Spacecraft. The Spaceship objects are deleted when the spacecraft departs.
The lifetime of a Spaceship object spans from receipt of docking request for AutoDock 1.0 Docking Procedure to the completion of Undocking Procedure that takes place when the Spacecraft wishes to detach itself from the Docking Station.
The Spaceship object is responsible for the following actions:
- Orbit Allocation
- Docking Port Allocation
- Orbit Deallocation
- Docking Port Deallocation
The Spaceship object also maintains timers for AutoDock 1.0 Docking and Undocking Procedures.
The Orbit Allocator manages a pool of Orbit resources. It allocates and deallocates the Orbit for a Spacecraft upon receipt of appropriate request message from Spaceship object. Orbit assignment during Docking is based on following rules :
- Spacecrafts approaching from other planets that use gravity assists to slow down are assigned the outermost orbits.
- Spacecrafts approaching from the parent planet are assigned the innermost orbits.
Orbit assignment during Undocking is based on following rules:
- Spacecraft destined for deep space is assigned the outermost orbit.
- Spacecraft that is headed for the parent planet is assigned the innermost orbit.
The Docking Allocator manages a pool of 32 Docking Port resources on the SpacePort 9000. It allocates and de-allocates the Docking Port resource for a Spacecraft upon receipt of appropriate request message from Spaceship object.
The Spaceship object creates the Docking object once it has received Ready For Docking message from the Spacecraft. The actual Docking Procedure from this point onwards is handled by Docking object. It takes the following actions:
- Air Pressure Adjustments
- Air Quality Measurements
- Opening the Air Lock
For message signaling details of docking, refer to message sequence chart documents in the EventStudio Documents section.
The Spaceship object creates the Undocking object after the receipt of Undocking Request message from the Spacecraft. The actual Undocking Procedure from this point onwards is handled by Undocking object. It seals the airlock at the Docking Station during Undocking.
For message signaling details of undocking, refer to message sequence chart documents in the EventStudio Documents section.