COMET NUCLEUS SAMPLE AND RETURN MISSION VIA ELECTRIC PROPULSION

摘要

The Comet Nucleus Sample and Return (CNSR) mission has been of great interest for many years. The mission objective is very clear and it provides the clues to the solar system and the origin of life. The paper presents the feasible CNSR scenario taking the advantage of Solar Electric Propulsion (SEP) to the comet Wilson-Harrington. The plan is found feasible, and the launch window is open in 2005 and the spacecraft can return the sample back to the Earth in only eight years. Another window that is open in 2009-2010 is also provided here. They are making use of the ion engine propulsion accumulating the orbital energy at Earth distance first, followed by the Earth gravity assist. This is the unique point enabling even the smaller spacecraft to accomplish this high energy mission. This strategy accelerates the spacecraft orbital energy up to 36 to 40 km2/s~2 in C_3 that is adequate for the flight to the comet Wilson-Harrington. The idea shown here also includes 1) the rendezvous point to be at Earth distance so that the electric propulsion is utilized at maximum, 2) the target comet to be extinct so that the sampling and in-situ measurement scenario be robust. The trajectory synthesis developed here and tactical target selection make this impressive mission to be envisioned even by smaller missions.