How NASA brought the F-1 “moon rocket” engine back to life (2013)

https://arstechnica.com/science/2013/04/how-nasa-brought-the-monstrous-f-1-moon-rocket-back-to-life/

109 66 2 years ago

ofalkaed• 2 years ago

As with everything else about the F-1, even the gas generator boasts impressive specs. It churns out about 31,000 pounds of thrust (138 kilonewtons), more than an F-16 fighter's engine running at full afterburner, and it was used to drive a turbine that produced 55,000 shaft horsepower. (That's 55,000 horsepower just to run the F-1's fuel and oxidizer pumps—the F-1 itself produced the equivalent of something like 32 million horsepower, though accurately measuring a rocket's thrust at that scale is complicated.)

jcims2• 2 years ago

That factoid, that the fuel pump on an F-1 was 55,000 horsepower, has stuck in my mind since the time I first read it. It's so mind-boggling. I would love to just experience the moment when the engineers on the program realized that this is what they needed to build and all they had was paper and pen and the will of a nation.

foobarian• 2 years ago

What really gets me is that SpaceX's Raptor engines have fuel pump power in that same neighborhood, and there are 33 of them on a Starship.

spiritplumber3• 2 years ago

I had a chance to do some electronics work on an oceanic tug and at the time it blew my mind that the starter for its main engine was about the size of a semi truck's engine. They'd start that one electrically, let it warm up, then use it to start the big engine, then they'd switch it to being a generator for lights and radio and so on.

tigerlily• 2 years ago

Just imagining that many horses on that space chariot.

M_bara• 2 years ago

There goes the god Apollo…

HPsquared2• 2 years ago

I wonder how they calculated that "32 million horsepower" figure. Is it in terms of kinetic energy of the exhaust stream, thermal combustion energy, or some other formulation (e.g. vehicle speed wrt Earth * thrust)?

DarmokJalad1701• 2 years ago

It is from the kinetic energy of the exhaust.

Power = Force * Velocity = Thrust * exhaust velocity = Thrust * Specific Impulse * 9.80665

dmd• 2 years ago

That's utterly insane. 32 million horsepower is ~24 gigawatts. That's roughly the same power as ALL OF CALIFORNIA.

dotnet005• 2 years ago

It is useful to add that the tradeoff is that the engines are running for far less time than, well, California. It's still an incredible feat of engineering to pull off those kinds of energy densities though.

sigmoid10• 2 years ago

Well, if all of California's energy were produced by petrol (~13.1kWh/kg), it would consume about 900l per second. The F1 burns about 920l of RP1 fuel per second. And it has to bring its own oxidizer along for the ride.

thereisnospork• 2 years ago

What I'm hearing is that California needs to step it's game up.

dotancohen2• 2 years ago

The fine article is from 2013 (thanks sjsdaiuasgdia). So it contains outdated information about the Saturn V legacy:

  > There has never been anything like the Saturn V, the 
  > launch vehicle that powered the United States past the Soviet
  > Union to a series of manned lunar landings in the late 
  > 1960s and early 1970s. The rocket redefined "massive,"
  > standing 363 feet (110 meters) in height and producing a 
  > ludicrous 7.68 million pounds (34 meganewtons) of thrust
  > from the five monstrous, kerosene-gulping Rocketdyne
  > F-1 rocket engines that made up its first stage.

Just this June the fourth Starship prototype flew, both taller (122 meters) and more powerful (74 meganewtons of thrust, twice that of the Saturn V).

sjsdaiuasgdia• 2 years ago

Check the date on the article - 4/14/2013

dotancohen2• 2 years ago

Thank you!

@dang, can we add the year to the headline? Thank you.

vhodges• 2 years ago

TFA was written in 2013... much before the BFR/MCT presentation was done let alone realised a scant 11 years later.

I do think it was an interesting option to replace the SRBs on SLS but alas we'll never know.

uticus• 2 years ago

2013, needs date

adolph• 2 years ago

Rocketdyne developed the F-1 and the E-1 to meet a 1955 U.S. Air Force requirement for a very large rocket engine. . . . The Air Force eventually halted development of the F-1 because of a lack of requirement for such a large engine. [0]

The fifties were such a crazy time where the USAF would commission wild things which in development were superseded or mooted by other developments, leaving the commissioned object as a cast-off vision of a future that didn't happen. Maybe the high point of this was the XB-70 Valkyrie. [1]

Today is the first day that I put two and two together on North American Aviation making both the XB-70 and the B-1: To take maximum advantage of [compression lift], they redesigned the underside of the aircraft to feature a large triangular intake area far forward of the engines, better positioning the shock in relation to the wing.

To bring things full circle, in 1955 NAA spun off its rocket division, which became Rocketdyne, the maker of the F-1 among other engineering marvels.

0. https://en.wikipedia.org/wiki/Rocketdyne_F-1

1. https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie

birdiesanders• 2 years ago

I never connected the b-1 and the Valkyrie, either. That’s a fascinating thought, the B-1 is the Valkyrie that we had all along.

jdougan• 2 years ago

Well, the B-1A was the Valkyrie that we had all along. The B-1B was more, "Man, I really wish we had a stealth bomber".

ethbr1• 2 years ago

To explain it somewhat, that was also pre-MAD (in the modern sense, since ~1975), which meant a combination of (a) sudden potential existential threats & (b) rapid technological change.

In that environment, it was more reasonable to run parallel development projects, as one didn't want to be caught flat-footed if one approach failed (e.g. SLBM + ICBM + bombers).

cmdrriker• 2 years ago

Fear and naivete are powerful motivators, catalyzing these early innovations. More often the realities of budget, politics, and competing priorities hampers the same creative energies.

flerchin• 2 years ago

referred to in shorthand as "LOX/RP-1" or just "LOX/RP" engines

Did we invent kerolox as a portmanteau in the last 10 years? This article is a total time warp.

JumpCrisscross3• 2 years ago

At least several decades, into the Space Shuttle era. But maybe not Apollo era.

schmidtleonard• 2 years ago

I usually hear the term "kerolox" in the context of methalox vs kerolox discussions (and hydrolox, but I often hear that just called "hydrogen"). Methalox is relatively new, at least as a front-running contender, so the numerical majority of these discussions (and by extension use of the terms and consensus around the terms) probably did happen in the last 10 years, even though the roots go much further back.

HPsquared2• 2 years ago

It's the language barrier between online forums and "the real world". Increasingly blurred, but still present.

supportengineer• 2 years ago

How did managers approve this and sell this up the chain to other managers?

spiritplumber3• 2 years ago

"We have to beat the Russians to the Moon".

Designs for this magnificent beast were probably started shortly into the Sputnik scare. At the time, the Soviet space program technical capabilities were overestimated by almost everyone because the Soviets managed to hit a bunch of milestones first by, essentially, being OK with taking on more risk.

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

akira2501• 2 years ago

"We have to exploit the resources gained in Operation Paperclip before anyone else does and we need sufficient public justification for it."

It's absolutely bizarre to me to watch ancient Disney videos featuring Wernher von Braun discussing guided missiles and doing his best to downplay his German accent.

avmich7• 2 years ago

At the time, the Soviet space program technical capabilities were overestimated by almost everyone

Correction: Soviet (liquid fuel) rocket engines became world state of the art in 1950-s and mostly remained as such till about 2010. Rocket engines is the technology which is enabler to most - relatively simple, looking from today - space flights of 20th century.

One can't hit a bunch of milestones first just by chance - you have to have something behind it, and in addition to engines there were a lot of less-than-announced flights - remember how the back side of the Moon was successfully photographed only on the third flight and soft landing on the Moon took quite a few more attempts?

One can't be about as successful as the other guy in terms of deaths in space just because of luck - corner cutters were on the both sides of the Iron Curtain, but there were also understanding that you'll lose all your advantage by just having a few more deaths. No amount of successes in unmanned flights will help (because people are much more interested in manned flights), so you just can't really allow people to die - in USSR you could also have very personal displeasures of uncomfortable size.

In "History of Liquid Propellant Rocket Engines" George Sutton mentions that USSR made about 10 times more liquid fuel rocket engine designs than USA. That should bring some perspective to the matters.

mhh__• 2 years ago

They got lucky, they clearly didn't consult enough stakeholders

zombot• 2 years ago

NASA is currently hitching space rides with the Russians.

If this doesn't spell defeat, I don't know what does. The richest country in the world is too poor for space launches. Or too cheap.

How NASA brought the F-1 “moon rocket” engine back to life (2013)

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