MOON ROCKET

That was not all. The following year, it was learned that consideration was being given to a huge launcher of 3,000 tonnes, three times more powerful than even the Long March 5, the information being given by CALT vice-president Liang Xiaohong. This would put it in the same category as the American Saturn Y, the Soviet N-l, and the later Energiya rockets. This could have only one purpose: a manned lunar landing. Preliminary studies were begun on how to launch a manned lunar expedition, with nine options under consideration [9]. Over time, this rocket acquired the name of the Long March 9 (CZ-9).

A real problem for the Moon rocket was what engines to use. The new YF-100 and YF-77 engines planned for the Long March 5 were simply too small and lacked sufficient thrust. Faced with a similar dilemma in the 1960s, the USSR clustered together no fewer than 30 low-thrust engines for its N-l Moon rocket, but its unhappy history argued for a different approach. By contrast, von Braun’s huge high-thrust F-l engines for the Saturn Y, able to generate 670 tonnes of thrust, were a major contributor to American success in the Moon race. Since then, only one country had developed high-thrust engines: the Soviet Union’s RD-170 series engines for the Energiya rocket, each of which had a thrust of 740 tonnes (only four would be necessary). If China were to match the Saturn V or Energiya, its foremost rocketry exert Li Ping expressed the view that at least a fourfold improvement in thrust on the YF-100 was needed, up to 7,800 kN (700 tonnes) for the first stage, with a doubling of thrust on the upper stage to 2,500 kN.

Accordingly, in 2010, China began design studies of engines in the 300-500-tonne class of thrust, the top end probably being the limit of their capability, with a combined first-stage thrust of 3,000 tonnes. The Chinese emphasized that they wanted a rocket with a long production run, not like the Saturn V, of which only 13 flew, nor the Russian Energiya, of which two flew, nor the N-l (six completed). These studies obliged China to give detailed consideration as to how to best go to the Moon, for they were aware of the long debates on this in both the United States and the Soviet Union in the early 1960s, for this would affect the design. The initial design with 3,000 tonnes of thrust of the proposed new launcher marked it as less powerful than the Saturn V’s 3,470 tonnes and would have offered, with a single launch, only a minimalist lunar expedition (there and back, with up to three days on the surface).

There was little indication, though, that the Chinese were interested in a minimal landing and return, which indicated that the Chinese would make multiple launches so as to establish a long-term base from the start. Li Ping gave more details of the Moon rocket engines at the Xian Asian conference in 2012. There, he displayed a number of possible designs for the Moon rocket, which had a 9-m-diameter base (slightly smaller than the 10 m of the Saturn V), fuelled by either hydrogen or kerosene, with four kerosene-fuelled strap-ons, each of 3.35 m, the familiar diameter of large Chinese rockets, with a new hydrogen upper stage. The Chinese were considering not only the best method to get to the Moon, but how to return and the intricacies of a high-speed re-entry to the Earth’s atmosphere [10].

In summer 2012, the new rocket had progressed to technical studies, with two main options under consideration. The favored one had oxygen and kerosene engines, while the second had oxygen and hydrogen engines, with solid-fuel strap-on rockets. Four YF-650 liquid-oxygen and kerosene engines, broadly similar to the Russian RD-180 and assisted by four smaller strap-ons, would generate 5,200 tonnes of thrust, able to put 130 tonnes into low Earth orbit. The monster rocket would be 15.7 m in diameter, 98 m tall, dwarfing the CZ-5, and have a launch mass of 4,100 tonnes. For the upper stage, two liquid-hydrogen-fuelled YF-220 engines, broadly comparable to the European Vulcain engine, would generate 200 tonnes of thrust [11]. More details were expected as Chinese plans continued to evolve. Perhaps the most intriguing aspect was the early start that China had made on a rocket not expected to mature for many years.