Author Topic: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time  (Read 12521 times)

Offline ka9q

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #45 on: February 16, 2015, 10:56:15 AM »
Of course those militarily-significant optical aspects of rocket plumes are not limited to visible light. Sutton and Biblarz talk at length about their infrared and ultraviolet emissions. Organic fuels seem to emit a lot of infrared while I think ultraviolet is important for hydrogen. Solid fuel plumes tend to be opaque from lots of condensed solid matter (mainly Al2O3).

Their radio-frequency properties are important too for their effects on radar and communications.  I've seen a lot of otherwise excellent rocketcam videos spoiled by plume interruptions at their most interesting moments, like staging. I suspect that retrorocket and ullage rocket plumes are the main culprits. As a comm engineer, I know how to fix this...




Offline Glom

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #46 on: February 16, 2015, 01:14:24 PM »
Don't forget that distinctively sooty turbopump exhaust layer, thick enough to partially obscure the actual rocket exhaust.

Exactly the motive for my question.  The default guess for liquid-fuel exhausts is that it will be transparent.  But the F-1 is unique for its annular turbine exhaust.  But again, intuition is notoriously wrong on these questions.  In later years, knowing the optical characteristics of rocket plumes would become enormously important in military applications.

And yes, transparent doesn't mean like glass.  You can get the Schlieren effect if you're lucky.
Annular? How was the F-1 annular?

I hate annular. We produce our wells that way. Modelling is such a pain. Plus it's just bad practice. Greater capacity though.

Offline JayUtah

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #47 on: February 16, 2015, 03:14:08 PM »
Amphiboly attack!

I mean the exhaust is annular -- the turbine exhaust forms the annular layer to the propulsive plume before they mix.
"Facts are stubborn things." --John Adams

Offline BazBear

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #48 on: February 16, 2015, 04:37:22 PM »
Now what were we talking about again?

The latest in a long string of "experts" no one has ever heard of, who advance claims based on the most inept caricatures of science, all saying that for one reason or another the Saturn V couldn't possibly have done what vast numbers of people physically saw it do.
It wasn't about how Apollo was staged to distract the public, while our extraterrestrial Bigfoot overlords completed their infiltration of the NWO, the Illuminati, Freemasonry, and the Federal Reserve? My bad  ;D
"It's true you know. In space, no one can hear you scream like a little girl." - Mark Watney, protagonist of The Martian by Andy Weir

My Youtube Apollo playlist http://www.youtube.com/watch?v=8SfyE9qsG8k&list=PL2aEC7cUMrGCNrtGMMWRXYob-kqCz2zz8

Offline bknight

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #49 on: July 15, 2015, 11:39:24 AM »
I have really learned a lot about the Saturn V performance from the Pokrovsky thread and this one.  Makes the Auils claim very weak.  But the HB's don't need strong evidence, they only need a misguided reinforcement to make them salivate.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Zakalwe

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #50 on: July 15, 2015, 04:52:07 PM »
But the HB's don't need strong any evidence, they only need a misguided reinforcement to make them salivate.

I hope you don't mind, but I've corrected that for you...
"The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.' " - Isaac Asimov

Offline bknight

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #51 on: July 15, 2015, 07:18:10 PM »
Of course, how careless of me. :)
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline JayUtah

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #52 on: July 17, 2015, 11:14:15 AM »
I have really learned a lot about the Saturn V performance from the Pokrovsky thread and this one.  Makes the Auils claim very weak.  But the HB's don't need strong evidence, they only need a misguided reinforcement to make them salivate.

That's a nugget of wisdom.  Conspiracism is a shortcut to erudition.  Some people latch onto them because it makes them feel smart to believe that they know something few others do, and that it's because of their special acumen that they know it.  Some expressions of conspiracy theories are just pseudo-scientific veneer over what people have already decided they want to believe.  It gives it the feel of an intellectual conclusion without needing to acquire any actual skill or expertise.
"Facts are stubborn things." --John Adams

Offline bknight

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #53 on: July 17, 2015, 11:46:59 AM »
Well I wanted to major in aeronautical or aerospace engineering, but they didn't offer scholarships.  So I took and petroleum engineering and haven't kept up on the stuff you guys are involved.  But I was/am very interested in manned/unmanned space endeavors.

Edit: Forgot to say Univ. of Wyo.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline QuietElite

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #54 on: March 17, 2018, 10:37:38 AM »
You dont even need to look at most of the article to conclude that this is bogus.

The first question that I had when I first looked at this Aulis article was: "How can a rocket travel that slowly about 100s into the flight ?"
To travel this slowly the thrust-to-weight ratio would have to be just above 1 during the whole ascent but a rocket burns fuel and the TWR rises since the rocket gets lighter which accelerates it more and more quickly.

So there are basically only 2 options I can think of:
1. The rocket shuts down some of its engines during flight but this cant be seen and it would also make no sense to do that. The Saturn V only shutted down its inboard engine on the first stage but at this point the acceleration was already at 4 G's anyway.
2. The mass flow rate of the propellant is very low and therefore the rocket doesnt lose that much weight and the acceleration stays roughly the same. However to have such a low mass flow rate you would need an specific impulse that is physically impossible for chemical engines. Also with such a high specific impulse your rocket couldnt just get you to the moon but also far beyond. So basically it would have been overpowered and not underpowered as the author tries to suggest.

Offline Nowhere Man

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Re: The Popov/Bulatov "analysis" of Apollo 11's velocity vs time
« Reply #55 on: March 18, 2018, 10:31:26 AM »
Thread necromancy alert, almost 3 years.

Fred
Hey, you!  "It's" with an apostrophe means "it is" or "it has."  "Its" without an apostrophe means "belongs to it."

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