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Author
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Topic: Apollo 15 launch films (National Archives)
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LM-12
Member Posts: 4088
From: Ontario, Canada
Registered: Oct 2010
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posted 03-28-2025 08:49 AM
  
Here are some films of the Apollo 15 launch from the National Archives. Probably the best 16mm launch footage I have ever seen.
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Blackarrow
Member Posts: 3818
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-28-2025 12:46 PM
That slow-motion footage of the Saturn V lifting off is always impressive. I confess that as I watched the footage of the third stage moving sedately past the camera, I muttered, "That's a really rough paint-job on that SIVB!" Then a large piece of "paint" broke away and joined a small avalanche of ice falling past the camera. |
LM-12
Member Posts: 4088
From: Ontario, Canada
Registered: Oct 2010
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posted 03-28-2025 04:40 PM
I read years ago an estimate of how much all that ice weighed, but I don't remember the number. |
NukeGuy
Member Posts: 123
From: Irvine, CA USA
Registered: May 2014
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posted 03-29-2025 07:21 AM
From a 2012 post by mikej: For SA-506 just before launch — - S-IC - 1400 lbs
- S-II - 460 lbs
- S-IVB - 300 lbs
At holddown arm release: - S-IC - 650 lbs
- S-II - 450 lbs
- S-IVB - 200 lbs
I was about to ballpark numbers (for pre-ignition) based on LH2 and LOX boiloff rates, latent heat of vaporization of water, the thermal conductivity of ice and surface area of stages. I don’t know how I would have estimated mass at holddown arm release. His reference was a dead link so I don’t know how these numbers were obtained. |
Dietrich
Member Posts: 90
From:
Registered: Jul 2009
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posted 03-29-2025 07:22 AM
For Apollo 12/AS-507, the Flight Evaluation Report states following ice masses at launch (tables 17-1 to 17-9): - S-IC: 635 kg at launch, 340 kg at S-IC separation
- S-II: 204 kg at launch, 0 kg at S-II ignition
- S-IVB: 227 kg at launch, 136 kg at S-IVB both ignition
Total 1066 kg at launch, 590 kg lost at lift-off, remainder at stage separation. |
LM-12
Member Posts: 4088
From: Ontario, Canada
Registered: Oct 2010
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posted 03-29-2025 07:57 AM
Thanks for digging up all those numbers. Amazing.In the second film, a large tube-shaped piece of debris can be seen falling to the platform level. Both camera views captured it. |
NukeGuy
Member Posts: 123
From: Irvine, CA USA
Registered: May 2014
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posted 03-29-2025 10:41 AM
I’m guessing they got the ice numbers from static test measurements and adjusted them for changes in ambient temperature, relative humidity and perhaps insulation characteristics. |
Axman
Member Posts: 729
From: Derbyshire UK
Registered: Mar 2023
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posted 03-29-2025 11:11 AM
Whereas I'm guessing they got the numbers from straightforward extrapolation of time from cryogenic fuel input until launch.Insulation was minimal, they used instead the principle of vacuum insulation between two skins. Plus the fuelling was one of the last things before launch. The Saturn V didn't sit around fully fueled for days beforehand! Also, ice only formed on the liquid oxygen tanks. External air from the atmoshere condensing on liquid hydrogen tanks turns into liquid, not ice. And finally, the engineers didn't care how much ice accumulated. Mainly because the ice itself helped to insulate the fuel tanks, and secondly because the extra weight was inconsequential as it was shed at, or soon after, launch. |
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