Flags on the Moon

[Tormod]

Although it is off-topic here, you'll find a very simple explanation of what causes the auroras here:

 

index

[CraigD]

specific heat capacity aluminium 900J/(kg.kelvin)

1sqmeter aluminium 10 cm thick= 270kg

 

tempchangealuminium= energy/(900 x 270kg)

per sec = 80000/(900x270)= 0.329K per second

per minute = 19.75K

per 30min = 592K + ambient = melted

 

Phenolic would be a lot worse.

Using the mass and service area of an Apollo Command/Service Module, I get similar results:

Power density of Van Allen belt protons if completely absorbed: 8e4 W/m^2

Apollo surface area: 160 m^2; mass: 30332 kg

Power of absorbing Van Allen belt protons: 8e4*160 = 1.3e7 W

Specific heat of Al: 897 J/kg/K; melting point: 933 K

Heating rate of Apollo c+s module: 1.3e7/897/30332 = .48 K/s

Time to heat from 273 K to 933 K (660 C) = 1381 s = 23 min

 

This assumes that the spacecraft is all aluminum. Much of it is wrapped in a 1.27 cm layer of phenolic, a good insulator with roughly the same proton stopping power as aluminum, but for estimation purposes, I think we can use this simplified model.

 

While I don’t think we’ve considered all the factors necessary for a definitive engineering calculation (radiative and matter exhaust cooling, the precise particle energies, densities and location of the Van Allen belts, Apollo spacecraft flight path and speed, etc.), these calculations appear to support at least a concern that, as silverslith puts it

If you shield them they are cooked.

For many social reasons (ie: I don’t believe so many astronauts, engineers, scientists, etc. could be kept from revealing a hoaxed series of missions), and technical (if the “cooking” scenario were true, designers would have known from calculations like ours, and designed a spacecraft capable of a polar escape orbit) I don’t believe the Apollo spacecraft was incapable of passing safely through the Van Allen belts. While personally satisfied that the Apollo missions were not a hoax, I don’t believe we’ve conclusively, technically proven the point yet in this thread. :) Calls of “case closed” are, I think, premature. :)

 

PS: I’m delighted by the amount of engineering physics I’ve learned in this thread. From a vague, unpromising beginning, I think it’s become a really good thread. :)

[Qfwfq]

Btw - wasn't the one lander photographed by some moon probe last year?

By the same folks that rigged up the hoax!

 

[Boerseun]

By the same folks that rigged up the hoax!

 

Well, with the advent of Photoshop and similar programs, I predict that future moonlanding will happen much sooner than we think, at a much lower cost!

 

The don't have to rent and fit out expensive studios anymore!

[Qfwfq]

Yup, I'll send you a poicture of me on the shores of the Sea of Tranquillity, stretched in the sunlight on a deck chair with a straw hat and a cocktail and Earth just above the horizion!

[Guest Lambus]

There are only United States flags on the moon?

 

To date, no other nation has planted a flag on the moon?

 

Does a crashed russian probe with painted flag count?

[TheBigDog]

There are only United States flags on the moon?

 

To date, no other nation has planted a flag on the moon?

 

Does a crashed russian probe with painted flag count? ;)

It counts for "crashed probes". The Soviets landed some probes on the moon successfully in the 60's. They also have landed on Venus successfully, something only they have accomplished. There are even some pictures from those probes if you search for them. Hot stuff!

 

Bill

[LaurieAG]

Well, with the advent of Photoshop and similar programs, I predict that future moonlanding will happen much sooner than we think, at a much lower cost! :)

 

The don't have to rent and fit out expensive studios anymore!

 

Hello Boerseun,

 

It's funny that you say that.

 

A couple of years ago, when the Russian cargo vessel had a slight accident with the Space Station the TV stations all played a small clip filmed from the cargo vessel. The Australian newspaper (NEWSCORP) published a still from this film clip where they had inserted a whole pile of fake stars of varying sizes.

 

I don't dispute that the moon landing occurred, but the really important question is, considering that there is no atmosphere on the moon, where are all of the stars in the moon landing photo's?

 

I know that the earlier video technology wasn't that crash hot but optical photography has always been pretty good (B/W or colour) and our current film technology (digital or otherwise) should be up to scratch by now.

 

If you disbelieve me get a hold of the old (early 1970's) Time Life Science series on Space and count how many stars you do actually see.

[Janus]

Hello Boerseun,

 

It's funny that you say that.

 

A couple of years ago, when the Russian cargo vessel had a slight accident with the Space Station the TV stations all played a small clip filmed from the cargo vessel. The Australian newspaper (NEWSCORP) published a still from this film clip where they had inserted a whole pile of fake stars of varying sizes.

 

I don't dispute that the moon landing occurred, but the really important question is, considering that there is no atmosphere on the moon, where are all of the stars in the moon landing photo's?

 

I know that the earlier video technology wasn't that crash hot but optical photography has always been pretty good (B/W or colour) and our current film technology (digital or otherwise) should be up to scratch by now.

 

If you disbelieve me get a hold of the old (early 1970's) Time Life Science series on Space and count how many stars you do actually see.

 

 

Sure, the cameras could of shown stars, if that what they were interested in showing in the pictures. But all of these photos were taken of objects brightly lit by the Sun, so the f-stop and shutter settings were set for such. If your exposure is set so that a brightly lit object shows up properly in the photo, it is to low for stars to show up in the photograph, no matter how good your camera is. If you set the exposure to show the stars, the object would be over-exposed and washed out.

[LaurieAG]

Sure, the cameras could of shown stars, if that what they were interested in showing in the pictures. But all of these photos were taken of objects brightly lit by the Sun, so the f-stop and shutter settings were set for such. If your exposure is set so that a brightly lit object shows up properly in the photo, it is to low for stars to show up in the photograph, no matter how good your camera is. If you set the exposure to show the stars, the object would be over-exposed and washed out.

 

Janus, you miss my point.

 

Stars were added into the still image that were not evident in any way shape or form in the video.

[Janus]

Janus, you miss my point.

 

Stars were added into the still image that were not evident in any way shape or form in the video.

 

Only because some idiot producer most likely told them to put them there. (Probably over the objections of people who knew better.)

 

My answer was to the question as to why you do not see stars in any of the lunar landing pictures.

[silverslith]

Heres that telescope answer from my optics mate. Seems active optics on earth scopes have made hubble obsolete.

 

Sorry I'm pretty busy at the moment, just got back from mount Graeme, my new job at the LBT, two 8 m mirrors, full AO, amf’ingazing.

 

Here's a bit of optics.

 

The smallest angle that any optical system can resolve is approximated by 2.44*lambda/D where the wavelength lambda and mirror diameter are in meters and the resultant angle is radians.

 

Therefore, the Hubble, with a 2.4 m mirror is particularly easy as the smallest angle it can resolve is just the value of the wavelength in meters (this answer being a radian measure of resolution).

 

Say, lambda is 500 nm or 0.0000005 m, then the angle in radians is 0.5 microradians, or 0.1 arc seconds roughly.

 

So, if the moon is 250 000 000 m away, say, then the smallest resolvable feature would be 125 m unless I slipped a decimal point somewhere. However, teh hubble is no longer the last word in resolution, ground based telescopes with AO kits are now reaching the diffraction limit with 10 m mirrors, so Keck say could get down to about 30 m, and with processing more like 15 m.

 

I look at the moon often enough with our 1.8 m mirror, and given that atmospheric extinction of vis is negligible, no the answer is that looking at the moon , especially at high mag (= low brightness) would not have any adverse effect on the Hubble's CCD array.

[LaurieAG]

My answer was to the question as to why you do not see stars in any of the lunar landing pictures.

 

You do see a couple of bright points of light in the images but they are probably planets. I thought that the opportunity wouldn't be missed to observe the stars from the moon without any atmospheric interference.

[TheBigDog]

You do see a couple of bright points of light in the images but they are probably planets. I thought that the opportunity wouldn't be missed to observe the stars from the moon without any atmospheric interference.

Observatories on the moon would be fantastic! Imagine having one at each of the poles giving the ability to do spectacularly long exposures. It would be great.

 

Bill

[Jim Colyer]

How could anyone believe man did not go to the moon?

 

American astronauts went 6 times 1969-72.

[Jim Colyer]

Skeptics who say the moon landings were staged point to this picture of the American flag. They contend that the flag is being blown by wind, and since there is no wind on the moon, the scene must have taken place on earth.

 

Fact is, NASA placed a horizontal bar at the top of the flag so that it would not go limp, so that it could be seen. This is obvious if you study the picture.

[Jim Colyer]

Charles Duke - Apollo 16