NASA has been analyzing the Saturn V's F-1 engine (powered the first stage) and test-firing the gas generator. There is a lot of awe expressed in the article about how meticulously and over-built those engines were. The idea is to possibly build modern versions of them.
I've thought for a very long time that the closing of the Saturn-V production line was one of the dumbest things that the Nixon Administration did.
But I digress.
If you don't feel like reading the articles, here's something I didn't know. This is a line drawing of the F-1.
On the right side, you'll see the turbine which powered the fuel pumps. The turbine's exhaust goes down the side of the engine and then into a ring surrounding the bell of the rocket's exhaust, about half-way down the length of the bell. The engineers did that for a reason: The exhaust of the turbine was fuel-rich and cooler than the exhaust of the rocket engine. Feeling the exhaust of the turbine into the side of the rocket nozzle served to protect the rest of the nozzle's length from the heat of the rocket exhaust.
You've probably seen this close-up shot of the engine of a Saturn-V firing on a test stand:
You can see the darker lawyer of exhaust at the outer edges of engine's plume. That's from the turbine's exhaust.
The engineers today think that a newer F-1 won't need to do that. They hope to get 1.8 million pounds of thrust out of a F-1B.
If they make them, I sure hope they put five together for a booster. I'd surely love to see and hear that monster fly.
Saturday, October 12, 2013
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9 comments:
I recall as an eight-year old child on the farm, my grandfather told me that whenever they launched the Saturn V, we would get rain in two days. I remember it raining two days later, but it may have just been coincidence. I wonder if that monster really did affect the weather.
I just read a lot about this engine after looking up the Atlas V on wp. Yes, it is still very much the shit!
I just remembered the jaw dropping awe I felt as a kid watching those things light off.
Somethings you just never forget and that be one of them.
Thanks for the F1 story. BTW, I don't think it's fair to really pin the blame for the closing of the program on the Nixon administration, at least not directly. At the time, the Space Shuttle program was way over budget and increasingly forcing the termination or delay of other NASA programs, including lots of unmanned/science projects. In effect, with a fixed budget, the Shuttle was crowding out other programs.
Well plus there is the fact that the only thing we need such a big rocket for is to send people to the moon. There is no commercial use for such a big rocket, there are no satellites big enough to need a Saturn V to get it into orbit and there are no space station components big enough to need a Saturn V to get to orbit. The two-F1 booster that Dinetics/Rocketdyne is proposing is more than big enough to get anything into orbit that we could possibly get there. Then there was the fact that the Apollo booster had been thrown together very quickly and basically each F1 was hand-built and quite expensive. There were single welds on the engine that took all day to weld, by hand, and there were thousands of such welds. The engineers working on the new F1 copy say that theirs has less than 1/10th the parts of the original F1 and should be easily mass produced.
So basically, the Saturn V was ridiculously overengineered in a short amount of time and could not be made cost-effective. And even then, every time it flew engineers were wincing because so much of its design was seat-of-the-pants and there were things they *knew* weren't ideal about it. If the Saturn V had flown as many times as the Shuttle, it would have blown up probably more often than the Shuttle, each launch was a throw of the dice even after the Apollo 1 review -- not all of the things found in that review were fixable within the basic Saturn V design.
So basically, while Nixon was a jerk and a criminal, the Saturn V program would have been shut down after the last two Apollo missions regardless. It simply was not cost effective. It had never been built to be -- it had been built to get men to the moon before 1970. Period. And it did that. Having done that, its time was done.
I do think it's a shame we disappeared down the STS rathole for the next three decades though. The STS system's only advantage over a regular booster was if you're returning things from orbit. But that turned out to be a capability we simply never used because it's more expensive than just sending up a new satellite.
Neil DeGrasse Tyson had an interesting observation in a discussion about his (then) new book, shown on Book Talk on C-SPAN. Here's a link to the clip—two hours, well worth watching.
In there he asserts that the Saturn V was unique in man's technological history, as it was version 1.0—we developed it, ran it for a couple dozen missions, and then shelved it. Most all other technological marvels have been continually developed, refined, improved, and used.
I loves me some NDT.
LRod
ZJX, ORD, ZAU retired
LRod, you could say the same thing about Egyptian pyramids. For many centuries they were the largest structure built by man. In the end there was no practical use for the things, they were just status items, and eventually there was no more status to be gotten by building pyramids and the Egyptians quit building them.
There was no practical use for the Saturn V either. The ability to throw a 110 ton payload into orbit is useless for any commercial purpose, commercial satellites simply are not that big. Even putting up a space station doesn't require a rocket that big. The biggest rocket used to send up the ISS was Russia's Proton rocket, which will put roughly 20 tons into orbit. That appears to be the upper limit for boosters that are commercially viable, and even then the Proton rarely flies, most launches are by rockets in the Soyuz range (roughly 6 tons to orbit). The Arienne 4 will put 7 tons to orbit, SpaceX's Falcon9 will put 10 tons to orbit and China's Long March 3B will put 12 tons into oribt, just as another set of points of comparison.
So yes, the Saturn V was a colossal accomplishments, but, like the Pyramids, had no practical use and so we quit building them, just like the Egyptians quit building pyramids. So it goes.
If you don't have the capability to do something, saying that you don't need the capability is kind of circular. We can't lift 100 tons into orbit at a whack, so everything that goes up is built to be compatible with what exists to launch it.
The other thing that a big rocket can give you is speed, which is nice to have for sending probes to distant places higher up the gravity well. Might not have to spend a few years sling-shotting things around the inner planets if we could throw them out harder.
Heck, maybe we don't need very large cargo airplanes. But the An-124s seem to stay reasonably busy.
Comrade, the 20-ton launchers (Proton, Ariane 5) launched 18 out of the 78 total launches last year, and several of those were military payloads. The Atlas V Heavy is capable of launching 20 tons to orbit but all the Atlas V launches last year were of the light or mid-weight versions, the heaviest load it launched last year was around 10 tons LEO equivalent. You'd expect that if there was significant demand for higher payloads to orbit, the 20-ton launchers would be doing the majority of launches, rather than less than 1/4th of the launches. But it's not so.
NPO Energia had a 100 ton launcher, the Energia. They still make some of the components for the Energia, which are marketed as the Zenit space launch system -- but Zenit is a 13 ton launcher, not a 100 ton launcher. You'd think that they would market the Energia itself if there were a demand for 100 ton launchers. Apparently there isn't one...
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