When it comes to exploring the far reaches of our solar system (and eventually beyond), it simply isn't practical to send out human beings. Until such a time as we develop faster-than-light travel, the only eyes through which we'll really be able to see the universe are those of a machine. Unfortunately, the utilization of these probes faces its own array of unique challenges and roadblocks.
One of the most significant is tied to landing a probe safely on a planetary surface. The landing process for a planetary probe tends to be incredibly complex, consisting of multiple stages and requiring the use of a lander equipped with parachutes and retro-rockets. This can tend to be quite costly, and should a probe become damaged during - or as a result of - its descent, there's little the team operating it can do except hope their robot still functions. If it doesn't, well...that's money spent that they won't be getting back.
Though such failures are less common than they used to be, I'm given to understand that they're still far more common than the teams at institutions such as NASA would like.
Mechanical failure isn't the only thing that can make landing hazardous, either. Atmospheric conditions, gravitational pull, and debris can all severely complicate the landing process. What's more, even after getting to the surface of a planet, a probe might find itself trapped, faced with both impassable terrain and inclement weather.
Inspired by the extreme challenges faced by their probes, engineers at NASA have developed a new robot which might well be capable of taking interplanetary exploration to new heights. It's called Super Ball Bot and it's...well, it's basically a wire mesh ball. To be frank, it looks more like the product of a magnetic toy set than it does an actual robot.
It's most definitely legitimate, though - and far more durable than anything NASA has fielded to date. The cylindrical rods that make up Super Ball Bot are hollow and highly flexible, while its unusual design draws on a principle NASA refers to as "tensegrity" (tensional integrity). Because of this, the robot's shape allows it to safely disperse an impressive amount of kinetic force, meaning that it can safely survive drops of up to 62 miles (100 km) in height. It's been suggested that scientific instruments could be housed either within the rods or at the robot's center.
Super Ball Bot is also quite compact, weighing only a few kilograms and standing at only a few feet in height when fully expanded. In the future, NASA hopes to send out exploration vessels packed with potentially hundreds of the bots, which can then be released en masse above a planetary body that's been flagged for exploration. Titan - the largest of Saturn's moons - will likely be the first target explored by a Ball Bot legion.
There are several reasons Titan has been suggested. The planet's thick atmosphere makes it ideally suited for a drop, while its unpredictable weather patterns and uneven, relatively unknown terrain make single-probe exploration an exercise in futility, at best. Coincidentally, Titan has also been designated as one of the most liveable bodies in our solar system aside from Earth.
NASAs newest invention isn't ready to take to the skies just yet, however. Movement is still proving to be a significant challenge for engineers. The robot achieves locomotion through the compression and expansion of the tubes that make up its body, basically allowing it to 'roll' along virtually any surface. Though this allows it to conquer terrain which might leave other exploration probes stranded and useless, it's also significantly more complex than more traditional methods. This complexity in turn makes it far more difficult for scientists to nail down precise movement.
"A benefit and a curse of these robots is that there's a whole lot of control points and a lot of flexibility," explains NASA researcher Adrian K. Agogino. "It's really great in that they can go up hills, they can handle bumps, they can handle uneven terrain, but it's also very difficult to control."
Given Super Ball Bot's unique design, the team behind it has had to take something of a unique approach to working out the kinks in its movement.
"Our primary approach has been to evolve the controls," Agogino continues. "The best we can hope for is to give it lots of options for what it may do, so we can select hundreds if not thousands of different options. Some are good, some are bad. At the beginning, most are bad. Like evolution, you replicate the good ones and make small changes. Eventually, the good ones get better and better, and out of the thousands of bad controls, you get a set of good ones."
In short, it's only a matter of time before Super Ball Bot is ready for its first real mission. One day in the very near future, we may well see legions of these small, spherical droids rolling across the surface of distant moons and planets, both within our solar system and beyond.