How to XPointer
The X-Pointer instrument is used to provide lateral velocities or displacements. When configured for landing, the X-Pointer can be used to nullify sideways movement, ensuring a vertical landing. When used for rendezvous, the X-Pointer can be used to place a target directly in front of the vessel, and to cancel any sideways drift relative to the target.
The instrument consists of the X-Pointer display, the MODE selector switch, the SCALE selector switch, and the X-PTR ERR error indicator.
The MODE selector switch controls which mode the X-Pointer is operating in.
- OFF: The X-Pointer is powered down. The backlight is switched off, and the needles return to zero.
- LDG: The X-Pointer is in landing mode. It provides the lateral velocity of the craft in m/s (as adjusted by the SCALE selector).
- D-DIST: The X-Pointer is in docking distance mode. It provides the lateral displacement of the craft from its target in meters (as adjusted by the SCALE selector).
- D-VEL: The X-Pointer is in docking velocity mode. It provides the lateral velocities of the craft relative to its target in meters/second (as adjusted by the SCALE selector).
When used with the [ARRT](How to ARRT), this instrument can be used to guide a craft to a stable landing (no lateral velocity), or to rendezvous with a target.
The SCALE selector switch changes the units being displayed by the X-Pointer. It can be switched to x1/10, x1, or x10. When the X-Pointer is active, the selected scale is displayed below the main window.
This indicator is enabled when the X-Pointer is configured for target for docking while there are no valid targets being tracked.