Mission to the sun: The Solar Pioneer

The Solar Pioneer is a mission concept developed by the Johns Hopkins University Applied Physics Laboratory (JHU/APL) to do exploratory science in the inner heliosphere and outer solar corona. The concept is derived from the Near Earth Asteroid Rendezvous (NEAR) spacecraft now being built by JHU/APL for NASA and draws upon that design to the maximum extent possible. The primary purpose, to conduct an exploratory in situ basic science investigation, has been focused to emphasize in situ particles and fields measurements of the outer solar corona and inner solar wind region. The purpose of the Solar Pioneer is to deliver a payload of scientific instruments to approximately 4 solar radii. The basic characteristics of the JHU/APL baseline concept provide for delivery of 30 to 50 kg of scientific payload to 4 Rs while maintaining a high data rate. Life-cycle cost control is obtained by: (1) focusing on prime science objectives, (2) applying advanced technology where it makes sense, and (3) capitalizing on developed subsystems derived from the NEAR spacecraft. By implementing a focused strategy from science goals through all stages of program management, such a mission can be carried out for less than one quarter of previous Solar Probe mission cost estimates.