Were the Lunar Rovers faked?

[nomuse]

JAQing around, pretending expertise, random bicycles -- should we start up a special Bingo card, you think?

[BazBear]

Someone else has probably said something like this by now, but I don't think we even need to address the numbers to discount the OP's assertion (I'm certainly not saying it's a waste of time, it's very educational to us more math challenged types, and the more thoroughly a claim such as this is debunked, the better). We have hours of footage of the rover moving, both from the rover and observing the rover, all taken in what would be an impossibly large movie set, in a vacuum no less. We are also to believe that the LRV wouldn't be rugged enough for a 1/6 g environment, yet would handle the 1g found on the impossible Earth film set with no problem.

All of this is true.  However, I do still firmly believe that, if the OP cannot provide the numbers to back up his assertion, it's proof he doesn't know what he's talking about.  I am so math-challenged that I don't get the numbers even when they're presented, and I acknowledge this.  However, that's also why I'd never make the assertion in the first place.  I know I don't know enough to make it.  I know the assertion is ridiculous on its face for several reasons, but if you can't present it in the right language, there's no reason to believe you know enough to know why it is ridiculous.  Even with the whole "impossible Earth film set" aspect thrown in.

No argument here. He's the one who brought up the physics aspects, and his feet should be held to the fire, since he wants to play that game.

[Noldi400]

Some Real Numbers:
According to a 1972 Boeing handout, the Apollo 17 LRV had a weight capacity of 1,140 pounds [517 kg] Earth weight). This allowed for 400 lbs for each astronaut (and his gear) and 340 pounds of equipment and samples.

That's about 86 kilos earth equivalent, so yes, two astronauts even in street clothes would be over its capacity on earth. The document seems to be some kind of public or press handout, so it's not really very long on technical specs.

http://www.hq.nasa.gov/alsj/a17/A17_LunarRover2.html

^Edit:
I'm aware that the onus is not, um, on us to provide the numbers, but I was getting a little tired of the sound of beating this particular dead horse.

[anywho]

This youtube clip has a sequence at the 2:04 mark showing how they tested for 1/6g.
https://www.youtube.com/watch?feature=player_detailpage&v=FVMfjPXwRO4#t=124s

Thanks for that, I don't have sound so I don't visit youtube much.

I can't hear what is being said but looking at the footage it shows that they did indeed use a skidcar equivalent setup for testing.

If you look at the testing it shows the difficulty of driving on the moon, even at those slow speeds (looks like walking pace) you can see wheels rising up into the air and that is on a very smooth surface compared to the mogully type terrain in the famous "grand prix" footage which was posted earlier.

I see the last test where they had to steer a bit, and lost a bit of control, that they appear to have not made it all the way across the test bed.

The biggest criticism I would have of the test is that they don't start on the loose surface. Why not? that is the most obvious test for traction. I live in a very sandy area and if I want to drive my 2wd over a sandy area that is a bit dodgy the way to do it is to get a bit of a run up and don't, under any circumstances, stop.

My 2wd is not suitable for sandy terrain yet it would pass that test.

To be honest, looking at that car bouncing around on that relatively smooth surface, at relatively slow speeds, I can't see how anyone could have confidence to drive at much higher speeds over much worse terrain, and, when only one person is on board, in a significantly unbalanced vehicle.

And, they seemingly have to have have a run up to help the vehicles across the test bed. At 2.18 it looks like both rear wheels rise up off the ground.

Thanks for posting it though, and I will take the time to look at the whole rover series later when I am at a better computer.

I am a bit stretched for time but I will address a some other comments later.

[Chew]

To be honest, looking at that car bouncing around on that relatively smooth surface, at relatively slow speeds, I can't see how anyone could have confidence to drive at much higher speeds over much worse terrain, and, when only one person is on board, in a significantly unbalanced vehicle.

You keep saying but you have not provided any evidence it was "significantly" unbalanced or unbalanced at all.

[raven]

I am not an engineer, not do I play one on TV, (though I do a dandy fake Scottish accent) but the LRV looks quite the opposite of unbalanced to me.  Wide, soft, tires, low looking centre of gravity, It shares a gross similarity to a dune buggy to my, uneducated, eyes.

[Andromeda]

To be honest, looking at that car bouncing around on that relatively smooth surface, at relatively slow speeds, I can't see how anyone could have confidence to drive at much higher speeds over much worse terrain, and, when only one person is on board,in a significantly unbalanced vehicle.

Others have discussed the "unbalanced" and other faulty physics claims very well, but I just want to point out the problem with the bolded.

Just because you wouldn't have the confidence to do something, doesn't mean no-one else would. The astronauts were highly trained and disciplined - and already doing something incredibly dangerous even without bringing the lunar rover into it.  Why would they balk at it?

[nomuse]

More than that, they were test pilots.

The "Grand Prix" was exactly that; it was testing the Rover to find the practical limits, within the safest framework they could find (close to the LM, only one astronaut on the thing so if the other rolled and was knocked out his buddy could carry him back inside).

When they hit the trails on geology expeditions following, they knew what they could drive on or up with a very high probability of not crashing in the process.

And they were STILL within walking distance of the LM (just, a bit longer of a walk!)

[Noldi400]

Not to mention that "high speeds" aren't that high. The top speed of the LRV was about 12 mph [20 kph] which is a fast trot for a person - about the average speed of a marathon runner.  We're not talking about zipping around at 100 kph here.

Anywho, if this is a point you have serious questions about, do some research first. So far, all you've really presented is an Argument From Incredulity - i.e., your common sense tells you that it doesn't look right.

But your "common sense" (and mine, and everyone elses) comes from a lifetime of experience here on planet Earth in a one-gee field, a 14.7 psi atmosphere, and a 24-hour day/night cycle.  The surface of the moon is a wildly different environment; the engineers at NASA and elsewhere spent years and years working out solutions to the multitude of problems they faced. You can't, for example, judge the extent of testing of the LRV by a couple of minutes of video. Here's a link to get you started:

http://www.hq.nasa.gov/alsj/alsj-LRVdocs.html

All text, no sound needed.

[raven]

At least Anywho isn't asking how they got it out the LM hatch. So much ignorance packed into one sentance, and so easily refuted too.

[gillianren]

Anywho, what research did you do?

[Jason Thompson]

If you look at the testing it shows the difficulty of driving on the moon, even at those slow speeds (looks like walking pace) you can see wheels rising up into the air and that is on a very smooth surface compared to the mogully type terrain in the famous "grand prix" footage which was posted earlier.

I can see the wheels doing exactly what would be expected on such a vehicle with the suspension it had. What I don't see is this causing any difficulties for control or balance, so why is this an issue?

The biggest criticism I would have of the test is that they don't start on the loose surface.

So because there's some short film of them not starting on the test bed you think that's all there was? Do you honestly think they made that entire setup for less than two minutes of testing?

To be honest, looking at that car bouncing around on that relatively smooth surface, at relatively slow speeds, I can't see how anyone could have confidence to drive at much higher speeds over much worse terrain, and, when only one person is on board, in a significantly unbalanced vehicle.

You keep saying the vehicle is 'significantly unbalanced' with only one person on board. Yes, the centre of mass is shifted to one side, but why is this an issue? The rover is wide, flat, and the astronaut sits well inboard of the wheels. Do you have any calculations to show just how 'unbalanced' the rover is with one astronaut on it?

[nomuse]

I used to have as my desktop a dirt bike being tested in the vomit comet.  That must have been an exciting few minutes...

[ka9q]

More like an exciting 20 seconds. That's all the weightlessness you get even on the vomit comet.

It would be fun to see the papers documenting this research. If it was NASA sponsored, they should be out there somewhere...

[raven]

Wow, that sounds fun, lunar motocross. They get some amazing height here on Earth. Imagine doing it in 1/6th gravity! I'd wait until mechanical pressure suits are perfected though.