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Questions tagged [apollo-11]

Apollo 11 landed the first humans, Neil Armstrong and Buzz Aldrin, on the surface of the Moon on July 20, 1969.

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Why was Apollo 11 launched in summer?

The question could seems stupid, but I think that best moment to launch a rocket is when temperature is lowest in order to achieve the best performance in a reaction engine. I do not know if there is ...
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Why did a phase mismatch between the Apollo 11 LM's RR and AGC generate a large numbers of interrupts?

A critical aspect of the cause of the famous 1202 and 1201 alarms reported by the Apollo Guidance Computer (AGC) during the decent of the Apollo 11 LM is that the rendezvous radar (RR) was using a "...
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Where in orbit was Michael Collins when the LM landed?

In the NPR podcast On Apollo 11 Anniversary, A Former Crew Member Reflects On The Lunar Trip Scott Simon interviews Michael Collins. Near the beginning is this exchange: SIMON: We asked the man who ...
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Did the 1202 error and associated reboot prevent disaster on Apollo 11 landing?

Most accounts of the famous 1202 error reported by the AGS during landing of the Apollo 11 LM characterize the event as result of the successful operation of the AGS, flushing an resetting an ...
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Help understanding this Apollo 11 docking probe image, what are we looking at, and from where?

The New York Times mix media "article" Apollo 11 As They Shot It shows original photographic images taken by the astronauts and related quotes by them. In one section the text says: Inspecting the ...
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What's the “thump” I hear listening to Apollo 11 playback?

I've been listening to live playback of the Apollo 11 mission at https://apolloinrealtime.org/11/ Besides the expected static and hums, from time-to-time I hear a "thump", sometimes one, sometimes ...
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How much could “sublimator operation” have possibly contributed to Apollo 11's “sizable downrange miss”?

This answer to the question Apollo-11 delta-v “due to residual pressure in the docking tunnel pushing the spacecraft apart” detected as it happened? Was it corrected? quotes from the Apollo 11 Mission ...
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What are “uncoupled attitude maneuvers” and why do them?

This answer to the question Apollo-11 delta-v “due to residual pressure in the docking tunnel pushing the spacecraft apart” detected as it happened? Was it corrected? quotes the following passage from ...
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Apollo-11 delta-v “due to residual pressure in the docking tunnel pushing the spacecraft apart” detected as it happened? Was it corrected?

This answer to How far off did Apollo 11 land? mentions that: Eagle was already 3 miles downrange from the expected position at the start of descent, due to residual pressure in the docking ...
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How far off did Apollo 11 land?

Armstrong wasn't able to land exactly in the designated landing location, as far as I know it was too rocky. So he had to fly a bit farther to find a suitable spot. But how much farther from the ...
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Why was the Apollo 11 in-flight video better than the moon landing video?

Using the incredible site: https://apolloinrealtime.org/11/ as it replays the entire mission in real-time. One great feature is that the site plays the in-flight TV transmissions that the crew made ...
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What were the problems on the Apollo 11 lunar module?

In the movie First Man we see that there were problems with some button, when Buzz said "We should tell them about that." Also there was an alarm, that they then turned off.
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What was the temperature of the Apollo 11 moon landing zone?

It's soon 50 years from the Apollo 11 moon landing, so in honor of that event, I decided to post a question here. I understand that moon has due to its long day and long night and also due to the ...
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Could the crash sites of the Apollo 11 and 16 LMs be seen by the LRO?

This BBC article mentions that the crash sites of the Apollo 11 and Apollo 16 Lunar Modules are unknown. The Lunar Reconnaissance Orbiter has mapped most of the moon’s surface at 100m resolution and ...
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What's the “big monstrosity” mentioned by the Apollo 11 crew?

Mission day three, sitting in lunar orbit, the LM docked to the CM, and this conversation happens: What are they talking about? "Little fluorescent circles"? "All the engineering that went into ...
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Luna 15 - Any official confirmation of objectives?

Russia's Luna 15 crashed into the lunar surface shortly after Apollo 11 landed. It's widely considered a failed sample return mission, but did Russia ever officially announce that sample return was ...
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Who filmed the Apollo 11 trans-lunar injection?

In the recent Apollo 11 documentary we're shown footage of the mission undertaking a 'trans-lunar injection' burn after having conducted two orbits of the Earth. Who was filming this sequence?
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How serious was the leaky hydrogen valve on the Apollo 11 mission?

The recent Apollo 11 documentary highlighted that the rocket suffered a 'hydrogen valve leak' in the hours prior to launch. Technicians were still trying to fix it even as the astronauts were boarding,...
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Did Apollo-11 astronauts rehearse their photoshoots on Earth?

After asking Have astronauts in space suits ever taken selfies? If so, how? I started to think about the photo below, and especially the cropped and rotated section that I found in the Wikipedia ...
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Why do the two Apollo 11 PSEP solar panels appear to have different backing materials?

The PSEP (Passive Seismic Experiment Package) was powered by a pair of solar panels mounted on extended arms. The one on the left (when looking towards the LEM) appears to have a matt grey backing: ...
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What did Apollo 11's SSTV signal sound like?

The TV signal from Apollo 11 had limited bandwidth, and an oddball format was used to send and convert the signal. All of the modern SSTV demos I've seen on YouTube seem to take around a minute to ...
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What is the meaning of “Bravo”?

There is movie called, " First Man (2018), which is about Apollo 11 mission. CAPCOM-APOLLO 11 speaks to Apollo 11 crew: CAPCOM-APOLLO 11: Apollo 11, now entering lunar orbit. Your roll should ...
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How soon after “The Eagle” landed did they first attempt to bounce a laser off the Moon? When did it first succeed?

The question When did Houston figure out where the Eagle had landed? says (in part): During Apollo 11's stay on the surface, Michael Collins was given seven different locations to look for the ...
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When did Houston figure out where the Eagle had landed?

Between starting the descent burn three seconds late, and having to avoid landing in a boulder field, the Apollo 11 descent module almost completely missed the target landing ellipse. During Apollo ...
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Who were the major manufacturers of the Apollo 11 rocket?

Organizing an exhibition around photographs from the 1969 launch and wanted to invite manufacturers.
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Looking for Apollo 11 powered descent video

At a science museum I visited on my 2018 fall vacation (I think it was the Chicago MSI), I saw a video loop that looked and sounded very much like part of the moon landing multimedia show at the ...
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Transfer of astronauts from CSM to LM

Did the astronauts "remove" the docking probe, the drogue of the LM, and related mechanisms from the CSM to enter the LM of Apollo 11?
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What was the colour of the shoes used by the Apollo astronauts in moon landing?

The pictures from Apollo landing despite being in high resolution, does not reveal the right colour of the shoes used by the astronauts during the EVA on the moon. An example - Buzz Aldrin picture ...
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Why did Neil Armstrong alone, not NASA, end up coming up with the first words uttered on the moon?

"That's one small step for a man, one giant leap for mankind" (Neil Armstrong) These words are now firmly established in the history of space travel, and at least according to his bio, was concocted ...
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Apollo moon landings - any contingencies for meeting Russians?

I have wondered for years if the Apollo moon missions, especially Apollo 11, had any contingency plans in case they met either aliens or other humans (presumably Russians) on the Moon. Granted that ...
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Did Michael Collins ask for a fourth gimbal for Christmas? Is there a recording or transcript?

Did Apollo 11 Command Module Pilot Michael Collins ask for a fourth gimbal for Christmas, while looking for the lunar ascent module? If so, is a recording of this available for posterity? Or a ...
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Why didn’t the Spacecraft used for the Apollo 11 mission melt in the Earth’s Atmosphere?

My brother has recently been converted to a Flat Earther and is convinced that something that proves his theory is the moon landings being faked by NASA. I have managed to counter argue the majority ...
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Apollo-11 AGC core memory has 5 wires per core (rather than 3 or 4) - why?

Apollo-11 AGC core memory has 5 wires per core (rather than 3 or 4) - why? I am referring to this image in Wikipedia: https://en.wikipedia.org/wiki/Apollo_Guidance_Computer#/media/File:...
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How were the Flight Journals of the Apollo missions originally transcribed/recorded?

I've been reading throught the Apollo 11 Flight Journals and was wondering how they were originally recorded and transcribed. It seems that they were painstakingly accurate down to the last second ...
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Apollo 11 mission report shows velocity well below escape velocity thousands of km on the way to the Moon

This is from the Apollo 11 mission report. It says the vehicle was going at 7.6 km/s when the CSM separated from the third stage. It was not in orbit at this point, it was thousands of KM from earth. ...
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Apollo 11 ascent data/observation mismatch

I'm researching the Apollo 11 ascent to orbit and found an article showing a mismatch between the observation and the Boeing data The launch video shows the rocket punching through what appears to be ...
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Who was the first person to touch the moon rocks?

This might be a stupid question, but I can't find and don't know the answer: Everyone knows that Neil Armstrong and Edwin "Buzz" Aldrin were the first men to land on/ walk on the moon. But were they ...
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Would Luna 15 have been visible to any of the members of the Apollo 11 crew?

According to Wikipedia, Luna 15 crashed a few hours before Eagle lifted off from the moon, and since it crashed North-east of the landing site, it must have overflown them. Would any of the crew have ...
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How did NASA choose who descended in the LEM during the Apollo missions?

Referring to the Apollo missions, As many know, during Apollo 11, Michael Collins didn't descend with Neil Armstrong and Buzz Aldrin towards the moon. I can only begin to imagine the sadness of not ...
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Length of shadows apollo 11

Apollo 11 Landing: 102.75 GET EVA Start: 109.00 GET, 14.0 deg. Finis: 111.75 GET, 15.4 deg. According to NASAs website the sun angles during apollo 11 mission is the ones stated above. At 15 deg ...
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Provenance of the Apollo 11 landing presented in a NASA PR film

"The Eagle Has Landed: The Flight of Apollo 11" is the title of an 18 minute NASA public relations film from 1969, available through the National Archives Catalog. One section shows the view from the ...
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If the astronauts on Apollo 11 had landed safely on the moon but could not take off, would there have been a rescue mission?

Say they landed on the moon but discovered the ship was damaged during the landing and they could not launch again. What would have been the plan? Would another crew have been sent to rescue them? ...
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Any potential downside to throwing personal life support out the door on the Moon?

I found this really interesting description of the ALSEP instrumentation placed on the moon during the Apollo 11 landing, written by Hamish Lindsay, (also, author of Tracking Apollo to the Moon). One ...
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What were the chances of failing the Apollo 11 mission? [duplicate]

What were the chances of the Apollo 11 mission failing? Consider the following scenarios: least one of the crewmembers dying, failing to land on the Moon, unable to return to Earth, the Soviets ...
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Apollo guidance

I am studying the Apollo Guidance, specifically the derivation of guidance equation. While laying the baseline, a Target-referenced time (T) is chosen as time variable for guidance calculation of the ...
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What's the story behind this Apollo-era image?

This photo has been bothering me for quite a while, so I decided to look into it further. It is shown in Wikipedia's Opposition Surge article, which is a fascinating topic that I'd like to avoid here ...
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Details of Apollo 11 video transmission [duplicate]

NASA has the video of Neil Armstrong on the moon. I'm interesting in the technology how the signal was created and transmitted. There are some details about it in Wikipedia but I'd like to know in-...
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What is the scientific reason for selecting July 20 1969 for the moon landing?

There might be no reason but I doubt the date had simply no reason. I believe there may have been personal significance to Neil Armstrong. Alternatively picking a summer date may have been safer.
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The speed of Apollo 11 at first stage separation was apparently only about 40% of what NASA claims? What does this indicate?

The second stage of Apollo 11 generated a greater than 20 deg shock-wave half angle which corresponds to less than $1000 \frac{m}{s}$ forward speed not 6000 mph ($2682.24 \frac{m}{s}$)? I measured ...
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How did the Apollo 11's Eagle ascent stage find the CSM after leaving the Moon?

I've always been curious how did the Apollo 11's Eagle ascent stage of the Apollo Lunar Module navigate back to the Apollo Command/Service Module (CSM) that was in lunar orbit? Was it simply a case ...