A spectrometer having a housing, where the housing also includes a
structure located within the housing, the structure being adapted to hold
a reflective dispersive element and being movable in a direction
substantially perpendicular to an interior longitudinal axis. An actuator
arm extends from a location exterior to the housing to another location
inside the housing. The actuator arm is disposed through an opening in
the housing and is operatively connected to the structure. A cryogenic
actuator motor is operatively connected to the actuator arm, thereby
enabling movement of the structure and the reflective dispersive element
in a direction substantially perpendicular to said interior longitudinal
axis, whereby alignment of the spectrometer is enabled.