Soviet and Russian Lunar Exploration

them on a visit to Samara and could not believe their eyes: hundreds of moon rocket
engines in mint order! The American Aerojet company at once bought 90 of them for
$450 million and in 1995 sent them off to its Sacramento, CA plant for testing and
evaluation. They worried if there would be any problems in relighting motors that had
been in storage since 1974. They ran two tests - of 40 sec and 200 sec - and there were
not. Aerojet's evaluation of the engine found that it could deliver over 10% more
performance than any other American engine and enthused over its simplicity, lightness
and low production costs. The hydrogen upper stage, originally planned for a
later version of the N-1, became the upper stage of the Indian GSLV launch vehicle
more than 25 years later.
The basic problem with the N-1 was the lack of thorough ground-testing. It was
here that the much smaller resources of the Soviet Union and poor organization told
against its moon programme. Rocket designers continued to underestimate the problems
associated with the integration of engines on stages and the resulting problems of
vibration, sound, fuel flow and control. Testing engines individually, however good
they are, can be a poor guide as to how they behave collectively. Even where this is
done, there is no guarantee of success, as the thoroughly prepared Proton proved.
The world's space programmes are full of histories of rockets that proved extraordinarily
difficult to tame: the American Atlas and Centaur, the Chinese Feng Bao,
Europe's Europa and India's SLV. Even programmes that have built on the experience
of all that has gone before can suffer nasty surprises, like Europe's Ariane.
Having said all that, it is hard to believe that thorough ground-testing would not have
stacked the odds much more in favour of the N-1. The four flight failures all had their
roots in problems that could have been identified in thorough ground-testing. The real
issue is not that the N-1 was a bad rocket, but that the Saturn V was so exceptionally
good.
Were the rival UR-700 and R-56 proposals better? The UR-700 scheme developed
by Chelomei might well have worked. In promising exhaustive ground-testing first,
Chelomei rightly hit on one of the great weaknesses of Korolev's approach. Chelomei
was a superb designer but he was also slow: his Almaz space station was approved in
1964 but he did not get it ready for its first flight until 1973 and there is no reason to
believe he could have built his moon rocket any sooner.
In retrospect, the Russian moon programme might have been better to go for the
large RD-270 engines which Glushko began to develop. Korolev probably correctly
judged that the development of the RD-270s would have required an extensive range
of ground facilities and taken too long. With time against him, he calculated that it
was better to go with a tried-and-tested system, even if it meant 30 engines. Korolev
was always battling time to get his N-1 airborne, struggling with government departments
for budgets and travelling endlessly to Samara, Leningrad and Baikonour to
keep things moving. Korolev may have reckoned that he had to be lucky with only one
successful N-1 launch and he would then get, from the political bosses, the resources
he needed to bring the project to fruition.
If the N-1 had eventually worked, then a Russian moon landing would definitely
have been possible at some stage. Alternatively, if the Russians had decided not to
pursue a moon landing, then they would have had available to them a large rocket able