Robot bugs on other planets

When the National Aeronautics and Space Administration (NASA) decided to build a robot to explore the surface of Mars, scientists studied bugs to help them with its design. They knew the robot would be in a hostile environment. It would have to move around and survive on its own. They also knew it would not have room for a huge computer. It couldn't be very "smart." All this sounded a lot like insects, so that's where they started looking.

The Sojourner rover that explored Mars in 1997 looked and acted a lot like a bug. It had six wheels, similar to the six legs on an insect. This gave it a lot of stability. The wheels were programmed to work together in the same way an insect uses its legs.

Scientists on Earth were able to send Sojourner some of its instructions, such as "pick up some soil" or "point the color camera over there." But Sojourner needed to be able to make some decisions on its own. That can require a lot of intelligence, and there wasn't room for a big computer on a robot that was only the size of a microwave oven.

So Sojourner was programmed to make decisions much the same way an insect does.

When an insect tries to go forward and hits a rock, it doesn't consider a lot of possibilities. It just turns to the right or to the left and moves forward again. It doesn't consider what might be on the other side of the rock or which direction is the quickest way around. It just sort of thinks: "Can't go forward. Go right."

Sojourner had similar programming. If it hit something it couldn't climb over, it turned right or left and tried again. It traveled by making one small decision at a time, as insects do.

Some bugs look like they might have come from Mars, but it was the Sojourner from Earth that brought the first bug behavior to the Red Planet.

(c) Copyright 2000. The Christian Science Publishing Society

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