Recent Patents on Space Technology, 2010, 2, 59-66 59 1877-6116/10 2010 Bentham Open Open Access Aerobot Dynamics Simulations for Planetary Exploration of Titan Giacomo Colombatti * , Alessio Aboudan, Nicola La Gloria and Stefano Debei Center of Studies and Activities for Space, University of Padova via Venezia, 15 35131 Padova, Italy Abstract: A future mission to return to Titan after Cassini/Huygens has now a really high priority for planetary exploration. Recent Cassini discoveries have revolutionized our understanding of the Titan system and its potential for harboring the ingredients necessary for life. These discoveries reveal that Titan is one of the most exciting places in the solar system; data show a complex environment, both for the atmosphere and for the surface. The data obtained, enriched by continuing observations from the Cassini spacecraft, show hydrocarbon lakes, river channels and drainage basins, sand dunes, cryovolcanos and sierras. All these features demonstrate that dynamic processes are present on Titan and have raised the scientific interest in a follow-up mission to Titan. A robotic lighter-than-air vehicle has been suggested as a possible platform for an extensive exploration of the moon. NASA centers and universities around the US, as well as the European Space Agency, are studying the possibility of sending, as part of the next mission to this giant moon of Saturn, a hot-air balloon or similar for further and more in-depth exploration. Recent studies on airships have demonstrated the high capability of airships to be considered as scientific platforms for extended explorations, both in space and time, on planets with atmosphere. Here we analyse the dynamics of the airship in response of the encountered Titan’s environment. Possible trajectories for an extended survey of the moon are investigated; these allow us to have a precise quantitative analysis of the energy necessary for a journey on the moon. Analysis on stability is performed in order to check the possible scientific slot windows available for investigations. A 1.2 km x 1.4 km region is selected as baseline: time necessary for performing a complete survey is investigated. Investigations are conducted both in a quiet situation with no wind and in wind conditions. Trajectories are followed with airship at 1.5, 3, 5 and 7 m/s velocities; surface science (< 100 m) scenarios are proposed. Considered winds are in the range 0.0  1 m/s parallel and orthogonal to the ground track. Keywords: Airship, titan, exploration, simulator, dynamics. 1. INTRODUCTION Exploration of the planets and moons of the Solar System has up to now relied on remote sensing from Earth, fly-by probes, orbiters, landers and rovers. Today mobility is a key requirement because enables extensive geographical coverage and in-situ science. In this context robotic lighter- than-air (LTA) vehicles are a possible platform for the exploration of planets and moons with an atmosphere, such as Venus, Mars, Titan and the gas giants. NASA’s 2006 Solar System Exploration Roadmap clearly states [1]: A dedicated Titan orbiter or lighter than air cruise vehicle to observe more closely and continuously the surface of this complex world to find and explore such sites would be a better way to observe potential surface changes associated with geologic activity. And further clarifies the scientific importance of such a mission [1]: This important opportunity to study a fourth planetary body with an actively evolving and complex climate can be realized through orbital and lighter-than-air platform obser- vations of surface geology (including a search *Address correspondence to this author at the Center of Studies and Activities for Space, University of Padova via Venezia, 15 35131 Padova, Italy; Fax: +39 049 827 6855; E-mail: giacomo.colombatti@unipd.it for fields of impact craters with a size distribution inconsistent with the present day atmospheric thickness), examination of regionally varying erosional features and organic deposits, sampling of selected sites to assess organic deposits for chemical signatures of varying atmospheric methane to nitrogen ratios, and relative age dating of organic, cryovolcanic, and impact related deposits. An airship can provide the low-altitude coverage of a wide area of the moon or the planet for a long duration mission (months or even years) with a very low power consumption respect to conventional aircrafts or orbiters. Furthermore airships can identify scientifically interesting sites and reach them, thanks to their higher mobility compared to balloons, which are, for their nature, passive vehicles. A detailed analysis of advantages of Airship w.r.t. other aerial vehicles for planetary exploration is presented in [2]. Cassini/Huygens instruments have uncovered a very complex world with various surface and crustal processes including lakes and seas and fluvial erosive features: large- scale drainage patterns and flow directions of Titans channels and rivers have been pictured by Huygens during 2005 descent [3]; the observed channels have shown a large- scale flow pattern often several hundreds of kilometres in length with valley widths of up to 3 km across and depth of several hundred meters [4]. Lakes have also been definitively