To fly to the Sun: the mission and technology challenges of the Solar Probe

To fly close to the Sun (to a perihelion of 4 solar radii) represents many unique challenges to a mission and spacecraft design. The Solar Probe design is a result of over two decades of studies that have allowed the evolution of both the mission and trajectory design, as well as the spacecraft configurations. During these studies some of the most significant design challenges have been the trajectory design, the spacecraft shield design, the spacecraft configuration, the telecommunications near perihelion, science instrument accommodations, and minimizing the cost of the mission. This latter challenge (minimum cost) permeates all of the other design issues suggesting specific solutions consistent with this constraint. This paper presents the evolution and rationale that has taken place to arrive at the current design for this challenging mission.