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Soviet Moon Rocket
TestBoy writes "There is a decent article about the Soviet Union's moon rocket and why it was doomed to fail. From one of the pictures on the website, you realize how large just one of its multiple engines were."
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Nooo, the first stage of the Saturn V used Kerosene and LOX too. Despite the higher power offered by liquid hydrogen, Koelle's studies indicated that little would be gained by using it in the first stage also, where it would have needed disproportionately large tanks. (Liquid hydrogen is only one twelfth as dense as kerosene, so a much larger tank volume would have been required.)
Eve Fairbanks says I drive a hybrid!LOL
When things go BOOM, this is technically not a good thing.
Here is a summary of the Russian lunar launches. Here is the data from 1969
Jan. 20, 1969 7K-L1/ 13L - Circumlunar UR-500 Launch failure
Feb. 19, 1969 E-8 - Lunar rover 8K82K (UR-500) Failed to reach orbit
Feb. 21, 1969 7K-L1S - Circumlunar N-1 / L3 Exploded during launch
June 14, 1969 E-8-5 #402 - Sample return UR-500 Failed to reach orbit
July 3, 1969 7K-L1S - Circumlunar N-1 / 5L Exploded at launch
July 13, 1969 E-8-5 Luna-15 Sample return UR-500 Crashed on lunar surface
Aug. 8, 1969 7K-L1 Zond-7 Circumlunar UR-500 Flew around the Moon
Sept. 23, 1969 E-8-5 Cosmos-300 Sample return UR-500 Failed to leave Earth orbit
Oct. 22, 1969 E-8-5 Cosmos-305 Sample return UR-500 Failed to leave Earth orbit
Give them points for effort.
"It is a greater offense to steal men's labor, than their clothes"
Nope, sorry, but thanks for trying.
To clarify, the name "Saturn V" refers to an assembly of several stages: the S-IC, S-II, and S-IVB. The first and biggest stage, the S-IC, was a pure LOX-kerosene stage. Its F-1 engines (1.5 million pounds thrust each) burned kerosene, only the upper stages burned hydrogen.
This makes a lot of sense -- "efficiency" (in terms of Isp) is only one figure of merit in rocket engines. It's more relevant when the engine no longer has to lift the mass of the vehicle against gravity. For lifting power (as with a first stage), you care about thrust, which is proportional to the mass of the exhaust products (and thus the mass of the fuel). Hydrogen is just too light to generate useful thrust except at very high exhaust velocities, which means very high engine pressures, which means heavy engines, etc, etc. (Also, because of LH2's low density, you need bigger fuel tanks, which weigh more, etc, etc.)
Case in point, the three Shuttle SSMEs together (which burn LO2/LH2) have barely more thrust than a single F-1 engine, and run at a much higher chamber pressure.
There's a reason the Shuttle uses those god-awful, low Isp solid boosters -- to create enough thrust to get off the pad!
-- Alastair
Mishin, Sergei Korolev's successor, was not an experienced engineer. This was a major factor in the failure of the N-1 program.
Korolev, on the other hand, was very successful -- a rocket sharing the same basic design as the one that launched Sputnik 1 was rolled to the launch pad in support of a Progress freighter launch to the ISS. When?
This morning.
i am a soviet space shuttle
All the 30 first stage motors are identical Kuznetsov Design Bureau NK-33's generating 154 metric ton's of thrust each.
There is a lot of debate about why the Soviets chose this approach, but for me its a combination of three reasons:-
a) Previous Soviet Rockets were also based on the "many small engines" approach - they worked fine. (Even if it was not the most efficient approach)
b) A key reason the the N-1 ended up with 30 NK-33 engines instead of something more manageable was political infighting. The Soviet chief engine disigner Glushko had an intense argument over fuel choice with the N1 designer Korolov and ended up taking experience to the Soviet military with the UK-500 and 700 boosters. That left Korolov with no engine designer and in the end the N-1 had it's engines designed from existing templates.
c) At the time there were real doubts over the feasibility of combistion stability in engines with large injector surfaces. (Ie - large engines). It took Rocketdyne many, many tests to get the F-1 to work. The Soviets felt that developing these large engines was simply too risky (and expensive), despite the obvious efficiency gains.
Encyclopedia Astronautica is a great, and I mean the best, site on the internet for rocketry info. Here are some of their links to the N-1, and reasons why they built it the way they did:
THe N-1 StoryMore technical than the bbc article
Soviet space history, broken down by year
great site with a ton of content if you want to waste a few hours.. =)
Now that you've read all the posts about how the Russian space program is done, read this Wired article (http://www.wired.com/wired/archive/9.12/rd-180.ht ml) that describes how US companies are launching their payloads using Russian propulsion.
Here's a quote: "They build the thing and test the shit out of it. This engine cost $10 million and produces almost 1 million pounds of thrust. You can't do that with an American-made engine."