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 .