An article in Popular Science about explorer robots:
This is a nice idea for an explorer. I’m a bit surprised it is in Popular Science, unless it’s an old edition, since the idea first appeared ages ago, but then again, why not, it’s still a good idea. Anyway…
The most impressive idea I ever saw for an explorer robot was back in the 90s from Joe Michael of Robodyne Cybernetics, which used fractal cubes that could slide along each face, thereby rearranging into any shape. Once the big cubes were in place, smaller ones would rearrange to give fine structure. That was way before everyone and his dog new all about nanotech, his thinking was well ahead of his time. A huge array of fractal cubes could become any shape – a long snake to cross high or narrow obstacles, a thin plate to capture wind like a sail, a ball to roll around, or a dense structure to minimize volume or wind resistance.
NASA tends to opt for ridiculously expensive and complex landers with wheels and lots of gadgetry that can drive to where they want to be.
I do wonder though whether people are avoiding the simple ideas just because they’re simple. In nature, some tiny spiders get around just by spinning a length of thread and letting the wind carry them. Bubbles can float on the wind too, as can balloons. Where there’s an atmosphere, there is likely to be wind, and if simple exploration is the task, why not just let the winds carry you around? If not a thread, use a balloon that can be inflated and deflated, or a sail. Why not use a large cloud of tiny explorers using wind by diverse techniques instead of a large single robotic vehicle? Even if there is no atmosphere, surely a large cloud of tiny and diverse explorers is more capable and robust than a single one? The clue to solving the IT bits are that a physical cloud can also be an IT cloud. Why not let them use different shapes for different circumstances, so that they can float up, be blown around, and when they want to go somewhere interesting, then glide to where they want to be? Dropping from a high altitude is an easy way of gathering the kinetic energy for ground penetration too, you don’t have to carry sophisticated drills. Local atmosphere can be used as the gas source and ballast (via freezing atmospheric gases or taking some dust with you) for balloons and wind or solar can be the power supply. Obviously, people in all space agencies must have thought of these ideas themselves. I just don’t understand why they have thrown them away in favor of far more heavier and more expensive variants.
I’m not an expert on space. Maybe there are excellent reasons that each and every one of these can’t work. But I also have enough experience of engineering to know that one of the most likely reasons is that they just aren’t exciting enough and the complex, expensive, unreliable and less capable solutions simply look far more cool and trendy. Maybe it is simply that ego is more important than mission success.