Comments on: This is a post that explains the sky flying thing that makes a lot of noise and fire

This is a post that explains the sky flying thing that makes a lot of noise and fire

Brandon Blatcher — Mon, 19 Nov 2012 18:11:40 -0800

XKCD explains explains the major parts of the Saturn V rocket.

By: user92371

user92371 — Mon, 19 Nov 2012 18:17:28 -0800

"City, we are go for Up Goer Five, over."

By: fiercecupcake

fiercecupcake — Mon, 19 Nov 2012 18:20:42 -0800

Nice! As a kid growing up in Clear Lake, home of the Johnson Space Center, which still has a Saturn V hanging out by the entrance [though it's now housed and not immediately visible and exposed to corrosion anymore], I got regaled with a much more technical version of this fairly often from my scientist dad, but I really could have used this one. "Bad problem," indeed. I get a little nostalgic for that rocket sometimes -- I can't imagine how many times I've passed it in my life. This would make a great poster.

By: Artw

Artw — Mon, 19 Nov 2012 18:22:10 -0800

Ooh! I did not know about the use of the air that makes you talk funny to fill up the space left by cold air you burn - that makes A lot of sense now I think about it, cool.

By: deo rei

deo rei — Mon, 19 Nov 2012 18:24:42 -0800

Sniff. I get all sentimental looking at it. Isn't it one of the most beautiful machines ever built?

By: Scientist

Scientist — Mon, 19 Nov 2012 18:33:28 -0800

Still the greatest rocket of all time, if you ask me.

By: kafziel

kafziel — Mon, 19 Nov 2012 18:43:53 -0800

By: ardgedee

ardgedee — Mon, 19 Nov 2012 18:46:28 -0800

xkcd's mentioned his fascination with Simple English Wikipedia before. It can be hard to explain what you do. Now try explaining some abstruse bit of it to somebody who doesn't understand the general context of your profession's jargon -- explaining nuclear physics to your grandmother, or literary theory to a statistician. Now try writing that explanation for strangers, using a vocabulary and grammar that's constrained according to certain rigorous rules. It's not a shallow exercise. Explaining what you do to people who don't understand it is the essence of education. These extreme disjoints of topical complexity and linguistic simplicity are kind of stunty but at the same time it seems like a good way to make oneself aware of how many assumptions we make of our audiences sometimes. It's practically Oulipian, but saying that is probably self-defeating.

By: LobsterMitten

LobsterMitten — Mon, 19 Nov 2012 19:16:26 -0800

I saw this yesterday and really enjoyed it. I think part of what makes talking to young kids fun is that this kind of simplifying exercise is itself so intrinsically fun and satisfying.

By: dry white toast

dry white toast — Mon, 19 Nov 2012 19:36:09 -0800

A little surprised 'moon' isn't a more common word. But, as always, great job xkcd.

By: localroger

localroger — Mon, 19 Nov 2012 19:46:41 -0800

I'm kind of surprised that often is one of the ten hundred words used most often. And because they had a really big problem with that part once, I kind of hear the whole thing in Tom Hanks' voice.

By: eriko

eriko — Mon, 19 Nov 2012 19:46:52 -0800

Still the greatest rocket of all time, if you ask me. No. Energia was a better basic design, and had the most powerful rocket motors ever built, the RD-170. It didn't have quite the throw weight that that the Saturn V did (88vs118 tons LEO, 32 vs 45 tons to the moon) but it was shorter than the Shuttle stack, massed 2/3rds of the Saturn V, and cost basically a *tenth* as much. What killed Energia was two things. One was the Soviet Union becoming, well, not. The other is a hard fact of life. There is simply no real use for 75+ tons to LEO other than manned space exploration, and nobody's willing to pay the bills for that. It also had what has to stand as the most heart stopping launch of any successful boost. At liftoff on it's first launch, it started to fall over until the attitude control system woke up. The booster performed flawlessly after that -- the payload failed, but the booster did it's job just fine. And compared to the N1, it was a gem in the fact that it didn't blow up. The 2nd launch, the launch of the Buran shuttle, was flawless. If I had to go to the moon RIGHT NOW, I'd be trying to build Energias, not Saturn Vs. For one thing, they still make the engines.

By: zardoz

zardoz — Mon, 19 Nov 2012 20:03:31 -0800

K O Y A A N I S Q A T S I I I I I...

By: localroger

localroger — Mon, 19 Nov 2012 20:04:14 -0800

No. Energia was a better basic design Yeah but achievement counts, and Saturn actually went to the fucking Moon. That loss of tons to the Moon also isn't trivial. An Energia-based mission would have probably needed two liftoffs and Earth orbit rendezvous to mate systems. That would really suck if one of the two launches failed. Later designs would of course be better than Saturn, DUH. (Don't need no "ring where the computers are" now. And wow the computer models for aerodynamics and engine design, wouldn't those guys in the 1960's loved to have those.) But the thing is Saturn did what nothing did before and what nothing has done since, and until something else does it it's the rocket that will be enshrined in myth. (Doesn't hurt that they replaced the moon going booster stage with an entire space station for a pretty successful mission pre-ISS, too.)

By: loquacious

loquacious — Mon, 19 Nov 2012 20:07:12 -0800

If anyone wants to try writing anything like this with just a thousand word vocabulary list an XKCD fan wrote an online editor called Up-Goer Five Text Editor. Considering that my username is more of a dire warning than an idle boast and that the main strength of the English language is made up words and nonsensical bullshit I find it to be excruciatingly painful to use.

By: localroger

localroger — Mon, 19 Nov 2012 20:07:21 -0800

Oh, has anyone told the SpaceX people that the RD-170 engines are still being made?

By: localroger

localroger — Mon, 19 Nov 2012 20:09:49 -0800

LOL according to the editor loquacious links, "fuck" is permissible.

By: Zalzidrax

Zalzidrax — Mon, 19 Nov 2012 20:18:01 -0800

This end should point toward the ground if you want to go to space. If it starts pointing to space, you are having a bad problem and you will not go to space today. Reading this, I am reminded that I haven't played Kerbal Space Program in a while...

By: ovvl

ovvl — Mon, 19 Nov 2012 20:24:35 -0800

No. Energia was a better basic design The R-7 Semyorka was more ominous-looking.

By: Rhomboid

Rhomboid — Mon, 19 Nov 2012 21:06:56 -0800

If anyone is curious why they bothered with different fuels, it's due to the fact that for a given engine size, you can get much more raw thrust out of RP-1 (technical term for highly purified kerosene) than hydrogen due to the fact that the molecules of the combustion product are more massive, and Newton's laws, etc. However, hydrogen's lightness means you get a higher specific impulse, which is the moral equivalent of a MPG rating for fuel efficiency of rockets. Apollo 11 used five giant F-1A engines for the first stage where the grunt work of lifting all that mass was greatest, and then the more efficient hydrogen burning F-2 engines for the second and third stages after a lot of mass had been shed. Because of the sheer amount of thrust and that lower specific impulse (i.e. being a gas guzzler muscle car) the combined flow rate (kerosene + LOX) of the first stage was just crazy -- around 670 gallons per second per engine, or 3,360 gallons per second total across all five. The RS-25 (Space Shuttle main engine) by comparison had a flow rate of 350 gal/s. You can't just stick a pipe in a tank and expect fuel to flow out that fast, you have to build a hell of a pump to do it. And even more impressively, the F-1/F-1A did it with a single turbine that powered both pumps at once, which was fed by a 55,000 HP gas generator. So in a very real sense, putting a man on the moon came down to building a pump, among countless other things of course.

By: Rhomboid

Rhomboid — Mon, 19 Nov 2012 21:13:12 -0800

(Arg, J-2 for the upper stages, not F-2. Missed the edit window.)

By: bleep

bleep — Mon, 19 Nov 2012 21:15:27 -0800

Your favorite spacecraft sucks.

By: drdanger

drdanger — Mon, 19 Nov 2012 22:07:53 -0800

A little off topic, but I couldn't resist the editor: To be or not to be, that is the question: Whether it is better in the mind to be hurt By the pain that life throws at you, Or to take arms against life's troubles And end them by force? To die, to sleep; No more; and by a sleep to say we end The heart's pain and all the many shocks That come to living humans. It is an ending everyone should want. To die, to sleep; To sleep: perhaps to dream: yes, there's the rub; For in that sleep of death what dreams may come When we have slipped out of our bodies, Must make us stop and think. That's the reason That we keep going through life's problems. For who would take time's hurting again and again, The mean man's bad act, the high man's bad words, The pain of one-sided love, the wait for truth, The wrongs of those in power and the bad things That good people should not have to take, When he himself might end it with a cut? Who would carry something heavy, Would tired and hot pull it through life, But that the fear of something after death, The strange place from which No one returns, holds the will in check And makes us stay with the problems we have Than fly to others that we know not of? In this way our minds keep us in fear; And in this way our own true power Is made soft and sick by thinking. And great important plans By such thoughts are turned and lost And are not acted on. Oh! Here is the beautiful girl! In your songs be all my faults remembered.

By: flaterik

flaterik — Mon, 19 Nov 2012 22:23:18 -0800

3,360 gallons per second total Oh yeah, that's what boggling feels like

By: communicator

communicator — Mon, 19 Nov 2012 22:55:49 -0800

drdanger I am impressed by how much is retained

By: Ripper Minnieton

Ripper Minnieton — Mon, 19 Nov 2012 23:13:38 -0800

It's prose that make you feel dumber as you read it - and yet, I now know more about how a Saturn V rocket works than I ever have before: as a technical writer, this is very interesting.

By: ActingTheGoat

ActingTheGoat — Mon, 19 Nov 2012 23:26:17 -0800

I like the comic, but I was surprised at how much I enjoyed 8:43 of the annotated, slow motion lift off and subsequent pouring water.

By: ...possums

...possums — Tue, 20 Nov 2012 00:04:02 -0800

Travel to space made more simple.

By: hades

hades — Tue, 20 Nov 2012 02:32:00 -0800

A friend of mine did something similar: Albert Einstein's Theory of Relativity (In Words of Four Letters or Less)

By: MartinWisse

MartinWisse — Tue, 20 Nov 2012 03:38:41 -0800

Bah The Mad Ape Den (rip) did jot all in one or two or two or one but no two and two nor two and two and one. To say how the big 5 did go off the Orb in one and two or one and one, now it is a big ask of thy.

By: Thorzdad

Thorzdad — Tue, 20 Nov 2012 04:11:39 -0800

Manned space flight is one of the few reasons I miss my childhood. Growing-up during the years of Mercury, Gemini, and Apollo was really, really cool.

By: Metroid Baby

Metroid Baby — Tue, 20 Nov 2012 05:02:21 -0800

"This end should point towards the ground if you want to go to space. If it starts pointing toward space, you are having a bad problem and you will not go to space today." For some reason, the way those sentences are phrased makes me break out in the giggles every time I see them. "I will not go to space today" has become my new favorite thing to say when I'm having a bad day. It's like an English version of the stuff Bumblebee Man yells on The Simpsons.

By: ricochet biscuit

ricochet biscuit — Tue, 20 Nov 2012 05:10:31 -0800

We look for things to make us go.

By: ricochet biscuit

ricochet biscuit — Tue, 20 Nov 2012 05:13:55 -0800

Also: that's one small step for man, one big jump for everyone. (Thanks, text editor.)

By: cog_nate

cog_nate — Tue, 20 Nov 2012 06:16:27 -0800

Goes well with "Apollo Flight Controller 101: Every console explained" and "Going boldly: Behind the scenes at NASA's hallowed Mission Control Center".

By: DU

DU — Tue, 20 Nov 2012 06:40:08 -0800

xkcd's mentioned his fascination with Simple English Wikipedia before. It can be hard to explain what you do. Now try explaining some abstruse bit of it to somebody who doesn't understand the general context of your profession's jargon... This is the exact reason I keep trying to go to the Simple English pages for math concepts I've never used before, but I'm always disappointed. Sometimes I wish the internet wasn't maintained by nerds. A BUNCH OF JARGON AND EQUATIONS IS NOT AN EXPLANATION. (Guy across the hall doesn't get this either. YOUR MATRICES AREN'T HELPING ME. DRAW A PICTURE.) But if you want to be on the explaining end, nothing beats trying to explain things to kids.

By: Mcable

Mcable — Tue, 20 Nov 2012 06:53:25 -0800

"Oh, has anyone told the SpaceX people that the RD-170 engines are still being made?" Yes. Their competition uses a variant of it.

By: Foosnark

Foosnark — Tue, 20 Nov 2012 06:54:18 -0800

http://youwillnotgotospacetoday.tumblr.com/

By: Mcable

Mcable — Tue, 20 Nov 2012 07:03:26 -0800

These guys use the RD-170. In fact the boosters on the side of the Energia are the first stage of this rocket.

By: Brandon Blatcher

Brandon Blatcher — Tue, 20 Nov 2012 08:21:29 -0800

This end should point toward the ground if you want to go to space. If it starts pointing to space, you are having a bad problem and you will not go to space today. This happened on Apollo 6, which was thankfully unmanned (my addition is in italics):.

After the two engines had gone out, the vehicle had maintained a pitched-up attitude known as chi-freeze for far longer than it would have under ordinary circumstances. "Well, the S-IVB lit up," Flight Dynamics Officer Jay Greene recalled, "and the first thing it said was, 'Omigod, I've got too much altitude.' And so it pointed its nose straight at the center of the earth." This battle between the guidance system and the gimbal limits on the engine continued for about eighty seconds, with Greene getting closer and closer to an abort call of his own. When the S-IVB finally gave up trying to get to the altitude it wanted, it had a flight-path angle that was unacceptably low. "So then the little devil said, 'Well, this is bad, I've got to pick up the flight-path angle,' so it started pitching up, and as it started pitching up it said, 'Now I'm over speed,' so it actually went into orbit thrusting backward." The plot boards showing where the Saturn had wandered looked as if a drunk had been drawing the trajectory. It was without question the most exciting powered launch anybody in the MOCR had ever witnessed. "A fascinating flight," Greene said tersely—his very first shift in the MOCR. What was he doing all this time? "Puckering."¹

The next time a Saturn V was launched, it was manned and the mission was Apollo 8, the first time humans orbited the Moon. That was a helluva bold step. 1. Cox, Catherine Bly; Charles Murray (2004-07-29). Apollo (Kindle Locations 5157-5158). South Mountain Books. Kindle Edition.

By: ckape

ckape — Tue, 20 Nov 2012 10:41:34 -0800

I just want to point out how cute the Saturn IB (from Apollo-Soyuz) looks, sitting on its booster seat so it can use the big boy gantry.

By: Galaxor Nebulon

Galaxor Nebulon — Tue, 20 Nov 2012 11:08:19 -0800

Here's my plan for how to get small things to space cheap. First, use balloons to lift up some sort of launch platform. Next, use ground-based lasers to heat up some gas stored in the rocket. Don't perform chemical reactions on the rocket, and don't bother lugging any oxygen around with you to perform combustion with. Just heat it up with lasers and let it spew out the back. Get to orbit this way. Next, deploy an IKAROS-style solar-sail. Now you can go anywhere. Sincerely, the Galaxor Nebulon Space Agency.

By: jjj606

jjj606 — Tue, 20 Nov 2012 16:18:49 -0800

Because of the sheer amount of thrust and that lower specific impulse (i.e. being a gas guzzler muscle car) the combined flow rate (kerosene + LOX) of the first stage was just crazy -- around 670 gallons per second per engine, or 3,360 gallons per second total across all five. Here's the famous ultra slow motion Saturn V liftoff youtube clip. It has an appropriate Bach organ soundtrack. And in real time, 35 seconds long. (William Tell Overture soundtrack)

By: tavella

tavella — Tue, 20 Nov 2012 16:27:15 -0800

I'm still kind of surprised that "escape" is one of the thousand most common words, but "thousand" isn't.

By: localroger

localroger — Tue, 20 Nov 2012 16:32:45 -0800

Wow, it is really eerie how well the Toccata and Fugue in D Minor scores that slow motion launch footage.