N1 (rocket) - Problems

Problems

Complex plumbing was needed to feed fuel and oxidizer into the clustered arrangement of rocket engines. This proved to be extremely fragile, and was a major factor in the design's launch failures. Furthermore the N1's Baikonur launch complex could not be reached by heavy barge. To allow transport by rail, all the stages had to be broken down and re-assembled. As a result, the complex and destructive vibrational modes (which ripped apart propellant lines and turbines) as well as exhaust plume fluid dynamic problems (causing vehicle roll, vacuum cavitation, and other problems) were not discovered and worked out before flight.

As a result of its technical difficulties, in turn due to lack of funding for full-up testing, the N1 never successfully completed a test flight. All four unmanned launches out of 12 planned tests ended in failure, each before first-stage separation. The longest flight lasted 107 seconds, just before first stage separation. Two test launches occurred in 1969, one in 1971 and the final one in 1972.

Mishin continued with the N1F project after the cancellation of plans for a manned moon landing in the hope that the booster would be used to launch a large space station comparable to the US Skylab. The program was terminated in 1974 when Mishin was replaced by Glushko. Two N1Fs were being readied for launch at the time, but these plans were cancelled.

The program was followed by the "Vulkan" concept for a huge launch vehicle (with Syntin/LOX, later replaced by LH2/LOX as fuel on the 2nd and 3rd stages), and then in 1976 by the commencement of the Energia/Buran program.