The feasibility of delivering devices from a satellite to the Earth's surface implies the possibility of bombing from a satellite, note of which has been taken in both the United States and U. S. S. R. 1-6
The extent of the propulsion installation required on the satellite to eject the warhead depends upon the distance to be covered by the warhead during its descent phase. If the warhead is to descend essentially straight down from directly above the target, the propulsion requirement is very severe indeed. However, the problem quickly becomes an entirely reasonable one if distances of several thousands of miles are allowed for accomplishing descent, as illustrated in figure 1. If the descent range is, for example, 5,500 nautical miles, descent from a 300-mile orbit can be accomplished by reducing warhead velocity by less than 1,000 feet per second. This is the approximate speed of a projectile from a 75-millimeter field gun, with reduced charge, to cover about 7,000 yards. 7
Some additional propulsion capacity would be needed to deflect the warhead to the right or left, since a prospective target will rarely lie directly under the satellite orbit path.
For unmanned satellites, the ejection operation can be initiated and controlled directly from a ground radar station in sight of the ejection point; or, alternatively, ejection and descent guidance could be carried
1 Gavin, Lt. Gen. J. M., War and Peace in the Space Age, Harper & Bros., New York, 1958.
2 Pokrovskii, Maj. Gen. G. I. (Red Army), The Role of Science and Technology in Modern War, The RAND Corp., translation T-79: translated by H. S. Dinerstein, February 5, 1958.
3 Inquiry Into Satellite and Missile Programs, hearings before the Preparedness Investigating Subcommittee of the Committee on Armed Services, United States Senate, 85th Cong., 1st and 2d sess., pt. I, W. von Braun, p. 601.
4 Leghorn R. S., Warfare, Stalemate, and Security, an address presented at the Franklin Institute, December 18, 1957.
5 Statement by Senator Clinton P. Anderson in the United States Senate, May 6, 1958.
6 Compilation of Materials on Space and Astronautics, No. 2, Special Committee on Space and Astronautics, United States Senate, 85th Cong., 2d sess.; C. Holifield, p. 100.
7 Firing Tables for Gun, 75-MM, M 1897, Firing Shell, H. E., M 48, Ordinance Department, U. S. Army. FT 75-Z-2, 1940.
out on a fully automatic basis in the satellite at any time after receipt of a general signal from the ground to proceed to the attack. The accuracy of fully automatic delivery would depend upon the performance of internal equipment, as well as upon orbit data acquired from time to time from ground installations. A critical factor is the need for very precise knowledge of attitude direction references in space. For example, an error of one one-hundredth degree in azimuth reference will cause a strike error of 1 nautical mile for a 5,500-nautical-mile descent range.
For such a bombing system, satellite launchings could be conducted long in advance of a war, with any desired degree of leisure in a completely peaceful environment. Propellants used in the launching rockets could be chosen for maximum payload performance, and launchings could be conducted from one or a few sites located favorably with respect to weather, population density, convenience to production and supply sources, etc.
These features of convenience must be balanced against the fact that the rather extensive installation in a bombing satellite on orbit must operate reliably for some long period, if the replacement rate is to be held to a supportable level. Development of space-vehicle equipment with a very long reliable life is a basic necessity for a great many astronautics activities -working life spans of the order of a year or more would be representative of the requirements for interplanetary flights, various satellite missions, etc.
Bombs could also be delivered from manned satellites; for such a case, the guidance operation could include direct line-of-sight steering of the bomb-carrying missile to the target - even a moving target.