Stamatios (Tom) Krimigis

Principal Investigator of Low Energy Charged Particle Instrument

Principal Investigator of Low Energy Charged Particle Instrument

Chios, Greece

I think back to the days we launched Voyager 40 years ago, and it seemed like one more shot into the unknown -- albeit rather ambitious. We just wanted to get to Jupiter and Saturn in the next four years and explore the “uncharted territory.” Never mind that Carl Sagan had talked us into including a "Message from Earth" on a golden disc the previous year – we (the scientists) were very utilitarian at the time. We just wanted more facts about Jupiter and Saturn.

It was after we got past Saturn that we began to realize that with these “little spacecraft that could,” we may really score a scientific “home run” -- the edge of the solar system and maybe, just maybe, the door to the galaxy. As the years went by the border seemed farther and farther away. Would we ever get to it? Or would the Voyagers continue to work year after year? And if they didn’t get there soon, would we be around (especially me!) to see the exit?

As hope for the breakthrough was fading, the data from May through August 2012 began to look tantalizing! Something was really happening, especially with the Low Energy Charged Particle detector (LECP) but also the Cosmic Ray Subsystem (CRS) data. And then on August 25 the cosmic rays shot up and the solar stuff that had been with us for 35 years disappeared. I really mean that: The intensity was down by 10,000 times, just what we might have expected if we were outside the solar atmosphere and into the galaxy!

I remember the meeting at Von Karman auditorium at the Jet Propulsion Laboratory with Voyager veterans on Sept. 5, 2012, when the current principal investigators spoke about what they had seen . We were all perplexed, as the data were not entirely what we expected --especially with the magnetic field. But I was pretty convinced that I finally saw the exit to the galaxy. What a thrilling event -- to know that I was a member of the delegation from humanity to the cosmos, and that Voyager would be going on forever. Perhaps Carl Sagan was right after all. We needed the little disc to tell the universe that we were here!