IceWorm: Ice Climbing Robots for Glaciology and Beyond

Obtaining physical access to key glacial processes can be dangerous, impractical, or impossible for humans. To extend the reach of glaciologists, JPL's IceWorm project has developed the first ice climbing robots. These systems will climb on and in ice to enable breakthrough science: creating comprehensive 3D maps of englacial drainage networks, monitoring icebergs in-situ from calving to melt, collecting large volumes of tephra from ice cliffs or crevasses. Developing robotic ice climbing systems on earth also paves the way for planetary missions on extreme icy terrain, exploring places like Enceladus, Europa, Pluto, and the polar ice canyons of Mars.

During our early investigations of of robotic ice climbing, we targeted fumarolic ice caves. These dynamic geothermal systems form on glaciated volcanoes when fumarolic vents drive basal melting of horizontal passages which can extend for kilometers. In addition to providing basal access to the glacier, the caves are of astrobiological interest. We tested prototype robot "feet" with anchoring and ice sampling capabilities in fumarolic ice caves on Mt Erebus in 2016, and on Mt Rainier in 2017. These robot are based on commercial ice climbing screws designed for alpinists. The IceWorm systems climb like an inchworm with an ice screw at either end, alternately inserting and retracting screws so that at least one screw is anchored at all times.

In June 2018, we tested an ice climbing robot inside firn caves and glacier caves of Mt St Helens. Climbing was unsuccessful in firn, but successful in glacial ice. We present engineering data regarding the forces and torques imparted and experienced by the robot, and some thoughts on the nature of mechanical interactions with the ice. We also present results of a laboratory testing campaign to determine forces and torques required to insert ice screws. The testing campaign has recently been extended to include ice under vacuum and at cryogenic temperatures. We discuss future prospects for science using ice climbing robots and welcome your input.