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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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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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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Why does the ascent stage of Apollo 11's lunar module look like it's made of paper?

Here's an image (AS11-40-5922) from Apollo 11 that NASA describes as: View of the ascent stage from the northeast. Note the wrinkled surface of the RCS plume deflector and the warping of the rear ...
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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 ...
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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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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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How did they access the LM to mount the flag package while the Apollo stack was already on the launch pad?

NASA decided rather late to take a flag to the Moon on the Apollo 11 mission. In fact, they were so late that the package containing the flag was only attached to the leg of the LM on July 9th, two ...
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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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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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Why did Apollo 11 land at the sea of tranquility?

As we all know in 1969 Apollo 11 landing made history but, why did it land specifically at the sea of tranquility also known as Mare Tranquilitatis. Probably they would have chosen this because of ...
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Why didn't NASA simulate the conditions leading to the 1202 alarm during Apollo 11?

If I understand it, the alarm during the first Lunar descent was due to the computer being overloaded by too much RADAR data. That sounds like something that they would have thought to simulate, but ...
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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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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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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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Success-fail probabilities for Apollo XI?

Is it known whether probabilities of success vs failure (and specifically fatal failures) were estimated at the time for the Apollo XI mission? Or perhaps some current estimates?
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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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What are the “18 rescue missions” on Apollo 11, and which 10 of them did Michael Collins not feel comfortable with?

Regarding this tweet from the man himself. I take it to mean abort modes in some form or other for the entire mission? Perhaps just after LM descent? What are the 18 failure modes, and (if there's any ...
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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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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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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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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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How did LM circuit breakers operate? (famous engine arm CB broken by Aldrin)

From Apollo Lunar Surface Journal: "112:56:28 Aldrin: Houston, Tranquility. Do you have a way of showing the configuration of the engine arm circuit breaker? Over. (Pause) The reason I'm asking is ...
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was Saturn V engine J-2 throttleable?

Were the J-2 engines of the third stage of Saturn V throttable? I know that the F-1 for first was not, but what about J-2? I could not find any information about it. Any reference or info for this? ...
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What was the procedure to stop the descent engine on the Apollo 11 LEM?

What was the correct procedure to stop the descent engine on the Apollo 11 LEM? When the LEM had a contact light on Apollo 11, there was some terminology spoken that I'm assuming is important (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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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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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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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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apollo 11 moon landing longitude latitude from PDI to Touchdown

I'm reconstructing the entire apollo 11 mission trajectory. I'm now at the moon landing. Does someone know specific documents specifying longitudes and latitude at the different interfaces starting ...
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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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What was the nature of the communication problems during Apollo 11's Eagle's descent? How were other antennas selected?

In the video of Los Angeles station KTLA's Frank Buckley interviewing astronaut & Apollo 11 CAPCOM Charlie Duke a communication problem and antenna selection is described: BUCKLEY: Many of us who ...
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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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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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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 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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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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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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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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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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Why was Buzz Aldrin not Awarded the Congressional Space Medal of Honor? [closed]

According to the award's requirements, the Congressional Space Medal of Honor may be awarded to "any astronaut who, in the performance of his duties, has distinguished himself by exceptionally ...
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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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Astronauts of Apollo 11 facing extreme temperatures

I recently read that temperatures on the moon can vary from -100 °C in the shade to 100 °C in the sunny part. How did astronaut suits cope with these extreme temperatures? Is the same technology used ...
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What was back-up plan in case of Apollo CSM Primary Guidance System IMU went to gimbal lock?

In Apollo-11, during preparations for docking with Command and Service Module in lunar orbit, Armstrong and Aldrin managed to put Lunar Module Primary Guidance System Inertial Measurement Unit (IMU) ...
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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: ...
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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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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 were these bent clamps at the top of Apollo 11 CM used for?

An image of the top of Apollo 11 CM from heroicrelics dscc9638 and dscc9660. What were these bent clamps (marked with green arrows by me) used for?
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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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What happen to the Smithsonian Institutes 3d scan of the Apollo 11 Command Module?

"Since its landing on July 24th, 1969, the Columbia has been kept sealed in plexiglass at the Smithsonian Institute in Washington, DC. That is, until recently, when the software company Autodesk was ...
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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 ...