Patent ID: 8848290
Filing Date: 2014-09-30
Classification: G02B

Abstract:
1. A method for reducing thermal wake proximate to an optical element of a telescope, the method comprising: generating signals related to respective temperatures of support struts supporting the optical element, each support strut having a corresponding heating element; determining the respective temperatures of the support struts based on the signals; heating, with at least one of the heating elements, one or more of the support struts based on the temperatures of the support struts, wherein heating a given support strut causes the given support strut to thermally expand, wherein each of the support struts is at least partially enclosed along with the corresponding heating element by a corresponding shroud, and wherein airspaces are disposed between the support struts and the corresponding shrouds; and ejecting heat in the airspaces from the heating elements away from the optical element to prevent a thermal wake from reaching a volume proximate to the optical element, wherein ejecting the heat includes generating airflows in the airspaces disposed between the support struts and the corresponding shrouds using airflow generation devices; wherein, for each airflow generation device, a transition apparatus is coupled to an output of the airflow generation device and to an exhaust duct, the transition apparatus having a larger opening coupled to the output of the airflow generation device and a narrower opening coupled to the exhaust duct.