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Author
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Topic: Apollo 13 lunar drill design evolution
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Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-04-2021 06:08 PM
  
It is well known that a design flaw in the lunar drill on Apollo 15 made inserting the heat-flow equipment very difficult, and made extraction of the deep core a real problem.I note that the description of the lunar drill and heat flow experiment in the Apollo 13 press kit is in identical terms to the description of the equipment in the Apollo 15 press kit. It has often occurred to me that if Apollo 13 had been successful, Fred Haise would have uncovered the design flaw in the drilling assembly, thus allowing it to be fixed for Apollo 15. It's a bit of a stretch, but redesigning the lunar drill might have led someone to ask: "Are those cables attaching the heat-flow sensors to the central station strong enough to withstand an astronaut tripping over them and detaching them? That would have spared John Young's blushes on Apollo 16. But were the drilling assemblies on Apollo 13 and Apollo 15 identical? Were any modifications made between the missions? |
Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-08-2021 11:59 AM
I'm a little surprised no-one has tackled this. Let me turn the question around: My assumption is that the drilling assemblies on Apollo 13 and Apollo 15 were identical, as evidenced by the identical wording in the missions' press kits. Does anyone know of any information to contradict or modify that assumption? |
Robert Pearlman
Editor Posts: 46233
From: Houston, TX
Registered: Nov 1999
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posted 05-08-2021 12:56 PM
I don't know if this helps, but comparing the part numbers for the drills on Apollo 13 and Apollo 15 as listed in their respective stowage lists, they are similar but not identical: - Apollo 13: 467A806000-069
- Apollo 15: 467A8060000-099
Does the addition of a zero indicate a design change? I don't know. |
NavyPilot
Member Posts: 55
From:
Registered: Nov 2015
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posted 05-08-2021 05:02 PM
As a lifetime serviceman and government engineer, I wouldn't underestimate the propensity for typos in typewritten docs, especially ones with long, droning part numbers throughout. Just sayin'.Having offered that, the different dash number indicates a configuration roll of the same basic part. |
Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-09-2021 12:23 PM
Thank you both for your input. Robert: what was the source of your information? Navy pilot: I fully concur!It seems to me that if you design a system and clear it for use on the Moon, you probably wouldn't feel the need to change the design just because your experiment unfortunately ends up as charred fragments on the bed of the Pacific Ocean. |
Robert Pearlman
Editor Posts: 46233
From: Houston, TX
Registered: Nov 1999
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posted 05-09-2021 12:41 PM
As mentioned, the stowage lists for Apollo 13 and Apollo 15. |
oly
Member Posts: 1214
From: Perth, Western Australia
Registered: Apr 2015
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posted 05-10-2021 12:41 AM
The November 1968 Apollo Lunar Surface Surface Drill (ALSD) Final Report states that three flight specification drills were manufactured, while Table II-1 identifies component part numbers that appear to have been superseded by the time the missions launched.The change of part number on the flight list may also reflect a change to the accessories associated with the drill. While the Familiarization and Support Manual for Apollo Lunar Surface Drill, table VII-4, ALSD Assembly Deployment Verification, indicates that the number after the dash is allocated at deployment. |
Andy Anderson
Member Posts: 99
From: Perth, Australia
Registered: Dec 2009
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posted 05-10-2021 02:53 AM
Some info on the ALSD is here in the Apollo Program Summary Report pages 3-33 to 3-35.Not really much to see but this a closeout image of the ALSD on Apollo 13.  |
Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-10-2021 06:23 PM
Thanks, all - plenty to drill down into. |
oly
Member Posts: 1214
From: Perth, Western Australia
Registered: Apr 2015
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posted 05-10-2021 09:26 PM
quote:
Originally posted by Blackarrow:
Fred Haise would have uncovered the design flaw...
From what I can figure out with the available information, the "design flaw" was that the drill extension tubes were constructed from fiberglass and Boron fiber, with spiral grooved flutes designed to extract the cut material from the drill hole. The groove flutes stopped near the end of the tubes, providing an area that the cut material could stockpile and jam the tube in the hole bore.The fix for this for subsequent missions was to the joint of the bore stems was changed from Boron/fiberglass tapered joint and was replaced with threaded titanium inserts, which provided continuous flutes that cleared the cut material from the drill hole bore. The stems were also increased in length to reduce the number of joints. I can't find any information about changes to the drill design between Apollo 13 and Apollo 15. I am curious about the design of the drill and would like to find more information about its design, construction, and effectiveness. I remember seeing a video of the drill in use during training and was impressed by how fast the thing could cut through rock. |
Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-11-2021 04:13 PM
That's certainly my understanding of the issue. If Lovell and Haise had been able to land at Frau Mauro, the design flaw (as you have set out) would surely have become apparent to Fred Haise. The correction would have allowed Dave Scott to drill much more easily at Hadley-Apennine, possibly allowing enough time for a visit to North Complex on EVA-3.You make a good point about the drill operating well in a training video, presumably without the problem of cut material jamming the tube. Two reasons why it seemed to work on Earth occur to me: either the rock-type makes all the difference (in which case the drill might actually have worked perfectly at Fra Mauro??) or the key issue is an astronaut on the Moon having only one-sixth of the weight of an Earth-bound astronaut with which to press down on the drill. Or perhaps a combination of those two issues?
As for effectiveness, the re-designed drill assembly seems to have worked very well on Apollos 16 and 17 (if we overlook John Young's unfortunate misstep). One other point which always puzzled me: - Apollo 13: LMP
- Apollo 15: CDR
- Apollo 16: LMP
- Apollo 17: CDR
It seems odd that there was no consistency in whether the drill would be operated by the commander or by the lunar module pilot. |
oly
Member Posts: 1214
From: Perth, Western Australia
Registered: Apr 2015
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posted 05-12-2021 07:39 AM
The crewmember tasked with using the Apollo lunar surface drill was probably the person who demonstrated the best handling technique during training. Using power hand tools is not something every crew member would have been familiar with before their training. Perhaps it was the crew member with the greatest mass, lowest center of gravity, or ability to control the drill and stand on the treadle at the same time.Some crew may have exhibited better control of the drill and may have displayed better hand skills when working with the drill stems, treadle, and jack. As for the effectiveness of the drill, the Working on the Moon website covers the drill tasks in detail, including specific tasks and voice transcripts. |
Blackarrow
Member Posts: 3298
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 05-12-2021 09:21 AM
Yes, I also came upon the "Working on the Moon" site, which seems to clarify most of the issues. For instance, it does seem from the post-Apollo 15 tests that the "design-flaw" might not have come to light on a successful Apollo 13 if the subsurface material was fairly loose, since the displaced particles rising up the discontinuous helical grooves would simply have been forced into the surrounding loose "soil." Only if the surrounding material was very dense would it have found no place to go (as happened on Apollo 15) resulting in downward progress literally grinding to a halt.I also note with interest the discussion about the difficulty of "applying weight" to the drill on a world where the astronaut is only one-sixth of his Earth-weight. I think the bottom line is that if Fred Haise had had a chance to operate the drill at Fra Mauro, the problem with the drill stems would probably, but not necessarily, have come to light. |
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