A Precursor Interstellar Mission to a Possible Exoplanet Beyond the Kuiper Belt T. Marshall Eubanks Asteroid Initiatives LLC, E-mail:
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Submitted to the Icarus Interstellar Starship Congress 2015 July 3, 2015 Travel to the nearby stars, the ultimate goal of interstellar travel, will be facilitated by a sequence of interstellar precursor missions, each providing a gain of knowledge and experience from ever deeper penetrations into interstellar space. The first such precursor missions are in fact already in progress: the Voyager spacecraft have provided the first in situ exploration of the interstellar medium past the heliopause, while the New Horizons probe to Pluto shows that current technology can reconnoiter objects at a distance of 32 AU with a travel time of ∼ 10 years. New Horizons is currently beginning its encounter with the Pluto system, with plans for a New Horizons Kuiper belt mission, a post-Pluto flyby of a Kuiper belt object at ∼ 44 AU. The apparent initial success of this mission indicates that it is time to begin planning the next such interstellar mission. With the propulsion technology that could be realistically available by the end of this decade (solar sails and electric sails) there are at present two objects, the “Sednoids” (90377) Sedna and 2012 VP113, both currently near their perihelions at ∼ 80 AU, available for missions beyond the outer limit of the Kuiper Belt. These two dwarf planets are the only known objects in the solar system that could possibly be exoplanets (their orbits are very hard to explain without either the presence of undiscovered large bodies in the “First-Generation Oort Cloud,” or an interaction with a passing star), and there is no realistic prospect of the mystery of their origin truly being resolved except through in situ exploration. It should be possible to design and launch in the near future an interstellar precursor mission with a velocity “at infinity” of ∼ 70 km sec−1 (or ∼ 14 AU year−1 ) which would reach either Sedna or 2012 VP113 within a decade, the heliopause within 15 years, and the Solar Gravitational Lens at 550 AU within about 40 years. Such a mission would be a true interstellar precursor mission, both improving the propulsion and spacecraft systems for travel into interstellar space, resolving fundamental questions about the nature of the bodies in the “First-Generation Oort Cloud,” meeting the NASA Heliophysics decadal survey goals of better understanding the heliopause and the fundamental physical processes of the interstellar medium, while in an extended mission possibly providing the first sounding of the Sun as a gravitational lens. If Sedna (or 2012 VP113) can indeed be shown to be an exoplanet, it would be by orders of magnitude the most accessible exoplanet and undoubtedly would become the target of more intensive direct exploration subsequently.
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