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.

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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,...
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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?
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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....
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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 ...
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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 ...
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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 ...
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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.&...
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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 ...
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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 (...
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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 ...
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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 ...
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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. ...
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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 ...
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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....
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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 ...
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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 ...
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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 ...
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What if Apollo Lunar Rover failed on the Moon?

Let's assume that our Apollo astronauts are on the Moon, driving their Lunar Rover and they are far away from the LM. What if LRV failed during the mission? Would they be able to get back to the LM on ...
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How long was Apollo put on hold after Apollo 1?

After Apollo 1, the Apollo program was put on hold while the accident could be investigated. How long was the program put on hold? How much did it delay the actual Moon landing?
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Could the ascent stage of Apollo 11's Eagle still orbit the Moon?

This video: Is Apollo 11's Lunar Module Still In Orbit Around The Moon 52 Years Later? claims, based on orbital simulations, that there is a chanche that the lunar module of Apollo 11 might be still ...
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Why did Apollo missions open the propulsive Hydrogen vents during the coast phase?

According to Figure 2-1 of the SA-503 flight manual the LH2 continuous vent was opened during the coast phase, and closed during the ullage stage of the S-IVB restart T_6 + 0:00:42.0 (but open for ...
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Are there any markings that uniquely identify each Saturn-Apollo combination?

This question made me wonder: are there any markings on the Saturn I/IB/V launch vehicle, Apollo service module or command module that uniquely identify each vehicle (i.e. AS-5xx)? It doesn't have to ...
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Does anyone know the source of this video?

I would like to know the source of this video? I cannot find it on youtube, but I think it's from the Apollo 17 launch (because it's night). Any ideas? Is my Apollo 17 guess correct? This is the video:...
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Did any Apollo missions have enough fuel left to bring back the LM ascent stage?

A recent question asks why the Apollo lunar module wasn't routinely brought back when returning from the Moon, so it could be used as an Apollo 13 style lifeboat. The answers correctly state that ...
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Apollo 14-17 - Why didn't they keep the Lunar Module docked as a lifeboat for the way back to Earth?

During Apollo 13, the Lunar Module had to be used as a lifeboat in order to save the astronauts. Then, it was only jettisoned from the Command Module shortly before Earth re-entry (even after the ...
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How did the Carbon Dioxide gauges work on Apollo?

The book Lost Moon by Jim Lovell and Jeffrey Kluger had this interesting description in Chapter 10 (page 254 in my copy) regarding the CO2 gauges (emphasis added): Carbon dioxide concentrations in ...
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Would've the CO2 scrubbers failed before the O2 supply ran out during an Apollo moonwalk?

This absurd video on Reddit of the Earth blowing up while Apollo astronauts were walking on the Moon got me thinking. Assuming something catastrophic happened to the Lunar Module the moment the two ...
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How did "ACA Out of detent" work?

This is a related question about the words said during Apollo 11 as soon as the LM touched the ground. My question is specific to ACA out of detent As soon as the LM touched down on the surface it ...
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What is the origin of the Lunar Module in the US Space and Rocket Center in Huntsville, AL?

I recently had a chance to visit the US Space and Rocket Center. While I was there, I saw a lunar module. It is very clear that the ascent portion is a mock-up, but the decent portion looks real, ...
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Where exactly are the Apollo space suit sublimators venting steam into space? is there a photo of an astronaut in space that shows the opening?

This excellent answer to How have space suits dissipated the heat removed from astronauts? shows a diagram including the sublimator unit in the red square where the phase transition of water from ...
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Why were the apollo CM RCS thrusters all placed in only one half of the module?

All the apollo CM RCS thrusters for pitch, roll, and yaw control were placed only in the upper half of the capsule (as seen in the image below). Why is that? (I think I read somewhere that it was due ...
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Other than astronauts, did any equipment go to the moon more than once? [duplicate]

It's been well documented elsewhere that three astronauts made multiple trips to the moon (whether to just orbit it, or actually land), these being Lovell, Young, and Cernan. Other than these 3 ...
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What barge route did the Saturn S-II take from California to Florida?

The first stage (S-IC) of the Saturn V rocket was produced at the Michoud Facility in New Orleans. Too large to be transported by railroad or airplane, it was delivered to Kennedy Space Center by ...
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Was anything manufactured at the Michoud facility between Apollo and the Shuttle?

The Michoud Assembly Facility is a manufacturing complex in New Orleans owned by NASA. During the Apollo program, the first stages of the Saturn I, IB, and V rockets were built there. During the ...
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Back up plan to use LOX-RP1 for Apollo mission

Today it might seem to be an hypothetical question. I read that Surveyor mission confirmed "re-igniting" a LOX+LH2 engine in space is successful. What if the use of H2 was not successful ? - ...
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Lunar Terrain Model in Apollo Guidance Computer

In the book Apollo Guidance Computer by Frank O’ Brian, on page 279, he talks about the lunar terrain model in the Apollo Guidance Computer, which has the several segments of the surface with slope. ...
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Correcting Accelerometer Readings when Offset from Center of Mass: How?

A follow-up to an earlier question. So I've accepted that I need to correct my accelerometer readings for the accelerometer offset from the center of mass. The offset means that whenever the rocket ...
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Was emergency burial of the Lunar Receiving Laboratory planned?

Regarding the Lunar Receiving Laboratory, in Sunburst and Luminary Don Eyles wrote in Debriefing (p.162 of 2019 edition): ...all this in case they had, against expectation, brought home some ...
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Why was a completely new (an "inexperienced" crew, w.r.t. Moon mission) selected for Apollo 11? [duplicate]

Apollo 10 was practically a full dress rehearsal of moon landing, except the landing act. As such, its crew (astronauts) gained all the experience needed for a moon mission. They were best suited to &...
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How did the Apollo guidance computers deal with radiation?

I was wondering how the Apollo guidance computer handled the radiation encountered in space
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What was the volume of the Rocketdyne F-1 engine's main combustion chamber?

In the specifications of the F-1 available online, I can find its dimensions, weight, thrust, etc. but I couldn't find what was the volume of its main combustion chamber. Is this information available?...
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When was the general approach to the Apollo moon landings finalized?

When were the major aspects of the Apollo program decided? Multi-stage rocket, CM pulling the LM out of the rocket through a docking maneuver, LOR, and a parachute landing in the ocean. I've seen ...
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Would the Apollo LM be able to land on Mercury?

If we set aside the question how the Apollo LM got into orbit around the celestial body in question, I wonder which celestial bodies other than the Moon the LM could successfully land on. Mercury for ...
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RCS jet select algorithms (e.g. in space shuttle)?

I'm looking for a clear description of RCS jet selection logic. The space shuttle, for instance, had tens of RCS thrusters, only three of which would be called to fire at a time given a 3D attitude ...

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