Lunar temperature during Apollo landings

[tuboapollo]

Hi guys, first of all my compliments to you: Your site and forum are great and surely one of the best Apollo source over the net, when not the best as far as it concerns the moon hoax debunking.

I'm an Apollo fan and i'm writing from Italy.

I have some questions I hope you can help me to answer:

Studing the Apollo space suits ( a-7l & a-7lb), I was looking for a good source where to find infos and data about heat's behaviuor on the lunar surface.
Given the near total lack of an atmosphere and the long period of moon's rotation on its axis I'd like to better comprehend how the heat works on the astronauts and the hardware on the surface such as the LM, the rover and the other instruments during the missions' duration.

For example in which way (and if) the astronauts could experience hot or cold feelings except for the soil from which they were widely insulated by boots other than irradiation? And which would be the time lenght to appreciate it?
More, is it correct to say that, again due to the lack of atmosphere, they could not feel cold in the shadow of a big boulder?

Is it correct that due to a near dawn landing site the surface temp was between 20-30°C?

( sorry if this post could be part of an existent one and I missed it...)

Thanx!

[PhantomWolf]

While this might or moight not be helpful. On Apollo 12, Al and Pete talked about being able to feel the heat from the RTG through their gloves. Given that the RTG was extremely hot, that they could feel it as only warm through the gloves would indicate that the suits were pretty well insulated.

116:45:27 Bean: I tell you what worries me, Pete. If I pull on it too hard, it's a very delicate lock mechanism. Maybe (I should) not push the pins in quite so far, and wiggle it a little. I just get the feeling that it's hot and swelled in there or something. Doesn't want to come out. I can sure feel the heat, though, on my hands. (Pause) Come out of there! Rascal. (Pause)

116:50:05 Bean: That cask's going (in?). Okay, Houston. The fuel element is in the RTG. I can feel it radiate heat already! (To Pete) Put your hand over here.

116:50:54 Bean: Hey, feel the heat off that machine. That's amazing.
116:50:59 Conrad: 1400 degrees (Fahrenheit or about 760 Celsius). (In a conspiratorial tone) Almost as hot as the Sun! (Chuckles)

On the surface temperature, during Apollo 16, just as the 3rd EVA is due to start, the NASA Public Affairs commentator tells the press that the surface temperature is about 185 F (85 °C).

[laurel]

From the Apollo 17 ALSJ at about 119:54:40:

[Cernan - "One thing I ought to mention here, in case I forget it, is that on the first day you never felt any heat soak into your gloves. But I remember that on the third day you could feel the heat soaking in. That's because the Sun was 26 degrees higher than it was on the first day. You couldn't feel it on your body because you had the liquid-cooled garment; but your hands had no liquid cooling on them and, also, your hands were sitting out in the sunshine a lot of the time."]

[tuboapollo]

Thanks, I've found important and interesting the cue about gloves, being them not cooled by the coolant system.

What I'd like to know specifically, if possible and known by any, is an official or following report about the insulation behaving in a non atmospheric situation on a satellite as the Moon is.

I'm pretty sure my deduction about heat-cold perception is true, but it just comes from a reasoning, data given.

E.G: Which was the temperature felt by astronaut inside the suit during mission and which was the temperature at the soil in that moment? (Knowing that the coolant system guaranteed a livable and comfortable one)
How long it would take for an object (Apollo's) to reach a critical temperature knowing that it was dawn time?

By now i've find nothing about that.

Edit: Typos corrected

[Apollo Gnomon]

Here's a chart that I like - it shows the cycle of heating and cooling over a month: www.monstein.de/astronomypublications/MoonEnglishHtml/Image281.gif


One factor to keep in mind about heat perception - our skin can detect heat several different ways, but our brains simplify the information to "hot" or "cold." Thus, a radiator (or radiant floor, or hot stove surface, like soapstone panels or Ceramic tiles on woodburning stoves) in a cold house can make the occupants "feel comfortable," even though the air temperature is lower than might be cozy otherwise.

The insulation in space suits has to do two things - prevent heat flow by conduction, and reflect radiant (infrared) heat. The gold mylar on the LM was used to reflect heat to keep the LM cooler- it's very thin, but is really great at reflecting IR. Suits also used layers of mylar.

edit to fix dumb thing.

[scooter]

The significant thing on that graph is the slow, gradual rise in surface temperature after sunrise. It wasn't the HB's "instant 250F broiling death at sunrise" scenario.
I'll bet the surface was relatively cool coming out of the long night during the first EVA.

Now, the long term Constellation trips will have to deal with much greater challenges, hot, and cold.

[smlbstcbr]

Moon is not that forbidding after all, the chart shows a very close resemblance with Earth's temperature (at least the temperature of the poles).
Wonder what are the HB going to say about this topic.