Earth and Space 2018 68 © ASCE Combined Seismic and Penetration Tests on the Planetary Analogue Site Mount Etna S. Papamichael 1 ; A. Becker 2 ; and C. Vrettos 3 1 Division of Soil Mechanics and Foundation Engineering, Technical Univ. Kaiserslautern, 67663 Kaiserslautern, Germany. E-mail: papamich@rhrk.uni-kl.de 2 Division of Soil Mechanics and Foundation Engineering, Technical Univ. Kaiserslautern, 67663 Kaiserslautern, Germany. E-mail: becker@rhrk.uni-kl.de 3 Division of Soil Mechanics and Foundation Engineering, Technical Univ. Kaiserslautern, 67663 Kaiserslautern, Germany. E-mail: vrettos@rhrk.uni-kl.de ABSTRACT Within the frame of the major national research project ROBEX dealing with the robotic exploration of extreme environments, dynamic penetration tests combined with seismic tests have been conducted at an altitude of over 2,600 meters on Mt. Etna. Focus was placed on the assessment of the near-surface soil properties. A light dynamic sounding penetrometer with variable impact energy has been employed. Parallel to this, seismic data generated by a surface impact source were collected with geophones mounted on embedded spikes of different lengths. In addition to the performed in situ tests, samples of the volcanic soil were collected for classification and shear strength testing in the laboratory. The paper describes the experimental set-up and the deduced soil properties from the two types of in situ test. The results show the limits of available empirical relationships derived for routine geotechnical applications. After refinement, the methodology employed may be transferred to planetary missions. INTRODUCTION Planetary analogue sites are essential for testing technologies and equipment for future exploration missions in Space. These sites exhibit extreme conditions similar to those prevailing on the Moon and on Mars, or on other planets. Mount Etna is one of the extra-terrestrial analogue sites with particular adverse conditions characterised by continuing volcanic eruptions. It has been certified as such due to its unique features similar to those of planetary bodies (Preston et al. 2012), and has already been a destination for field tests (Ciarletti et al. 2011). The lava landscape of Mount Etna has a volcanic structure, lava flows, rilles and channel systems and is composed of basalt, features of both Moon and Mars. Within the frame of the major national research project ROBEX which is dealing with the robotic exploration of extreme environments, dynamic penetration tests combined with seismic tests have been conducted at an altitude of over 2600 meters in order to assess parameters relevant to rover mobility. Focus is placed on the assessment of the near-surface soil properties. A light dynamic cone penetrometer with variable impact energy has been employed to estimate relative density and strength. Seismic tests were used to determine wave propagation characteristics. Laboratory shear tests accompanied the field tests. The paper describes the site and the testing procedures, and summarizes the findings. EXPERIMENTAL SET-UP AND SITE CHARACTERIZATION Mount Etna is an active stratovolcano for the last 500,000 years. It is located on the east coast of Sicily and lies above the convergent plate margin of the African and Eurasian Plates (James et al. 2016). As a stratovolcano, Mt. Etna has high silica content, which makes the