Novel Methods for Deep Ice Access on Planetary Bodies

Under NASA funding several new ice penetration technologies were developed at Stone Aerospace that represent significant departures from traditional approaches. The concepts discussed in this chapter are self-contained devices, known as cryobots, that are intended to be deployed by a planetary lander. Heretofore, terrestrial ice penetration systems have fallen into three major classes: mechanical drills (Vago et al. 2006, Weiss et al. 2008, Hsu 2010, Vasiliev et al. 2011, Zacny et al. 2013, Chu et al. 2014, Goodge and Severinghaus 2016), hot water drills (Humphrey and Echelmeyer 1990, Thorsteinsson et al. 2008, Benson et al. 2014, Rack 2016), and passive melt probes (Philberth 1962, Zimmerman 2000, Ulamec et al. 2007, Kaufmann et al. 2009, Biele et al. 2011, Lorenz 2012, Winebrenner et al. 2013, Dachwald et al. 2014, Talalay et al. 2014, Wirtz and Hildebrandt 2016). We first describe new test results from a fourth approach, Direct Laser Penetration (DLP), using a specific wavelength laser as the power source. The second half of this chapter will focus on current work in planetary mission closed-cycle hot water drilling technology (CCHWD) that will down-convert to a less effective, but still functional, thermal passive probe for the purpose of addressing the “Starting Problem” (Stone et al. 2018) on planetary bodies with no atmosphere. Each of these approaches fills a specific niche in planetary mission ice penetration. The direct laser approach is well suited for lightweight, short range penetrations (10–100 m depth) from a lander with the power source being based on the lander; the CCHWD approach is better suited for very deep penetrations (10–30 km) where the power source, presumed to be a 50–100-kW fission reactor, would be carried by the cryobot descent vehicle.