Science and Enabling Technologies to Explore the Interstellar Medium

September 8-11, 2014
California Institute of Technology - Pasadena, CA 91125

Workshop Overview:

Recent discoveries reported in 2012 and 2013 by Voyager-1 and Kepler have brought into focus two end-points of what is now commonly referred to as the Interstellar Medium (ISM). Whereas Voyager-1 is beginning to explore the ISM in-situ, the Kepler space-based telescope and other Earth-based telescopes have detected a plethora of potentially Earth-like planetary systems around other stars or "exoplanets". The results of these two missions frame the context for further intellectual curiosity, scientific questions, and exploration goals that will define objectives for innovative and far-reaching missions heading out of our solar system and someday reaching for the stars.

The goals of the workshop are to:

  • articulate key scientific questions
  • identify near-term science exploration goals
  • derive mission objectives and preliminary design concepts that can be realized in the next two decades
  • derive flight system and science measurement requirement
  • assess key mission, system, and operations technology drivers
  • develop a technology maturation plan that will be proposed to KISS and JPL for follow-on funding.

The technical challenge and the focus of the workshop is to assess mission implementation techniques that will enable affordable robotic probes to reach the ISM within 10 years with velocities up to 10 times faster than Voyager, and be designed to last 50 years or longer. By comparison, Voyager-1 is now traveling at a speed of 17 km/sec, and has taken 35 years to reach the ISM. Meeting this challenge would constitute a revolutionary capability that would enable multiple scientific probes to launch and return initial scientific results of and from the ISM within a decade, and continue for several decades.

Workshop Participants:

  • Leon Alkalai - JPL/Caltech
  • Nitin Arora -JPL/Caltech
  • Manan Arya - Caltech Campus
  • Nathan Barnes - L. Garde Inc.
  • Mike Brown - Caltech Campus
  • Bob Cesarone - JPL/Caltech
  • Freeman Dyson - Institute for Advanced Study
  • Lou Friedman - The Planetary Society
  • Darren Garber - NXTRAC
  • Paul Goldsmith - JPL/Caltech
  • Mae Jemison - 100 Year Starship
  • Les Johnson - NASA George C. Marshall Space Flight Center
  • Paulett Liewer - JPL/Caltech
  • Philip Lubin - UC Santa Barbara
  • Claudio Maccone - International Academy of Astronautics and Istituto Nazionale di Astrofisica
  • Jared Males - University of Arizona
  • Ralph McNutt - Johns Hopkins University Applied Physics Laboratory
  • Richard Mewaldt - Caltech Campus
  • Adam Michael - Boston University
  • Merav Opher - Boston University
  • Elena Provornikova - Catholic University of America
  • Jamie Rankin - Caltech Campus
  • Seth Redfield - Wesleyan University
  • Michael Shao - JPL/Caltech
  • Ed Stone - Caltech Campus
  • Nathan Strange - JPL/Caltech
  • Mark Swain - JPL/Caltech
  • Slava Turyshev - JPL/Caltech
  • Michael Werner - JPL/Caltech
  • Gary Zank - Univesity of Alabama in Huntsville

Reference List

Below are some references we have gathered relevant to our study. Many more references about particular technologies, scientific investigations, and orbits will be cited during the study. We welcome additions and suggestions for this compilation of references.

Interstellar Precursors (e.g. 50-1000 AU)

The JPL Library compiled this selective list of publications. The emphasis is upon review articles and publications from 2000 to the current date.

Interstellar Flight (i.e. to other star systems)

Actual Interstellar Flight is not part of our study. It is too far out. But the idea of interstellar flight motivates interest in missions that explore into the interstellar medium (ISM) and make observations from the ISM. And the reverse: ideas to exit the solar system at high velocities to hundreds of AU naturally lead to thinking about possibilities beyond that. There is a rich literature about interstellar flight, most of it science-fiction, but also some technical papers, especially in the Journal of the British Interplanetary Society and on the web sites of organizations devoted to research and studies about the topic. A compendium of literature and organizations is given in the following:

Short Course Presentations

Ed Stone

The Interstellar Medium

Freeman Dyson
Institute for Advanced Study

Missions Beyond Pluto
(280 KB .pdf)

Mike Brown

Kuiper Belt, Oort Cloud
(1.5 MB .pdf)

Slava Turyshev

The Solar Gravity Lens Focus
(9.4 MB .pdf)

Ralph McNutt
Johns Hopkins University Applied Physics Laboratory

Previous ISM Mission Studies
(15 MB .pdf)

Nathan Strange

How Fast, How Far
(1.6 MB .pdf)

Les Johnson
NASA George C. Marshall Space Flight Center

Propulsion Candidates
(5.2 MB .pdf)

Workshop Presentations

Michele Judd, Leon Alkalai, Lou Friedman, Ed Stone

Logistics and Objectives
(933 KB .pdf)

Seth Redfield
Wesleyan University

Science Objectives Heliophysics
(2.4 MB .pdf)

Merav Opher
Boston University

Science Questions from inside 150AU Heliosheath/Heliopause
(4.3 MB .pdf)

Slava Turyshev

Science Objectives in Astrophysics
(390 KB .pdf)

Post-Workshop Presentations

Leon Alkalai, Ed Stone, Lou Friedman

Post Workshop: Summary of Action Items
(642 KB .pdf)
(5.48 MB .pptx)