A Rocket-Propelled Miniature Robot for Planetary Exploration

In terms of overall bang for your buck, solid-fuel rockets are pretty great: They're dead simple, very reliable, and offer respectable efficiency in a very small form factor, as long as you're prepared to handle a lot of thrust all at once and then never again. While some robots have attempted to use rockets to jump from place to place, controllability has always been an issue, since solid-fuel rockets give you a fixed amount of thrust whether you want it or not, and that thrust isn't always directed in exactly the way you'd like. At ICRA last week, researchers from the Japan Aerospace Exploration Agency (JAXA) introduced a small robotic explorer that uses a single solid-fuel rocket to launch itself into the air. What's new is that their robot includes some braking rockets that help it make pinpoint landings, as well as a clever gyroscopic system to make sure that it flies straight as well as providing a way for the robot to get around after landing. The 450-gram robot consists of a housing with batteries and sensors, a reaction wheel (also inside the housing), a primary solid-fuel rocket engine (an Estes C11 with a total impulse of 10 newton-seconds), and two smaller opposing thrust motors.