Title: Phase Change cell demonstration onboard the International Space Station
Presenting Author: Shane Topham
Organization: Space Dynamics Laboratory
Co-Author(s): Martin Mlynczak, Harri Latvakoski

Abstract:
Orbital sensors that monitor global climate change during the next decade will require high stability and accuracy from their onboard thermometry, which is challenging and perhaps unattainable currently. Phase change materials (PCM) such as those that make up the ITS-90 standards are the references used for international commerce and are potentially good candidates for orbital recalibration references. The Space Dynamics Laboratory has been developing miniaturized phase change references standards for deployment on orbital blackbodies for the past decade. To answer the critical questions about their potential utility as orbital references, an experiment was flown to determine if the microgravity environment would affect these phase transitions. In November, 2013, two PCM experimental configurations were launched to the international space station in partnership with the Institute for Biomedical Problems (IBMP) in Moscow Russia. This joint team completed the flight qualifications, scheduling of the launch and return vehicles, and crew time necessary to carry out these experiments. The experiments, designed to test melts and freezes of three different phase change materials in various containment apparatuses, were conducted in January and February, 2014 and returned to SDL in June. SDL is currently analyzing the pre-flight, flight and post flight performance of the hardware and comparing the observed melt temperatures with ITS-90 standards. This presentation will detail the experiments, the results and conclusions, and comment on the suitability of using phase change materials for long-term, on-orbit recalibrations.