In Search for the Exit from the Heliosphere: The Odyssey of Voyagers 1&2 Interstellar Missions (1977-2021) with Stamatios Krimigis

When the Voyager spacecraft were launched in 1977, the objective was to explore Jupiter and Saturn over the ensuing four years. At that time, estimates of the radial extent of the solar system were as small as 5 astronomical units (1 AU= 150 million km=the Sun-Earth distance). The Voyager science team, however, was fully aware of the unique arrangement of the outer planets that occurs every 175 years, enabling successive exploration of each planet through gravitational assists at each one. The endurance of the Voyager spacecraft provided the opportunity to not only explore Uranus and Neptune, in addition to Jupiter and Saturn, but also to initiate the Voyager Interstellar Mission, in search of the boundary between our solar system and the local interstellar medium (LISM). It was a long wait, since the Neptune encounter at 30 AU took place in 1989, but the heliopause was crossed some 23 years later by Voyager 1 in 2012 at 121.6 AU. The speaker has been a Voyager Principal Investigator since 1971, and will describe this remarkable journey, a modern Odyssey of the space era.

Stamatios Krimigis is Emeritus Head of the Space Exploration Sector of the Johns Hopkins Applied Physics Laboratory (APL), Counselor on Space to the Minister of Digital Governance of Greece, serves as Chairman of the National Committee for Space Research at the Academy of Athens, is Principal Investigator (PI) on NASA’s Voyagers 1, 2, and PI Emeritus on the Cassini-Huygens mission to Saturn, among others. He received B. Phys. from the University of Minnesota (1961), his Ph.D in Physics from the University of Iowa (1965) under J.A. Van Allen, served on the faculty, moved to APL in 1968, became Chief Scientist (1980), Space Department Head (1991) and Emeritus in 2004. He has built and/or participated in instruments that have flown to all nine classical planets beginning with Mariner 4 to Mars in 1965, ending with New Horizons to Pluto in 2015, and culminating with the Parker Solar Probe to the Sun launched in 2018. He has published over 630 papers in peer-reviewed journals and books with over 23,000 citations. He is a three-time recipient (1981, 1986, 2014) of NASA’s Exceptional Scientific Achievement Medal. In 1999 the International Astronomical Unionnamed asteroid 1979 UH as 8323 Krimigis. He is a Fellow of the American Physical Society (APS), the American Geophysical Union (AGU), the American Association for the Advancement of Science(AAAS) and the American Institute of Aeronautics and Astronautics (AIAA). More recent awards include the Council of European Aerospace Societies CEAS Gold Medal in 2011, the European Geophysical Union Jean Dominique  Cassini Medal (2014), the AIAA Van Allen Space Environments Award (2014), the National Air and Space Museum (NASM) Trophy for Lifetime Achievement (2015), the International Academy of Astronautics (IAA) Laurels Award for the MESSENGER Team (2015), the American Astronautical Society Space Flight Award, the NASM Trophy for Current Achievement (New Horizons Team), and the NASA Distinguished Public Service Medal, all in 2016, and the IAA Theodore von Karman Award (2017). He is a member of Academia Europaea, and was honored by a special resolution of the U. S. Senate “for exceptional contributions to space science” (2018).

Seminar was recorded on March 4, 2021