NASA really is trying everything in its quest to build better robotic craft. Wasn't too long ago that the space agency tried bean bag wheels. Now, it's duct-taped skateboards to a lander's legs to allow it to ollie across the surface of distant planets (or, in this case, help test it here on Earth).
Actually, the skateboards won't be accompanying the robotic lander on any of its missions. The skates and track were set up by NASA as a cheap way to control its movement as the craft's sensors, thrusters and other systems were put through the final paces.
The diminutive lander is part of NASA's push to develop the next generation of robotic craft for future missions, and it's smaller, smarter and can touch down more accurately than the landers before it.