As NASA missions continue to extend the horizon beyond near-Earth missions, higher performance systems must evolve to address the challenges of reduced power resources, longer mission durations, higher radiation exposure, and more broadly, harsher space environments. The vision of the low-temperature and input power Deep Space Cryocooler System (DSCS) is to advance the state of the art in Cryocooler systems by developing a low-cost single stage cryocooler, designed to target low heat rejection temperatures (150K) and low cold-tip temperatures (35K), and integrate it with a set of high reliability, micro-sized Low Cost Cryocooler Electronics (μLCCE) customized to operate efficiently at very low power levels (10W). Additionally, the low-cost, light weight, and small size of the DSCS will enable instrumentation on miniature satellite platforms. A key objective of this effort is to develop and demonstrate cryogenic cooling technologies for science measurement capabilities with smaller, more affordable spacecraft and concurrently reducing system risk, cost, size, and development time, consistent with NASA SBIR Science Subtopic S1.09. In the Phase I effort, the uLCCE brassboard will improve upon the mLCCE (TRL6 in 2016) design by evaluating a handful of candidate improvements that will reduce the SWaP requirements of the electronics. Detailed circuit modeling will verify performance of key parameters , which will then inform the final schematic and layout of the uLCCE. The accompanying Thermo-Mechanical Unit will be designed by Lockheed Martin. The conceptual coldhead design leverages their existing TRL 6 Microcryocooler, and will introduce design improvements to target the low heat reject and cold-tip temperatures specified in this solicitation. The design approach will be confirmed with detailed thermodynamic modeling. A prototype uLCCE and upgraded microcryocooler will be built and integration tested in a future Phase II effort.