A NASA heliospheric program

Direct exploration of the heliosphere out to distances of about 40 AU has been carried out with Pioneer 10, 11 and Voyager 1, 2 while making use of supplementary observations by various spacecraft near 1 AU. In the past, these heliospheric observations have involved at least three divisions in the NASA Office of Space Science and Applications: Solar System Exploration, Astrophysics and Earth Observations. Consideration is now being given to combining the various missions into a single coordinated heliospheric program. A committee has been formed, the Heliospheric Science Working Group, consisting of the project scientists of the ongoing as well as future missions. The HSWG has drawn on appropriate members of the scientific community to assist in the development of a plan and in documenting it in a report. The highlights of the plan, with emphasis on both short range and long range scientific objectives, are described.