AN EASY STUMPER WHEN YOU'RE SITTING AT THE BAR...:

Korolev's mega booster program moved steadily forward until 1964 when a strange Soviet decision suddenly derailed years of work. To this point in the space race, the Soviets had been in the lead -- it had launched the first satellite, the first animal, the first man into orbit, the first woman, and done the first spacewalk. But the United States was starting to pull ahead with promises from the Gemini program, and Apollo was (metaphorically) already on its way to the Moon. NASA was, effectively, racing against itself to the Moon. But then on August 3, the Soviet Union decided to take on the American challenge of landing a man on the Moon by the end of the decade. Three years after the America officially started its lunar landing program, Soviet leadership endorsed its own.

To spare the N-1 being cancelled in light of this new goal, OKB-1 presented a proposal to go to the Moon with this rocket rather than build a new one. The plan was ultimately accepted and in 1965 the burden of getting a cosmonaut to the Moon before the Americans fell to Korolev and his N-1.

But there was a problem. The N-1 was powerful enough the launch a Mars or Venus flyby mission, but it couldn't send a landing mission to the Moon. A landing mission is heavier than a flyby mission, especially a free-return trajectory mission. With a flyby, you don't need to carry fuel for an orbit insertion burn, for a transearth injection burn, and you certainly don't need a landing vehicle with its own complicated life support and propulsion systems. But these are all things you absolutely need on a landing mission.

So by design the N-1 was a poor Moon rocket. Consider as a comparison the Saturn V, which was honed for Apollo's lunar orbit rendezvous mission architecture. The Saturn V could put 130 tons into low Earth orbit, enough for even the long-duration Apollo missions that took rovers to the Moon. The N-1 was limited to 75 tons.

This left Korolev's bureau with a choice: either assemble the lunar spacecraft in orbit with multiple launches or make the N-1 more powerful. They chose the latter to avoid losing a mission from a launch failure. The solution was to decrease the temperature of the Kerosene and overcool the liquid oxygen to store more in the existing tanks, upgrade all the rocket engines, and add six more to the first stage. To get to the Moon the N-1 would have 30 engine powering its first stage, but it could still only take 95 tons into orbit.

The final arrangement of the N-1 emerged after this decision. At the bottom of the stack was Block A, the first stage powered by 30 engines, all of which were managed by a system called KORD. This was a realtime diagnostics system that monitored the crucial parameters for all the engines that was also capable of making the decision to shut down individual engine should it show signs of pending catastrophic failure. This took advantage of the redundancy of a rocket with 30 engines; losing one engine or even two wouldn't completely ruin a launch. The others could compensate.

But power isn't all you need for a launch. That rocket also has to be directed in flight. Pitch and yaw control in the N-1 were achieved through differential thrust. Rather than use a complicated and heavy system to swivel the engines, the N-1 was used differential thrust; less power from one side of the rocket would tilt it in the desired direction of flight. Roll control came from six small nozzles outside the main engine cluster could swivel to move the stack around it's vertical axis. Like the Saturn V, the N-1 was a multistage rocket. There were two stages above Block A. The second stage was Block B, powered by eight engines. Block V was the third stage and ti was powered by four engines.

On top of Block V was the payload, and for the lunar mission this was the L-3 complex consisting of four parts. Block G sat directly above Block V, and this was the translunar injection stage that would send the crew to the Moon. Above that was Block D, the stage that would perform any midcourse correction burns, the lunar orbit insertion burn, and the burn to start the crew's descent to the lunar surface. And then there were the two spacecraft, the Block I LOK lunar orbiter and Block E LK lunar lander.

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