---
abstract: 'The Sun, driving a supersonic solar wind, cuts out of the local interstellar
  medium a giant plasma bubble, the heliosphere. ESA, jointly with NASA, has had an
  important role in the development of our current understanding of the Suns immediate
  neighborhood. Ulysses is the only spacecraft exploring the third, out-of- ecliptic
  dimension, while SOHO has allowed us to better understand the influence of the Sun
  and to image the glow of interstellar matter in the heliosphere. Voyager 1 has recently
  encountered the innermost boundary of this plasma bubble, the termination shock,
  and is returning exciting yet puzzling data of this remote region. The next logical
  step is to leave the heliosphere and to thereby map out in unprecedented detail
  the structure of the outer heliosphere and its boundaries, the termination shock,
  the heliosheath, the heliopause, and, after leaving the heliosphere, to discover
  the true nature of the hydrogen wall, the bow shock, and the local interstellar
  medium beyond. This will greatly advance our understanding of the heliosphere that
  is the best-known example for astrospheres as found around other stars. Thus, IHP/HEX
  will allow us to discover, explore, and understand fundamental astrophysical processes
  in the largest accessible plasma laboratory, the heliosphere.'
adsnote: Provided by the SAO/NASA Astrophysics Data System
adsurl: https://ui.adsabs.harvard.edu/abs/2009ExA....24....9W
authors:
- Robert F. Wimmer-Schweingruber
- Ralph McNutt
- Nathan A. Schwadron
- Priscilla C. Frisch
- Mike Gruntman
- Peter Wurz
- Eino Valtonen
category: publications
date: '2009-05-01'
doi: 10.1007/s10686-008-9134-5
draft: false
featured: false
journal: Experimental Astronomy
month: May
number: 1-3
pages: 9-46
projects: []
publication: Experimental Astronomy
publication_types:
- '2'
tags:
- 'Ism: general'
- 'Solar system: general'
- Interplanetary medium
- 'Space vehicles: instruments'
- Cosmic rays
title: 'Interstellar heliospheric probe/heliospheric boundary explorer mission\textemdasha
  mission to the outermost boundaries of the solar system'
type: ARTICLE
volume: '24'
year: '2009'
---