A close-approach solar probe design feasibility and mission study

Abstract

A probe to approach the sun to a perihelion distance of three solar radii is shown to be scientifically desirable and feasible within the next two decades. This probe will perform measurements of the coronal magnetic field, coronal bulk flow patterns, and super-thermal particles. The mission will utilize nuclear-electric propulsion with a simple thrusting program. The final orbit is highly elliptical and does not require thrust to be applied at distances too close to the sun for operation of a 500-kwe SNAP-50-type nuclear-electric system. The electrically propelled spacecraft that transports the sun orbiter contains power, propulsion, attitude control, command, and communications systems, as well as a system to separate the orbiter from the spacecraft. At the conclusion of powered flight, the sun orbiter is separated from the propulsion system and is completely self-sufficient. The gross initial weight of the spacecraft is 28,330 Ib, of which 1450 is attributed to the orbiter.