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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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I don't know why they had so much trouble getting the thing to work. This isn't rocket sci.... oh. Never mind.
From the University of Texas website:
N-1 Stages
30 NK-33 LOX/kerosene engines; 10.1 million lb. total thrust.
8 NK-43 LOX/kerosene engines; 3.1 million lb. total thrust.
4 NK-39 engines; 360,800 lb. total thrust.
1 NK-31 engine; 90,200 lb. thrust; trans-lunar boost stage.
1 engine; 19,200 lb. thrust; lunar orbit insertion & initial lunar descent stage.
Why didn't they use fewer, but more powerful engines? Was it a matter of money, or engineering?
From one of the pictures on the website, you realize how large just one of its multiple engines were
The photo shows the base of the N1, inside which were housed 30 smaller motors. The Soviet philosophy for building large rocket boosters was to take existing stuff that worked and cluster them together, rather than to invent whole new, larger motors as the US did. This worked well - up to a point, as they discovered with the N1. Even today, most Russian space boosters are variations on the old Vostok booster that put Sputnik and Gagarin into orbit in the early 60's. The US tends to invent whole new technologies but even today tried-and-true designs from the early part of the Cold War are still in widespread use: American Atlas and Titan boosters originated as missiles and the Delta booster has been around forever.
Rocketboy
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
The article does say that, but the article is wrong. The N-1 actually had a pretty ingenious system for balancing the thrust of those engines, with engines on opposite sides of the vehicle linked together in terms of fuel feed and control. If one shut down, its mate on the opposite side automatically shut down to balance the thrust. (The Saturn V had similar control logic.) Although the number of engines made it a bit of a plumbing nightmare.
The real problem with the N-1 was (probably) pogo oscillation, which is the result of a feedback loop between engine thrust and rate at which fuel flows into the engine (influence by acceleration). The Saturn V was plagued with this in its early development too, since it's a problem that only shows up in flight.
-- Alastair
Listen the Americans beat the USSR in the race to get to the moon but that is absolutely it.
_ __
They got:
1st satellite.
1st man in orbit.
1st woman in orbit.
1st lunar rover.
1st space station.
1st long term space station.
The US my country that I love so well got to the moon first.
The Soviet's took us down in every other first. It terms of keeping people in space for long periods of time they had it down while we had lost interest after seeing some guys hope around on the moon.
_______________________________________________
ACK
The decline of NASA started with the moon landings. After that, NASA could not justify itself to the public, because the Russians had been beaten, and the race was over.
Thus NASA had to become more "cost effective" (the moon landing was done by crash-program techniques such as paying for several alternatives and selecting the best one after it is developed). So NASA sold the concept of the Space Shuttle as an inexpensive way to get mass into orbit. In order to justify it, they also had to make it the launcher for military payloads, so they connived to force the military into fitting their payloads into the shuttle, and defunding their own launch capabilities.
The problem with the shuttle is that is far more expensive that projected (big surprise). A primary reasonis that it is man-rated, which greatly adds to cost.
In order to continue to justify their existence, NASA needed a mission. The environmental movement came along just in time for them - they could devote their resources to studying the environment, and get government bucks to put up space-borne systems to do that. But, to justify continuing the shuttle, they needed a big, manned project... and thus was born the International Space Station.
But the ISS caused NASA to put almost all of their money into one bucket, leaving little else for other research. And ISS is not a particularly good way of doing most things - because most things don't need a manned space station, they can get by with a much less expensive non-manned launch.
Furthermore, NASA did its best to quash competition in the space launch business - again to keep justifying the money for the shuttle. After the Challenger disaster and subsequent grounding, NASA had to allow the military to use its own launchers for critical payloads, but they still have not been nice to little guys.
As a result, we have a small fleet of aging shuttles, that launch at an average cost of $500,000 per mission, at a mission rate a fraction of what they were supposed to be able to do.
One solution is not to give more money to NASA. It is to create incentives for private enterprise to get into the game.
As an example, what would happen if there was a $30 billion prize to the first company to land humans on mars and bring them back successfully? Hopefully, it would lead to some pretty innovative work.
Another approach that might work is to stimulate the public with some historic vision (like Kennedy did with the moon landing) and get public support for a truly imaginative leap.
The only good weather is bad weather.
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."
Korolev, the "Grand Designer" of the Soviet space program, was easily the equal of Von Braun. With his ability and the fact that the Russians got all the German V2 production lines and factories and, many of the people who operated them during WWII, also gave the Soviets a huge boost.
And the US *DID* use the V2 scientists to the best of their abilities, but initially only for military projects. The doomed satelite launches made in response to Sputnik (Vanguard) were on not-ready-for-prime-time civilian launch vehicles, not military rockets. In fact, the military already had proven technology on the shelf that could put a satellite in orbit, but Von Braun was expressly forbidden by the President from using 'military hardware' for such a purpose.
Eventually, Von Braun was allowed to put the first American satellite (Explorer 1) in orbit with his Jupiter C rocket.
(NOTE: Jupiter C was a slightly modified Jupiter missle, which was designed during Von Braun's 'satellite ban' for a 'special nose-cone' test. After the initial testing, Von Braun kept a few Jupiter C's in storage for a 'certain time' and a 'certain nose-cone test'. Later it was obvious that the 'nose-cone test' was his plan to put a satellite in orbit.)
Anyway, I picked all this up last weekend at the Kansas Cosmosphere. Very neat place, and the current home of the Odyssey command module from Apollo 13.
Uh... Gravity and inertia?
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