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50

It's all to do with ullage in the fuel tanks. Newton's laws of motion mean that when a rocket is no longer firing and no force is being applied, the rocket receives no acceleration. It continues at its same velocity (if we assume a perfect model). The fuel in the tanks goes into free-fall, just as the astronauts do when they reach orbit. You've seen those ...


31

They used an extremely large rail-based transporter/erector nicknamed the "grasshopper". Image source This image shows the N-1 in the process of rotation. Image source russianspaceweb says the hydraulic ram visible in this image "boasted a hydraulic cylinder one meter in caliber, which had a length of nine meters and would extend up to 16 meters". Two ...


27

In order to use the direct ascent method of landing on the moon, which is where the entire vehicle descends and leaves the moon, you would need a rocket an order of magnitude bigger than the Saturn V, not just a bit bigger. Here's an early comparison NASA made back before they decided to use Lunar Orbit Rendezvous: The C1 became the Saturn I, the C-5 ...


24

That claim is rather dubious. First, there is the claim of 320,000 channels of telemetry, while one paragraph earlier it lists 13,000 sensors on board. There will be setpoints in addition to sensor data, but 20x as many? The earlier 5L mission had 10,000 telemetry channels. I found these specifications for the S-530 computer: speed: 0.1 MIPS RAM: 256 ...


24

Generically the program was underfunded, and the main issue was lack of full up testing of each stage. With 30 engines, the interactions in the plumbing were very complex and caused imperfect fuel/oxidizer flow that affected the engines. Engines that were sensitive to fuel/oxidizer flow issues with lots of them, lots of plumbing, huge volumes, needs lots ...


21

During the early part of the Apollo program, the "direct ascent" mode was favored and Lunar-orbit rendezvous (LOR) was considered far too complex. In fact, the specifications of the Apollo service module were set by the direct ascent plan: the SPS engine is sized to lift off from the moon, and the fuel tankage is sufficient for lunar ascent and return to ...


19

To add to geoffc's excellent answer, another issue that might have been worked out with more testing was the KORD, a computer system for controlling the 30 different engines. Ideally, the KORD would handle the failure of one engine by stopping the engine on the opposite side of the rocket, maintaining symmetry of thrust. However, during the first and second ...


17

The Jupiter-C and Juno second stage was a cluster of 11 (!) solid rockets. Depending on what you're willing to count, the R-7 & Soyuz launcher family have 20 thrust chambers going at launch -- 16 on strap-on boosters, 4 in the sustainer core. (Each cluster of 4 chambers shares one set of fuel pumps, etc., so it comes down to whether you define that as 5 ...


15

Combustion instability is a very hard problem to crack. It gets harder as the engine gets larger. The Americans took on the challenge of a 1.5 million lb thrust engine and beat it (F-1, I suppose even the J-2 on the second (5) and third stages (1)). The Soviets tried and failed and went with a small (NK-15) engine. They needed the thrust so they ...


11

On the Soviet side, Vladimir Chelomey's UR-700/LK-700 project would have used a direct ascent mission profile. The UR-700 was 76 meters tall and 17.5 meters wide at the base; it would have looked something like this: (left-to-right: N-1, Saturn V, UR-700) The UR-700 didn't have much design work done on it, but there were problems developing the high-thrust ...


8

No N1s remain intact as far as I know. Wikipedia is pretty clear about the disposition of the individual N1s constructed. I found a photo gallery showing various scraps and wreckage from the N1, including a garden shed made from a payload fairing, but the origins of the pictures is unclear. Astronautix claims the "gazebos" are at Baikonur, which ...


8

The most obvious effect is the lack of a suitable rocket to lift heavy cargo into orbit. That set a constraint, especially on the manned space program. For example, the N1 was basically the backbone of the Soviet effort for a manned mission to the Moon, and a termination of the program meant that the most basic requirement for that kind of mission was gone. ...


7

Its not rocket science, well actually, it is rocket science. Rockets are not very efficient at all and the worst bit is that to carry anything useful, they have to carry the fuel to push the useful bit, then they have to carry the fuel to carry the fuel to push the useful bit and so on. Saturn V was about three thousand tons at takeoff, and was able to push ...


6

I suspect this confuses "bandwidth available" with "bandwidth that can be used concurrently at any one time". It certainly could not be processed at that rate by the ground based systems, let alone on-board.


6

According to Max Wade website: As payloads for his rocket, to be developed in accordance of the Central Committee decree of 10 December 1959, the following would be developed for launch in the period 1963 to 1965: Three to six geostationary communications satellites of 2 to 3 metric tons mass for global communications Heavy manned space stations ...


5

The OTRAG rockets, with von Braun involved until his death, apparently fired off at least one rocket with 12 engines, and had plans using the same basic hardware to build a 1 metric ton to orbit rocket with 64 engines, 48 in the 1st stage, 12 in the 2nd, and 4 in the 3rd. All were mounted in parallel with each stage peeling off after firing.


5

Almost, not quite: Black Arrow - UK satellite launcher (1 success in 3 launches) had 8 "Stentor" engines in the first stage plus what appear to be two significant sized gas generator exhausts. The two exhausts would definitely have added small but measurable thrust. Whether you count them as 'engines' is up to you (but I suspect that you won't :-)). ...


5

There was another argument against the direct ascent mode. A very large and complex rocket should be landed and started on and from the moon surface. But rockets of this size would require on earth a launch pad, a start tower, connections to a control room, a count down with many steps and a lot of personnel. But the rocket motors of the service module and ...


4

Compare the extra work to build a bigger rocket (and don't forget that costs have the ugly tendency to be exponentialised, thanks to our good friend, the Tsiolkovski equation) with a few hours for the docking. Rockets aren't cheap. The main thing to consider is that you need to dock anyway - to get the lunar crew back from the Moon. So you're not saving on ...


4

yall are forgetting the electron. 9 engines on the first stage and 1 engine on the second stage. to be honest its just a smaller version of the falcon 9 Electron


4

As far as I know, SpaceX holds the record. The Saturn 1B takes second place with 8 engines. Everything else I know off has smaller numbers. The Delta has up to 9 boosters, but they would not all fire simultaneously so you could argue those amount to 2 stages. (shows you what I know, @Russell has found the winner)


4

The best reference for Soviet and Russian space information is Anatloy Zak's wonderful web site (Russiaspaceweb.com) and book (Russia in Space: The Past Explained, the Future Explored). If you like space related things, his book will be a purchase you will not regret. On the topic of the N-1, he writes: Originally proposed as a multipurpose vehicle for ...


4

I don't have any original sources, but I'd say: 9.6 GB/s are possible, albeit not an accurate description. It's very likely that the largest amount of data was not transported digitally but as raw analog signals. This has the advantage that you can take the raw output of the sensors and send them to ground where they can be recorded and/or digitized later on....


3

No. 110L and R were rebuilt for Energia, but the 2 Energia launches were from pad 250 and from 110L. They have not been used since then.


1

During the Apollo missions the Lunar lander was separated, turned around and docked during flight. This point hasn't really been addressed by any of the other answers. Unlike separation to land the lander, then subsequent docking to get the crew back, there is a fairly simple reason for this manoeuvrer. The command pod needs to be the top of the stack on ...


1

They might have been going for the advantage of you manufacturing a greater amount of individual engines, similar to what SpaceX is going for. SpaceX instead of manufacturing rockets with 1 or two engines goes for now with 9 per rocket and can improve on the manufacture using the methods that made so many industrialized things so much cheaper today. That is ...


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