In the exploration of Mars, unmanned vehicles have already soft-landed, and only a little further in the future they will roam about the surface of the Red Planet, as some now do on the Moon. We are not ready for a manned mission to Mars. Some of us are concerned about such missions because of the dangers of carrying terrestrial microbes to Mars, and Martian microbes, if they exist, to Earth, but also because of their enormous expense. The Viking landers deposited on Mars in the summer of 1976 have a very interesting array of sensors and scientific instruments, which are the extension of human senses to an alien environment.
The obvious post-Viking device for Martian exploration, one which takes advantage of the Viking technology, is a Viking Rover in which the equivalent of an entire Viking spacecraft, but with considerably improved science, is put on wheels or tractor treads and permitted to rove slowly over the Martian landscape. But now we come to a new problem, one that is never encountered in machine operation on the Earth’s surface. Although Mars is the second closest planet, it is so far from the Earth that the light travel time becomes significant. At a typical relative position of Mars and the Earth, the planet is 20 light-minutes away. Thus, if the spacecraft were confronted with a steep incline, it might send a message of inquiry back to Earth. Forty minutes later the response would arrive saying something like “For heaven’s sake, stand dead still.” But by then, of course, an unsophisticated machine would have tumbled into the gully. Consequently, any Martian Rover requires slope and roughness sensors. Fortunately, these are readily available and are even seen in some children’s toys. When confronted with a precipitous slope or large boulder, the spacecraft would either stop until receiving instructions from the Earth in response to its query (and televised picture of the terrain), or back off and start in another and safer direction.
Much more elaborate contingency decision networks can be built into the onboard computers of spacecraft of the 1980s. For more remote objectives, to be explored further in the future, we can imagine human controllers in orbit around the target planet, or on one of its moons. In the exploration of Jupiter, for example, I can imagine the operators on a small moon outside the fierce Jovian radiation belts, controlling with only a few seconds’ delay the responses of a spacecraft floating in the dense Jovian clouds.
Human beings on Earth can also be in such an interaction loop, if they are willing to spend some time on the enterprise. If every decision in Martian exploration must be fed through a human controller on Earth, the Rover can traverse only a few feet an hour. But the lifetimes of such Rovers are so long that a few feet an hour represents a perfectly respectable rate of progress. However, as we imagine expeditions into the farthest reaches of the solar system-and ultimately to the stars-it is clear that self-controlled machine intelligence will assume heavier burdens of responsibility.
In the development of such machines we find a kind of convergent evolution. Viking is, in a curious sense, like some great outsized, clumsily constructed insect. It is not yet ambulatory, and it is certainly incapable of self-reproduction. But it has an exoskeleton, it has a wide range of insectlike sensory organs, and it is about as intelligent as a dragonfly. But Viking has an advantage that insects do not: it can, on occasion, by inquiring of its controllers on Earth, assume the intelligence of a human being-the controllers are able to reprogram the Viking computer on the basis of decisions they make.
As the field of machine intelligence advances and as increasingly distant objects in the solar system become accessible to exploration, we will see the development of increasingly sophisticated onboard computers, slowly climbing the phylogenetic tree from insect intelligence to crocodile intelligence to squirrel intelligence and-in the not very remote future, I think-to dog intelligence. Any flight to the outer solar system must have a computer capable of determining whether it is working properly. There is no possibility of sending to the Earth for a repairman. The machine must be able to sense when it is sick and skillfully doctor its own illnesses. A computer is needed that is able either to fix or replace failed computer, sensor or structural components. Such a computer, which has been called STAR (self-testing and repairing computer), is on the threshold of development. It employs redundant components, as biology does-we have two lungs and two kidneys partly because each is protection against failure of the other. But a computer can be much more redundant than a human being, who has, for example, but one head and one heart.
Because of the weight premium on deep space exploratory ventures, there will be strong pressures for continued miniaturization of intelligent machines. It is clear that remarkable miniaturization has already occurred: vacuum tubes have been replaced by transistors, wired circuits by printed circuit boards, and entire computer systems by silicon-chip microcircuitry. Today a circuit that used to occupy much of a 1930 radio set can be printed on the tip of a pin. If intelligent machines for terrestrial mining and space exploratory applications are pursued, the time cannot be far off when household and other domestic robots will become commercially feasible. Unlike the classical anthropoid robots of science fiction, there is no reason for such machines to look any more human than a vacuum cleaner does. They will be specialized for their functions. But there are many common tasks, ranging from bartending to floor washing, that involve a very limited array of intellectual capabilities, albeit substantial stamina and patience. All-purpose ambulatory household robots, which perform domestic functions as well as a proper nineteenth-century English butler, are probably many decades off. But more specialized machines, each adapted to a specific household function, are probably already on the horizon.
It is possible to imagine many other civic tasks and essential functions of everyday life carried out by intelligent machines. By the early 1970s, garbage collectors in Anchorage, Alaska, and other cities won wage settlements guaranteeing them salaries of about $20,000 per annum. It is possible that the economic pressures alone may make a persuasive case for the development of automated garbage-collecting machines. For the development of domestic and civic robots to be a general civic good, the effective re-employment of those human beings displaced by the robots must, of course, be arranged; but over a human generation that should not be too difficult-particularly if there are enlightened educational reforms. Human beings enjoy learning.