| For the past several years, cryogenically cooled sensors have become an increasingly popular method of observation and study for both space and ground based operations. This report focuses on the use of a mechanical cryocooler in conjunction with RAMOS, a future pair of earth-imaging satellites which will fly infrared radiometers.;The Russian American Observational Satellites (RAMOS) program consists of mapping the earth's surface in stereo using two co-orbital satellites. The American Observational Satellite (AOS) will utilize an infrared radiometer with the telescope focal plane assembly (FPA) operating at approximately 60 K. The FPA will be cooled using a multiple cryocooler configuration. The use of multiple coolers introduces redundancy into the cooling system---a redundancy which has been absent from many previously flown satellites. In addition, the cooling system will incorporate various other new technologies such as thermal disconnects, a thermal storage unit, low resistance flexible thermal links, etc., to meet the overall system objectives and requirements.;This thesis considers various options involving cryocoolers and other cryogenic technologies as a means of cooling space-based infrared sensors. Thermal disconnect ideas and options are considered to introduce redundancy into the RAMOS cooling system. In addition, thermal storage units are also discussed as a means of eliminating cryocooler induced vibration and passively controlling FPA temperatures.;Past and current cryocooler development has produced long life coolers with expanded cooling performance at lower temperatures (<10 K). In addition, incorporating thermal switches and thermal storage units into a cooling system design can alleviate the concerns of cryocooler vibration and parasitic heat loads. An understanding of these concepts and configurations will assist in the design of similar optical instruments for both space and ground based exploration campaigns. (Abstract shortened by UMI.). |
