Three-Stage Cryocooler Cold Head for Advanced Heterodyne Sensors

Future advanced heterodyne sensors for submillimeter-wave receivers require 50 to 100 mW of cooling at 15 to 20 K for the sensor, and 1 to 2 W cooling at 80 to 120 K for the local oscillator, with size and input power suitable for use in a Small Sat. nbsp;A 3-stage pulse tube cryocooler is well-suited for this type of application, offering a simple, reliable option with TRL 5 heritage in a larger cryocooler size, and allowing a design optimized to the sensorrsquo;s cooling and temperature requirements. nbsp;CU Aerospace (CUA) will use innovative materials and low cost cold head design and assembly, coupled with Lockheed Martinrsquo;s (LM) industry-leading multi-stage pulse tube expertise, to provide NASA with a compact, affordable cryocooler for submillimeter detectors. nbsp;Our team proposes to: 1) nbsp;Perform a thorough thermodynamic trade study of 2-stage and 3-stage cold head configurations optimized to provide simultaneously 50-100 mW cooling at 15-20 K and 1-2 W cooling at 80-120 K, to achieve high efficiency, low mass, and compact packaging. nbsp;Different regenerator materials and heat exchanger configurations will be included in the trade study. 2) nbsp;Additively manufacture using Direct Metal Laser Sintering an optimized finned heat exchanger and demonstrate its capability to survive thermal cycling when press-fit into a cold head flange. 3) nbsp;Generate a solid model of the cold head during Phase I so that it is ready for procurement, assembly, and testing in Phase II. 4) nbsp;Continue the process of qualifying CUA to provide flight cold head subassemblies for future LM Space programs as a way to reduce cost and schedule. nbsp;This work will leverage the MDA SBIR Phase II as well as CU Aerospacersquo;s past flight hardware development and delivery on programs such as Propulsion Unit for Cubesats (PUC) delivered to the Air Force.