IAC-05-A3.2.A.09 EXPLORING TRITON WITH MULTIPLE LANDERS by Tibor S. Balint Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive, M/S 301-170U Pasadena, CA 91109-8099 e-mail: tibor.balint@jpl.nasa.gov ABSTRACT In our pathway for Outer Planetary Exploration several mission concepts were considered, based on the proposed JIMO mission architecture. This paper describes a JIMO follow-on mission concept to Neptunes largest moon. Triton is a target of interest for outer solar system studies. It has a highly inclined retrograde orbit, suggesting that it may have been a Kuiper Belt object captured by Neptune. Given this assumption its composition, which may include organic materials, would be of significant scientific interest. The present concept considers a surface mission architecture with two landers, each powered by a standard multi-mission radioisotope thermoelectric generator (MMRTG). The landers would operate on the surface for several years providing science data, thus expanding our understanding of the environment, the dynamic surface and atmospheric processes, and some of the seasonal variations. A JIMO class orbiter would provide telecommunication link between the landers and Earth, and would be instrumented to observe both Triton and Neptune. In this paper all key aspects of the mission architecture are addressed, including the science instru- ments, the main subsystems, trade options for the power system and a conceptual design for the landers. INTRODUCTION The Vision for Space Exploration [1] identi- fies three major exploration pathways, targeting Mars, the Moon and the Outer Planets. Within this roadmap the first planned science mission to the Outer Planets was the Jupiter Icy Moons Orbiter (JIMO) mission. Potential JIMO follow- on missions were envisioned to target other outer planetary destinations, such as Saturn, Neptune or Pluto. This paper describes a landed mission concept to Neptune’s largest moon, Triton, with the aim of expanding our incomplete knowledge of the Neptunian system, which is based on the August 25, 1989 flyby of the Voyager 2 space- craft and on more recent Earth and space-based observations. Since the completion of this study, the JIMO mission has been deferred. Although this Tri- ton lander concept baselined a JIMO follow-on architecture, alternatives were also addressed. Thus, this generic lander concept is not depen- dent on JIMO follow-on architectures and could be considered as a “black box” concept for other Neptune/Triton exploration missions. SCIENCE AND MISSION GOALS Triton is a target of great interest for outer solar system studies. Thus, potential science objec- tives for a Triton lander mission would include a more complete characterization of the com- position and circulation of the atmosphere; in- vestigation of the physical processes responsible for plume formation; surface composition mea- surements; and geophysical monitoring. In par- ticular, seismological measurements could po- tentially refine our knowledge of the physics of plume eruptions, and could detect Triton- quakes, if such are occurring at the present time. A pair of landers, one located in the summer hemisphere and the other in the winter hemi- sphere, could collect complementary information 1