Abstract
Up to the present time, 58 kinds, or 331 of the artificial Satellites have been launched in U. S. A. and in U. S. S. R., of which two thirds are in the former and the other in the latter country. Centering around these countries, the rapid progress in the space development researches is being made world-wide, France, England and Japan are planning to launch their first artificial Satellites in the near future.
The author describes various kinds of power sources for rocket propulsion, status of chemical propellants, electric propulsion as non-chemical propulsive power, and nonpropulsive power for use in communication and recording; and then discusses their future possibilities.
