Enceladus and the Icy Moons of Saturn (2016) 3031.pdf ENCELADUS EXPLORER: NEXT STEPS IN THE DEVELOPMENT AND TESTING OF A STEERABLE SUBSURFACE ICE PROBE FOR AUTONOMOUS OPERATION. B. Dachwald1, J. Kowalski2, F. Baader1, C. Espe1, M. Feldmann1, G. Francke1, E. Plescher1, 1Faculty of Aerospace Engineering, FH Aachen University of Applied Sciences, Hohenstaufenallee 6, 52064 Aa- chen, Germany, [email protected], 2Aachen Institute for Advanced Study in Computational Engineering Sci- ence, RWTH Aachen University, Germany Introduction: Direct access to subsurface liquid flexibly organized initiative with sub-projects focused material for in-situ analysis at Enceladus' South Polar on key research and development areas. The sub- Terrain is very difficult and requires advanced access project at FH Aachen is called EnEx-nExT (Environ- technology with a high level of cleanliness, robustness, mental Experimental Testing). Since the EnEx- and autonomy. A new technological approach has been IceMole was quite large (15 x 15 x 200 cm) and heavy developed as part of the collaborative research project / (60 kg), a much smaller (8 x 8 x 40 cm) and light- initiative “Enceladus Explorer” (EnEx) [1]. Within weight (< 5 kg) probe is currently developed within EnEx, the required technology for a potential Encela- EnEx-nExT. In the next two years, this smaller probe dus lander mission [2] is developed, evaluated, and will be tested in a vacuum chamber under simulated tested, with a strong focus on a steerable subsurface ice space conditions (pressure < 6 mbar, temperature probe. The EnEx probe shall autonomously navigate < 100 K) to prove the applicability of combined drill- through the ice and find a location where a liquid water ing and melting probes under more Enceladus-like sample can be taken and analyzed in situ. EnEx is environmental conditions. More detailed information funded and managed by the DLR Space Administra- about these experiments will be given in a separate tion and comprises several German universities. conference contribution. Within the sub-project EnEx- The Enceladus Explorer Project (2012–2015): DiMIce (Directional Melting in Ice), the complex Several prototypes of a steerable subsurface ice probe, melting behavior of such probes is modeled and simu- called IceMole, were developed and tested at FH Aa- lated at RWTH Aachen University. Information about chen since 2009. The IceMole design is based on the these computational models will be given as part of a novel concept of combining melting and mechanical separate conference contribution. feed – using an ice screw at the tip of the melting head [3]. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully Figure 1: EnEx-IceMole (with hull removed) tested between 2010 and 2012 on glaciers in Switzer- land and Iceland. They demonstrated downward, hori- zontal and upward melting, as well as curve driving and dirt layer penetration. Within the EnEx project, a more advanced probe, called EnEx-IceMole (Fig. 1), was developed between 2012 and 2015. It provides concepts for obstacle avoidance, target detection, and navigation in ice. This probe was successfully tested on Canada Glacier (Fig. 2) and Taylor Glacier, Antarc- tica, in 2013 and 2014, respectively [1]. During the 2014 deployment, it was used in international collabo- ration with the US-American NSF-funded MIDGE (Minimally Invasive Direct Glacial Exploration) pro- Figure 2: EnEx-IceMole deployment during Antarctic ject for clean access into Blood Falls, a unique aquatic field test subsurface environment, with subsequent return of a Acknowledgements: The project is supported by clean subglacial brine sample to the surface. Since the Federal Ministry of Economics and Technology, Blood Falls is categorized as an ASPA (Antarctic Spe- Germany, on the basis of a decision by the German cially Protected Area), we had to pay particular atten- Bundestag (FKZ: 50NA 1503) tion to clean protocols for the sampling of subglacial References: [1] Kowalski J. et al. (2016), Cold materials for biogeochemical analysis. Reg. Sci. Technol., 123, 53-70. [2] Konstantinidis K. et The Enceladus Explorer Initiative (2015+): After al. (2015), Acta Astronaut., 106, 63–89. [3] Dachwald the successful Antarctic deployment of the EnEx- B. et al. (2014), Ann. Glaciol., 55(65), 14-22. IceMole, EnEx was continued in the form of a more .