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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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Why not build Saturn V's again?

Why is the US developing a new rocket and spacecraft as opposed to building the Saturn V and Apollo stacks again? The SLS / Orion development programs certainly can't cost less than the unit cost of ...
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Launch Accelerations: Values, history

This topic: What G-forces do different launchers cause? indicates that current satellite launchers are limiting peak acceleration to about 4g. I'm pretty sure the STS (Shuttle) did the same. My ...
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Can I borrow a lunar rover?

According to Wikipedia there are 3 LRVs sitting on the moon, in very well defined locations. Would China, or whomever gets to the moon with a person next, be able to get in and drive around in an LRV ...
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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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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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What are these structures on the Lunar Ranging Retro Reflector (LRRR) arrays for?

In this question I used images of the retro-reflector arrays that were left on the moon by Apollo 11, 14, and 15. The Lunar Ranging Retro Reflectors (LRRRs) are there for Lunar Laser Ranging. The ...
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How was dust-mitigation addressed during the Apollo program?

Dust mitigation in the context of manned landings is now a rather vital topic of research and testing, but back in the days of Apollo it was a fairly new problem. 'Dusty' Gene Cernan inside the LM ...
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Reasons behind the “Transposition, docking and extraction” maneuver

The Transposition, Docking and Extraction (TD&E) maneuver was done during the Apollo Moon missions right after the translunar injection. The Command/Service Module (CSM) separated from the S-IVB, ...
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Why did Apollo 11 need someone to stay behind in lunar orbit?

When Neil Armstrong and Buzz Aldrin descended to the moon in the Lunar Module, Michael Collins stayed up in lunar orbit in the Command Module. Why did they need someone to stay behind? At this point,...
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Could a single crew member fly the Apollo LM?

We know that the Apollo astronauts were subject to rigorous medical testing prior to launch, and we know that this caused at least one Apollo crew member to be replaced very late in the process. ...
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Two totally different pictures of Apollo 15 landing site released by NASA 40 years apart. What causes these differences? [closed]

A report of NASA, dated December 1971, shows at page 18 a picture on which the traces left behind by the Apollo 15 mission are superimposed. In 2012 NASA released a computer enhanced photo of the ...
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Were the Apollo lunar activities observed from Earth?

I understand that all manned landings on the Moon were on the near side, so technically they could be visible from Earth. Was it possible to observe landings and/or extravehicular activities (EVAs) ...
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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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For an Apollo Lunar Module Ascent Stage launch, what is the optimal profile of $\beta$ (or $\gamma$) vs time?

When Apollo astronauts departed the lunar surface in the Lunar Module's Ascent Stage, it appeared to rise vertically ($\beta$ = 0) for ~10 seconds and then begin the "tipover" (videos of Apollo 15, 16 ...
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Why were there beeps punctuating the voice communications during missions such as Apollo?

Voice communication between ground and spacecraft during missions such as Apollo seemed to be always punctuated by beeps. What was the origin of these beeps? Were they some sort of unavoidable ...
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How does the Apollo LM ascent guidance program P12 actually work?

P12 is the AGC guidance program for normal ascent from the lunar surface to orbit. According to the mission planning documents, after separation and ignition, the ascent stage holds its initial ...
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Were the Apollo 11 astronauts aware of any parts of the Luna 15 mission?

I just learned today about the Luna 15 mission which was a Soviet attempt to land an unmanned probe on the moon which coincided with the successful Apollo 11 mission. Were the Apollo 11 astronauts ...
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Where were the various Apollo Lunar Modules (LMs) discarded?

The LEM was comprised of an ascent, and a descent stage. Whilst the descent stage was in most cases left behind on Luna, the ascent stage ferried the astronauts upstairs to the CSM. Where are these ...
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How was temperature and humidity maintained inside the Apollo mission capsules?

What mechanism was used to control the temperature and humidity inside the Apollo mission capsules? For example, did they employ an electric heater? Did they utilize solar radiation? Was humidity ...
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Was the Apollo sextant used (or tested) to determine position while in Earth orbit?

The video Apollo Program Guidance and Navigation System 79974 explains that the spacecraft's sextant could be used together with the navigation computer to determine a position fix while in Earth ...
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Why such a large observed doppler shift from Apollo 17 orbiting the moon?

Following the links in this comment by @Uwe I've found some interesting sources of information on Ham (amateur) radio operators trying to listen in on Apollo transmissions. One of them is Sven Grahn's ...
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NASA at sIxty years, will there be a new moonshot mandate?

NASA is sixty years old still going strong. There are few organizations that have made such an impact to man's quest for knowledge in such a short time span. The contributions are many, and its ...
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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 Apollo missions solve the cosmic radiation problem?

One of the major hurdles of space exploration is cosmic radiation. How did the Apollo missions solve the radiation problem? NASA would have shielded the astronauts to some level by some material. How ...
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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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Was the Apollo 13 CM guidance computer fully shut down?

I was watching the movie Apollo 13, and one thing struck me as quite odd. According to Wikipedia, [Movie director Ron] Howard went to great lengths to create a technically accurate movie, employing ...
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What does 'Switch SCE to AUX' mean?

During the launch of Apollo 12 a major malfunction was caused by 2 lightning strikes. See http://www.realclearscience.com/blog/2013/02/apollo-12-struck-by-lightning.html for more info. The solution ...
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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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Picture of equipment left on the Moon?

When people visited the Moon, they left sizeable items behind. I know that taking picture of this from Earth is incredibly hard, but: Did someone try? And what pictures do we have?
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Calculations Apollo astronauts were trained to do by hand if loss of guidance computer and/or data & coms link to Earth?

This answer to the question is it possible to navigate space travel with no computer? currently contains the line Yes, as long as you don't care where you end up but I am not so sure this is true. ...
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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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Usage of Apollo Lunar Surface Hasselblad Camera with 500 mm lens?

Here is a list of photographic cameras used for Apollo 16. There were two Lunar Surface Data Hasselblads equipped with a 60 mm lens for both astronauts to be used with chest mounts to the space suits....
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What would have happened if the skin of an Apollo lunar module was ruptured?

The Apollo lunar module had thin skins of foil for protection / air containment. What would have happened if a hole was made in this skin by a flailing astronaut, screwdriver, asteroid, etc.? Would ...
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How was reserve fuel calculated for the Apollo missions?

A quick follow-up to How much fuel was used for a Space Shuttle launch? My memory is a little foggy; I seem to recall reading the Apollo 11 mission commander depleted his reserve fuel landing Eagle. ...
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Why wasn't the Apollo 13 Service Module jettisoned until hours before reentry?

Looking at the Apollo 13 mission timeline within three hours after the explosion of O2 tank two all oxygen in the SPS was completely depleted. Fuel cells #1 and #3 were off line. CM had even started ...
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Could an Apollo crew have been killed by Solar radiation?

The Sun throws lots of high speed protons around. Especially during its sudden and short intensive "events". Much of that is blocked by Earth's magnetosphere and atmosphere. But astronauts work ...
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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. ...
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Why did the Apollo Lunar Module have four landing legs?

Why did the Apollo Lunar Module have four landing legs? Is not just three legs enough? Also, three legs guaranties they always form a plane, four does not, as the fourth leg may dangle. To have the ...
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Size of Apollo era astronauts

I had read that the early astronauts were all 'short guys'. This made a lot of sense. A short man can have as much stamina and endurance as a large man, yet eat less, consume less oxygen & (...
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Could an Apollo LM land unmanned?

I believe that Apollo mission control had the ability to upload data and commands to the LM's guidance computer as long as they had an operational communications link. I'm wondering if, from the point ...
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Which astronaut travelled farthest from Earth?

To-date who has flown farthest from the center of the Earth? Is he alive now?
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Apollo era remote control of vehicle

I am wondering what kind of ability NASA had during the Gemini or Apollo program era to control the vehicle from the ground. From reading some capcom transcripts and looking through some random ...
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Why was the Apollo CM main engine thought to be unreliable on Apollo 13?

When Apollo 13 had most of its internal systems destroyed by an explosion, NASA decided that the best course of action would be to fire the main engine on the dark side of the moon to send the capsule ...
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Did any Apollo missions have backup parachutes?

NASA's Apollo modules, the ones that went to the moon, had a fairly standard-for-the-time reentry method: Hit the atmosphere at the right angle, deploy a parachute after things are done burning up, ...
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Lunar rover footage?

How many hours of publicly available footage is there of the lunar rover moving around? Youtube only has 2 min. I want more. Especially with rooster tail.
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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 “peak Apollo levels” of support have gotten NASA astronauts to Mars in the 1980's?

In an "alternate universe" where NASA continued to receive a mandate, funding and public support at say peak Apollo levels, could another ten or twenty years have gotten boots on Mars, with astronauts ...
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Which Apollo “mystery” was said to be finally solved by a better rendering engine?

I remember reading several years ago about a mystery or puzzle about a photograph from an Apollo moon landing mission that had to do with why someone's suit was as bright as it was in the photo. There ...
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How did NASA prevent third parties from spoofing Apollo communications?

The Apollo crews transmitted footage to Earth using SSTV, a ham radio technique that amateurs and pirates can use to send similar messages around the world. Did NASA have any technical ...