Author Topic: Distance Travelled by the Apollo Missions  (Read 822 times)

Offline Bryanpoprobson

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Distance Travelled by the Apollo Missions
« on: September 15, 2018, 12:50:31 PM »
An idiot hoax believer (expattaffy) seems to think that the concrete proof that Apollo didn't happen is the fact that it took 2 and a half days to get to the moon. He comes up with the nonsense reasoning that if the craft was travelling at 24,000 mph (give or take) the journey should only take 10.5 hours. Falling to understand that the craft were decelerating to the gravitational mid point between the Earth and Moon, and then accelerating into the Lunar Gravitational Well. Additionally failing to understand the path taken was a Hohmann transfer orbit and not a straight path. Additionally the TEI speed was only about 2,400 mph only accelrating as the craft fell into the Gravitational well of the Earth.
He then tried to use an average speed calculation, which is again nonsense as the calculation is far more complex.  However it got me thinking as to the actual distance travelled by the Apollo craft between the Earth and Moon. I couldn't find the figures, does anyone have them? Or will I have to get my calculator out?
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline bknight

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Re: Distance Travelled by the Apollo Missions
« Reply #1 on: September 15, 2018, 02:17:22 PM »
This book may be of assistance, no guarantee.
Apollo: The Definitive Sourcebook. Richard Orloff & David Harland.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Obviousman

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Re: Distance Travelled by the Apollo Missions
« Reply #2 on: September 16, 2018, 03:02:48 AM »
Probably the reference it was made from:

Apollo By The Numbers

https://history.nasa.gov/SP-4029.pdf

See page 315 (PDF)

Offline Bryanpoprobson

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Re: Distance Travelled by the Apollo Missions
« Reply #3 on: September 16, 2018, 05:32:09 AM »
Probably the reference it was made from:

Apollo By The Numbers

https://history.nasa.gov/SP-4029.pdf

See page 315 (PDF)

I did try this as a first reference, but the distance figures are given in altitudes from Earth and Moon so these are linear distances. I have a slight obsession with finding the actual distance travelled now. I will put my mind to it when I have some time.
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline QuietElite

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Re: Distance Travelled by the Apollo Missions
« Reply #4 on: September 16, 2018, 06:15:51 AM »
I don't think that there is a straightforward answer for this. You can't simply use basic orbital mechanics to calculate it since we are dealing with a 3-body problem and therefore we don't have a strict Kepler orbit. Also in the vicinity of the moon they probably used the moon as reference for their orbital parameters which makes it even harder to know how the spacecraft actually moved in relation to the earth.

I think the best way to approximate it would be to model it with a simulator that takes n-body systems into account like Orbiter and somehow make it record the distance travelled by the spacecraft relative to the earth.

Offline Bryanpoprobson

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Re: Distance Travelled by the Apollo Missions
« Reply #5 on: September 16, 2018, 12:07:07 PM »
I don't think that there is a straightforward answer for this. You can't simply use basic orbital mechanics to calculate it since we are dealing with a 3-body problem and therefore we don't have a strict Kepler orbit. Also in the vicinity of the moon they probably used the moon as reference for their orbital parameters which makes it even harder to know how the spacecraft actually moved in relation to the earth.

I think the best way to approximate it would be to model it with a simulator that takes n-body systems into account like Orbiter and somehow make it record the distance travelled by the spacecraft relative to the earth.

I’m of the same opinion, I was wondering if there is a possible way to use the orbit of the S-IVB to get a rough guide?
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline bknight

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Re: Distance Travelled by the Apollo Missions
« Reply #6 on: September 16, 2018, 12:49:19 PM »
I don't think that there is a straightforward answer for this. You can't simply use basic orbital mechanics to calculate it since we are dealing with a 3-body problem and therefore we don't have a strict Kepler orbit. Also in the vicinity of the moon they probably used the moon as reference for their orbital parameters which makes it even harder to know how the spacecraft actually moved in relation to the earth.

I think the best way to approximate it would be to model it with a simulator that takes n-body systems into account like Orbiter and somehow make it record the distance travelled by the spacecraft relative to the earth.

I’m of the same opinion, I was wondering if there is a possible way to use the orbit of the S-IVB to get a rough guide?

It might be useful, but remember on A-13-17 the S-IVB was decelerated by venting Oxygen/Hydrogen so that it would impact the Moon, so it would be a different trace than the CSM/LM.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Bryanpoprobson

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Re: Distance Travelled by the Apollo Missions
« Reply #7 on: September 16, 2018, 01:07:55 PM »

It might be useful, but remember on A-13-17 the S-IVB was decelerated by venting Oxygen/Hydrogen so that it would impact the Moon, so it would be a different trace than the CSM/LM.

The Apollo 11 data says the trajectory after passing from the lunar sphere of influence resulted in a solar orbit with an aphelion and perihelion of 82.000 million by 72.520 million n mi, an incli­ nation of 0.3836°, and a period of 342.00 days. But there are many variables.
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline bknight

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Re: Distance Travelled by the Apollo Missions
« Reply #8 on: September 16, 2018, 01:31:12 PM »

It might be useful, but remember on A-13-17 the S-IVB was decelerated by venting Oxygen/Hydrogen so that it would impact the Moon, so it would be a different trace than the CSM/LM.

The Apollo 11 data says the trajectory after passing from the lunar sphere of influence resulted in a solar orbit with an aphelion and perihelion of 82.000 million by 72.520 million n mi, an incli­ nation of 0.3836°, and a period of 342.00 days. But there are many variables.

That was true of A11, A12 since no seismometers had been placed.  When one was place during A12 then from that time on the S-IVB's were targeted to impact the Lunar landscape.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Bryanpoprobson

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Re: Distance Travelled by the Apollo Missions
« Reply #9 on: September 16, 2018, 01:46:49 PM »
It’s Apollo 11 that I am particularly interested in. 😎
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline bknight

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Re: Distance Travelled by the Apollo Missions
« Reply #10 on: September 16, 2018, 02:26:28 PM »
It’s Apollo 11 that I am particularly interested in. 😎


Ok, good luck in the simulation/calculation. :)
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline ajv

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Re: Distance Travelled by the Apollo Missions
« Reply #11 on: September 16, 2018, 11:06:17 PM »
Note that Obviousman's "PDF page 315" reference lists Apollo 11 having travelled 828743 nautical miles - the spacecraft "odometer" - presumably including the Earth and Lunar orbits.

Bob Braeunig did some 2-body (Earth and spacecraft) trajectory calculations for Apollo 11 i.e. based on the TLI and as if the Moon had not been there. They're not on his website anymore but they are on the WaybackMachine.

https://web.archive.org/web/20171124132216/http://www.braeunig.us:80/apollo/apollo11-TLI.htm

You might be able to pick up the translunar orbital elements he used if you want something to start with. But if nothing else the page shows how the spacecraft velocity changes during the transit.

Offline Willoughby

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Re: Distance Travelled by the Apollo Missions
« Reply #12 on: September 26, 2018, 12:46:21 PM »
I've run across this HBer before.  I think you have already done enough to show that his estimate of 10.5 hours is based on a flawed understanding of how orbital mechanics work.  I wouldn't exert much effort to take it any further than that when he/she likely doesn't have the capacity to understand what you are saying anyway - of course you are just wondering for your own personal knowledge.  You could have also reasoned that using his logic, you could throw a rock straight up in the air at 100 mph and expect it to reach 100 miles high in an hour. 

Offline bknight

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Re: Distance Travelled by the Apollo Missions
« Reply #13 on: September 26, 2018, 01:08:41 PM »
I've run across this HBer before.  I think you have already done enough to show that his estimate of 10.5 hours is based on a flawed understanding of how orbital mechanics work. a flawed understanding of how anything works. I wouldn't exert much effort to take it any further than that when he/she likely doesn't have the capacity to understand what you are saying anyway - of course you are just wondering for your own personal knowledge.  You could have also reasoned that using his logic, you could throw a rock straight up in the air at 100 mph and expect it to reach 100 miles high in an hour.

FTFY

I have also had the unpleasant discourse with taffy(et al) I was even banned by him in his YT channel.  Fulgor, bitter, disabled taxi driver that ha an axe to grind with Apollo, and yet doesn't know much about Apollo.  Thankfully the are others who produce videos debunking his BS.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan