Questions tagged [apollo-program]

NASA's Apollo program was a 17-mission program that focused on landing a human on the lunar surface. The program was the third human spaceflight by NASA, after Mercury and Gemini.

Filter by
Sorted by
Tagged with
8 votes
1 answer
688 views

On the LM, what is the difference between ABORT and ABORT STAGE?

The LM had both ABORT and ABORT STAGE buttons. What was the difference and in which scenario would each be used?
  • 81
-6 votes
1 answer
141 views

did the Apollo ascent module have a rocket motor?

I was watching this video of an Apollo ascent module taking off (captured by a lunar rover credit: NASA) and there is no evidence of a rocket motor not even a glint of light that would signal rocket ...
8 votes
1 answer
265 views

Which is more accurate, a Saturn V IU or an iPhone?

In a comment, I mentioned that a modern cell phone could do almost everything the Saturn V instrument unit could do. How true is that? In particular, which would provide more accurate data for an ...
  • 11.8k
4 votes
1 answer
92 views

Which Saturn IB flights did or did not have hinged SLA panels?

Up until now, I had thought that petal fairings on all Saturn flights had been removed after an incomplete deployment on Apollo 7. But there's a picture of the Skylab 3 mission of the expended S-IVB ...
  • 91
7 votes
1 answer
229 views

What is this beige, pill shaped object on the back of the Apollo Lunar Module?

Is it an antenna, or something else? Image from https://upload.wikimedia.org/wikipedia/commons/0/04/Apollo_11_Lunar_Lander_-_5927_NASA.jpg
  • 71
3 votes
2 answers
231 views

Media coverage of Artemis vs Apollo

I remember the launch of Apollo 7 - the first crewed flight of the Apollo spacecraft. I was in grade school; we all gathered in the gym/auditorium to watch it on live TV. I was about 9 in 1967, and ...
  • 17.2k
7 votes
1 answer
287 views

In Apollo hardware, why were sump tanks needed?

I'm looking at the Apollo CSM Propulsion Systems. These were bi-propellant hypergolic systems. However, for some reason each type of propellant was divided into a storage and sump tank. For example, ...
  • 4,456
3 votes
1 answer
165 views

When was Apollo 11 scheduled for July 1969?

I recently read on Wikipedia about Apollo 8's interesting schedule history. Basically, a lunar orbital mission was supposed to be an F mission for 1969, with the LEM tested in lunar orbit. But they ...
  • 4,456
14 votes
0 answers
196 views

Does the post Apollo 13 roast mixtape still exist?

The debriefing party at the Hofbraugarten was merciless, beginning with a parody of the mission. The tape prepared by the Apollo 13 backup crew and the CapComs was not for the thin-skinned. The parody ...
2 votes
2 answers
176 views

Could dust kicked up from the Apollo landings reach Earth intact?

According to various sources (1,2, and 3) lunar landings kick up a lot of dust at very high speeds. Is it possible that some dust was able to get fast enough to escape the moon, fall towards Earth, ...
1 vote
0 answers
69 views

Design & selection of Saturn V for Apollo mission [duplicate]

While the Saturn project evolved out of von Braun's efforts to develop more and more powerful rockets to launch heavier payloads into space for the military, Saturn V, it seems was specifically ...
  • 3,598
4 votes
0 answers
147 views

Was Apollo 8 lunar orbit entry speed intentional at 7,777 ft/s?

When Apollo 8 first went behind the back side of the Moon, it was traveling at 7,777 feet per second (https://history.nasa.gov/afj/ap08fj/12day3_lunar_encounter.html). Was the speed being all 7s (the ...
  • 41
6 votes
1 answer
83 views

Apollo ALSEP RTG shorting switch to prevent overheat of the RTG?

I found these lines in the Apollo 14 Lunar Surface Journal: 116:07:37 Mitchell: Houston, the current reading is 8. 116:07:42 McCandless: Understand 8 amperes before pressing the (shorting) switch. ...
  • 47.8k
2 votes
1 answer
102 views

Understanding the Viewgraph by Dr. John Houbolt and the probability of success calculation of a Lunar Landing

The well known Dr. John Houbolt used a viewgraph to explain the much higher probability of success with LOR in comparison to EOR and Direct Flight for a lunar landing. I used Python to check the ...
  • 47.8k
2 votes
0 answers
122 views

What is the most efficient method of landing for space capsules returning to earth? [closed]

I have read that the Russians don't land on water because they don't have access to a large warm-water coastline like the US. US has large swaths of land and water and most US capsules (Apollo, Dragon,...
7 votes
4 answers
928 views

Were Hasselblad cameras used in space after the Apollo mission?

Analog Hasselblad cameras with photochemical film were used extensively during the Apollo mission to the Moon. Were they used later for Spacelab, Space Shuttle and Mir or ISS?
  • 47.8k
6 votes
2 answers
1k views

At what point did the Apollo 11's Eagle extend the landing gear?

I am trying to figure out, during Apollo missions, exactly when the lunar-module extended the landing gear. Was it closer to the time the CM and LM connected in the space rendezvous or did they ...
6 votes
1 answer
193 views

Reference request: Rocketdyne Document R-3896-4 "F-1 Rocket Engine Illustrated Parts Breakdown"

Various sections of the Rocketdyne F-1 document R-3896 can be found scattered about the web, but I can't find R-3896-4. It's described as R-3896-4 F-1 Rocket Engine Illustrated Parts Breakdown This ...
12 votes
1 answer
306 views

What does it mean to tune the Saturn F-1 engine to a frequency, and how is the tuning done?

Chapter 10 of Chariots For Apollo remarks the following in discussing the pogo problem of Apollo 4 and 6 and the role of the first stage F-1 engines in that: The mission analysts later discovered ...
  • 12.8k
13 votes
1 answer
1k views

What kind of signals and encodings were used to send tilt/pan commands to TV cameras on the Moon (up through Apollo)?

This answer to Has anyone in space beyond LEO seen or has anything photographed a non-pointer laser from Earth? shows a frame from video shot by Surveyor 7 on the Moon, looking at Earth, and ...
  • 148k
7 votes
0 answers
123 views

Apollo landing abort times T1, T2, T3,

In the transcript (1 and 2) of Apollo 11 lunar landing we can see ground control and crew talking about "T1" moment and "T2" moment: 102:47:09 Duke: ...T1. Over. Eagle, you are ...
  • 2,983
5 votes
2 answers
538 views

Where to find Apollo lunar landing checklists?

Is this the only document where I can read the checklists for Apollo lunar landing? They look more sidenotes than real checklists, and they contain hundreds of acronyms; I would expect instead a "...
  • 2,983
4 votes
2 answers
223 views

How did "STOP" button work on Lunar Module?

The button to stop the descent engine of Lunar Module was not "just a button": it evolved and changed multiple times during development, and this is one of the many existing designs: What ...
  • 2,983
39 votes
3 answers
6k views

Why did the Lunar Module have such an irregular shape? Didn't it add weight and complexity?

Given the very stringent mass requirements, why was such a complex design choosen? I think an irregular shape weights a lot more than a squared box, not to mention the complexity to build it. I saw in ...
  • 2,983
12 votes
1 answer
1k views

Would the free return trajectories of Apollo 8 to Apollo 11 have made them reenter Earth's atmosphere?

Apollo 8 to Apollo 11 flew on a free return trajectory (later missions left the free return trajectory during a mid course correction after TLI). If those spacecraft had just stayed on that trajectory,...
  • 1,987
11 votes
3 answers
2k views

Apollo Guidance Computer (AGC) Compiler?

I found a brochure by Raytheon about the Apollo Guidance Computer. A compiler was announced for the AGC. As far as I know the AGC was programmed in assembler only. What kind of high level language ...
  • 47.8k
3 votes
0 answers
112 views

How to "decode" this ancient log of Apollo Guidance Computer (AGC)?

I found this interesting document: https://www.ibiblio.org/apollo/Documents/apollo_11_computer_words.pdf But the scan quality is very very poor! I tried interpreting the headers, but some characters ...
  • 2,983
21 votes
3 answers
3k views

Why are unused launch abort rockets jettisoned rather than used to augment thrust?

Launch abort rockets use powerful rockets. For a pad abort, they must have enough thrust to lift the capsule to an altitude where parachutes can function. The Apollo launch escape rocket had a 155,...
  • 7,573
8 votes
2 answers
864 views

How long would it have taken to launch an Apollo contingency flight?

How long would it have taken to launch an Apollo contingency flight, if, for example, the lunar lander couldn't have got back up to orbit? Could the lander have held three astronauts?
1 vote
0 answers
78 views

Fuel profile for Apollo 11

I downloaded a dozen of NASA documents about post-flight analysis of Apollo 11 mission, but I cannot find a table or a plot of fuel usage and remains; Some of the documents which I found: http://www....
  • 2,983
4 votes
0 answers
133 views

Two additional Saturn V flights planned in 1967 - but for what?

Per this question, there was no "cancelled" second run of Saturn Vs: only the first fifteen were ordered, and no second batch was ordered and then later cancelled. This had always been my ...
  • 7,541
11 votes
3 answers
2k views

Docking in space

I read about the mechanism of "docking" of Command Modules & Lunar Modules of the Apollo missions (the probe & drouge). It seems it was far too complex & had too many parts. I ...
  • 3,598
12 votes
1 answer
1k views

Why did a solar eclipse of the sun as seen from Apollo 11 appear to have an elliptical corona?

When asked to recount an experience from the Apollo program, Neil Armstrong stated: [My] most indelible memory was approaching the moon and flying through the moon shadows so that the moon was ...
  • 1,111
8 votes
2 answers
280 views

How was AS-212 (Saturn 1B) supposed to carry both a CSM and LM?

I recently came across this overview image of Saturn 1B missions: (source: NASA) AS-212 is asterisked with the note (bottom-left of the image) that it is "scheduled to carry both a CSM and LM.&...
  • 12.8k
1 vote
1 answer
108 views

Does NASA use UTC for all their missions?

During Apollo 11 launch they said "Liftoff, we have a liftoff, 32 minutes past the hour", which is 01:32 p. m. or 13:32. This is UTC time, because Apollo 11 happened at 08:32 EST. The ...
15 votes
1 answer
2k views

What does the ATOLL programming language look like?

During the Apollo program, checkout tests of launch vehicle and spacecraft systems were gradually being automated, moving away from the manual processes during the early years of the space program to (...
  • 12.8k
14 votes
2 answers
2k views

Where did AS-206 go between 1967 and 1973?

The Apollo program was a bit stressful. In 1967 a lot of things went wrong, especially with the delivery of the lunar module: General Phillips's office originally planned to launch the first lunar ...
  • 12.8k
6 votes
0 answers
154 views

Would deorbiting a crippled Apollo spacecraft using the Saturn V third stage have been a reasonable contingency?

In the event of the loss of all fuel cells in an Apollo mission, would reaching orbit with the third stage, then using the relight to de-orbit somewhat near the normal location in the pacific be a ...
  • 854
9 votes
2 answers
1k views

How were registers in the Apollo Guidance Computer implemented?

I'm having a hard time finding information on the composition of the AGC's registers. Were they also Magnetic Core Memory or something else?
10 votes
2 answers
319 views

Could Apollo's Sextant navigation use similar geometry as Marine Navigation?

Could Apollo's Sextant navigation for Cislunar Celestial Navigation use similar geometry as Marine Navigation? My grandfather would be familiar with the instrument in this astronaut’s hands, although ...
  • 7,573
13 votes
1 answer
328 views

What space capsule is this part from?

One of my relatives has this metal component sitting in their backyard. It was a souvenir that my grandfather got to keep from his days working in the aerospace industry (primarily for Boeing). My ...
  • 231
12 votes
1 answer
1k views

What distance did the Apollo CSM go before turning round to pick up the Lunar module?

I have looked for quite a while to find this out, and as yet have not been able to work out the answer. On the Apollo missions 10 to 17 the CSM had to turn round to pick up the lunar module between ...
  • 121
2 votes
1 answer
78 views

What was the size and mass limit of a PPK for Apollo?

Astronauts are allowed to take a personal preference kit (PPK) with them to space. The Wikipedia page for PPKs states how they are defined by the Federal Aviation Regulations as of January 2001. This ...
  • 4,820
0 votes
1 answer
130 views

Star visibility from space

During the Apollo missions the astronauts of the Apollo 15,16,and 17 performed cislunar space EVAs to check on experiments located in an external bay but said they could see no stars: Transcript from ...
  • 35
14 votes
3 answers
2k views

How did the lunar module avoid problems with flying regolith when taking off?

In November 2020, a SpaceX rocket suffered damage due to a problem with the launchpad, and future missions to the Moon and Mars could suffer similar problems since there won't be a launchpad at all. ...
  • 4,820
6 votes
1 answer
119 views

Were there backup routes planned for the Apollo LRV?

I just finished reading "A Man on the Moon" by Andrew Chaikin, an amazing read. For the missions involving the Lunar Roving Vehicle (LRV, Apollo 15-17), there are some mentions of astronauts ...
  • 495
20 votes
2 answers
1k views

How Did One Stand in The LEM Before Descent? [duplicate]

This is really simple, but i've never seen it discussed. One piloted the Apollo LEM standing up, without many restraints. But before the LEM ignited the descent engine, it was practically in free fall....
4 votes
1 answer
107 views

Was the Lunar Topographic Camera ever used?

From the APOLLO EXPERIENCE REPORT - PHOTOGRAPHIC EQUIPMENT AND OPERATIONS DURING MANNED SPACE-FLIGHT PROGRAMS NASA TN D-69 However, more detailed photography was required to evaluate the ...
  • 47.8k
0 votes
1 answer
294 views

What would have happened if all Apollo computers failed?

Let's assume all available computers in the command module and the lunar module failed and the astronauts were unable to repair them in flight. Would they have been able to return back home safely ...
3 votes
1 answer
114 views

Saturn 1 booster performance/structures

I was recently comparing some basic performance stats and noted that the Saturn 1/ 1B has very similar load to orbit figures to the Falcon 9. This seemed interesting to me, which brings up several ...

1
2 3 4 5
15