Reflections on Qian Xuesen

Published December 15, 2018

As the Chinese lunar lander Cheng-e 4 prepares for descent to von Karman Crater on the far side of the moon later this month it is well to reflect upon the enormous recent accomplishment of the Chinese space program. Ironically, the father of the Chinese space program Qian Xuesen (whose name is also transliterated Hsue-Shen Tsien) long collaborated with Theodore von Karman at Caltech before being expelled from the United States in 1956. Qian’s early work in the United States was celebrated in 2012 when the Shanghai Jiao Tong University Press published the Collected Works of Hsue-Shen Tsien, 1938-1956. On pp. 296-314 is a paper entitled “Atomic Energy” that was originally published in Journal of the Aeronautical Sciences, vol. 13, pp. 171-180 on September 29, 1945. He notes here that “The very fact that the energy release of nuclear reactions is approximately a million times that of more conventional chemical reactions seems to stagger one’s imagination” and goes on to explain the technical details of the process of extracting nuclear energy at some length. The key argument of this paper is summarized in the line “The aeronautical engineers have a further interest in this matter due to the belief that the aeronautical power plant will probably be the first prime mover to utilize the atomic energy.

As it turned out, early enthusiasm for aircraft nuclear propulsion systems has not yet come to fruition though considerable advances were achieved in nuclear rocket engine technology in both the United States (1944-1972 and in the 1980s) and in Russia (1955-present). NASA revisited nuclear rocket propulsion after the loss of both the Challenger and Columbia as did the military as part of America’s “Star Wars” anti-missile defense system. Russia’s touted new nuclear-powered cruise missile was apparently designed along similar lines. The final article in this collection is entitled “Thermonuclear Power Plants” that appears on pp. 861-874 and was originally published in Jet Propulsion, vol. 26, pp. 559-564 in 1956. The closing paragraph states: “If the average chemical energy of coal is taken to as 11,000 Btu/lb, one pound of water is potentially equivalent to sixty pounds of coal! But even all of this is based on partial burning of deuteron to triton and proton. With complete burning of 2He4, the thermonuclear energy of deuterium will be still larger. Therefore, if thermonuclear power plants can be constructed, then the source of fusion energy far exceeds the other terrestrial energy sources, chemical or fission.”