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How NASA brought the F-1 “moon rocket” engine back to life (2013)
- ofalkaed 2y 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.)
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- jcims 2y agoThat 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 2y agoWhat 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.
- matrix2003 2y agoWikipedia lists it as 37 MW, which does seem to be in the same ballpark (my amateur calculations put an F-16 around 44 MW). Not sure why people are downvoting you, but objectively the Raptor really is a marvel of engineering itself (maybe less than the F-1 that was created with slide rules at the time, but it does seem poised to upend space flight again).
- reportingsjr 2y agoA Raptor engine has about 1/3 to 1/4 of the thrust of an F-1 engine. However, the Raptor is far more efficient and much more impressive technically. They are really a marvel of modern engineering and science.
- JumpCrisscross 2y ago> Raptor engine has about 1/3 to 1/4 of the thrust of an F-1 engine Correct for Raptor 2. Raptor 3 is closer to half [1][2]. [1] https://en.m.wikipedia.org/wiki/SpaceX_Raptor https://en.m.wikipedia.org/wiki/SpaceX_Raptor [2] https://everydayastronaut.com/raptor-engine/ https://everydayastronaut.com/raptor-engine/
- RoddaWallPro 2y agoI have what is probably a dumb question: How can a Raptor turbopump need almost double the HP of a F1 while putting out 1/3 or 1/4th the thrust? (Assuming Elon's 100k HP number was correct, and/or hasn't changed). That just doesn't settle out for me. If it's got double the power, it should be moving double the fuel, so double the power, no?
- TaylorAlexander 2y agoMaybe something to do with pressure. Maybe it is higher chamber pressure and maybe higher pressure even with lower flow rates could require more power.
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- tliltocatl 2y agoRaptor has much higher chamber pressure (35 MPa vs 7 MPa of F1) and hence higher Isp (380 vs 304 in vacuum).
- hereme888 2y ago[flagged]
- indoordin0saur 2y agoThere are many brilliant people at SpaceX, not just the one. Your opinion of him (negative or positive) shouldn't affect the very clear assessment that what the SpaceX team has accomplished is amazing.
- JumpCrisscross 2y ago> have fuel pump power It’s slightly wilder. Raptor uses 100,000 hp per engine [1]. That is two F-1 scale turbo pumps per engine, i.e. 66 pumps altogether. All for the dress rehearsal. [1] https://x.com/elonmusk/status/1076618886932353024 https://x.com/elonmusk/status/1076618886932353024
- trhway 2y agoThe even more impressive here is the power/weight ratio - about 2000hp/kg (whole Buggati engine in 1 kg). (My speculative estimate - the Raptor turbine in the turbopump can hardly weight more than 500 kg as the whole engine is 1600kg -> whole turbopump less than 1000kg -> the driving turbine is half of it max). So anybody who plans to beat Musk/SpaceX (like i do when i finally get a real garage :) has a very high bar to clear. Additional facet is that Raptor turbopump is full flow and thus runs at very low (relative to other gas turbine machinery out there like for example F-16 at 1200C+) temps like 500-600C which means that the power can still be almost doubled with the same regular materials they use - steel and Inconel (and this is what we're seeing - about 1.5X power increase from Raptor 1 to Raptor 3 in a span of mere few years while the engine weight is even decreasing a bit)
- reddog 2y agoBut even MORE impressive is the current raptor engines cost between $1m to $2m each with a target cost of $500k when in full production. The F-1 cost an inflation adjusted $85m-$100m each. And the raptors are reusable.
- matrix2003 2y agoYep! I understand why people don’t like Musk, but SpaceX is doing some truly amazing work.
- avmich 2y ago> (like i do when i finally get a real garage :) Cool :) > Additional facet is that Raptor turbopump is full flow and thus runs at very low You write it further yourself, but rocket turbopump turbines aren't running with cold gas - the hotter the input gas, the more energy can be provided to pumps, so turbine blades have roughly the same requirements as those in F-16. The design on those blades is pretty complex, with materials, processes and substructures like internal cooling channels - all to reach possibly higher temperature to work with.
- spiritplumber 2y agoI 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.
- paulkrush 2y agoSo this starter itself was a engine(ICE)?
- Dennip 2y agoDunno about OP, but old CAT bulldozers used to have smaller engines to start the main engine, before starter tech improved, iirc they were called "Pony engines(motors)"
- sethrin 2y agoWhich tug?
- spiritplumber 2y agoHeidi Brusco
- sethrin 2y agoNeat. I visited Valdez, Alaska lately and a friend was pointing out the tugs there. They seemed somewhat larger than other tugs I've seen. A data sheet says they have about 4x the horsepower of Heidi Brusco, coming from a pair of CAT C280-16 engines. I'm not clever enough to figure out how those are started. Cool boats are cool
- tigerlily 2y agoJust imagining that many horses on that space chariot.
- M_bara 2y agoThere goes the god Apollo…
- HPsquared 2y agoI 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 2y agoIt is from the kinetic energy of the exhaust. Power = Force * Velocity = Thrust * exhaust velocity = Thrust * Specific Impulse * 9.80665
- dmd 2y agoThat's utterly insane. 32 million horsepower is ~24 gigawatts. That's roughly the same power as ALL OF CALIFORNIA.
- dotnet00 2y agoIt 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 2y agoWell, 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 2y agoWhat I'm hearing is that California needs to step it's game up.
- avmich 2y agoWait till you learn about the power of femtosecond laser pulses...
- dotancohen 2y agoThe 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 2y agoCheck the date on the article - 4/14/2013
- dotancohen 2y agoThank you! @dang, can we add the year to the headline? Thank you.
- vhodges 2y agoTFA 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 2y ago2013, needs date
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- adolph 2y agoRocketdyne 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 https://en.wikipedia.org/wiki/Rocketdyne_F-1 1. https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie
- birdiesanders 2y agoI 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 2y agoWell, 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 2y agoTo 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).
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- flerchin 2y 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.
- JumpCrisscross 2y agoAt least several decades, into the Space Shuttle era. But maybe not Apollo era.
- schmidtleonard 2y agoI 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.
- HPsquared 2y agoIt's the language barrier between online forums and "the real world". Increasingly blurred, but still present.
- supportengineer 2y agoHow did managers approve this and sell this up the chain to other managers?
- spiritplumber 2y 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 https://en.wikipedia.org/wiki/Sputnik_crisis
- akira2501 2y 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.
- avmich 2y 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.
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- zombot 2y 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.