Collected Works of H. S. Tsien (1938-1956)

Rockets and Other Thermal Jets Using Nuclear EnergyWith a General Discussion on the Use of Porous Pile Materials^*

Hsue-shen Tsien

To bring out the crucial problem in rocket propulsion, consider the motion of a rocket in a force-free space, i. e., a space without a gravitational field. Let m₁ denote the mass of the rocket at any time and dm₂ the mass ejected from the rocket in a small time interval. The absolute velocities of the rocket and the ejected mass are u₁ and - u₂ respectively. The relative velocity w of the ejected mass with respect to the rocket is then u₁ + u₂ (Fig. 1).

1. Simple Theory of Space Rockets

To bring out the crucial problem in rocket propulsion, consider the motion of a rocket in a force-free space, i. e., a space without ...