Apollo 10 Stopped Just 47k Feet from the Moon | Hacker News Reader

Apollo 10 Stopped Just 47k Feet from the Moon

nytimes.com

200 pointssohkamyung134 comments

I just finished Moondust, which is a really good read for anyone interested in the Apollo story. The author was a journalist working on a story about the Apollo astronauts, and he was interviewing one of the men who walked on the moon. During the interview the astronaut took a phone call, and came back a while later saying, "Now there's only nine of us." I believe it was Pete Conrad that had just died.

Shortly after that, the author (Andrew Smith) decided to go find each of the men who had walked on the moon, and ask them what they'd done with their lives since walking on the moon. It's a wonderful mix of his own recollections of growing up when Apollo was happening, each of the astronaut's personal backstories and recollections of what it was like to be at the center of the Apollo program, and what life has been like after walking on the moon.

I can't recommend it highly enough. It's being re-issued this summer for the 50th anniversary of the first landing, but you can also order the original version from 2005.

https://www.amazon.com/Moondust-Search-Men-Fell-Earth-dp-006...

It's sad. Most of them did not do well in later life.

Isn't it sad, because we bought into the coldwar propaganda that this is something extremely valuable? I'm not saying that space exploration isn't worthwhile, I think it is. However, if they were framed as simply very skilled technicians, instead of heroes of a generation, would we feel this bizarre feeling of incongruity about their later lives?

It most certainly was not just about cold war propaganda. The dream to reach for the heavens has existed since antiquity. ad astra per aspera, as the saying goes.

The first humans to walk on another celestial body? I'd say that's a defining moment in human history alongside the discovery of fire, agriculture, metals, oil, plastic, flight, nuclear fission etc.

Just because we haven't fully achieved the potential of sending humans to space yet doesn't make it less of an achievement. Perhaps when we finally colonize space we'll appreciate how pioneering the Apollo program really was, especially as we forced it all through before we were even really ready, technologically.

To rephrase, I'm not saying this isn't a historical milestone. Though since you're leaning quite heavily on this, I'll add that printed word is probably a bigger deal than most of the things you mentioned, even if it doesn't have the ring of space flight or nuclear fission. But, this is not what I meant to discuss.

To come back to my point, the astronauts were singled out and idolized and that didn't have a bearing on reality. If today someone were to muster modern science into an astounding vehicle of marvelous engineering and ambition, and it would require a human technician to operate, and let's say I would be that technician, you wouldn't say that I'm a hero or a person of extreme merit, because I would be just a technician.

Enter framing. If I would operate the device or vehicle on some interesting journey, and I would then go off to shake hands with some politicians, and there was some incentive for the media apparatus to spin this in some simplistic, easily graspable way, they would have everything they needed, and I'd become a vivid symbol of that marvelous flowering of our civilization (or of US, given the Cold War context).

Will you ask the casual observer to grasp the grandiose complexity of what led to this event, or will you just give him a pawn-head in the form of an astronaut and say "idolize him", thus letting him confuse a flashy front-man for the real thing?

They are heros because they risked their lives. There was a serious chance of dying, but they went out there for something that was more of a benefit to other people than it was to them.

That's true, I guess I got carried off with my point and didn't think about what the journey was like for them. Though, it doesn't really retract from my point about misplaced idolization.

It’s not really different from the first person standing on the South Pole. At the time we did not have the capability for people to live there making the trip pointless. Now that we have that capacity, we gained nothing from the first explores to make it to the South Pole.

Space exploration is meaningful when the first person is born, grows up, and has a kid on some other celestial body. Whoever that is will be a milestone worth remembering, until that point it’s just flags and video.

You're actually trying to argue that the Apollo program was not meaningful?

Let alone all exploration that doesn't result in immediate colonization?

Not really a wonder .. they where a special kind of men. Adrenalin junkys and very smart .. they had been Testpilot and Astronaut. What can you do after that .. what job can compete with that ..

They could go back to regular test piloting I guess. But I agree that anything would be unfulfilling compared to what they achieved.

Reminiscent of one of Tom Hanks' lines in Apollo 13 when Jim Lovell announces his retirement: "I'll be walking in a place where there is 400 degrees difference between sunlight and shadow. I can't imagine ever topping that."

Genuinely curious what do you mean by that?

Did they do meth/heroin type of stuff, have tumultuous personal life, or professionally they didn't achieve much after being astronauts ?

Buzz Aldrin had serious problems with depression and alcoholism for years.

They also had rather unique, severe, physical problems that are being studied in other astronauts (macular degeneration, joint problems, etc)

I recently finished Rocket Men by Robert Kurson, about Apollo 8. That was great. But the ultimate book on Apollo for me is still Chaikin's 'Man on the Moon' which details all of the Apollo missions from interviews with the astronauts not too long after, as well as some of the pre-Apollo stuff (Gemini and Mercury).

Tom Wolfe's The Right Stuff is also great to understand the test pilots from which most of the astronauts were picked.

I love the Chaikin book. It covers everything in so much detail, yet remains interesting throughout. The audiobook is also very well narrated, and at 23 hours is quite long, which I like.

> Cernan speculated that the lander’s ascent module had been short-fueled on purpose: “A lot of people thought about the kind of people we were: ‘Don’t give those guys an opportunity to land, ‘cause they might!’”

I've always loved this anecdote. It really illustrates the adventurous attitude and boldness these astronauts. If they were fully fueled, there was a non-zero chance they would have just landed. What's Houston gunna do about it?

> What's Houston gunna do about it?

Preventing them from flying another mission, ever, presumably.

That's why you turn off the radio, land, take off again, and say something about technical difficulties.

A small price to pay to be the first man on the moon.

That would be Apollo 7 which had a near mutiny in space. None of the astronauts on that flight ever flew again. In their defense, they were dealing with motion sickness and a head cold.

https://en.wikipedia.org/wiki/Apollo_7

So far as I can tell, none of the Apollo 11 ever flew another mission, so it may well have been worth it.

(Though the 10 astronauts all did at least one more, with two of the three eventually getting their turn on the moon)

> the 10 astronauts

To other readers: OP is talking about the astronauts of Apollo X, not a quantity of ten astronauts.

Not the same as prematurely landing on the moon, but John Young smuggled a corned beef sandwich aboard Gemini 3 [1]. He then proceeded to fly on another Gemini mission, 2 Apollo missions and 2 shuttle missions.

[1] https://www.space.com/39341-john-young-smuggled-corned-beef-...

You just landed on the moon, it's either a mission to Mars next or you just don't care anymore

Any real punishment after successful return would have been politically impossible.

JFK would have called: "Give them written warning and yell at them, Then you bring them to DC. I have to shake their hand and we have to plan for celebration and other stuff."

I remember reading that NASA's psychological selection/screening process is top secret or something like that, but if you read between the lines and analyze the astronauts themselves, you quickly conclude that yes, if there is fuel and a giant unexplored opportunity nearby, don't get in their way. Not only are they adventurous, but they will push just about any boundary; that is their default setting.

Sometimes there are "interesting" incidents where you get to see this psychology in weaponized form, like the Terminator-esque jilted astronaut lover story from back in 2007. I'm not surprised at all to hear that contingency means might be taken to limit related risks on space missions.

What is the "Terminator-esque jilted astronaut lover story" you're referring to? That doesn't ring a bell but I would love to read more about it!

https://www.denverpost.com/2007/02/05/diaper-wearing-astrona...

Isn't that a story that inspired "Lucy In The Sky" movie?

Yea it's about her

Ukulele version: https://youtube.com/watch?v=YrUwqc0sF7U

This is more or less exactly the scenario explored in this classic sketch comedy video: https://www.youtube.com/watch?v=Xj3pJudQi7A

Wasn't there some story about Chuck Yeager in a Bell X15 on his last flight just saying 'Screw it, what are they gonna do, fire me? I'm going to go to space today.' and taking it up as high as it would go?

I'm not aware of that story, but there is much speculation about why Yeager was never selected for the astronaut corps. His biography (I haven't read it yet, it's second-to-next on my shelf) specifically mentions that Chuck "had the right stuff" which during the Mercury time was code word for "good enough to be an astronaut".

I thought it was explicitly just that he didn't have a college degree? Or is there more to it than that?

I'll know as soon as I finish the book!

In his own words:

JC: Any regrets you were never selected by NASA as an astronaut?

CY: In order to get into the space program, you had to have a degree. I only had a high school education. In the early Mercury program, everything was done from the Cape [Kennedy] anyway. The guys didn’t have a hell of a lot of control, and that to me isn’t flying. I wasn’t interested.

https://www.forbes.com/sites/jimclash/2017/01/23/chuck-yeage...

> Q: Why didn't NASA ever select you to become an astronaut? A: They knew I didn't want to wipe the monkey crap off the seat before I sat down

Edit: https://twitter.com/genchuckyeager/status/918320874947715074...

The X15 was built by North American, and I do not think Yeager flew it. You may be thinking of an ill-conceived idea for Yeager to use one of the NF-104A rocket-boosted Starfighters to set an altitude record. According to this series of articles by the pilot running the NF-104A test program [1], Yeager did not follow the flight profile and consequently ended up in an irrecoverable flat spin from which he had to eject. Yeager could not be blamed, so the author claims he got shafted by the inquiry, with no opportunity to defend himself.

[1] http://www.kalimera.org/nf104/stories/stories_11.html http://www.kalimera.org/nf104/stories/stories_12.html http://www.kalimera.org/nf104/stories/stories_13.html

It’s a joke.

This would make for a great conspiracy theory, let's say in the alternative world where Apollo 11 had a catastrophic failure and the Apollo program was pushed back by years and eventually cancelled. "NASA did go to the moon in the 60s, but they covered it up!"

> It really illustrates the adventurous attitude and boldness these astronauts.

I remember reading something years ago along the lines that the astronauts they would select for a hypothetical mars mission would be a totally different type than the Apollo astronauts.

The Apollo guys were more the cowboy and daredevil type, where for an 18 month space mission you’d need much more level head types.

Not sure if that was a thing NASA had already planned for, but it always made sense to me.

The astronauts of the early programs were basically all picked from the military test pilot pool. Which was a natural fit given how everything related to spaceflight was new and experimental and ridiculously risky. They needed people who could stare death in the eye and live to tell the story.

These days astronauts routinely spend months in space, and indeed their selection process and education requirements are rather different—as of course is the whole purpose and character of the manned spaceflight program.

It should be said, though, that Neil was selected as the CDR of the first mission to land exactly because he was not a gung-ho type but instead extremely calm, collected, and not one to make a number of himself. Buzz, on the other hand, was and is a much more hot-blooded personality.

Neil also seemed to be a guy who really loved analysing and solving problems - as well as a total love of flying.

Interesting interview with him from 2011:

https://www.youtube.com/watch?v=KJzOIh2eHqQ

>The Apollo guys were more the cowboy and daredevil type, where for an 18 month space mission you’d need much more level head types.

This was the premise of MARS-500 mission/experiment.

https://en.wikipedia.org/wiki/MARS-500

I was staring at a picture today (I think it was a screen capture from the Apollo 11 documentary).

It was a view out across the Moon’s horizon and then total darkness. At first I felt this strange sense of dread and emptiness but then reframed the feeling into awe.

I can’t even begin to imagine what that must have felt like to be actually standing there. Or to be in that tiny little shuttle orbiting around the moon at what is essentially the height of an airplane flying across the ocean.

> Or to be in that tiny little shuttle orbiting around the moon at what is essentially the height of an airplane flying across the ocean.

Minor correction: the lander was not "orbiting" the moon, the command module was.

And it wasn't a "shuttle".

Yeah, but I didn't want to sound too pedantic (I did change it silently in my response, though).

It was not the STS orbiter commonly referred to as "the space shuttle" but it most certainly was a shuttle in the sense of taking one there and back again.

Didn't it orbit too?

I mean, sure: it was part of the Apollo spacecraft until it detached. But it didn't orbit that low from the surface of the moon, unless you want to call the descent/ascent stage part of an "orbit".

Um, I hate to be that person. But as long as the periapsis doesn’t drop below the surface, the body is still orbiting. Technically speaking, even if that event occurs i.e. it is on a descent trajectory, then it becomes a suborbital flight. In this case, that didn’t happen, according to the mission report, the spacecraft;

> The lowest measured point in the trajectory was 47 400 feet from the lunar surface. Following one revolution in the phasing orbit, about 8 by 194 miles, the lunar module was staged, and the ascent engine was used to perform an insertion maneuver at about 103 hours https://www.hq.nasa.gov/alsj/a410/A10_MissionReport.pdf

It never entered a suborbital trajectory. Consequently, it was orbiting the moon and the article is accurate.

An orbit is not defined by height for bodies with negligible atmospheres, it’s defined by velocity and (as a side effect) the apogee and perigee of the trajectory. As long the trajectory never hits the surface, it can be 1/4 of an inch above the highest surface feature under the trajectory and still be an orbit.

Huh, I thought that they were suborbital and decided to boost back up. If they completed a full ellipse then that's a pretty valid orbit, albeit I wouldn't call it one "at the height of an airplane" without qualification.

Apollo 11 is such a great documentary. They restored a lot of 70mm film and the clarity of the image is surreal.

It didn’t get screened in any cinemas where I live, but the bluray looks absolutely stunning. I wish they did a 4K release.

It was such a great documentary, I saw it twice. A tiny detail I picked up the second time around-- they gave Collins, Armstrong and Aldrin cinematography credits.

This movie keeps sounding better and better, I’m so annoyed that it didn’t show in any theatres in my hemisphere of the planet. It was pretty much a USA only release. I really want to see it, enough to fly across my country to see it, that’s a crazy day trip and a story to tell, but not enough to fly to the other side of the planet, return flights from Australia to the USA is a rather expensive trip for a movie, probably close to ten times the cost of my worst case, a cross country flight to Sydney.

I saw a trailer for Apollo 11 last night when I was at a rerun of First Man at a local cinema - the release date in the UK is 28th June so perhaps where you are also has a similar release date.

I have the same thing with many, many filmfestival films. I'm glad that there are torrents for some of them, including Apollo 11. Would love to pay for streams of filmfestival films, but there aren't many.

For Apollo 11 thankfully, there are plenty of options here: https://www.uphe.com/movies/apollo-11-2019 Scroll down a bit to find the 'find out more' heading. I used the iTunes version.

https://www.tiff.net/events/apollo-11-4k

At least some places aired it as such, but a quick Google implies there are no current plans to release it in 4k. Shame really.

I saw it in a theater. It was astounding. I bought the soundtrack. I find that when explaining what it is to other people, I have to take care to emphasize it is not the normal documentary format of: historical footage with narration, interview with participant, cut to more footage, cut back to different interview. It's a unique film because they were able to make a documentary with a "normal" film narrative entirely using real footage and no narration. I also think there's not many historical events one could do this with; most events don't have so much footage that you actually can construct a coherent narrative. (Consider: they have high quality footage of the crew getting to the rocket, going from different buildings to vans to suit prep.) And the 65mm footage is some of the highest quality film we have of 1969. Even the crowd footage is fascinating for that reason. It will certainly be nominated for a documentary Oscar.

Would the astronauts have seen only blackness? While under dark skies on Earth, we see the stars of the Milky Way. Wouldn’t the Astronauts on the moon see the same? Or does the illumination of the moon surface mask the stars?

I think the astronauts would have seen stars but the cameras would have required longer exposures to capture them.

Exposure is not the problem, dynamic range is. You could either get the stars and have surface all blown out or retain details of the surface and lose the stars.

Right, and exposure is what allows you to pick between those two cases.

At the risk of sounding like a crazy person, I'll share the words of the astronauts themselves: https://youtu.be/--AaixSNCUg?t=00m30s

Armstrong says that they couldn't see stars with their naked eyes. There seems to be a slight disagreement between him and Collins as to whether they could see stars while photographing the solar corona; Armstrong says he can't remember which stars he saw, Collins says he doesn't remember seeing any stars, and Armstrong nudges Collins with his elbow. I'm not claiming anything more than I've said, which is all there in the video linked above. I believe that those men probably landed on the moon, but don't know exactly what to make of them seeming to discreetly disagree on this topic. I could imagine a number of explanations.

It’s probably just a minor detail, the human eye is very good at adapting and perhaps a few of the moonwalking astronauts looked at the sky away from the high contrast regolith, long enough to adapt and saw some of the brightest stars, while others didn’t. As for the nudge, I suspect it was a warning, simply a heads up between fellow astronauts that poorly chosen words might become annoying conspiracy fodder for decades. They went there, they know it, the idea that their words might be used to argue otherwise is probably not their first thought when describing anything about their time on the lunar surface. To them they are describing the material evidence that we went there, so I wouldn’t be surprised if there was a shared desire to keep each other from making mistakes, likely born from years of training together.

Not saying you're wrong about the eye adapting, but note that Collins was not a moonwalking astronaut. I've considered that this could be some difference between viewing the solar corona from the command module as opposed to the surface. It could also be memory issues. Perhaps they ran so many drills with a simulated solar corona photographing sequence that the guy who stayed in the sky mixed up this experience and the real thing, whereas Armstrong knew what it actually looked like. I've entertained wilder thoughts as well, but on the whole I think there's probably a mundane, down-to-moon explanation for the disagreement and elbow nudge.

I read a description of the final approach to the moon (it might have been from Michael Collins) and how unlike the way we see it from Earth, as they got very close it filled your view and was clearly spherical — had depth — hung there like a thing made of plaster of Paris…

My jaw would be hanging open the whole time — well, you know, if I weren't in free-fall.

That's 14 kilometers for those wondering.

Thanks, I initially saw the article title as 'Apollo 10 Stopped just 47 feet from the Moon' and I thought, gee that's rather strange, why would you do that. Also, how would you do that. Thanks for saving me from embarrassment. [edit] I always read the comments before the article.

No atmosphere on the moon, technically you could orbit it at 47 feet. Just hope you miss any mountains and large boulders.

Even assuming no obstacles, gravitational perturbations due to irregularities in the distribution of the moon's mass would upset the orbit and cause a crash.

You couldn't get into a circular orbit that was always 47 feet from the surface. That's impossible anyway, because a great circle route across the moon's surface is not a perfect circle, it dips down into craters and up over mountains. But could you achieve a stable elliptical orbit whose lowest approach to the surface was 47 feet? It sounds plausible to me, if not particularly safe.

Actually it's hard to get a stable orbit around the moon at all. See https://en.wikipedia.org/wiki/Lunar_orbit#Perturbation_effec...

Nevertheless, there's a short story from the SF golden age exactly featuring a satellite orbiting a few feet off the ground. Including perfectly drilled tunnels in the elevations ...

Ah, here we go - "The Holes Around Mars" by Jerome Bixby: https://scifi.stackexchange.com/questions/143541/short-story...

I’m wondering if Apollo mission was actually using feet or meters for calculations.

https://github.com/chrislgarry/Apollo-11/blob/master/Luminar...

Code seems to use SI, but imperial in comments.

Wikipedia says: "Although data was stored internally in metric units, they were displayed as United States customary units."

https://en.wikipedia.org/wiki/Apollo_Guidance_Computer#DSKY_...

I recently found this list of spaceflight-related accidents and incidents. There are some truly harrowing experiences, including an astronaut whose helmet began to fill with water during an EVA. He was having difficulty speaking by the time he was removed from the suit.

https://en.wikipedia.org/wiki/List_of_spaceflight-related_ac...

For those not in the exclusive clique and up on the jargon: EVA = Extra Vehicular Activity.

The exclusive clique of everyone who has played Kerbal Space Program?

Never heard of it. But thanks for not calling it "KSP".

Since KSP is, of course, the Korellia Secret Police (who can be identified by a 'KSP' tattoo on the hand, which is only visible under ultraviolet light.)

How about Vektor Grafix' Shuttle from 1992: https://en.wikipedia.org/wiki/Shuttle_(video_game)

There is an EVA mission where you have to move around with the MMU.

Ivy league? Neigh - it's space camp that will keep you out of the world's most elite social networks.

Chris Hadfield told a good story about "going blind in space" in his TED talk: https://www.youtube.com/watch?v=Zo62S0ulqhA&t=31s

About the EVA

> By December, 2013, NASA had determined the leak to have been caused by a design flaw in the Portable Life Support System liquid coolant. The designers failed to take into account the physics of water in zero-g, which unintentionally allowed coolant water to mix with the air supply.

They did not take into account that a space suit will primarily be used in… space. wat?!?

>> The designers failed to take into account the physics of water in zero-g, which unintentionally allowed coolant water to mix with the air supply.

> They did not take into account that a space suit will primarily be used in… space. wat?!?

That's not entirely fair. It's easy enough to know that something will be used in particular circumstances, but not to realise all of the consequences. Water behaves very, very weirdly in microgravity as compared with here on Earth, and unless you, personally, have experienced it and experimented with it, it's very, very easy not to notice something, or to expect something other than what actually happens.

I went digging because I was confused about that too, from https://en.wikipedia.org/wiki/Luca_Parmitano#Expedition_36/3...

> Engineers found that contamination had clogged one of the suit's filters, causing water from the suit's cooling system to back up.

So one of the failure scenarios didn't behave well in zero gravity, I think that's (more) reasonable.

Parmitano is going back to the ISS in July. Also he is going to be the first Italian to take command of the space station.

Dave Wolf told stories about his EVAs to Radiolab. It's a good listen: https://www.wnycstudios.org/story/242184-dark-side-earth

Why didn't the Apollo 10 astronauts fly back up as part of Apollo 11 since they handled their mission so well and the 11 was pretty much identical?

Maybe because it was considered too stressful to do two missions close like that?

Maybe because that's how the military do things - recce and offensive action are usually done by different units or subunits within a unit, with the recce briefing the other group.

Also, the effects of space travel were barely known then. Even today we have little idea what actually happens to the human body when it's in space; only a few weeks ago, NASA published the results of the first twin study on space travel and had a lot of new and interesting findings. In the 1960's we knew even less, and given an abundance of caution, it's probably safest not to recover a crew of astronauts from the Moon and then immediately send them back to the Moon.

Right - the recce proved a fresh team could reach the moon. So that's what they did - sent a fresh team to the moon. Sending a team back to the moon would have been something untested.

Apollo 8 went to the moon and the crew didn't turn into xenomorphs. I don't think they were quite unsure what to expect out there but there were lots of other factors in the scheduling.

> Apollo 8 went to the moon and the crew didn't turn into xenomorphs.

I obviously wasn't suggesting anything as stupid as that, was I?

What I mean is I don't believe either of 'they had no idea what space would do to them' or 'they were just following some military convention' had much to do with the way they scheduled crews.

This is sort of what I was getting at with the phrase “abundance of caution”. At this time we were still quarantining people who returned from the moon.

One thing we do know (and knew at the time) is that the earth->space and space->earth transitions require a period of adjustment. The added stress of repeating this adjustment has, so far as I know, still not been tested, let alone understood.

Yes of course. But as a factor it would be far lower in importance than lots of other much more basic ones. Like, say, the fact that the missions were quite different, you have to prepare crews for them, you have to prepare backups, you have a limited set of highly trained, highly ambitious overachiever volunteers to pick from, all of whom expect to fly (in history-making missions), etc, etc, etc.

I imagine both crews were pretty well set in stone years before 10 launched.

Would make sense. If something happened to the original crew, you need to have more crews ready and already trained.

Every Apollo mission had a primary crew and a backup crew (which was usually also the primary crew of a future mission). Apollo 13 famously swapped one of their primary crew, Ken Mattingly, for backup Jack Swigert because of a risk that Mattingly had contracted rubella. Mattingly was in good health, however, which allowed him to help NASA figure out how to keep the astronauts alive after the failure of the service module.

Ironically Apollo 13 was the final spaceflight for all three of its crew but Mattingly went on to fly on Apollo 16 and a couple shuttle missions.

The Apollo 11 backup crew was the prime crew for Apollo 13.

Crew scheduling was somewhat messy, but generally the backup crew for a mission were the prime crew for the next+2 mission. (13 and 14 crews were swapped for reasons).

Let’s not forget that these were all very complicated missions and not duplicative. It would be nearly impossible to train for two at once, and do it well. Too disfocussing.

This was a duplicate mission, at least according to the article.

Well, you know, except for descent, touchdown, exiting the lunar lander, performing some exploration, gathering moon rocks, re-entering the lunar lander, take-off, and lunar orbit insertion.

Yes. Identical, apart from those things.

It was an extension of the mission they just went on.

The mission details were quite different so there would have been no time for training. In addition they tried to rotate the crews and not rely on a few people.

Then you end up like the tech company where only one guy does deployments, because he's the only guy management trusts, because he's the only guy who's ever done a deployment.

FYI, 47k feet is 14325 meters.

Anyone who has played Kerbal can tell you the hardest part of this mission is getting back to the orbiter.

I wish I had a gaming PC for that (hit rock bottom). Guess I'm gonna watch YouTube instead?

It's obvious, it had to be the 11th mission.

(/joke).

"47k feet"? Metric prefixes on American units, interesting. There's hope! :)

Hey, we tried. This is the closest we’ll get. It’s an inter-unit handshake.

This is aviation standard. Nothing special.

"47 kilofeet"

My preferred term is "47 kilofeeters"

Shortened to "kliffs".

HN's software (or sometimes mods) abbreviate large numbers in this way because they are often used as attention-getting devices, a.k.a. bait, in titles.

It would be oxymoronically metric if the k attached to the unit, but it attaches to the number.

Actual title is “Why Apollo 10 Stopped Just 47,000 Feet From the Moon”.

Yes, but HN's software sometimes takes out leading "Why" because it tends to be a clickbait device, and many titles work just fine without it.

Stopped? Yeah right

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