Cosmos - Carl Sagan [181]
A few million years ago there were no humans. Who will be here a few million years hence? In all the 4.6-billion-year history of our planet, nothing much ever left it. But now, tiny unmanned exploratory spacecraft from Earth are moving, glistening and elegant, through the solar system. We have made a preliminary reconnaissance of twenty worlds, among them all the planets visible to the naked eye, all those wandering nocturnal lights that stirred our ancestors toward understanding and ecstasy. If we survive, our time will be famous for two reasons: that at this dangerous moment of technological adolescence we managed to avoid self-destruction; and because this is the epoch in which we began our journey to the stars.
The choice is stark and ironic. The same rocket boosters used to launch probes to the planets are poised to send nuclear warheads to the nations. The radioactive power sources on Viking and Voyager derive from the same technology that makes nuclear weapons. The radio and radar techniques employed to track and guide ballistic missiles and defend against attack are also used to monitor and command the spacecraft on the planets and to listen for signals from civilizations near other stars. If we use these technologies to destroy ourselves, we surely will venture no more to the planets and the stars. But the converse is also true. If we continue to the planets and the stars, our chauvinisms will be shaken further. We will gain a cosmic perspective. We will recognize that our explorations can be carried out only on behalf of all the people of the planet Earth. We will invest our energies in an enterprise devoted not to death but to life: the expansion of our understanding of the Earth and its inhabitants and the search for life elsewhere. Space exploration—unmanned and manned—uses many of the same technological and organizational skills and demands the same commitment to valor and daring as does the enterprise of war. Should a time of real disarmament arrive before nuclear war, such exploration would enable the military-industrial establishments of the major powers to engage at long last in an untainted enterprise. Interests vested in preparations for war can relatively easily be reinvested in the exploration of the Cosmos.
A reasonable—even an ambitious—program of unmanned exploration of the planets is inexpensive. The budget for space sciences in the United States is shown in the table above. Comparable expenditures in the Soviet Union are a few times larger. Together these sums represent the equivalent of two or three nuclear submarines per decade, or the cost overruns on one of the many weapon systems in a single year. In the last quarter of 1979, the program cost of the U.S. F/A-18 aircraft increased by $5.1 billion, and the F-16 by $3.4 billion. Since their inceptions, significantly less has been spent on the unmanned planetary programs of both the United States and the Soviet Union than has been wasted shamefully—for example, between 1970 and 1975, in the U.S. bombing of Cambodia, an application of national policy that cost $7 billion. The total cost of a mission such as Viking to Mars, or Voyager to the outer solar system, is less than that of the 1979–80 Soviet invasion of Afghanistan. Through technical employment and the stimulation of high technology, money spent on space exploration has an economic multiplier effect. One study suggests that for every dollar spent on the planets, seven dollars are returned to the national economy. And yet there are many important and entirely feasible missions that have not been attempted because of