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.

Filter by
Sorted by
Tagged with
19
votes
2answers
3k views

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 ...
-7
votes
3answers
212 views

Lot 345 of Christie's “Voyage To Another World” auction supposedly has the only photo of Armstrong on the Moon, but isn't this one also?

Christie's press release Christie's Voyage to Another World: The Victor Martrin-Malburet Photograph Collection includes the following: Lot 345, The only photograph of Neil Armstrong on the Moon, July ...
5
votes
1answer
677 views

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 ...
12
votes
2answers
2k views

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 ...
1
vote
1answer
88 views

How was a safe tilt angle ensured for liftoff of the Apollo LM?

Recently I read that one of the pre-conditions (among many others) of a successful lift off of the LM ascend stage, from the moon surface, was that the LM ascend stage "axis" should be "...
5
votes
1answer
286 views

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?
5
votes
1answer
618 views

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: ...
2
votes
1answer
112 views

What is the constant g-phase in Apollo re-entry, and why does it not show up on the graph?

On the Apollo 11 Flight Journal Day 9: Re-entry and Splashdown, it says something about the "Constant g-phase". This is what the ALSJ says: Planned drag level (deceleration) during the ...
5
votes
1answer
113 views

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?
7
votes
1answer
138 views

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 ...
4
votes
1answer
98 views

Apollo 11 first stage separation

Did Apollo 11 climb vertically upwards i.e. radially outwards, or "normal" to earth surface till it separated its first stage (approximately 38 Miles/60 Km or so..), or did it tilt at or ...
-2
votes
4answers
214 views

Computers for Apollo Mission

Why did NASA invest so much amount of time and money on developing computers for Apollo Missions? Wouldn't the Man on Moon mission have been far easier and faster if the Astronauts drove the ...
21
votes
2answers
4k views

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 ...
108
votes
8answers
27k views

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? ...
27
votes
1answer
1k views

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 ...
5
votes
1answer
90 views

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 ...
19
votes
5answers
4k views

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 ...
1
vote
0answers
39 views

Was there any effort made to have Apollo 11 land on July 4? [duplicate]

President Kennedy set a goal of landing a manned mission on the moon by the end of the 1960s, as stated in his well-known speech to Congress on 25 May 1961 ("I believe that this nation should commit ...
7
votes
2answers
438 views

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 ...
9
votes
1answer
5k views

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 ...
1
vote
0answers
35 views

Apollo 11 Moon orbital elements [duplicate]

I'm simulating several pieces of the Apollo 11 mission. I'm now at the point of performing lunar landing sequence, and I'm looking for data. I found this report, but it only has partial data, while ...
9
votes
1answer
702 views

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? ...
7
votes
1answer
234 views

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 ...
4
votes
0answers
106 views

Apollo 11 trajectory logs [duplicate]

is there any place where to download the log files of the entire Apollo 11 mission? I want to rebuild it in Matlab and I'd use it as reference. I've seen that there is AGI's reconstruition with STK, ...
4
votes
1answer
2k views

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. ...
3
votes
1answer
1k views

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 ...
5
votes
1answer
242 views

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) ...
2
votes
1answer
178 views

What do these Apollo era terms mean?

@Ludo's answer to If I wanted to reconstruct an entire Apollo mission's crewed spacecraft trajectories, what are the key sources of historical data I'd look for? links to Apollo Mission 11, ...
10
votes
2answers
957 views

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 ...
5
votes
2answers
278 views

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 ...
35
votes
1answer
12k views

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 ...
5
votes
1answer
173 views

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 "...
12
votes
2answers
3k views

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 ...
21
votes
2answers
4k views

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 ...
7
votes
1answer
212 views

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 ...
4
votes
1answer
117 views

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 ...
1
vote
0answers
60 views

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 ...
8
votes
1answer
369 views

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 ...
7
votes
1answer
215 views

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 ...
27
votes
5answers
5k views

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.
8
votes
2answers
8k views

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 ...
11
votes
2answers
3k views

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 ...
9
votes
1answer
260 views

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 ...
6
votes
3answers
873 views

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 ...
4
votes
2answers
228 views

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 ...
19
votes
1answer
2k views

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?
3
votes
1answer
970 views

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,...
2
votes
0answers
111 views

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: ...
3
votes
2answers
334 views

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:...
2
votes
0answers
250 views

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 ...