Reddit reviews The Soviet Space Race with Apollo

There's a major wrinkle missing: the war between the two chief designers of the soviet space program that torpedoed all possibility of a soviet moon success.

Sergei Korolev and Valentin Glushko had a long-standing and increasingly vitriolic disagreement over which propellants the Soviet space program should be using. Korolev was in favor of cryogenic propellants—liquid hydrogen and liquid oxygen (or RP1 + LOX, too). Glushko, on the other hand, favored storable hypergols instead of cryogens.

Both have their advantages and disadvantages; cryogens need to be kept very cold (or for LH2, very very cold) and because of that, fueling procedures for cryogen-powered rockets are very complex and involve a lot of conditioning and chill-down, and extra mechanisms for recapturing boil-off. Further, rockets can't be stored with fuel in them (important for ICBMs), and generally have to be de-tanked immediately if a launch is scrubbed.

Hypergols, on the other hand, are generally fine at room temperature and you can leave hypergolic-powered rockets fueled up and ready to go for extended periods without worrying about the fuel boiling away. However, hypergolic fuels tend to be murderously, hideously toxic. This means that not only are your pad workers in danger whenever they work with fuel—it means that if your rocket crashes or blows up, it spews out a horrifyingly toxic death-cloud.

The N1 was Korolev's baby. Originally intended to be used to reach Mars (or Venus, depending on who you ask), it was retasked by the Politburo and the N1-L3 plan was quickly beaten into shape. By that point in their careers, Glushko and Korolev were no longer speaking to each other; Korolev was in very poor health and died during an operation in 1965. The N1 eventually flew four times, but all four flights ended in various failures (one of the rockets exploded with the equivalent of about 1kt of TNT, making it one of the largest human-created non-nuclear explosions ever recorded). Glushko was eventually installed as the chief designer of the entire program and canceled the N1. His decision was made at least partially to spite Korolev's memory, as the N1 was Korolev's rocket.

The truly disappointing thing here is that it's very likely the N1's fifth flight, had it had one, would have been successful. However, it was 1972 at that point and the Moon wasn't really seen as a worthwhile destination for the Soviet space program anymore. Without a destination, the N1 was just a ludicrously expensive and overpowered rocket with no mission.

A fascinating historical footnote is how the Soviet space program in general, and their lunar program specifically, operated much more like how one might expect a US program to operate—numerous design bureaus were simultaneously executing several different plans at the same time, with the idea that the most successful would be expanded upon to become the "official" program. Conversely, the US used a much more Soviet-style "centrally planned" approach, allowing NASA to coordinate and control all aspects of the program through its army of contractors.

If you want to read about the Soviet space program, there are some great books available. The first—and the one I'd recommend most—is a two-volume work by Dr. Asif Siddiqi, who is the preeminent living expert on the Soviet's aborted lunar program. Part one is here, and part two is here. You can also get a single combined PDF of the whole thing (for free!) here.

The other work is Boris Chertok's Ракеты и люди ("Rakety i lyudi," or "Rockets and People") which you can get for free from NASA here, split into four volumes. Chertok was an engineer who worked in the Soviet aerospace industry and who was part of the Space Race from that side of the Iron Curtain; his first-hand experience with the Soviet side of the race makes for an incredibly illuminating read.

Well the best place would be to start from technical side of things.
RPE by Sutton
https://www.amazon.com/Rocket-Propulsion-Elements-George-Sutton/dp/0470080248

And Taming liquid hydrogen shows the problems of hydrolox that had to be solved to make lunar flight possible with rocket as small as SaturnV

https://www.history.nasa.gov/SP-4230.pdf

Russian N1 relied on kerosine and had only 1/2 the power of Saturn for TLI trajectory and that forced the design of their single person lander.

The historical perspective on the race is well shown in here https://www.amazon.com/Soviet-Space-Race-Apollo/dp/0813026288

Sputnik and the Soviet Space Challenge, and The Soviet Space Race with Apollo by Asif A. Siddiqi

Two excellent, if exhaustively detailed books on the Soviet space program.

I also liked At the Edge of Space: The X-15 Flight Program by Milton O. Thompson.

Try The Soviet Space Race with Apollo

Korolev

Sputnik and the Soviet Space Challenge

The Soviet Space Race With Apollo