Progress towards an optically powered cryobot

Abstract

VALKYRIE (Very-deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice Explorer) is a NASA-funded project to develop key technologies for an autonomous ice penetrator, or cryobot, capable of delivering science payloads through outer planet ice caps and terrestrial glaciers. This 4 year effort will produce a cylindrical cryobot prototype 280cm in length and 25cm in diameter. One novel element of VALKYRIE's design is the use of a high-energy laser as the primary power source. 1070nm laser light is transmitted at 5kW from a surface-based laser and injected into a customdesigned optical waveguide that is spooled out from the descending cryobot. Light exits the downstream end of the fiber, travels through diverging optics, and strikes an anodized aluminum beam dump, which channels thermal power to hot-water jets that melt the descent hole. Some beam energy is converted to electricity via photovoltaic cells, for running on-board electronics and jet pumps. Since the vehicle can be sterilized prior to deployment, and forward contamination is minimized as the melt path refreezes behind the cryobot, expansions on VALKYRIE concepts may enable cleaner access to deep subglacial lakes. This paper focuses on laser delivery and beam dump thermal design.