Were the Lunar Rovers faked?

[ka9q]

You know, anywho, instead of guessing about the LRV's characteristics you could actually read all about them:

http://www.lpi.usra.edu/lunar/documents/NTRS/collection2/NASA_TM_X_66816.pdf

A look at Fig 2-8, showing how the wheels deflected with load, just might give you a clue as to why the flight units could not support the astronauts' weight on earth.

[Echnaton]

[Snip long list of irrelevant information]

So they went 8 to 10mph over a sometimes very uneven surface with a very low coefficient of traction. If they end up sideways which will be very easy given the low traction and the uneven surface, and if they hit a trip hazard like an embedded rock, crater wall, or mound, then they will possibly roll at as little as 2 1/2mph.

And that is with the rover nicely balanced with two astronauts on board.

No roll cage is deemed necessary, no upper body harnesses, no worries.

It might be time to wake up and smell the coffee.

I wound up going sideways at about 40-50 MPH one time when my back end lost traction in a curve.  The car went into a field with no hint of a roll over.  It naturally preferred to roll on the tires than slide so it eventually came to be pointing backwards before it stopped.

Once again, your reasoning by analogy fails you.  A long list of analogies is no better than one example if they are all irrelevant.  The only thing that matters is the LRV operated on the lunar surface,  You must address that particular vehicle if you want to make your point.  If not you are just another in a line of one trick HBs.

[Jason Thompson]

Anywho, if the rover was faked, what is going on in all that TV footage with a rover in it?

[cjameshuff]

Anywho, if the rover was faked, what is going on in all that TV footage with a rover in it?

Faked using a specially-weighted rover. What else could the Saturn V launch have been for, if the official mission was a hoax?

And to revive an earlier question that anywho keeps avoiding...anywho, do you have a demonstration that the rover couldn't withstand the impact of an astronaut hopping into the seat yet?

[JayUtah]

I looked up how fast you have to be going to roll in a "tripped rollover", most cars and 4wds...

And if cars and SUVs were anything like the lunar rover, that comparison would mean something.

The rover has a wider wheel base but a higher COG so it will fit somewhere into the 5 to 6mph.

Try again.

It might be time to wake up and smell the coffee.

It might be time to get an engineering degree.  Handwaving argument by irrelevant analogy is growing tedious.

The most road-gripping car in your study had an SSF of only 1.5.  It happens to be a car I've driven and can't say much good about its gushy suspension, but on my favorite canyon drive it happens to hold the road reasonably well through some pretty nasty hairpins.  What was the SSF of the LRV again?  Can you compute it?  Did you compute it?  Since there is a roughly linear relationship between SSF and tripped rollover speed, please continue the analysis.

It appears you still can't decide whether the LRV would skid or trip.  If you believe it will trip, then your adhesion argument is bunk.  (BTW there is a very lengthy engineering analysis available on the LRV's tire-soil interface, complete with 1/6 g empirical tests.)  If it won't trip, then your rollover speed argument lacks foundation.

[JayUtah]

Your parking lot is not a very uneven surface with extremely low traction, nor are the streets and highways.

You were asked to quantify these.  You have not.  I conclude that you are unable to (or at least unwilling to) and are thus willfully drawing conclusions in the absence of evidence.

Why on a regular basis? It only has to happen once to roll the vehicle therefore it only has to be a possibility before a rollcage and harness are needed.

That is you imposing your personal rationale on NASA and its contract engineers.  No one is bound to accept your advice.

Not with two astronauts sitting up high and weighing 800lbs, especially when the vehicle only weighs 460lbs.

If you believe the unladen SSF is unacceptable for your argument, then compute a new c.g. and a new SSF and show your work.  I do not accept handwaving or "guesses" for where some other c.g. might lie.  You have belatedly discovered one of the four common models used to discuss rollover mechanics in automotive design.  However you don't get to simply guess what values to apply it to, or suppose that they will work out in your favor.  That's not rigor.  And it's certainly not engineering.

And since you are so late to this party, comments such as "wake up and smell the coffee" are inappropriate.  A more appropriate comment would be, "I see I have not yet done the proper study to support my conclusions.  Therefore I withdraw them until such time as I can investigate them."  Your approach is more consistent with a died-in-the-wool conspiracy theorist who arrived at his belief first, and is now play-acting at engineering in the firm hope that his pre-existing belief will be vindicated.  Since it is very much You vs. The Entire Engineering Profession, a little humility would be in order.

Here's a suggestion: work out how many scenarios cause cars here on Earth to end up traveling sideways, then work out how many of those could possibly transpire on the Moon.

Here's a suggestion:  do your own homework and some real engineering.  This is your argument, so you come up with the scenarios, the rationales, the operational requirements, the models, and the computations.  For the past dozen or so pages your argument has been based on the notion that driving the LRV on the Moon ought to embody the same requirements as driving an SUV on Earth.  In case it's not obvious, no one accepts that premise and they've given you good reasons for not accepting it.

Can we all agree that scenario is very likely to happen on the moon?

No.  Do not beg the question.  You are the one whose opinion differs from the entire engineering community.  Therefore if you're going to mount that type of arrogant challenge, you get to take nothing for granted.  Please provide the information we have asked for and show your work.

[gillianren]

A little hint, Anywho.  No, we can't all agree to whatever claims you're making.  Or at any rate, you have to show that they're something we should agree with if they contradict the established historical record.

[nomuse]

Which is why cars are rolling over all across the streets and highways.

Heck, I rarely drive at under 6 MPH, even in a parking lot.  I have driven a bit less than 20 times that -- and on just a two-lane blacktop.

Your parking lot is not a very uneven surface with extremely low traction, nor are the streets and highways.

I've driven fire trails.  Parked on dirt and gravel, including when it was rutted and soaked with rain.  I've driven down from Tahoe without snow chains (THAT was fun!)  I used to drive my old micro-pickup out of the parking lot, down a walking trail, across the grass, and down the beach with a bunch of tools and lumber in the back.  Never managed to roll any of those, either.

Now, I know you were hoping to lose the connections in the forest of uneeded detail, but your scenario requires the LRV -- a vehicle with a top speed of 15 MPH, typically driven at half that -- to be traveling SIDEWAYS at 2.5 MPH or more.  On a regular basis! 

Why on a regular basis? It only has to happen once to roll the vehicle therefore it only has to be a possibility before a rollcage and harness are needed.

And, on an uneven surface with an extremely low coefficient of traction it is not exactly an unforeseeable possibility, more likely a highly probable event.

Please describe the scenario by which a vehicle, particularly one with such a "poor grip" (your description) on the ground, manages to wrench its full mass (torque applies to mass, not weight) a full 90 degrees.  Without expending all of the forward velocity in doing so, either!

Note that the calculation of the LRV's SSF that Jay provided is a good margin higher than any of the Earth vehicles.

Not with two astronauts sitting up high and weighing 800lbs, especially when the vehicle only weighs 460lbs.

You can't calculate, okay.

And how will they end up sideways?

Here's a suggestion: work out how many scenarios cause cars here on Earth to end up traveling sideways, then work out how many of those could possibly transpire on the Moon.

One scenario is gong off road onto uneven terrain in slippery conditions, then it is very easy to end up sideways. If you are ever in that scenario you would be well advised to crawl along, even here on earth.

Can we all agree that scenario is very likely to happen on the moon? Or do you guys just want to relate your experiences in parking lots to the moon.

Amazing a couple of test pilots couldn't think of that, then!

[nomuse]

Hey, I just realized:

The astronauts are trying to walk around in 1/6 g.  Not only do they still have their Earthly mass, they are wearing extremely heavy packs that make them even more unbalanced.  Their boots have no more contact area than my tennis shoes, but at 1/6 g get only 1/6 the traction.  It should have been impossible for them to move.  They would have slid across the landscape like a kid on his first day at the skating pond, then toppled over with all that extra mass.

So all the EVAs are fake.

[Trebor]

(BTW there is a very lengthy engineering analysis available on the LRV's tire-soil interface, complete with 1/6 g empirical tests.)

I would be interested in seeing this, is there an accessible version about?

[Allan F]

Hey, I just realized:

The astronauts are trying to walk around in 1/6 g.  Not only do they still have their Earthly mass, they are wearing extremely heavy packs that make them even more unbalanced.  Their boots have no more contact area than my tennis shoes, but at 1/6 g get only 1/6 the traction.  It should have been impossible for them to move.  They would have slid across the landscape like a kid on his first day at the skating pond, then toppled over with all that extra mass.

So all the EVAs are fake.

First of all, their boots had much bigger contact area than any tennis shoe you could buy - probably about 4 times the area. Secondly, the tread had big deep grooves, to improve the traction. Third, they pushed into the surface with their boots. Fourth, you confuse mass and weight (hint: the PLSS weren't heavy in lunar gravity).

Edit: Aldrin's boot prints were 13x6 inches - about 511 cm2.

[Laurel]

AllanF, I'm fairly certain there was an implied wink at the end of nomuse's post.

[Allan F]

AllanF, I'm fairly certain there was an implied wink at the end of nomuse's post.

Sorry - Dogs and bells.

[JayUtah]

I would be interested in seeing this, is there an accessible version about?

With NTRS down, perhaps not.  I may have a local copy I can post.

[Jason Thompson]

Here's another thing for anywho to consider, though still just a sideline really.

In a car on Earth if you roll it it flips quickly and you're strapped inside a metal box, powerless to stop physics from doing its thing. If the rover flipped, how quick would it be, and given that the astronauts are not confined within, wouldn't just sticking a leg outhave some effect in slowing the roll? Or maybe they could just jump off. Either way, rolling an open vehicle you're not strapped into at speeds lower than normal human walking speed hardly seems like a catastrophe....