The Last First Planetary Mission

September 14, 2016 • by Marc Airhart

University of Texas at Austin alumnus Alan Stern describes the challenges, and the joys, of the last first mission to a planet.

Artist's illustration of a spacecraft flying past a planet

The New Horizons spacecraft brought humanity face to face with the last unexplored planet in our solar system: Pluto. What we're learning is amazing. But, time and again, the mission almost didn't happen. University of Texas at Austin alumnus Alan Stern describes the challenges, and the joys, of the last first mission to a planet.

Show Notes

Alan Stern visited Austin on September 16, 2016 for the Hot Science - Cool Talks series. Watch is archived presentation at: "The Amazing Mission to Pluto: Three Billion Miles and We Made It!"

View "New Horizons' Top 10 Pluto Pics"

Alan Stern Bio

Alan Stern holds bachelor's degrees in physics and astronomy as well as master's degrees in aerospace and civil engineering from The University of Texas at Austin. He earned a doctorate in astrophysics and planetary science from the University of Colorado, Boulder. Stern is the principal investigator of the New Horizons mission and a vice president for the Southwest Research Institute (SwRI) in Colorado. Stern has received the 2016 Carl Sagan Memorial Award, the 2015 Neil Armstrong Space Flight Achievement Award and the Smithsonian American Ingenuity Award. He was also recognized as one of Time's "100 Most Influential People" in 2007, then again in 2016.


Marc Airhart: This is Point of Discovery. In the summer of 2015, the New Horizons spacecraft whizzed past Pluto and its moons. It was humanity's first up-close view of the mysterious little world out in the uncharted reaches of our solar system. And what we're starting to learn about Pluto is pretty amazing. But the mission almost didn't happen. I talked to Alan Stern, head of the New Horizons mission and a graduate of the University of Texas at Austin.

Alan Stern: The last time that a NASA mission, or any mission, turned a point of light into a planet before the public's eyes was 1989 …

MA: That was when Voyager 2 flew by the gas giant Neptune. More than a third of Americans were either not alive then or were too young to remember.

AS: … so for literally hundreds of millions of people around the world, they'd never seen anything like this …

MA: When it came time for its moment in the spotlight, Pluto didn't disappoint. For the first time, we could see that Pluto's atmosphere is blue – and it has a Texas-sized feature shaped like a heart that turns out to be the largest known glacier in the solar system. Who knew? There were hints that down below its icy surface, Pluto might have a liquid ocean. Perhaps most startling – Stern and his colleagues showed that Pluto isn't some boring, lifeless rock.

AS: Contrary to all scientific opinion before the flyby, Pluto is geologically active on a massive scale after 4 billion years and conventional wisdom is that small planets should not be that. So we really made a paradigm-shifting discovery in flying by Pluto.

MA: But these discoveries -- and more -- were still just a dream back in the early 1980s. Stern was a new graduate student at the University of Texas at Austin looking for a research project when he met Larry Trafton, a researcher at the university's McDonald Observatory. Trafton turned him on to the study of Pluto's atmosphere.

AS: I could have walked in and Larry said I've got this project on Saturn's moon Titan, blah blah blah.

MA: But instead, it was Pluto -- and he was hooked. He became one of a few voices crying out in the wilderness throughout the 80s and 90s for a Pluto mission. NASA was really focused on other places, like Mars. Even in 2001 -- when NASA finally agreed to do a mission -- many people doubted it would even get off the launch pad.

AS: If the story of New Horizons was ever written in a book in all of its detail, no one would believe it, it's too fantastical.

MA: For starters, to get to Pluto quickly and cheaply, the spacecraft needed to get a gravitational kick from the planet Jupiter. But when NASA approved their mission in 2001, the planets were only going to be aligned for such an assist for a few more years.

AS: We had four years and two months from the time that we were told we won the competition to the time we launched.

MA: That's about half the usual time to design and build such a complex mission. They were short on time – and they were short on money. Their budget was about a fifth of what a typical planetary mission costs.

AS: Essentially with New Horizons, there was no kidding yourself. We were up against really gargantuan challenges, any one of which could have stopped it. So we turned that into energy for the team. We told people, "They don't think we can't do it."

MA: There were more challenges. The spacecraft's plutonium power source -- supplied by another government agency -- ended up smaller – and less powerful -- than the original design called for. The team also lost key personnel in a tragic accident.

AS: One of the instruments on board required a technology that only a few people in the world knew how to do. They were all in one place. And a month after we were selected, the two principals in inventing that died in a plane crash together.

MA: It was a terrible day – for the mission – and for the victim's families.

AS: But fortunately we had a very talented and motivated team of people who were willing to do whatever it takes and despite the fact that there were many alligators in the water, we managed to emerge unscathed.

MA: New Horizons finally lifted off from Cape Canaveral in January 2006.

MA: The spacecraft – about the size of a baby grand piano -- roared across the solar system at a speed that could get you from New York to Los Angeles in about 4 minutes. Except this trip was 3 billion miles and took 9-and-a-half years. The onboard computer crashed a few times during the trip, which made for some tense moments. But each time, team members were able to restart it and New Horizons safely made it to Pluto.

MA: Earlier generations had gotten used to seeing planets explored for the first time -- right there on their TVs -- every few years. Stern recalls how he pitched this flyby to a new generation.

AS: … and as we told them before the flyby, not only have you never seen anything like this, you might want to watch. You'll never see it again. No space agency anywhere on the Earth is planning on doing something like New Horizons again.

MA: In 1989, Pluto was the last planet in our solar system unvisited by human technology. But just a few months after the launch of New Horizons, a professional society of astronomers demoted Pluto to the status of dwarf planet – a decision Stern sharply disagrees with. But, regardless of what you call Pluto, he still sees New Horizons as a kind of historic bookend to an effort started by his parent's generation.

AS: We completed a task begun under President Kennedy -- it took 50 years of presidents and Congresses and engineers and scientists to do -- and we're the ones that got to summit Everest. I didn't think that there was a bigger scientific contribution that I could make in my career than to complete the reconnaissance of the solar system … I still pinch myself.

MA: By the way, Alan Stern will be giving a free, public talk at the Hot Science - Cool Talks series here in Austin this Friday night, September 16th. If you can't make it in person, you can stream it live online from anywhere. The link is on our website at -- . And -- if you can't get enough of space exploration – and you happen to be in Austin on Wednesday, September 21st – you can also hear a talk by David Reitze, he's UT Austin alum who headed up the mission that discovered the first evidence of gravitational waves. You can find information on that on the College of Natural Sciences website at .

MA: Point of Discovery is a production of the University of Texas at Austin's College of Natural Sciences. I'm Marc Airhart. Thanks for listening.


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