Might one utilize laser infrared spectroscopy to measure approximate temperature of space? Have a suitable container of simple molecules, and measure motion (stretching, vibration, perhaps rotation), utilizing infrared spectroscopy. Correlate such set up with the coldest temperature we can obtain in earth laboratory. Is there just a linear relationship between temperature and molecular vibration? Perhaps utilize Japanese space station module, and any external platform, together with internal residing laser and infrared spectroscopy. Even simpler would be setting some limits vis-a-vis placing an air filled container on outside platform, and seeing if nitrogen (etc.) component liquifies or not; indicating a limit of ~77 degrees kelvin; 90 degrees kelvin for oxygen liquification. How close to absolute zero is temperature of space?
Also If comet 67P surface ice (or sub-surface) is 4 Byr old, then might it be like alleged 4 Byr old Martian rock ice? Utilize infrared spectroscopy to measure hydrogen bonding between molecules, indicating mainly vibration, and perhaps some rotation. Then as above using space station as temperature control experiment, with external platform or bay, or tether; then do infrared spectroscopy to measure isolated temperature effect upon earth ice hydrogen intermolecular bond.
Also cryochemistry might shed light on the Dark Age (~300-400 Myrs after recombination at 380 kyrs). That is, did just neutral hydrogen form, or did molecular H_2 form quickly? Mass density would seem a factor. Also temperature is a general background catalyst. More specifically, one could ionize hydrogen with a laser for transparent canister on platform outside of space station. Then use infrared spectroscopy to see how long it takes for molecular hydrogen to form. So can such simple experiments outside of space station shed light on Dark Age cryochemistry of hydrogen? TMM
Also see blog: Hematite, photosynthesis, silicates – connections? Martian rock ice?