MOPITT Stirling Cycle Cooler and Cooler Drive Electronics Evaluation

Abstract

This paper summarizes the vibration compensation results of a Stirling cycle cooler (SCC) for the Measurements Of Pollution In The Troposphere (MOPITT) instrument which will fly on the Earth Observation System AM (EOS-AM) platform. MOPITT is an infrared radiometer that measures global concentrations of CO and CH₄ in the lower atmosphere and requires a pair of vibration compensated SCCs to cool the detectors while meeting the NASA EOS platform’s stringent jitter requirements. The Canadian Space Agency (CSA) has contracted COM DEV Atlantic to design and build the instrument which was conceived by a multinational science team. The MOPITT Principal Investigator is Dr. James R. Drummond of the University of Toronto.

A market study identified the British Aerospace (BAe) 50–80 K SCC and the Lockheed low vibration cooler drive electronics (CDE) as the best available combination to meet the MOPITT Engineering Qualification Model (EQM) requirements, however, there was no previous test data available for this hardware configuration. A CSA-funded evaluation was undertaken to interface a pair of University of Toronto BAe 80 K SCCs to Lockheed CDE. The objective was to successfully operate the coolers, verify cooling performance, and demonstrate vibration cancellation using force transducer and acceleration feedback compensation.

All test objectives were met. The SCCs and CDE were successfully interfaced and vibration compensation was performed with position feedback, force feedback and acceleration feedback. The combination was subsequently selected for the MOPITT EQM.