Were here to commemorate with them the 48th anniversary of the voyager spacecrafts. It was an epic mission to exprope explore the outer plants and is one of the most ambitious that nasa has ever sent out to the solar system. The mission for me has personal relevance not because i was ever involved with it. But because as a child, encounters with the planet uranus and neptune i was too young to enjoy the fly buys of jupiter and saturn, but uranus and neptune, i remember quite clearly the images on the news and just really being impressed by what we were doing out there in the Solar Systems that i began to feel that i was once of the first to see these planets in such great resolution and im sure that many others of you that were born in the 70s might feel the same way. And i want to note before going any further, that we do have a wonderful model of the voyager spacecraft upstairs in our exploring the planets ba s gall thats true to the actual voyager, and its some of the parts used for the engineering and testing of the voyager, and if you want to see that spacecraft in its real full size and glory, i suggest that you take some time if youre here in our audience, to go upstairs and take a look at the model and if youre watching us on nasa tv, please come to the museum when you can and take a look at that model, i dont think youll be disappointed. So to get started, i would like to introduce thomas zubrikan. Hes the is headquartered here at the doctor has authored or go authored more than 200 articles on hilo sphere kl phenomenon. Hes been involved in several special missions. So dr. Zubrikan. Well, thanks, everybody. Its really a pleasure to be here with you today, to celebrate this pioneering moment for both nasa and for exploration history of himg hum, happy anniversary to voyager. Yes. Of course you know that on september 5, four decades ago in 1977, nasa launched the voyager 1 space craft, only a little over eight years to the blast off to apollo 11, voyager was and still is, to me the apollo 11 of space science, its a mission that changed everything. It not only change whads we kt but how we think. Its about redefining what we can and cannot do as humans. Imagine this fall, children all around the region, around the country going to school, getting their schoolbooks and looking at these pictures in these books and looking at, especially the pictures of the planets. Many of these pictures, of course, are pretty young. Mercury has pretty cool pictures, i know because i was on the messenger mission, as you just heard, you take images there, you go look at mars images, some of the most amazing investigations going on right now, both on the surface and in orbit. And then you go farther out and you get to neptune and uranus. Every picture comes from spacecraft that are out there from the spacecraft that flewably that are out there and we have not gone back. To me, its also the beginning of my interest in space science, the first book i ever got under the Christmas Tree for me when i was just under 10 years old, was to celebrate the upcoming launch of the first voyager, and voyager 2 and i have this book with me and its still in my office. For me it was an inspiration. We all is my point have a perm story that relates to voyager, even if we were not fortunate to be there with hands on like so many people who are working on it now. Voyager affects the lives of children of all ages all over the world. Know that children were not born that are going to school right now when voyager was still on the ground, well, not even their parents were born for many of them, half humanity that lives today was not born when voyager was launched. And so really what were celebrating today is 40 years of discovery and exploration history eclipsing everybodys expectations. Nearly 40 years later, the successful voyager and its sister spacecraft voyager 2 continue to provide us with unpress definiu unprecedented information about the space we live in. Its now traveling through the emptiness and loneliness of intrastellar space, having left a atmosphere sphere of influenc sun sun, its expected to transmit data until 2025, if none of the tech nothinologies fail. Voyager 2 is just mindboggling, its still going. A robotic explorer to space and beyond the imageable. It is a Mission Driven by Scientific Research and a mission of pioneering and inspiration. Its a mission that has opened entirely new questions that keep us awake at night today, the questions that are a subject of ongoing science investigations. Casini, in its last orbits, its hard to imagine without voyager ahead of it. The images of saturn ring are all over monitoring today and on my phone as well. And we think of the injection of water from below, this icy surface, again starting with voyager. Every 450 days or so, we see ne images from juneau. And remember galileo, one of the most recent passages of jupiters dynamic storm which has lasted for a getting weaker. A whole ocean of wonders that remain to be explored. In fact, we just put an announcement out to the science can community to make the next step towards understanding the boundary of that sphere of influence of the sun, the helio sphere. Also deduct interstellar gas in ways we have never seen before. Again, a Research Topic started with voyager. Because, guess what . Were dreaming even bigger, these technologies that we have today, allow us to go the distance, but we want to go farther, we want to go faster, and were inventing these technologies together with the children of the world about possibility traveling to other stars, thats the direction voyager has pushed us in. So i want to congratulate all the generations of the voyager team. Remember of course the ones that are no longer with us. And we celebrate the ones who are making voyager work today from nasa jpl all the way to australia, where a big satellite dish listens to voyager in the deep sky. Congratulations and encouragement to those who are squeezing every ounce of science out of these pits, these rare and precious pits that are coming from deep space to us. So i want to thank suzanne dodd, the current voyager project manager who first began working on this mission in 1984, and suzanne told me that many of her friends are here and im just so excited to welcome you all from jpl who are, you know, many of you have started in the 80s, some of you have started more recently and we wont say who. But im just really excited that youre here and celebrating with us. Dr. Ed stone is my friend for decades, the retired director of Nasa Jet Propulsion Laboratory and on the voyager project since 1972, a major spokesperson aboard the voyager science team and one of the key contributors to the science. Still inspiring to me, i keep going back to these, so thanks for all the work you have done. The creative director of nasas voyager intrastellar messages. The innovator here who using the gravity from 40 years to less than 10 years. Nasa used this with voyager 1 and voyager 2 missions. And dr. Allen cummings, a friend for many years and one of the funniest guys at any party youll ever go to. Look at him when hes out there. Youll know what i mean. Senior scientist, cal tech physicist who works with ed stone, studying the nature of particles entering the solar system from the local int intrastellar medium. I want to tell you right now, im coming here with my children or with myself, you all are performing a Remarkable Service educating and inspiring people of all ages and drives us to keep pushing dpe ining against of ignorance, to be researchers, explorers and in fact voyagers. With that, what i would like to do is kick off a movie that was prepared for this event. Thank you so much. In six months to make the voyage record and we wanted everything we could possibly compress into the space allotted on the record. As the idea of making a record that represents the type of planet and our movies. Hello from the children of planet earth. We wanted to convey something about the joy of being alive. We knew that the spacecraft itself would speak volumes about us, as much perhaps as the message, which i might add has exceeded its design specifications in every conceivable way. This was a spacecraft that was supposed to function for Something Like a dozen years, here we are 40 years later, and were still in touch. And look at the discoveries that both voyagers have given us, including most recently the borderline of the heliopause, that place where the wind from the sun and the intrastellar medium begins. Nasa has every reason to feel the utmost pride. 20 seconds. 20 seconds. Stand by. Stand by. [ applause ] its now my pleasure to introduce our first panel of the day, the doctor already gave them all pretty good introductions, we have dr. Ed stone, who has been a project scientist on voyager from 1972 to the present. We have dr. Gary flandro who is the expert in space propulsion, and who was the first to sort of propose is grand tour multiplanet exploration of the outer planets. We have Allen Cummings, Allen Cummings has been employed at the Space Radiation Laboratory at cal tech since 1973, and he is presently a current Senior Scientist and member of the professional staff there. We have suzanne dodd, suzanne dodd is jpls director for the Interplanetary Network director and she has more than 30 Years Experience serving as project manager role and also other missions. And we have anne drea. Who is work is largely concerned with the effects of science and technology on our civilization, she was cowriter on the Emmy Winning Television series cosmos. So without further adieu, i will ask our panelists questions to start with the voyager mission. Well start with dr. Stone. So dr. Stone, to you what is so special about voyager . Well, from many points of view, voyager really represents humanitys most ambitious journey of discovery and that i think is its legacy. And tell us about the beginnings of the mission, the early years . Voyager began when gary flandro which youll hear about in a few minutes discovered that there was a year 1997, plus or minus a year, where a single spacecraft would be launched that could fly by all four giant planets was called the grand tour, that was in 1965, by 1972, they had been sort of downsized to mjs77, which is mariner, jupiter, saturn, four missions just to those giant planets and their moons and rings. That fortunately was to be launched in 1977, however, so if they continued to work they could go on to uranus and finally neptune, which is what voyager 2 did. As gary promised a way to do that in 12 years rather than 30 years so we really have him to thank that we could do it in a 12year journey. Voyager obviously has made many discoveries, what are some of your favorites . If i could have the first slide please, which shows jupiter and its great red spot, along with two of jupiters moons, ioa and yoeuropa. The only known active volcanos in the solar system were here on oert a earth and then voyager flew by one of the moons and has ten times the volcanic activity of the earth. Before earth, the only known liquid water erosions wither here on earth, and then voyager flew by another one of jupiters moons and it was covered with ice, and voyager saw it was cracked ice, though it was on the liquid water ocean, you see the two moons in this image, io being the orangish color one because of the volcanic activity and europa being the one thats ice packed. Going on to saturn, before voyager, the only known nitrogen solar then we flew by titan, has 70 times the nitrogen, but has methane in the atmosphere not oxygen. So the effect of sunlight is to create organic molecules that creates this haze. Another mission appeared several decades later moved through the clouds and the haze, and saw that indeed there are lakes of liquid methane, liquid natural gas on this moon. On to uranus, before voyager, the only known Magnetic Fields all had their north poles and south poles oriented to be near the rotational axis of the planet, because presumably it was that rotation which creates the Magnetic Field. And we found that the magnetic pole was nearer the equator, so our view from earth of what Magnetic Fields were like had to be great ly expanded and then w visited another moon around neping tune, 290 degrees below fahrenheit. So cold that the nitrogen is in the why polar cap, the dark streaks are geysers, erupting, and depositing and we found two active geysers at a time we flew by, in a world that is so cold that even the nitrogen as frozen. See this caused us time and time again to what we thought we knew about Magnetic Fields and moons, has created a legacy now for many future missions to the outer planets. So dr. Flandro, ill ask you the question next, in the early 1970s, if you would ask someone how long it would take to get a mission to neptune, the answer would be maybe a few decades, so how did this mission end up being possible in the span of only a dozen years . The key here is to use free energy, its not using rockets now, its using free energy which i will explain. Lets put the first slide up. First slide. Okay. This is actually the result of thousands of calculations. I had to run thousands and thousands of numerical calculations of trajectories looking for the possible outer planet mission, this was my favorite here, and the first one that was published, showing a 1978 launch from the earth. I put this up so that you can get some idea about the angles that you have to reflect the trajectory through to gain energy, so i start from the earth here in september 1978, on that little tiny dot along that dash line. Make 135degree turn over to jupiter. And heres now where we start gaining energy. If i didnt do anything, if i didnt go back past jupiter it come back to the earth. Jupiter is pulling us with that gravity field, often called the gravity assist, offers a tremendous amount of energy. If a volkswagen is equivalent to four or five rockets waiting out there, you can hook those up and you can really get a tremendous boost of speed. Now we have permanently lost the spacecraft, its on hyperbolic now. Youre going to ask me, where did i figure this out and ill show you. And we get to saturn, in 1978, i loved this because i could get so fast, i could get clear out to neptune in about seven and a half years. If you do it at neptune, i had to go between the planet and the rings, and that scares people. Although casinis been doing it now. And you can get to uranus really quickly. And then on the way out to the solar system, we get intrastellar at that point. Im doing these things, and i said how can we ever sell it . But the key to selling it is to notice that every event happens in a fouryear time span, if it doesnt, youre never going to get anything from the government. Thats how it works and let me show you how we found it. The next slide shows the actual thing i used to figure out you could do it. Along the bottom are the dates, i was looking to the next 10 or 20 years from when i was working in 1965. On the other axis, the vertical axis, these were the angles i was showing you in that slide. I can see something really remarkable here. That in the latest 1980s or so. All of the planets were all on the same side of the sun, i was like oh, my gosh, i better look there, because that means you could probably get one spacecraft that could get all of those planets and thats how it happened. Thats how that was discovered and you have to run all these trajectories until you find the best launch windows. 1977, 1978 and the real problem here is that only recurs only 175 years. So if you miss this one, youve lost it because it takes time to build a spacecraft. We had about 10 years to do it. And last time this opportunity ever came was when Thomas Jefferson was president and he must have muffed it. So you have already anticipated one of the questions. But let me ask you, the First Successful gravity assist was 1974 with mariner 10. So how did you know this was work or what other problems did you think might happen . I knew it would work because as astronomers have known about it since the early 1700s. And a lot of scientists know if you fly past a planet with gravity, it will give it a slingshot effect. We also fixtured that out with the venus and mercury trajectories. We knew we could do it, no problem, just getting the money to do it was the problem. Well move on to Allen Cummings, dr. Cummings, tell us how you first got involved in voyager . Well, actually i got involved in voyager because i lost the experiment i had been working on, it went missing in action, seriously. What happened was i was up in ft. Churchill canada, the summer of 73, and i was doing what we had been doing for years, which was attach our experiment to the bottom of a huge balloon and septemb sent it to the top of the atmosphere and we take our measurements and the idea was it drifts west about 500 miles during the course of a day, you bring it down, you rekocover it and bring it back down and then you start all over again. The command to cut it downtown work and the backup cut down timer didnt work, so it just kept going, it went right around the world, it went around the world twice, and the second time it went over russia and they got it. And that ended that experiment. And i got back to cal tech all dejected and they said how would you like to start working on a new pro project called mjs 77, which is the early name for voyager. And the rest is history, i have been working on it ever since, and now looking back on it in 1973 and losing that balloon, it wasnt all that bad, i got to start working on the greatest mission ever to put it bluntly. You started working with idle hands. Tell me about your experiences with voyager, what are some of your memories of it . Right off the bat, one of the early ones was, i think i was the last person to physically touch the spacecraft. Right after ensap encapsulation of the spacecraft. I gave each of the telescopes a little twist. It is otheerie to think, that i was the last person to touch them, the next person to touch them is going to be a space alien. Bring out this slide here. This is a picture of our cosmic grade team looking at our first data in 1977 from voyager 2. And im the one, by the way in the front there bent over. I could tell. I w i was the only one apparently that could read the data upside down. But at the time this picture was taken, we were not completely convinced that this was working. So getting voyager 1 in the intrastellar place was kind of the holy grail. Due to solar ac