Apollo Discussions > The Hoax Theory

Surveyor 3 anomalies

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Jason Thompson:

--- Quote from: Peter B on May 05, 2019, 09:12:14 AM ---When I pointed this out to Derek Willis over at UM he replied with a photo of the exhaust plume of a Space Shuttle RCS engine.
--- End quote ---

Probably worth pointing out that there is often a fallacious assumption that a photo shows the whole plume. Especially in the case of the shuttle RCS engine, where all you are seeing is an ignition transient rather than a steady state burn. The combustion products of that propellant/oxidiser combination are transparent. All you'll see on a picture is the part of the plume that generates or scatters enough light to be visible on the film or CDD. The stuff you can't see is still significant in terms of blowing stuff around.

As I once had to point out to someone who couldn't believe that things could be blown around by a rocket exhaust he couldn't see, you can't see the air around you but you can still be blown around by it.

Way better to use the mathematical methods as suggested by Jay rather than using pictures.

bknight:

--- Quote from: Jason Thompson on May 05, 2019, 11:22:30 AM ---
--- Quote from: Peter B on May 05, 2019, 09:12:14 AM ---When I pointed this out to Derek Willis over at UM he replied with a photo of the exhaust plume of a Space Shuttle RCS engine.
--- End quote ---

Probably worth pointing out that there is often a fallacious assumption that a photo shows the whole plume. Especially in the case of the shuttle RCS engine, where all you are seeing is an ignition transient rather than a steady state burn. The combustion products of that propellant/oxidiser combination are transparent. All you'll see on a picture is the part of the plume that generates or scatters enough light to be visible on the film or CDD. The stuff you can't see is still significant in terms of blowing stuff around.

As I once had to point out to someone who couldn't believe that things could be blown around by a rocket exhaust he couldn't see, you can't see the air around you but you can still be blown around by it.

Way better to use the mathematical methods as suggested by Jay rather than using pictures.

--- End quote ---

Excellent observation, but I'm not sure the poster will agree

Peter B:

--- Quote from: JayUtah on May 05, 2019, 10:16:21 AM ---It's possible to compute the angle, but I don't remember how off the top of my head.  I'm confident it's in Sutton and Biblarz, which I can consult when I remember where I put the book.  The problem is that the boundary of the plume is not sharp.  So you have to pick a cutoff density and say something like, "The half-angle of plume is X degrees out to D density."  That's only one of the ways that a plume is not homogeneous, especially when underexpanded.  You're still going to get the flat-sheet dispersal ka9q mentions, from the faster-moving still-somewhat-columnar core of the plume.

--- End quote ---

Excellent, thank you!

The key issue is that the Apollo 12 LM made its closest approach to Surveyor 3 at a distance of about 109 metres, when it was at an altitude of about 67 metres. But, crucially, at this point the LM passed only about 50 metres from the edge of the crater.

My suspicion is that this distance, given the LM's altitude, is close enough for at least the outer part of the exhaust plume to spray directly into the crater - and thus sufficient to blow dust onto Surveyor.

On top of this, the data suggests that for most of the rest of its path until touchdown its altitude was greater than its distance to the edge of the crater. And if you track the path of the LM as it flew past Surveyor, it traced a path nearly 150 degrees around Surveyor - which would explain why so much of the Surveyor is dust-covered.

bknight:
After reading descriptions of the hood containing the mirror, it had the appearance of being "sand" basted.  This does indicate that the descent engine was causing the surface regolith at least as far as the lander.  Because the hood was facing the LM most if not all the "dust" was in place during the landing of S3, bouncing at least twice.  Searching through history I discovered that scientists were a bit appalled by the blurred images of S3, dust on the mirror was their conclusion.
Anyway he doesn't have much of case of proving that their was an anomaly in A12's mission.  Just hard headed willful ignorance.

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