The funded proposal came from graduate student Melissa Tanner, who works with her advisor, Joel Burdick, professor of mechanical engineering and bioengineering, as part of the Caltech and JPL team developing Axel. The experimental rover is two-wheeled and tethered around its center, like a yo-yo, such that it can rappel down cliffs to access hard-to-reach places. A rotating onboard science drum can deploy scientific instruments, such as a thermometer, laser spectrometer, and microscopic imager, even when the rover is on a steep slope. Two of the rovers can also link together via a central module to form a four-wheeled, "DuAxel" vehicle that can traverse flat or rocky terrain en route to a target destination.
Tanner says she submitted the proposal for KISS funding because every summer there are more students who want to work with Axel than the team can afford to pay.