View Full Version : Rover Dust Again

2002-Jan-03, 09:57 PM
We've done this somewhere else, maybe even in a different forum (apollohoax.com?), but I was thinking about the dust kicked up by the rover when John Young was nailing over the lunar surface. The argument has been that the dust clumps because it is meeting resistance from an atmosphere. Now, if we assume that the dust is not following a ballistic arc, because it's light enough to be stopped by the air, then surely it would be light enough to be affected by the airflow around the back of the rover, and be 'swirled' into a haze, like water forms a hazy cloud behind cars travelling on wet roads. Even if we then think the rover was travelling too slowly to produce much of a 'wake', remember the HB's have decided that the film has been slowed down, and the rover was actually travelling much faster than seen on the film. ould this lack of haze be a proof that there was no air?

Donnie B.
2002-Jan-04, 12:44 AM
Sure, but you won't convince any devoted Hoax Believer of that.

2002-Jan-04, 02:50 PM
I think one of the best proofs of the astronauts being on the Moon is the parabolic trajectory of the dust coming off the rover tires - just try doing that in a studio! (Even 2001 couldn't, as has been pointed out elsewhere.)

2002-Jan-04, 10:05 PM
I think one of the best proofs of the astronauts being on the Moon is the parabolic trajectory of the dust coming off the rover tires

Or off the astronauts' feet, or in a number of other cases. Even those who don't understand the physics of how air and gravity cause particulates to behave can see that there's something "different" about it. And of course those who appreciate physics see exactly what they'd expect to see.

Even 2001 couldn't, as has been pointed out elsewhere.

Kubrick's movie failed to do a lot of things well, despite its enormous budget and the expertise of Douglas Trumbull. And Kubrick insisted on things like visible starfields moving behind the spacecraft. A valiant effort at realism, granted, but you just can't get away from how particulates behave in a vacuum. Unless you're actually shooting in a vacuum you won't get the right effect.

I don't understand the mechanics behind the argument that the clumping visible in the Grand Prix footage is due to interaction with the atmosphere. Usually the presence of a fluid medium impedes the collinear flow of a collection of objects through it. The trajectory of each dust particle through air depends on the precise aerodynamic conditions surrounding each particle, which of course vary greatly between individual particles. Therefore a flock of particles on initially identical trajectories will tend to diverge over time, not clump together.

I presume the hoax believers argue that the flow of dust should be a uniform "rooster tail" which does not congregate in any way. This expectation would be valid if the rover were constrained to operate smoothly over level, unvaried terrain in a constant state of power-skidding.

The so-called Grand Prix was designed to test the capabilities of the rover under extremes of operation -- speed, cornering, etc. Under normal operation very little wheel slippage was observed, evidenced by neatly formed rover tracks in various images.

The irregularities in the surface caused the rover to bounce and the wheels to periodically lose contact with the surface. This would naturally cause them to overspeed, and we expect that when they regained contact with the surface they would slip against it and throw dust.

Recall that lunar soil is highly cohesive, especially when compacted. Thus the impact of the rover wheel will compress the soil into a cohesive aggregate which will behave mechanically as a semi-solid. This explains why the wheel will throw a patch of soil on nearly identical trajectories. After passing out from under the wheel the external mechanical compression force is removed and each particle is free to pursue its own ballistic trajectory.

The clumping is due to the mechanical effects of simultaneous compression and ejection from under the wheel. As John will no doubt witness, this can be observed in earthbound particulates.

The other common argument is that the thrown dust seems to stop a short distance behind the rover, as if it had encountered resistance. The expectation is that it would move horizontally at a continuous high speed which would be easily visible on film. The constant horizontal speed is indeed confirmed by Newtonian physics, but the exact speed at which it moves is determined by its angle of departure from the wheel. The dust we see thrown from the wheels is thrown more upward than horizontally, therefore the horizontal component of the motion is rather negligible. The aggregations of dust that appear to "hang" in the "air" do so because they were thrown chiefly upward, not backward.

I tend to agree with John that photographing the Grand Prix in air would raise a cloud of dust. It's very common to see clouds of aerosolized dust affected by the confluence of the slipstream behind even slow-moving vehicles. The absence of such clouds would quite strongly suggest the absence of a slipstream.

2002-Jan-09, 01:41 PM
On 2002-01-04 09:50, ToSeek wrote: To: 2-1-09 7:05 A.M.PST
I think on
7:06 A.M. HUb' Yeah?
My problem
With tails of yesterCentury are
{ after spending all that money going }
Why oh Why
are there NO Lunar Rovers in operation
sending back "LIVE" videos today. Booo.

2002-Jan-09, 01:54 PM
On 2002-01-09 08:41, HUb' wrote:
Why oh Why
are there NO Lunar Rovers in operation
sending back "LIVE" videos today. Booo.

Yes, you'd think it wouldn't have been that much harder to make the rovers operate remotely - that would have been really cool! I doubt they would have lasted till "today," though.

David Hall
2002-Jan-09, 03:40 PM
I don't know about that. It's quite a step in magnitude from a remote control camera to a remote control vehicle. Maybe it wasn't really feasable at the time to control such a complex object from such a distance.

My personal suspicion though is that it mostly was a question of weight and cost. It probably would have added a lot of mass and complexity to the rovers, and they were already under quite serious mass considerations as it was. They also probably decided the potential gain would have been minimal. I mean, they only had limited range in the first place. How much more could they discover that the men didn't already check out during the landings themselves?

I agree it would have been neat though.

David Hall
"Dave... my mind is going... I can feel it... I can feel it." (http://www.occn.zaq.ne.jp/cuaea503/whatnots/2001_feel_it.wav)

<font size=-1>(stupid mistake)</font>

<font size=-1>[ This Message was edited by: David Hall on 2002-01-09 10:42 ]</font>

2002-Jan-09, 04:25 PM
There were probably a lot of issues, including pointing the antenna (which the astronauts had to do by hand). Oh, well, still a shame.

Weren't there plans to send a remote-controlled rover to the Moon and finance it by selling time to people to operate it? Whatever happened with that idea? I was ready to sign up!

2002-Jul-13, 01:09 PM
<a name="20020713.5:00"> page 20020713.5:00 aka JD2452469.5:00 A.M.
On 2002-01-09 11:25, ToSeek wrote: From the depths of page 16
Up to P1?
anyway just density packing [Level 3]
but with the addid twist of OLD electrons
{ so now i need to compute the oribital # }
lemme thin . an electron ..
in orbit around the New C
of an {um?} what element was this again
? Erbian? turbin? ittrium, Ytterium? Maybe its just phosphorus?

2002-Jul-13, 02:15 PM
I think as Jay has already pointed out 2001 had it flaws, and he's a list of them.


2002-Jul-13, 02:40 PM
yeah? yeah page 1 {& what shold be on it}
well search for sure [i dont use search much]
but it should be on page 1 (yes and memberlist)
that should also be on page 1
i've yet to use member list {maybe today?}[hmm?]
FORUM .. YES: by all means FOrum so sure i like
this BB just fine actually Glad its available
and I guess I should look in to how to get
one for myself? {any clues?} now back to chase DUST CLOUD { in reverse motion } 8..654..etc

Peter B
2002-Jul-14, 06:08 AM
The business of whether remote control ability could have been built into the Rovers is discussed in a bit of detail on the Apollo Lunar Surface Journal site for Apollo 15.

Basically, it boiled down to money. And IIRC, actually not a lot of it. The technology was there.

2002-Jul-14, 10:12 PM
<a name="20020714.2:02"> page 20020714.2:02 aka Dust
Just guessing but I `poise that the DUST
sequence WOULD be the part that got picked for
reverse playing [over & over] so my questions this
Do any of the memberslisted have the ability
to play the strip and clip out the sequence
of the "DUST" and reformat that so forward is
reverse and reverse is forward:? [dust up] into [dust down] ?
Now back to the regularyly scheduled TVtime slots

David Hall
2002-Jul-14, 10:56 PM
As I said before about remote-controlled rovers, I'm sure they decided it wasn't worth the effort. I mean, what would we gain from the extra expense? A few more hours of driving around an area already explored in person with only a video camera to take pictures with. Sure, there's a chance we could have found some more surprises, but chances are we wouldn't. It's the law of diminishing returns. The added expense and effort (and weight) is not worth the added benefit.

Now, something like the Mars rover, where we aren't going there in person, is a much better use of that technology.

One more point. About the idea to sell time to people to drive a rover around the Moon, do you really think that's such a good idea? If you consider the mentality of the average person out there, the last thing I'd want to do is put a multi-million dollar machine into the hands of some everyday street yutz. Within a week you'd have some punk kid driving the thing off a cliff or something.

2002-Jul-14, 11:13 PM
Even Capricorn One has its goofs.


2002-Jul-15, 11:46 AM
<a name="20020715.3:33"> page 20020715.3:33 aka Lunar Remotes
On 2002-01-09 10:40, David Hall wrote: To: 3:33 A.M. HUb'
from a remote control camera
Ok let me `poise for a while
that Yes { on the moon there WAS }
a remote controled camera to take the
sequence of the "Lunar" rover kicking up dust
{no i havent gotton to the end of thei thread yet}
_________________[ TO SEE IF THERES a revers version already READY]
considering those 1'st probes
that to my knowledge have "Left the solar system"
and still sent back signals
why acnnot we "NOW" get back signals from the Moon
"Remote Camera{$}" I would like to know!
why when the Made For Prime Time "Nightly" TV
is there no mention of those remotes? hmm? Hu? oh Uh hU:

2002-Jul-16, 02:46 PM
<a name="20020716.6:28"> page 20020716.6:28 aka RANT {after Math}
On 2002-07-15 07:46, HUb' wrote: To: HUb' 6:29 A.M. July 16, 2002
1: OK? `poise some ListedMember COULD actually view the DUST video
2: and `poise2 that she {Shirley 4. Short}
3: could do the trick: cut the clip: reverse the strip
4: so that [DUST UP] became [DUST DOWN]
5: now the Question for the Logical positivFisted
6: Assuming the origional was CopyRighted
7: {maybe by NASA] would the Right extend
8: over to the revised version [Dust Down]
9: or would Shirly be "allowed" to distribute
10 :"_HER STRIP_": ?/?
1: nOW i DO ADMMITT .. being an ill-Logical
2: negativist {and much of the time }
3: [unable to understand EVEN myself]
4: yeah, YEAH: But', Could She? if she could?
5: it seams positivly logical 2me
6: anyway Line 16 6:39 A.M. & anothet thing..
Well ater for thepush to page 1 and the Remote camere operator Questions?

2002-Jul-16, 02:57 PM
Well, I do think the reversed video would still be under NASA's copyright, but I would expect Shirley would be able to use it in either a pro- or anti-hoax production under the provisions of Fair Use . . . maybe?

I'm not hardly an expert on copyright law either . . . /phpBB/images/smiles/icon_frown.gif

2002-Jul-16, 03:00 PM
On 2002-07-16 10:57, SeanF wrote: To: HUb'
Well, I do think the reversed video would still be under NASA's copyright, but I would expect Shirley would be able to use it in either a pro- or anti-hoax production under the provisions of Fair Use . . . maybe?

I'm not hardly an expert on copyright law either . . . /phpBB/images/smiles/icon_frown.gif
aka Pioneer 10 Successfully Contacted

that was Quick ..{points for +'s} now back to slow Ahead

<font size=-1>[ This Message was edited by: HUb' on 2002-08-01 07:53 ]</font>