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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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How did the Apollo computers evaluate transcendental functions like sine, arctangent, log?

Navigation with a sextant or maneuvers using gimbal angles might be two examples of cases where an Apollo computer might need to do trigonometry. Trigonometric functions like sine, arctangent, etc. ...
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Could the Saturn V actually have launched astronauts around Venus?

One of the more interesting proposed uses of a Saturn V was to launch a manned flyby of Venus. Some of the cargo would have been stored inside the tank of the upper stage, which would be retained ...
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Did the Apollo missions use the Earth's magnetotail to lessen cosmic radiation?

I see a lot of images like this for the Apollo mission: 99% of them exclude the sun, and the ones that don't I can't be sure if they're accurate and cannot find sources. During the Apollo missions ...
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Why did the Apollo cabin repressurization valve cause a banging sound?

As portrayed in the movie Apollo 13, Fred Haise tried to spook his crewmates by trigerring the cabin repressurization valve, which creates a banging sound. Indeed, every Apollo crew reported hearing ...
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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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Any earth-based film or color still photography of Apollo CM re-entries?

After watching the IMAX Apollo 11 film today I wondered if there was any film footage from outside of an Apollo Command Module (CM) re-entry (or even color stills). It does not have to be from 11. ...
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What Apollo equipment could be salvaged from the Moon?

If humans returned to the original Apollo landing sites, what previously left-behind equipment could reasonably be salvaged as part of a future mission or colony? That is, is everything that was left ...
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Lunar ascent module: Guidance Law [duplicate]

I was wondering if there was an optimal law for the thrust (magnitude and direction) during the lunar ascent. I have read many things about this topic in this forum but I still have some doubts. It ...
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What joints of Apollo 17 space suits did moon dust get into, making the astronauts arms difficult to move?

At about 02:45 the Curious Droid video Apollo, the Lunar Dust and NASA's Dirty Problem says: During Apollo 17, crew members Harrison “Jack” Schmitt and Gene ...
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Could the Orion or Apollo command module safely land on land in an emergency due to a navigation error?

So we all know that the Apollo missions used a water landing, as will Orion, while the Soyuz lands on land but can land on water if needed. What would have happened if an Apollo crew began reentry in ...
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Could an Apollo Lunar Module have landed and returned without Earth assistance?

From the Apollo 12 flight journal: 087:31:29 Conrad (onboard): [Laughter] Yes. Let's take the LM down and land on the back side. Wouldn't that shake them up? [Laughter]. 087:31:36 Bean (...
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How did the Apollo guidance computer handle the Earth-Moon system's rotation around the Sun?

In this comment I just wrote: "...but at all other times it is just doing math to calculate its trajectory." The math needed a stable clock Timing accuracy of the Apollo Guidance Computer? (also 2, ...
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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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What was the “sour milk smell” during the 1967 Apollo 1 testing?

In the first edition of Andrew Chaikin's 1994 book, "A Man on the Moon, there is a paragraph in chapter 1 which talks about troubles the Apollo 1 testing crew were going through. Chaikin states that ...
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In what ways would the high elliptical orbit of Apollo “E missions” simulate lunar missions?

The vintage space video Missions we Lost When Apollo was Cancelled after 01:25 describes classification scheme for then-future Apollo missions: As Apollo took ...
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What exactly turned on the light indicating Apollo 8 was starting to fall towards the Moon?

@PearsonArtPhoto's answer links to the page Apollo 8, 21 – 28 December 1968 by Hamish Lindsay at honeysucklecreek.net from where I have quoted below. Question: What exactly turned on the light ...
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“Luckily with no Lunar Module, Tidbinbilla was able to keep tracking with no interruption…” Why is no LM significant?

@PearsonArtPhoto's answer links to the page Apollo 8, 21 – 28 December 1968 by Hamish Lindsay at honeysucklecreek.net. The page describes a problem with one of the dish antennas that needed to be ...
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How did NASA achieve their live TV broadcast in 1969?

In 1969, NASA not only went to the moon, but broadcast the whole thing live on TV. How did they achieve the TV broadcast? What technology did they need to use to send a video and audio signal from ...
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How many people spoke to Apollo 8 from outside the US?

@PearsonArtPhoto's answer links to the page Apollo 8, 21 – 28 December 1968 by Hamish Lindsay at honeysucklecreek.net. It shows a clipping from The Canberra Times front page, "With thanks to Mike ...
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Did Apollo's velocity slow down after TLI due to Earth's gravity?

I assume Apollo's velocity slowed down after it left Earth orbit, for how long was it decelerating. Did it start accelerating as it approached the Moon. What was the rate of deceleration due to ...
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Apollo Missions - Travel time to moon [duplicate]

I must be missing something - escape velocity is about 25,000mph. The distance to the moon about 240,000 miles. That computes to about a 9 hour flight. Why did it take 3 days for Apollo missions to ...
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What happened to Apollo 13 LM descent stage?

I see in the accounts of the Apollo 13 mission that the descent stage engine of the LM were used to propel the joined spacecraft into a return trajectory to earth and that the crew remained in the LM ...
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Looking for veterans of the Space Race [closed]

Hi everyone. I am writing an oral history of the men and women who worked at Cape Canaveral and KSC during Mercury, Gemini and Apollo. If you know someone that fits the bill, or know how to find them, ...
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Crashed LMs visible on LRO images?

I'm rewatching the old HBO "From the Earth to the Moon" series and then reading up about specific missions in detail afterwards. One thing I hadn't realised was that the LM for each mission typically ...
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Where did the famous “end of decade” deadline come from?

In his address to Congress on 25th of May 1961, John F Kennedy committed for the first time to land a man on the Moon and bring him safely back before the end of the decade. But the feasibility ...
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Puzzler: Precisely what maximum distance from the Earth did the Apollo 13 astronauts achieve?

tl;dr: Both this answer and this answer quote Wikipedia to state that the Apollo 13 astronauts reached 404,171 km from Earth. I'm not able to reproduce that value. According to JPL's Horizons the ...
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What's the closest that an Apollo mission passed GEO on its way to the moon?

@Uwe's comment No astronaut ever visited geostationary orbit at 22-23k miles to maintain or deploy satellites. The Apollo astronauts just rushed by on their way to the Moon and back. below the ...
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Was water ever taken outside a spacecraft?

Has an astronaut (or cosmonaut) taken water out of a spacecraft to see if it boils or freezes?
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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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How to get an initial setting of the range gate for a Lunar Laser Ranging using a new Retro Reflector for the first time?

From an answer to this question They were searching by aiming their laser at the moon and looking for reflections. But the system is set to only detect photons in a very narrow range of ...
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How do we know the Apollo Moon landings are real?

Since about 1976, conspiracy theories denying the Moon landing and claiming it was all faked have cropped up. As a website devoted to answering questions about space exploration, we receive questions ...
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Apollo communication between the Earth and Moon

How was it possible for astronauts to send back tv/radio signals to earth from the moon? I have just been teaching my son about waves behavior and understand that radio waves are reflected back to ...
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Launch window for the Apollo Lunar Module?

If something would have gone wrong after a successful Moon landing requiring to ascent as soon as possible, what about the launch window for the lunar rendezvous maneuver? Could they ascent at any ...
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How close did Apollo 16 astronaut Charles M. Duke Jr. get to the edge of Plum crater?

The New York Times article What Happened to Earth’s Ancient Craters? Scientists Seek Clues on the Moon’s Pocked Surface includes a NASA photo with the caption: Astronaut Charles M. Duke Jr., of the ...
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Left behind photo

After several trips to moon there were several items left behind on the moon's surface, including foot prints. Is there any photo or registry of any of those items taken recently?
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What was this Ziploc bag used for on an Apollo 14 moonwalk?

And how the heck would an astronaut have opened it with his gloves on? Is that bag likely to still be there in good condition, or would it have been broken down by radiation by now? Was it normal to ...
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Why did Apollo have a crew of 3?

Why did Apollo have a crew of three when only two actually reached the surface of the moon? I can see it makes sense for the Lunar Module only to seat two astronauts. Less mass to land softly on the ...
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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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How many Lunar Surface Hasselblad cameras were left on the Moon?

There were six Apollo missions that landed on the Moon. Each mission was equipped with at least two Lunar Surface Hasselblad cameras left on the lunar surface before ascent. But the total number of ...
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Why does the Apollo-8 Trans-Lunar Injection burn appear to be pulsing in this photo?

This tweet called my attention to The Smithsonian National Air and Space Museum story Photographing Apollo 8's Orbit Toward the Moon. The story is quite an interesting bit of space history and worth a ...
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Has in-space refueling been done?

Before the Apollo program committed to the lunar orbit rendezvous mode, one of the Earth orbit rendezvous proposals involved launching two Saturn Vs, one with the Apollo spacecraft and large lunar ...
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Apollo-SLA & LM air pressures at launch

At the time of launch what was the air pressure in the Apollo LM, and the spacecraft-LEM adapter section (SLA)? Was the air vented from the SLA as the vehicle entered orbit?
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Docking of CSM with LM

After separation from the SLA (by about 50-100 feet), the CSM "turned around" and docked with the LM to pull it out. This turning around was done by a 180 degree change in orientation. This could have ...
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Docking of Command and Service module with Lunar module

Is there any video available which is shot inside CSM during the process of docking with LM to pull it out of adapter?
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What do you call the Apollo LEM plus CM (Command Module) when they are connected?

In the question How far away can spacecraft be seen with an optical telescope? I used ...Apollo 14 CM & LEM and the Saturn IV B..." for lack of better words. Unlike some people I (don't) ...
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How did NASA get the video camera on the Moon to track the LM ascent stage, considering the substantial delay?

The Moon's distance can be as much as about 406,000 km from Earth. That's a round trip light time of roughly 2 x 406,000 / 300,000 = 2.7 seconds or more, depending on how the signal was relayed to ...
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At what time in the Apollo 14 mission did the maneuver shown in this image happen, and what exactly was happening?

In a search for information for this answer I received this google books link of Comment: The Relevance of Space, by Arthur Kantrowitz, Bulletin of the Atomic Scientists 197, 4 April 1971, pp 32-33. ...
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Exit film of moon landing departure

On Apollo 15, 16, and 17 NASA filmed the Lunar Module taking off and leaving the moon. With no-one on the moon how could the the camera move to follow it and who brought the exposed film back to ...
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How far from Earth were the Apollo astronauts when they left the Earth's magnetosphere?

I am assuming the Apollo missions recorded radiation levels as they travelled to the Moon. Have those records ever been released, as a way of determining when the Apollo astronauts left the ...
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What was the view from the Apollo spacecraft while travelling to the moon?

From what I read on the internet, I took around 3 days for Apollo 11 to get to the Moon. I'm curious what was the view from the windows of the spacecraft during the journey. What did the astronauts ...