Exploring our solar system can be a dangerous place for space rovers. In 1999, the ill-fated Mars polar lander journeyed millions of miles to reach Mars but then smashed upon landing. The Mars rover Curiosity made a successful descent in 2012, yet its wheels are growing more punctured and torn as it explores the planet.
The fragility of these expensive robots, loaded with precious data-gathering instruments, is limiting our ability to learn the long-secret mysteries of distant places. Once broken, they're useless. There is no nearby service station to fix them.
NASA wondered if there was a way to build tougher, cheaper space robots. Frustrated by the limits of today's technologies, the space agency wants something easy to land, easy to move and easy to fix from millions miles away. It wants something small and lightweight, something that could be safely dropped from heights, and something without wheels or fancy parachutes. NASA needs a survivor.
The Dynamic Tensegrity Robotics Lab, led by Vytas SunSpiral at NASA Ames Research Center in Mountain View, CA, enlisted the help of outside labs, including Alice Agogino and her team of students at the University of California at Berkeley. They know it will take collaboration among people with very different skills — mechanical engineering, electrical engineering and computer science — to solve this problem. Tossing aside traditional design ideas, they are taking a completely different approach to designing a robot.
The inspiration for this new kind of robot came when SunSpiral and a colleague were playing with Skwish, a toy for babies. It’s a web of rods, beads and balls secured by an elastic string. When they tossed it up in the air they noticed how well it absorbed impact when it landed.
“Playing around with the baby toy was a tactical brainstorming aid, helping us see the value of the idea,” says SunSpiral.
The toy — and their idea for a robot — are based on the concept of "tensegrity." It’s a quirky blend of geometry and engineering first conceived in the 1950s by futurist architect Buckminster Fuller. He coined the term by combining the words "tension" and "integrity" to describe a structure of compressed components held together by a net of continuous tension. Instead of using nuts and bolts to connect rigid pieces, tensegrity structures are held together by flexible cables. This gives them unique properties. Like a ball with bones, they flex and compress when dropped but spring right back into shape.
This ability makes a tensegrity structure the perfect candidate for a space robot. When dropped on hard terrain, it can handle the force of impact. Rather than break, it just bounces. This means its payload is protected. The precious cameras and other delicate instruments needed to gather data land safe and sound.
The structures offer other benefits, as well. They are cheap and small, so hundreds of these robots could be packed up and sent into space. They can squeeze into tight spaces like a space capsule. And they can twist through oddly shaped crevasses, something a rigid-bodied robot could never do.
Together, a herd of these sturdy robots could safely explore the hazardous surface of a planet or moon and send back information about these places so far away from Earth.
The world is full of interesting problems to solve. We are all constantly observing and assessing what's not working around us, and thinking of ways to improve it. That is the heart of engineering: being curious about a problem, investigating potential solutions, and designing and testing those solutions. KQED is inviting youth ages 11-18 to share ideas for solving a problem at school, at home or in your community. Learn more about the challenge here.