Topic: Apollo landings, from PDI to touchdown (videos)
Robert Pearlman Editor
Posts: 51864 From: Houston, TX Registered: Nov 1999
posted 07-04-2015 10:06 AM
Apollo Lunar Surface Journal video release
Apollo 14 landing from PDI to Touchdown
An annotated portrayal of the Apollo 14 landing on the moon with captions to explain the various stages of the descent.
David Woods notes:
Covering the 12 minutes from PDI to touchdown, this video has the 16-mm film that was shot from Ed Mitchell's window synchronised with the mission audio. It is fully subtitled and commented and has a brief explanation of the short circuit problem that had to be worked around by the mission control team and the crew.
gliderpilotuk Member
Posts: 3415 From: London, UK Registered: Feb 2002
posted 07-04-2015 10:17 AM
Great work!
David Carey Member
Posts: 1013 From: Registered: Mar 2009
posted 07-04-2015 11:11 AM
Superb. Gave me sweaty palms!
GACspaceguy Member
Posts: 3019 From: Guyton, GA Registered: Jan 2006
posted 07-04-2015 02:16 PM
After all the info I have read and heard on LM landings, this was the closest to being there I have ever felt.
Blackarrow Member
Posts: 3684 From: Belfast, United Kingdom Registered: Feb 2002
posted 07-04-2015 04:36 PM
Excellent work, greatly helped by the quality of the original 16mm footage, arguably the best quality of any of the six landing sequences.
Posts: 1260 From: Brandon, Fl Registered: May 2012
posted 07-04-2015 07:34 PM
Beautiful!
calcheyup Member
Posts: 125 From: Registered: May 2014
posted 07-05-2015 04:48 PM
Awesome. Thank you for sharing this.
mode1charlie Member
Posts: 1440 From: Honolulu, HI Registered: Sep 2010
posted 07-05-2015 05:19 PM
Excellent as always!
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 07-08-2015 03:55 PM
David, that was excellent. Thank you!!!
Having this webpage open while watching the landing video made it easy to see what the astronauts were seeing and get a feel for the 'lay of the land' with the ground track basically from right to left in the picture (turn on tabs for nomenclature and hardware).
Jeff Member
Posts: 603 From: Fayetteville, NC. USA Registered: May 2009
posted 07-08-2015 04:22 PM
David, great job, thanks for making this available.
Robert Pearlman Editor
Posts: 51864 From: Houston, TX Registered: Nov 1999
posted 07-08-2015 04:32 PM
As some may already know, the Apollo 14 video above is the latest in David Woods' series of mission videos presenting a similar look at PDI to landing.
As ever, I'm keen to hear feedback on it; errors, typos or just a commentary on the style, content or layout (though by now, I've pretty much settled down on a format).
calcheyup Member
Posts: 125 From: Registered: May 2014
posted 07-09-2015 10:14 PM
I was very surprised to see no explanation of Bean's comment of "Hey, you're really maneuvering around," when Conrad realizes that the LPD adjustments he's made are actually taking him away from where he wants to be, and takes matters into his own hands. To me, that's probably the most interesting part of their descent, and yet it was not even mentioned. For someone who is unfamiliar with the 12 landing, they would probably not even understand why Bean is saying that.
I don't mean to be critical, but I think as long as explanations are being put into the videos for what the astronauts are saying, it would make the video even better to have information regarding that in there.
Headshot Member
Posts: 1282 From: Vancouver, WA, USA Registered: Feb 2012
posted 07-10-2015 06:43 AM
I always thought that Bean's maneuver comment refers to the dogleg to the left that Conrad made just after Intrepid flew passed Surveyor and began heading away from it.
110:30:58 Bean: You got 11 percent. Got loads of gas. 300 feet (altitude), coming down at 5 (feet per second).
110:31:05 Conrad: Gosh, I went by it.
[Fjeld - "We all know what happened on Apollo 11. Slosh uncovered the Quantity Gauge, latching the (Quantity) light early, losing the crew half a minute of flight time. It also made the LPD unreliable. Apollo 12 flew with the same configuration and its Quantity light came on early, exactly the same way! Worse, Pete actually used the LPD to redesignate his landing, but he maneuvered away from his target because the slosh was messing up his view through the grid. He popped out of P64 and tried to slam on the brakes but it was too late ("Gosh! I went by it!"), so he had to make his heroic flight around the crater, scaring Al a bit. He would have been better off never using the LPD, letting the flight path settle out, switching to manual just before the crater, and landing uprange and north of the crater!"]
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 07-10-2015 08:22 PM
So are you saying that Intrepid was supposed to have landed east of Surveyor 3 and that Conrad overflew it? Where was Pete's Parking Lot with respect to Surveyor 3/Surveyor crater? I always thought it was a bit further west than where Intrepid actually landed so as to assure that Intrepid's engine didnt disturb Surveyor 3.
calcheyup Member
Posts: 125 From: Registered: May 2014
posted 07-10-2015 08:46 PM
It's covered in the link, if you begin reading the posted link from the time they enter P64 (110:29:10).
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 07-10-2015 09:08 PM
110:31:05 Conrad: Gosh, I went by it.
I've played David's video several times and I don't think I hear that. It would be at around 12:07. David does not caption it.
Headshot Member
Posts: 1282 From: Vancouver, WA, USA Registered: Feb 2012
posted 07-11-2015 11:59 AM
I have checked out the preliminary version of David's annotated Apollo 15 video and it is great.
Has anyone ever performed, or seen a simulation of what Scott and/or Irwin might have witnessed had they been able to look directly left or right while flying through the Apennines during the descent? It must have been a awesome sight.
Robert Pearlman Editor
Posts: 51864 From: Houston, TX Registered: Nov 1999
posted 08-05-2015 12:10 PM
Here is the final version of the Apollo 15 landing:
And here is Apollo 16:
Kite Member
Posts: 1116 From: Northampton UK Registered: Nov 2009
posted 08-06-2015 03:33 PM
These are amazing. I missed the first posts as been on holiday but been catching up. Interesting noting the differences in the personalities of the astronauts. Armstrong, Aldrin, Young, Scott, Irwin and Mitchell very calm, Conrad, Bean, Shepard, and in particular Duke exuberant. Looking forward to Apollo 17.
Robert Pearlman Editor
Posts: 51864 From: Houston, TX Registered: Nov 1999
posted 12-03-2015 07:10 AM
David Wood has uploaded the last in his series of Apollo landing videos, this one for Apollo 17.
...and it is just in time for the flight's 43rd anniversary.
This video covers the entire powered descent of LM Challenger from just before PDI to just after touchdown in the valley of Taurus-Littrow. It includes the 16-mm movie camera footage synchronised with the air/ground audio. The astronauts' speech is subtitled and there are comments throughout to help explain what is going on, moment by moment.
wdw Member
Posts: 59 From: Scotland Registered: May 2007
posted 12-05-2015 05:09 PM
I was only directed to this page today for the first time. First off, can I thank everyone for the very positive comments about these videos. It has been great fun to make them.
quote:Originally posted by calcheyup: I don't mean to be critical, but I think as long as explanations are being put into the videos for what the astronauts are saying, it would make the video even better to have information regarding that in there.
I think you are absolutely right.
Let me give you some background. The videos for 11 and 12 were done early on in this project and I was still feeling my way into them. As a video editor in the broadcast industry (BBC), I'm wary of packing in too much information and at this point, with Pete and Al yakking so much, I may have wanted to limit the amount of detail.
However, YouTube is not television. I've learned that its content can be richer, especially for specialist topics like this because those who are interested are likely to repeatedly watch a piece and soak up its richness. Given that there is plenty of room when Bean says "Hey, you're really maneuvering around," I think there is scope to try and at least give a very potted version of what's going on.
From Apollo 14 onwards, I set a revised style with music, narration and specific colours for the participants. I want to revisit the videos for 11 and 12 and that would be a good time to address calcheyup's concerns.
quote:Originally posted by Paul78zephyr: I've played David's video several times and I don't think I hear that. It would be at around 12:07.
It is in the video at 12:08 (10:22 since PDI).
I hope you all enjoy the new Apollo 17 video.
calcheyup Member
Posts: 125 From: Registered: May 2014
posted 12-07-2015 03:01 PM
Thanks for replying in this thread, David, and thank you for your efforts on these videos. They are a fantastic resource.
Revisiting the Apollo 12 landing discussion, the Lunar Surface Journal links to a nice chart detailing the LPD adjustments Conrad made, where it took him, and his final adjustments in P66 through to landing.
Kite Member
Posts: 1116 From: Northampton UK Registered: Nov 2009
posted 12-12-2015 09:44 AM
Thank you David. It was well worth waiting for. Both Cernan and Schmitt seemed quite excited and who can blame them. I never tire of listening to all of the landings. It brings back those memorable times again which I am so lucky and proud to remember.
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 02-22-2016 12:56 PM
In the Apollo 12 landing audio/video (above) at about 13:32 to 13:35 it appears that Bean says "18 feet, coming down at 2. He's got it made! Come on in there. 24 feet." And then he says "Contact light."
Why did Bean say "18 feet" (altitude) and then "24" [feet altitude] after that?
David C Member
Posts: 1424 From: Lausanne Registered: Apr 2012
posted 02-22-2016 05:03 PM
He may have just mis-spoken but my money is on a Landing Radar spike. The "18 feet" call corresponds nicely with a 2fps descent rate, the subsequent "24 feet" call seems spurious. The Apollo 12 Mission Report states in 8.4:
Three abnormally high data points appeared Just prior to touchdown. At altitudes below 50 feet, the range and velocity trackers are operating on highly attenuated signals resulting from the high discrimination of the receiver audio amplifiers to the low frequency signals at these trajectory conditions. Since the trackers are approaching signal dropout, the velocity trackers are particularly vulnerable to locking up on moving dust and debris generated by exhaust plume impingement on the lunar surface. Also, under these conditions, the range tracker is vulnerable to locking up at higher frequencies because of terrain features appearing in the range-beam side lobes.
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 07-05-2016 12:25 PM
I can never listen to these enough and each time I find something new.
For the Apollo 16 at about 3:15, MCC/'Jim' is Jim Irwin (capcom)?
For the Apollo 17 at about 2:19, they discuss that the Descent Quantity Light was on (came on).
I know this is discussed with MCC after landing and MCC says they "will have a story on that quantity light for you later." I know it was a "false" warning but was that ever discussed with the crew and was the reason for the failure ever determined?
YankeeClipper Member
Posts: 635 From: Dublin, Ireland Registered: Mar 2011
posted 07-05-2016 06:19 PM
quote:Originally posted by calcheyup: I was very surprised to see no explanation of Bean's comment of "Hey, you're really maneuvering around."
The detailed explanation for that comment is at 110:34:08 of the ALSJ - Apollo 12:
[During training, Pete and the other commanders flew the Lunar Landing Training Vehicle, or LLTV - and a similar, predecessor called the Lunar Landing Reserach Vehicle or LLRV - and, of course, 'flew' numerous landing simulations in immobile simulators on the ground. The LLRV/LLTV - or The Flying Bedstead, as it was sometimes called - was built for NASA by Bell Aerosystems, Buffalo, NY and consisted of an open frame that supported a large, down-pointing jet engine that removed 5/6th of the effective vehicle weight and allowed the pilot then to use the equivalent of the Descent engine and RCS thrusters to practice landings. The accompanying photo shows Pete flying the LLTV.]
[I asked Pete about the value of this training.]
[Conrad - "I think everybody agreed that the LLTV was very essential to a successful landing. One of the problems which we were talking about earlier at lunch is that you have to realize that the visual on the simulator was very bad. We had a plaster-of-paris lunar surface (called the L&A) and a B&W television camera (that flew to it). So you're looking at a flat, no-depth boob tube - a television - in the window. So, the last five hundred feet, if you were watching that out the window in the simulator, it wasn't any good. It just didn't really resemble the real world."]
[Bean - "It was a virtual image something or other. Which was a flat TV with some optics that..."]
[Conrad - "Tried to give it depth..."]
[Bean - "But it didn't."]
[Conrad - "It was the best they had at the time. We didn't have a moving-base simulator, either. (In more recent times, Shuttle crews have been able to train in simulators that move in response to crew inputs and, thereby, give much more realistic simulations.) So, the LLTV was critical, to get a real feel. And the reason Al made the comment about maneuvering at 110:31:06 is that the LMPs didn't fly the LLTV."]
[NASA built two LLRVs and three LLTVs. Three of these five vehicles were lost in accidents. Because of the jet engine, the LLTV was actually a less stable vehicle than the LM and, therefore, was harder to fly. For this and other reasons, it was decided that only people who absolutely needed the experience - mission commanders and their backups - would fly the LLTV. None of the LMPs ever flew one.]
[Conrad - "Al hadn't flown one, and that's why he made the remark (110:31:06) when I started really maneuvering the thing around. Because you had big attitude changes up there, because you're in a low gravity field. He had seen that kind of a maneuver, probably, inside the simulator. But that virtual image display and the fixed base didn't really give you any feel for it. So, the first time Al really experienced that was at the Moon. And I just passed it off 'Yeah, I'm busy doing what I was doing.'!"]
[Bean - "We were all flying helicopters and you didn't maneuver a helicopter any where near like that. Up there, you really had to move the LM to maneuver it. So Pete got used to it and I was thinking helicopter kind of stuff. So, when you (Pete) suddenly maneuvered much more than a helicopter, it caught me by surprise. But to you, well, that's the way you do it. I think it's because, on Earth, you're supporting the weight with a certain amount of thrust. So, let's say you've got to knock off ten foot per second forward. You pitch up (means tilt the LM back and, therefore, the direction of thrust up) to a certain angle to do that and you get used to that kind of maneuver. You go on to the Moon; you've got one sixth the thrust to hold this same mass up and ten feet per second forward with that mass is the same as it was on Earth. But, in order to stop it (meaning slow it down by ten feet per second) with one-sixth the thrust, you're going to have to pitch up (means tilt the LM back) a lot harder. So I think it's just strictly the fact that you're operating with less thrust than a helicopter for the same weight and the same momentum. So, in order to use it, you've got to get that thrust vector up higher faster or you're just never going to slow down the translations - or get one going and then stop it. When you think about it, it makes sense. But, at the time, it just seemed like 'God, what's he doing?' It felt to me like you were pitched too far (back), you know. And you probably were doing quite a bit because you've got to get it (pitched) up there to get the little ol' thrust vector to work."]
[Conrad - "That's right, you have to move it more to get the maneuver. So it looks really bad to you, although nothing serious is happening."]
[Bean - "It looked normal to you!"]
[Conrad, from the 1969 Technical Debrief - "I think the manual control of the LM was excellent. The LLTV is an excellent training vehicle for the final phases. I think it's almost essential. I feel it really gave me the confidence that I needed. I think the (immobile) simulator did an excellent job in manual control and LPD training all the way down to the last couple of hundred feet. I think both devices worked very well together."]
Paul78zephyr Member
Posts: 806 From: Hudson, MA Registered: Jul 2005
posted 07-29-2016 03:55 PM
Why is there a — seemingly — much smaller change in pitch angle at pitchover (P64) during the Apollo 11 landing (at about 10:10 in that video) than for the other landings?
YankeeClipper Member
Posts: 635 From: Dublin, Ireland Registered: Mar 2011
posted 02-21-2017 10:25 PM
Pete Conrad made an interesting observation regarding the difficulty of landing Intrepid, on page 33 of LIFE Magazine, December 19, 1969:
I suppose I did only a minute and a half's worth of real flying in that baby of mine, but during those 90 seconds I needed everything I had learned in 20 years of piloting.
Robert Pearlman Editor
Posts: 51864 From: Houston, TX Registered: Nov 1999
posted 02-14-2024 03:23 PM
Seven years later, an update from David Woods:
On the 50th anniversary of Apollo 11, I published a film showing its descent and landing on the moon in great detail. This video has achieved 2.5 million views.
This is the sequel - the descent and landing of Apollo 12 in November 1969.