For a relative definition of comfortable...

Like upstate NY in the winter. If you can maintain shirtsleeves conditions inside an old farmhouse at that outdoor temperature, NASA can do it for astronauts. Contrast that to the surface temperatures which swing from 260°F to -280°F.

The corollary is that ice buried on the moon with a vapor barrier to prevent sublimation could be stable.

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grues-dinner 6 days ago | parent | next [-]

Lunar subsurface temperatures even at only 2m depth are stable at around -20C. Considering the very low thermal conductivity of the regolith, and the relative ease of constructing a vacuum-flask-like structure in a vacuum, you can have a thermally stable subsurface habitat at 20C, even if the surface temperature is swinging wildly from -170C to 120C every two weeks.

In fact, you may have more problems venting heat in the lunar day than you will keeping warm in the night - presumably you'd dump the excess heat from the habitat into cold regolith in the day, and then from there either store it for a heat-pump heat source for night-time usage (à la Sand Battery https://polarnightenergy.com/sand-battery/), or radiate it into space at night if your heat dump heats up too much.

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stevage 6 days ago | parent | prev [-]

> If you can maintain shirtsleeves conditions inside an old farmhouse at that outdoor temperature

I don't know, can you? I would need an indoor temperature at least 18C to be comfortable in shirtsleeves, unless I'm doing something physical.

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pmontra 6 days ago | parent | next [-]

I'm comfortable in shirtsleeves at 24C (current temperature here) and I'm wearing wool and a scarf if I'm sitting at my desk at 18C. That's why they won't send me to the Moon or to Mars.

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PaulHoule 6 days ago | parent | prev [-]

With a wood stove, yes. Gets so hot sometimes I take my shirt off entirely.

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lostlogin 6 days ago | parent [-]

Now we just need moon wood.

	▲	stevage 5 days ago \| parent [-]
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