Mission design for the exploration of Neptune and Triton

In early 2013, the European Space Agency (ESA) invited the scientific community to propose themes for the next decades of fag-ship missions (specifically for the next L-class missions, L2 and L3). Researchers from European, American, and Japanese institutions submitted a white paper on the scientific case for a mission to Neptune and Triton. The document included an example mission concept and aimed to demonstrate that the proposed science theme can be addressed with technology that is expected to become available within the L2 and L3 time frames (2028 and 2034). We present here the trajectory design for the mission concept and a high-level discussion on its feasibility, which was included in the white paper. We also present details on the example Triton tour, a new search for interplanetary transfers, and a preliminary analysis of the gravity losses at Neptune orbit insertion (NOI), which suggests the use of a large chemical propulsion system.