I Watched "Apollo 13" Today

[spooked911]

Pretty good movie.

I do have one question though.

At one point, Lovell (Tom Hanks) says how the LEM in some sections is only two pieces of aluminum foil thick.

Later in the movie, of course, after the mishap with the oxygen tanks, they have to live in the LEM for most of the ride home. Because of the many problems from the explosion, they have to shut off all power to the LEM including the heat.

So-- how is it that they didn't freeze to death, with essentially no insulation from space in the LEM? Note, in the movie, they were NOT wearing their complete space suits-- hands and heads were exposed.

[SDuderstadt]

1. Dude...

if you have "time constraints" that make it difficult for you to respond to other poster's comments, then why the fuck do you keep starting new OP's?

[jberryhill]

2. "with essentially no insulation from space in the LEM"

Oh, where to begin...

There is nothing in space to be "insulated from". If you are talking about how the inside of the LEM maintains its temperature, I suggest you examine THERMOS bottle and figure out how (a) a reflective interior and (b) a surrounding vacuum, keeps your coffee hot all day long inside of it.

Thermodynamics is clearly not your strong suit, spooked.

However, I would not rely on that movie as a technical reference.

I would like you to explain what you believe to be the heat transfer mechanisms involved from the interior of the spacecraft into space. That should be interesting.

[spooked911]

7. that's a good point about the thermos

however, clearly a thermos is not a perfect insulator as the coffee will eventually get cold. Furthermore, the inside of the LEM did get cold (supposedly, unlike you think that was dramatization).

If the temperature did in fact drop, lucky that it only dropped to 40F or so.

[jberryhill]

8. How about you answer my question...

Spooked, I didn't say there would be no heat transfer, I asked you to explain the mechanism. I also didn't say a THERMOS keeps things warm forever

The only heat transfer mechanism from the exterior of the craft is radiative. There is no conduction or convection. It's going to be very slow - which is why the THERMOS is designed the way it is.

Your original post conveys the impression that the craft needed insulation "against space", as if the idea was to keep "the cold from getting in". Yes, deep space has a "temperature" of about three degrees Kelvin. Empty space, however, is not a good heat conductor, and is largely devoid of matter. The issue is not "letting the cold in". The issue is one of not letting heat out. When you are looking out of a single pane window on a cold winter day, the glass is cold because it is in contact with cold air on the outside. Those cold air molecules bounce into the window, pick up little bits of heat from the window (which is conducting it from the air in your room) and, bit by bit, carry that energy away. That's not happening in space. The only way to carry heat away from the exterior of the craft is by deep IR radiation which is not as effective as either conduction or convection - both of which rely on mass to do the work of absorbing energy.

Remarkably, you posted your response after Flatulo had already directly explained the situation in a manner that should be apparent to anyone with a rudimentary science education.
.

[spooked911]

10. Yes, well the question has been answered now, right?

Though I'm not sure what is remarkable about me responding to your post before reading Flatulo's.

[zappaman]

3. Spooked

Do you think it's possible that the aliens who have Earth quarantined had something to do with it?

[Flatulo]

4. Coupla points...

In the near-vacuum of space, there is no medium (air molecules) for heat convection to take place. There is also no lower-temp body pressed against the sides of the LEM for conduction to take place.

The only way the LEM could lose heat into space (and it certainly did get very cold in there) was by radiation. Things that are black in color and rough in texture radiate much more heat than things that are shiny and smooth. That is why teapots are silvery and highly polished - to hold in the heat, and why computer processor heat sinks are usually black anodized.

[jberryhill]

5. Dangit...

I wanted spooked to explain how radiative heat transfer from the exterior was supposed to chill the interior (which it will, over time).

I was going to buy him one of these as a prize...

http://en.wikipedia.org/wiki/Space_blanket

[Bolo Boffin]

6. Thanks, Flatulo

Spooked, that was actually a really good question. As Flatulo and others have pointed out, it has an answer. I hope you can recognize the truth of it.

[spooked911]

9. thanks

though when you say "There is also no lower-temp body pressed against the sides of the LEM for conduction to take place", presumably the outer shell of the LEM was cold.

[jberryhill]

11. No, it was not cold

Why would the outer shell be cold?

If you are in a sealed aluminum ball in space, and the interior temperature is 70F, then the outer shell of that aluminum ball is going to be just a tad below 70F. The slight temperature gradient will be due to the small amount of radiation that will, over time, cool the entire system.

The inner wall of the flask inside your THERMOS (i.e. the wall in contact with the coffee on the inside and the vacuum on the other side) is the same temperature as your coffee.

You still don't get how this works. If the exterior were "cold", then there would be significantly more heat transfer across that gradient. Plus, since metal is a good heat conductor, the inner wall would be cold too - and would certainly cool the air coming into contact with it.

(and at this point, it becomes important to define "cold" as low temperature, rather than a physical sensation. Try this experiment. Touch a piece of rubber at room temperature. Now touch a piece of steel at room temperature. The steel will feel "cold" and the rubber will not. Do you know why?)

I'm surprised you don't bring up the fact that urine, to the extent the water was not recovered, freezes almost immediately when ejected from the craft. I have five bucks that says you won't be able to explain why (nor would you be able to explain why snow making machines at ski resorts are supplied with hot water).

[AZCat]

12. And there's no guarantee the net heat transfer...

is from the object (whether it's a sealed aluminum ball, a spacecraft or the earth) to the rest of the universe. The radiation from the sun can be a significant source of radiation itself, either partially negating or even reversing the net flow of energy from an object. Calculating the heat balance of a system can be very difficult, and involves the view factor, a way of defining the geometric relationship between objects in the system.

[jberryhill]

13. I was thinking of bringing up the insolated side of things...

(that's "insolated" - i.e. exposed to sunlight, spooked, not "insulated")

But for purposes of casual discussion, thought it best to assume the craft is highly reflective (and, yes, I know that is a problem with considering it a radiator).

Apollo 13, however, did go into eclipse when it passed behind the moon.

And, spooked, if you are not getting AZCat's nit here, put yourself back into that aluminum ball. Half of it is lit by the sun and is receiving more radiation than it is giving off on the "dark" side. A black object exposed to sunlight in near earth orbit is going to get freaking hot, for the same reason as an iron skillet left in the desert sun.

[jberryhill]

14. And if you are still having trouble visualizing this...

You may know that temperature manifests itself in solids as vibrational energy.

Now, imagine the astronauts are zooming along and have AC/DC's Highway to Hell cranked up at max volume.

It's loud as hell inside the craft.

Now, place a microphone outside, an inch away from the hull of the craft. Does it pick up anything? No, it doesn't. There's nothing to conduct the sound.

Is the hull quiet? No, it's not. Go ahead and press that microphone up against the exterior hull. You'll find out that the hull is vibrating merrily away.

Now, instead of sound, think heat in the form of vibrational energy, and replace your microphone with a thermometer.

[whopis01]

17. That is ridiculous fantasy. You would not hear it even with a microphone attached to the hull.

Apollo 13 launched April 11th, 1970 and returned April 17th, 1970.

AC/DC released Highway to Hell was released July 30th, 1979 - over 9 years later.

The timeline you presented just does not line up.

[jberryhill]

18. Well, you got me there

Kudos.

[Bolo Boffin]

19. Try Buck Owens singing "Act Naturally" n/t

[dflprincess]

15. There may have been some artistic license in the movie

which would explain why hands and heads were exposed. It was more dramatic if you could see how Tom Hanks and the other actors were reacting.

Last night 20/20 did a segment and had an interview with Lovell and others involved in getting them back to Earth. I only saw the last 8 minutes or so and caught him talking about how cold it was. He said when they opened the hatch after they landed there was a cloud of vapor that came out the door when the warm air hit the cold air in the capsule.

It looked like an interesting segment and I need to remember to see if it has been posted on line as I'd like to see the whole thing.

[defendandprotect]

24. Seems there was a lot of "artistic license" in the whole . . .

Moon Landing farce --

[zappaman]

25. hahahahahaha

it amazes me that there really exists someone who thinks we didn't go to the moon.
Of course, you have ZERO evidence on your side, yet you persist.
Hilarious!!!!

[snooper2]

16. Yo Spooked, This is the only reason they lived

[jakeXT]

20. Humans work like heating, I imagine three of them in a LEM can be compared to one in a suit

A spacesuit also shields the astronaut from bombardment by micrometeoroids and insulates the wearer from the temperature extremes of space. Without the Earth's atmosphere to filter the sunlight, the side of the suit facing the Sun may be heated to a temperature as high as 120 degrees C; the other side, exposed to darkness of deep space, may get as cold as -160 degrees C. Paradoxically, the suit's life support system has to remove the heat and moisture generated by the sweaty working astronaut. This is usually accomplished by circulating cool water through an undergarment worn next to the astronaut's skin. Heat overload of space suits caused several crises on the first space walks in the Voskhod and Gemini programs.

http://www.astronautix.com/craftfam/spasuits.htm

[spooked911]

23. this is a good point

While cold was not such an issue due to heat transfer from a solid object into a vacuum. But heat radiation can travel well through vacuum. If the LEM was in contact with the sun's rays, I think over-heating would be a serious issue if they had no power for the cooling system.

[Rocket_Scientist65]

26. Cooling System

Spooked, that's what comes from watching the movie instead of reading the book. They DID have power for the cooling system. After the PC+2 burn was completed, the LEM was powered down with the exception of 3 systems.......communications, enviromental (basically the cabin air purification system) and the cooling system to keep the 2 active systems cooled. The LEM was drawing between 11 and 12 amps all the way back which ensured enough power for maintaining life support as well as recharging the depleated re-entry battery in the command module.

In addition, the crew had executed a PTC or passive thermal control "roll" prior to powering down to keep the spacecraft evenly heated. Also of note concerning the cooling system, the cooling system was the reason that the spacecraft kept shallowing in it's tragectory. The cooling system was a "loss" type system. The excess heat was removed by the coolent running through a subliminator and was essentially vented into space carrying the excess heat with it. That tiny propulsive force was enough to cause thier re-entry angle to shallow during the long drift home.

This is also the reason Fred, the LEM pilot, got a kidney infection. If the crew drank too much water, their means of cooling the electical systems would be gone. Unfortunately the crew took this rationing above and beyond what was needed and Fred suffered the worse for it.

[zappaman]

27. looks like just another thing

that Spooked doesn't understand and therefore must be some sort of conspiracy.
Spooked, tell us more about the aliens who have the earth under quarantine.

[jberryhill]

28. Reflection

If you read the thread, you will notice that the problem of keeping the ass end of the command module toward the sun in order to partially shield the LEM was indeed an issue.

The bottom of the re-entry capsule has a big ass insulating heat shield on it for re-entry, and metal surfaces reflect IR pretty well. So, yes, keeping the LM in the shade of the CM was done to avoid broiling the astronauts.

[defendandprotect]

21. Another "Opie" classic . . .

Tom Hanks and Opie seem regulars on the support the right wing myths journey --

Apollo 13 is just more "Moon Landing" farce --

Even on the "Moon" space suits weren't active . . . i.e., no visible signs of operation.

[Bolo Boffin]

22. Not a "right wing myth"

At the very least it's a left wing and right wing myth.

Nothing "rightwing" at all about recognizing the truth about the Moon landings, defendandprotect.

You should check out "For All Mankind", defend. I just watched it in Blu-Ray. Spectacular footage on the surface of the moon.

[zappaman]

29. Spooked, maybe you should watch less movies

If you are going to apply what you see in a movie to real life, then you probably also believe there is a multi-millionaire who flies around fighting crime in an iron suit he built with his own 2 hands.

[SDuderstadt]

30. That's what "they" WANT you to think...

can you imagine what would happen if people find out that Iron Man is real, not to mention the fact that he is illuminati?

[salvorhardin]

32. Huh. I would never have pegged Tony Stark for being Illuminati

Bilderberger, sure but Illuminati?

Now Bruce Wayne on the other hand...

Speaking of the Bilderbergers... Have you seen that they've got their own website now? Very tricky putting everything out there in the open on the web where nobody would ever think to look.
http://www.bilderbergmeetings.org

[zappaman]

31. I was watching LORD OF THE RINGS today

And there is something that doesn't seem right to me.

Every time Frodo or Bilbo went invisible with the ring they should have also gone BLIND. Your eyes cannot function unless light is reflected off the cornea. If light passes through it (as must be the case with invisibility) sight is no longer possible.

[Old Troop]

33. First of all, it was a movie...