Candidate regions on titan as promising landing sites for future in situ missions

The highly successful and still on-going Cassini-Huygens mission to the Saturnian system points to the need for a return mission, with both remote and in situ instrumentation. The surface of Saturn’s moon Titan, hosts a complex environment in which many processes occur shaping its landscape. Several of its geological features resemble terrestrial ones, albeit constructed from different material and reflecting the interiorsurface-atmosphere exchanges. The resulting observed morphotectonic features and cryovolcanic candidate regions could benefit from further extensive exploration by a return mission that would focus on these aspects with adapted state-of-the-art instrumentation affording higher spectral and spatial resolution and in situ capabilities. We suggest that some features on Titan are more promising candidate locations for future landing and we present the case for Tui Regio, Hotei Regio and Sotra Patera as to why they could provide a wealth of new scientific results

Surface albedo changes with time on Titan’s possible cryovolcanic sites: Cassini/VIMS processing and geophysical implications

We present a study on Titan’s possibly cryovolcanic and varying regions as suggested from previous studies [e.g. 1;2;7]. These regions, which are potentially subject to change over time in brightness and are located close to the equator, are Tui Regio, Hotei Regio, and Sotra Patera. We apply two methods on Cassini/VIMS data in order to retrieve their surface properties and monitor any temporal variations. First, we apply a statistical method, the Principal Component Analysis (PCA) [3;4] where we manage to isolate regions of distinct and diverse chemical composition called ‘Region of interest – RoI’. Then, we focus on retrieving the spectral differences (with respect to the Huygens landing site albedo) among the RoIs by applying a radiative transfer code (RT) [5;3]. Hence, we are able to view the dynamical range and evaluate the differences in surface albedo within the RoIs of the three regions. In addition, using this double procedure, we study the temporal surface variations of the three regions witnessing albedo changes with time for Tui Regio from 2005-2009 (darkening) and Sotra Patera from 2005-2006 (brightening) at all wavelengths [3]. The surface albedo variations and the presence of volcanic-like features within the regions in addition to a recent study [6] that calculates Titan's tidal response are significant indications for the connection of the interior with the cryovolcanic candidate features with implications for the satellite’s astrobiological potential

Planetary polar explorer – the case for a next-generation remote sensing mission to low Mars orbit

We propose the exploration of polar areas on Mars by a next-generation orbiter mission. In particular, we aim at studying the seasonal and regional variations in snow-deposits, which – in combination with measurements of temporal variations in rotation and gravity field – will improve models of the global planetary CO2 cycle. A monitoring of polar scarps for rock falls and avalanche events may provide insights into the dynamics of ice sheets. The mapping of the complex layering of polar deposits, believed to contain an important record of climate history, may help us understand the early climate collapse on the planet. Hence, we propose an innovative next-generation exploration mission in polar circular Low Mars Orbit, which will be of interest to scientists and challenging to engineers alike. Schemes will be developed to overcome atmosphere drag forces acting upon the spacecraft by an electric propulsion system. Based on the experience of missions of similar type in Earth orbit we believe that a two-year mission in circular orbit is possible at altitudes as low as 150 km. Such a mission opens new opportunities for novel remote sensing approaches, not requiring excessive telescope equipment or power. We anticipate precision altimetry, powerful radars, high-resolution imaging, and magnetic field mapping

Joint Europa Mission (JEM): a multi-scale study of Europa to characterize its habitability and search for extant life

Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species, biomolecules and elementary forms of life; the identification of candidate thermal and chemical energy sources necessary to drive a metabolic activity near the ocean floor. In this article we are proposing that ESA collaborates with NASA to design and fly jointly an ambitious and exciting planetary mission, which we call the Joint Europa Mission (JEM), to reach two objectives: perform a full characterization of Europa's habitability with the capabilities of a Europa orbiter, and search for bio-signatures in the environment of Europa (surface, subsurface and exosphere) by the combination of an orbiter and a lander. JEM can build on the advanced understanding of this system which the missions preceding JEM will provide: Juno, JUICE and Europa Clipper, and on the Europa lander concept currently designed by NASA (Maize, report to OPAG, 2019). We propose the following overarching goals for our Joint Europa Mission (JEM): Understand Europa as a complex system responding to Jupiter system forcing, characterize the habitability of its potential biosphere, and search for life at its surface and in its sub-surface and exosphere. We address these goals by a combination of five Priority Scientific Objectives, each with focused measurement objectives providing detailed constraints on the science payloads and on the platforms used by the mission. The JEM observation strategy will combine three types of scientific measurement sequences: measurements on a high-latitude, low-altitude Europan orbit; in-situ measurements to be performed at the surface, using a soft lander; and measurements during the final descent to Europa's surface. The implementation of these three observation sequences will rest on the combination of two science platforms: a soft lander to perform all scientific measurements at the surface and sub-surface at a selected landing site, and an orbiter to perform the orbital survey and descent sequences. We describe a science payload for the lander and orbiter that will meet our science objectives. We propose an innovative distribution of roles for NASA and ESA; while NASA would provide an SLS launcher, the lander stack and most of the mission operations, ESA would provide the carrier-orbiter-relay platform and a stand-alone astrobiology module for the characterization of life at Europa's surface: the Astrobiology Wet Laboratory (AWL). Following this approach, JEM will be a major exciting joint venture to the outer Solar System of NASA and ESA, working together toward one of the most exciting scientific endeavours of the 21st century: to search for life beyond our own planet

OSS (Outer Solar System): A fundamental and planetary physics mission to Neptune, Triton and the Kuiper Belt

The present OSS mission continues a long and bright tradition by associating the communities of fundamental physics and planetary sciences in a single mission with ambitious goals in both domains. OSS is an M-class mission to explore the Neptune system almost half a century after flyby of the Voyager 2 spacecraft. Several discoveries were made by Voyager 2, including the Great Dark Spot (which has now disappeared) and Triton's geysers. Voyager 2 revealed the dynamics of Neptune's atmosphere and found four rings and evidence of ring arcs above Neptune. Benefiting from a greatly improved instrumentation, it will result in a striking advance in the study of the farthest planet of the Solar System. Furthermore, OSS will provide a unique opportunity to visit a selected Kuiper Belt object subsequent to the passage of the Neptunian system. It will consolidate the hypothesis of the origin of Triton as a KBO captured by Neptune, and improve our knowledge on the formation of the Solar system. The probe will embark instruments allowing precise tracking of the probe during cruise. It allows to perform the best controlled experiment for testing, in deep space, the General Relativity, on which is based all the models of Solar system formation. OSS is proposed as an international cooperation between ESA and NASA, giving the capability for ESA to launch an M-class mission towards the farthest planet of the Solar system, and to a Kuiper Belt object. The proposed mission profile would allow to deliver a 500 kg class spacecraft. The design of the probe is mainly constrained by the deep space gravity test in order to minimise the perturbation of the accelerometer measurement.Comment: 43 pages, 10 figures, Accepted to Experimental Astronomy, Special Issue Cosmic Vision. Revision according to reviewers comment

Automation in Agriculture - Securing Food Supplies for Future Generations

According to Prof. D. Despommier, by the year 2050, nearly 80% of the earth's population will reside in urban centers. Furthermore, the human population will increase by about 3 billion people during the interim. New land will be needed to grow enough food to feed them. At present, throughout the world, over 80% of the land that is suitable for raising crops is in use. What can be done to avoid this impending disaster? One possible solution is indoor farming. However, not all crops can easily be moved in an indoor environment. Nevertheless, to secure the food supply, it is necessary to increase the automation level in agriculture significantly. This book intends to provide the reader with a comprehensive overview of the impact of the Fourth Industrial Revolution and automation examples in agriculture