A sensor system comprising: a first optical sub-system including a first plurality of optical elements; a second optical sub-system configured to rotate about a first gimbal axis relative to the first optical sub-system, the second optical sub-system including: an afocal foreoptics configured to receive electromagnetic radiation and to direct a collimated beam of the electromagnetic radiation to the first optical sub-system; characterized by a first coelostat mirror configured to rotate about a second gimbal axis substantially perpendicular to the first gimbal axis and to receive and reflect the electromagnetic radiation; and a second coelostat mirror configured to rotate about a third gimbal axis substantially perpendicular to both the first gimbal axis and the second gimbal axis, and to receive the electromagnetic radiation reflected by the first coelostat mirror and to direct the electromagnetic radiation to the afocal foreoptics, wherein the first coelostat mirror is further configured to rotate around a fourth gimbal axis substantially perpendicular to the second gimbal axis and in a plane of the first coelostat mirror, wherein a rotation of the first coelostat mirror around the fourth gimbal axis prevents a gimbal singularity in which a line of sight direction substantially coincides with the first gimbal axis. a first optical sub-system including a first plurality of optical elements; a second optical sub-system configured to rotate about a first gimbal axis relative to the first optical sub-system, the second optical sub-system including: an afocal foreoptics configured to receive electromagnetic radiation and to direct a collimated beam of the electromagnetic radiation to the first optical sub-system; characterized by a first coelostat mirror configured to rotate about a second gimbal axis substantially perpendicular to the first gimbal axis and to receive and reflect the electromagnetic radiation; and a second coelostat mirror configured to rotate about a third gimbal axis substantially perpendicular to both the first gimbal axis and the second gimbal axis, and to receive the electromagnetic radiation reflected by the first coelostat mirror and to direct the electromagnetic radiation to the afocal foreoptics, wherein the first coelostat mirror is further configured to rotate around a fourth gimbal axis substantially perpendicular to the second gimbal axis and in a plane of the first coelostat mirror, wherein a rotation of the first coelostat mirror around the fourth gimbal axis prevents a gimbal singularity in which a line of sight direction substantially coincides with the first gimbal axis. an afocal foreoptics configured to receive electromagnetic radiation and to direct a collimated beam of the electromagnetic radiation to the first optical sub-system; characterized by a first coelostat mirror configured to rotate about a second gimbal axis substantially perpendicular to the first gimbal axis and to receive and reflect the electromagnetic radiation; and a second coelostat mirror configured to rotate about a third gimbal axis substantially perpendicular to both the first gimbal axis and the second gimbal axis, and to receive the electromagnetic radiation reflected by the first coelostat mirror and to direct the electromagnetic radiation to the afocal foreoptics, wherein the first coelostat mirror is further configured to rotate around a fourth gimbal axis substantially perpendicular to the second gimbal axis and in a plane of the first coelostat mirror, wherein a rotation of the first coelostat mirror around the fourth gimbal axis prevents a gimbal singularity in which a line of sight direction substantially coincides with the first gimbal axis.