N1 (rocket) - Description

Description

The N1 was a very large rocket, standing 105 metres (344 ft) tall—among the world's largest launch vehicles, somewhat smaller than the Saturn V in height and mass, but greater in lift-off thrust and with significantly less payload capability. The N1-L3 consisted of five stages in total, three for immediate boost into orbit (the N1), and another two for the lunar portion (the L3). Fully loaded and fueled, the N1-L3 weighed 2,788 metric tons (6,150,000 lb). The lower three stages were shaped to produce a single truncated cone just over 10 m wide at the base, while the L3 section was cylindrical at about 4.4 m wide. The conical shaping of the lower stages was due to the arrangement of the tanks within, a smaller spherical kerosene tank on top of the larger liquid oxygen tank below.

The first stage, Block A, was powered by 30 NK-15 engines arranged in two rings, the main ring of 24 at the outer edge of the booster, the inner of 6 at about half diameter. The engines were the first ever staged combustion cycle engines. The control system was primarily based on differential throttling of the engines, the outer ring for pitch and yaw, the inner six on gimballing mounts for roll. The Block A also included four grid fins, which were later used on Soviet air-to-air missile designs. In total, the Block A produced 43 meganewtons (9,700,000 lbf) of thrust. This exceeded the 33.7 meganewtons (7,600,000 lbf) thrust of the Saturn V.

The second stage, Block B, was powered by 8 NK-15V engines arranged in a single ring. The only major difference between the NK-15 and -15V was the engine bell and various tunings for air-start and high-altitude performance. The upper stage, Block V (V being the third letter in the Russian alphabet), mounted four smaller NK-21 engines in a square.

During the N1's lifetime, a series of improved engines was introduced to replace those used in the original design. The first stage used an adaptation of the NK-15 known as the NK-33, the second stage a similar modification known as the NK-43, and finally the third stage used the NK-31. The resulting modified N1 was known as the N1F, but did not fly before the project's cancellation.

In comparison with the American Saturn V, the N1 is slightly shorter, more slender overall, but wider at the base. Generally the N1 produced much more thrust than the Saturn V. It used only kerosene fuel in all three of its stages, and had somewhat lesser overall performance than the Saturn; the N1 stack was intended to place about 90 metric tons (200,000 lb) of payload into low Earth orbit, whereas the Saturn V could orbit about 119 tonnes (131 short tons). The US's experience with higher energy liquid hydrogen as fuel gave them the confidence to use it on the Saturn upper stages, which significantly reduced the upper stages' take-off weight and increased the payload fraction. The Saturn V also had a superior reliability record: it never lost a payload in 13 operational launches, while four N1 launch attempts all resulted in failure, with two payload losses.

The US spent more money developing the Saturn V. Development of the Saturn V also began almost four years sooner, in January 1962.