Abstract

OKEANOS (Oversize Kite-craft for Exploration and AstroNautics in the Outer Solar system) is the future mission under study to cruise to the outer solar system using a large-area solar power sail, and to rendezvous with and land on a Jupiter Trojan asteroid for in-depth study there. Jupiter Trojans are the key targets to be explored, because they are mainly volatile-rich D/P type asteroids, located beyond the water ice snow line, and possibly originated from the EKBO scattered due to planetary migration. The conditions and materials that were lost in the inner solar system should be preserved there. This mission aims at investigating the origin and evolution of Jupiter Trojans and their materials by direct microscopy and mass spectroscopy of the collected samples. Geologic context of the landing site and the surrounding area will be observed with imaging, NIR and X-ray spectroscopy, and radiometry. The landing site will be selected by global mapping of imagery, NIR and TIR imaging spectroscopy, and ground penetrating radar to understand the global shape, surface geology, mineralogy, degree of hydration, thermo-physical properties, and so on. Gravity (or porosity) and magnetic property of the bulk asteroid to study the interior structure will be also measured by Doppler shifts and magnetic field measurements. Current activity of dust ejection and volatile eruption will be also measured. The details of the mission and instrumentation will be presented.