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NASA's Juno Probe Enters Jupiter's Orbit


After traveling more than one and a half billion miles and executing a complicated bit of outer space ballet, last night NASA's Juno probe entered Jupiter's orbit.


UNIDENTIFIED WOMAN: All stations on Juno co-ord, we have the tone for burn cut-off on Delta B. Juno, welcome to Jupiter.

SIEGEL: That was mission control at the Jet Propulsion Lab in Pasadena, Calif. Fran Bagenal was at JPL. She's a member of the Juno science team, and she joins us now. Welcome to the program.

FRAN BAGENAL: Thank you.

SIEGEL: Give us a sense. How hard was it to actually get this probe into position around Jupiter?

BAGENAL: Getting into position wasn't so difficult. What was difficult was dealing with the hazardous an unknown environment around Jupiter that we were really concerned might impact the going into orbit.

SIEGEL: And I gather what you told it to do in order to get into orbit was to flip backwards and then go forwards again.

BAGENAL: Well, it had to turn around and then fire its engines for 35 minutes to slow it down a little bit, and then that would get it into orbit. Then it turned back to Earth and to the sun to power its solar panels and talk to the Earth.

SIEGEL: How hazardous is that environment? When you say that, what are you speaking of?

BAGENAL: What we're talking about - the main hazard is the radiation - so very energetic particles, particularly electrons, that are trapped in Jupiter's very strong magnetic field. And we had to fly through or just under that hazardous environment. We didn't really know how extensive it was or just how fierce it was. But luckily it was not enough to damage the spacecraft, and we came out OK.

SIEGEL: What do you hope to learn on this mission?

BAGENAL: We want to learn about the interior of Jupiter - what's inside, how much water there is, how much heavy elements are inside. And then my particular interest is the Aurora, the very intense, bright northern lights and southern lights that we see in the atmosphere of Jupiter. What is causing that, and how does that all work? How does it compare with what we see on Earth?

SIEGEL: And do you think you get an authoritative, definitive answer from this or some clues? How would you describe what you're likely to learn, an answer to that question.

BAGENAL: Well, we get some major changes to our understanding, and but always with science, you never get the complete, total answer. We'll want to go back, I'm sure, sometime down the road. But these - if we're able to survive for a dozen - even a dozen orbits - we hope for 35 - we will revolutionize our understanding of this big gas giant.

SIEGEL: Can you compare the research on this mission to previous NASA missions like the recent Pluto mission? How does Juno fit in?

BAGENAL: Well, you're talking about something dear to my heart. I was heavily involved in the Pluto mission also. They're completely different in that when we went to Pluto, we had no idea what it was going to look like.

With Juno, it's very different because we're going to be going back to a place that we understand in some ways, but we really want to refine and understand some important details about what it's like inside. So it's a different kind of mission. And it's an orbital mission, so we'll be there for a year and a half taking detailed measurements.

SIEGEL: You know, just before we started recording, our recording engineer here in Washington asked you one of the standard voice level questions which we ask which is, what did you have for breakfast? I wonder (laughter) if you could repeat the answer.

BAGENAL: Well, I didn't have a whole lot to eat, but I drank an awful lot of coffee. We've had a pretty short night in terms of sleep but a lot of excitement.

SIEGEL: Well, congratulations on Juno's success so far, and thanks for talking with us today.

BAGENAL: It's been a pleasure. Thank you.

SIEGEL: That's Fran Bagenal, who is a member of the Juno science team at NASA. Transcript provided by NPR, Copyright NPR.