The baseline mission was chosen following multiple mission design and spacecraft technology iterations with JPL’s Team-X. All missions studied travel to an aim-point within 20° of the incoming interstellar wind direction by traveling outward from the Earth without Venus, Earth, or Mars gravity assists. We considered a "direct mission" with no gravity assists, single gravity assists (all four large outer planets), and double gravity assists (Jupiter plus one more) for launch during the 40 years from 2010 through 2050. It is not until the 2030s that single gravity assists at Saturn, Uranus, or Neptune, or a double Jupiter-Saturn gravity assist, can provide a solution. A single Jupiter gravity assist was chosen as the baseline mission design. This design was iterated further as the spacecraft design matured. Four technology options were devised with corresponding masses and power modes. For each a 30% mass contingency was added and the mission design reoptimized. Option 1, with the lowest level of new technology was selected as the baseline. Each option has a 20+ day launch window. Backups occur at ~13-month intervals (Nov. 2015, Dec. 2016, Jan. 2018) with the same spacecraft ( and increasing flyout time to 200 AU), and the cycle repeats about every 12 years (Jupiter’s orbital period) with the best opportunities in 2014, 2026, 2038, and 2050.