Were the Lunar Rovers faked?

[twik]

...we are told they cant be sat on.

Please cite your source for this claim.

To be fair, he did cite a footnote to a NASA publication in his first post. However, I do think he stretched the meaning slightly from "the rovers could not support the astronauts on Earth" with "can support no more than their own weight on Earth". The astronauts in full gear would be very heavy in Earth gravity; they would weigh only 1/6 of that on the Moon, while the Rovers would still maintain their rated strength.

[raven]

I'll ask again, if this was fake, what were they driving?
Why didn't some contractor notice that 'Hey, that's not what we built!'
I already went over the special effects techniques as available at the time and, frankly, they weren't up to snuff.
Therefore. it would have to be a practical effect, something that could do all that the LRV could do, be unfolded from the quad in the side of LM and be driven around at the same speeds, (or even faster if you claim the slow-motion was how they allegedly simulated lunar gravity) but work on Earth, in Earth gravity, but look, even in close up, identical to the LRV.

[Andromeda]

Anywho, you claim the rover could not be "sat on" in Earth gravity.

So where did they film it being driven by astronauts, if not on the Moon?

Your hand waving arguments are not even consistent.

[Zakalwe]

I'll ask again, if this was fake, what were they driving?
Why didn't some contractor notice that 'Hey, that's not what we built!'
I already went over the special effects techniques as available at the time and, frankly, they weren't up to snuff.
Therefore. it would have to be a practical effect, something that could do all that the LRV could do, be unfolded from the quad in the side of LM and be driven around at the same speeds, (or even faster if you claim the slow-motion was how they allegedly simulated lunar gravity) but work on Earth, in Earth gravity, but look, even in close up, identical to the LRV.

You've highlighted the fatal flaw in the HB argument- faking it successfully is actually much harder that just doing it!

[JayUtah]

I'm not sure where the centre of mass would be.  For the empty LRV, it's probably about the chassis, maybe a little above...

The unladen LRV had a c.g. 20.1 inches above the ground (3.1 inches above the bottom of the chassis).  The wheelbase is 72 inches wide, for an unladen SSF of 1.79.

[Chew]

Must--- resist--- Monty--- Python--- reference!

[raven]

Must--- resist--- Monty--- Python--- reference!

Do LRV's migrate?

[Not Myself]

Anywho, you claim the rover could not be "sat on" in Earth gravity.

So where did they film it being driven by astronauts, if not on the Moon?

Your hand waving arguments are not even consistent.

Mars has just a bit over 1/3 earth gravity.

[anywho]

You have computed the "roll stability factors for the lunar rover" and yet you question the premise that it would be many times easier to roll on the moon?

Yes, I dispute your claim.

Seriously? As an engineer who has done research into this area you dispute that claim?

This is quite unbelievable.

So if the rollover threshold for a car is 1g on earth it is not 1/6g on the moon?

If hitting a bump on one side causes the vehicle to rotate on it's axis will it not basically be gravity that stops that rotation? In space it will theoretically rotate forever, on earth 1g gravity will stop the rotation, and on the moon 1/6g will act against the rotation?.

On the moon if you hit a bump on one side will that side not rise up higher, and for longer, allowing for more rotation?

So simple trig tells us that the lateral acceleration will be the same as the gravitational field at the point of tipping, which is 1.6m/s².

So basically 1/6th lateral acceleration is needed to roll a vehicle on the moon as on earth, can we move on from disputing that it is many times easier to roll a vehicle on the moon than it is on earth? (this comment, although posted after quoting you, is not directed at you, Glom)

Is anyone amused by anywho trying to saying at the same time that the vehicle wouldn't have enough traction and that the vehicle would easily roll over?  In order to roll over, you need traction or the vehicle will just slide.

Oh, I don't dispute that on a perfectly smooth surface with very low traction it would be nigh on impossible to roll a car, but the moon is not a perfectly smooth surface. At times it was a very uneven surface they were driving on, and in this situation very low traction is more dangerous for rolling because you are more likely to end up sideways, therefore increasing the chances of a tripped rollover, which is by far the most common cause of rollovers.

Even if you don't slide sideways, just hitting bumps and dips will toss the unbalanced vehicle around a lot more than on earth.

I know I would not drive such an unbalanced vehicle (3/4 the weight on one side) over such an uneven surface at 10 or 15kph here on earth, let alone the moon where the low traction and low gravity both work against you making it many times easier to roll.

To be fair, he did cite a footnote to a NASA publication in his first post. However, I do think he stretched the meaning slightly from "the rovers could not support the astronauts on Earth" with "can support no more than their own weight on Earth".

To be even more fair, the comment "can support no more than their own weight on Earth" is not from me but is a quote from a NASA document for which I supplied a reference.

[gillianren]

Seriously? As an engineer who has done research into this area you dispute that claim?

This is quite unbelievable.

Yes, it is unbelievable that the assertion of a trained engineer who has done research into the field won't cause you to change your mind.  Won't even make you think that the issue isn't as cut-and-dried as you think it is.  However, we're used to that.  If you really wanted to impress people, you'd think for a while about what it means about your assumptions, you'd recognize your ignorance (or else show your work), and you'd apologize for your attitude.  Somehow, I don't think this is what you're going to do.

[Not Myself]

Must--- resist--- Monty--- Python--- reference!

Do LRV's migrate?

Yes, but only once.

(I'm assuming here they didn't pack the thing up and bring it back with them.)

[Allan F]

Must--- resist--- Monty--- Python--- reference!

Do LRV's migrate?

Yes, but only once.

(I'm assuming here they didn't pack the thing up and bring it back with them.)

No, they left it there so the TV-camera could film the liftoff from the moon. And it couldn't fit through the hatch anyway.

[Not Myself]

The moon's a good neighbourhood.  You can leave your car out and not have to worry about it being stolen.

[Tedward]

The moon's a good neighbourhood.  You can leave your car out and not have to worry about it being stolen.

There was a photoshop of the rover up on bricks. Probably still on the net if you look for it. Quite funny.

Anyway, anywho. I am still having issues with your claim. Using your methodology I can see how an astronaut can hit/land/jump/handstand whatever into the rover. My intuition, using the same as you here, and I have no maths to back me up, same as you, says there will be a tipping point but it will take a wallop before it goes. That point is the bit I fail to see from your claim, I think it will be OK. Using your methods here don't forget. I am not an engineer. Don't mind being proven wrong and shown why I am wrong.

So, for example I know tyres comes in different flavours. They are usually round and black but dig deeper and there is a lot to them. The composition of the tyre has an effect. The side wall stiffness, tread pattern profile, wheel diameter and width and so on. All this will alter your family cars handling, ride quality, MPG, same car you are using for a comparison I think. And that is before you get to suspension. What points are attached, how, what dampers, spring rates and so on, this is the same as your generic family car that you are using. The Moose test showed what happens when you get it wrong. So we do not have a ridged welded and bolted solid structure as far as we can see and this will have a bit of give a stability. Enough for the moon. Using your methodology here.

Now comes the fun part. I take your family car that flips over if you look at it funny, and modify it a tad, I can make it do things the maker never envisaged. That includes not falling over at the slightest gust. So I have the same frame/chassis/shell/sub frames whatever and it is more stable. Rally and race teams do this all the time.

Give the car designers a big cheque and say we want this in silver, open top, oh, and it needs to run on the moon, I expect there to be a solution that is not beyond the bounds of credibility. Looking at the solution, as a lay person, it looks the biz for not falling over. The evidence behind it is there and your claim makes an assumption that I cannot see ever being done. That is filming on Earth.


By the way. You have the info on why the motors could not do it yet?

[Not Myself]

The moon's a good neighbourhood.  You can leave your car out and not have to worry about it being stolen.

There was a photoshop of the rover up on bricks. Probably still on the net if you look for it. Quite funny.

I'll have a look.

Of course, if you have to call for a tow, it's going to take a while, and be really expensive