Wheel comes poor second to froglegs

30 November 2000

A proposed NASA unmanned mission to Mars faces the problem of how to send survey rovers across the Martian terrain to collect data. A wheeled robot, for example, is likely to become hopelessly stuck—with no-one around to lift it out of holes or over rocks.

Inspired by the humble frog, NASA is testing the ‘frogbot’. The small hopping one-legged robot moves and steers by rolls and hops, controlled by an on-board computer. ‘To be effective, a small exploratory robot vehicle must frequently go over obstacles that are many times its body size,’ explained one researcher. ‘Hopping or leaping motions are some of the few effective ways for small vehicles to overcome such relatively large obstacles.’

The frogbot has shown better mobility than rovers over troublesome terrain. Also being tested is a multi-segmented robot design (‘robosnake’) that can slither across soft or variable surfaces. Researchers are also trying to develop a robot that can adhere to and climb vertical walls (as geckoes do) so it can explore canyon walls and other remote areas.

A NASA press release, Leaping into the future: one hop at a time says:

‘Hopping is a more efficient form of transportation in low-gravity environments,’ said Dr. Paolo Fiorini, an engineer in the robotics group at JPL. ‘Our hopping robot performs much like a frog, except that it only has one leg and no tongue. It has a spring between its knees that makes it bend its legs and hop. When the spring releases, the frogbot takes a 1.8-meter (6-foot) hop on Earth, which could become a 6- meter (20-foot) leap under low-gravity conditions on planets like Mars, depending on terrain.’

Some teachers of evolution have liked to point to the ‘fact’ that animals never ‘evolved’ the wheel as showing that evolution was not ‘perfect’—precisely what one would expect from ‘chance processes’. (By implication therefore, there was no ‘Designer’.) However, this report reinforces beautifully how the Master Designer foreknew perfectly what equipment His various created kinds (including frogs, grasshoppers and kangaroos) would need to colonize a world of uneven terrain with boulders, ravines, tall grass and thornbushes.