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Brunt: Fourteen days,

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two PistenBullies, four people,

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so yeah, 750 kilometers, door to door.

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Brunt: Recently, we just got back from

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Antarctica where we completed about a two-week ground traverse

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near the South Pole. We were basically driving PistenBullies,

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tracked vehicles similar to the ones that groom your ski areas.

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Behind those PistenBullies were 60-foot long

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plastic sled trains. And ultimately those trains carried things like our sleeping tents,

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fully erected and left standing during the day when we were driving.

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Kitchen tent, fuel, generators,

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all sorts of cargo--
Neumann: Everything we needed for the trip.

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Brunt: And from a both science and survival standpoint.

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So this entire traverse was in support of ICESat-2, which will launch

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later in the year.
Neumann: ICESat-2 is all about elevation, and

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the natural question is how you're getting the right answer? This is how we will know. We'll go

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out and collect a reference data. We'll be ready to compare and evaluate, see how we're doing.

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Radio: 3-1-9 is feeling kind of ready, how you guys doing over there?

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Neumann: So the big measurement we were making was to measure the elevation of the ice

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sheet surface around our traverse. And we had the two GPS running, one on each vehicle

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measuring that elevation. One of the other experiments we were doing is leaving out

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what we call corner cube reflectors to get an assessment of the pointing

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of ICESat-2. When we make an elevation measurement how are we sure it's in

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the right place. So in this picture you can see a bamboo pole with a little

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white cap on the end of it. And embedded in that cap, little piece of glass

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about as big as your pinky nail and calibrated to return

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green laser light from the satellite, bounces off of this thing

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and goes right back up to the satellite again. Super reflective. So these things, as

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Kelly has demonstrated, show up in data with altimeters

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like ICESat-2. When you first get to South Pole, and you're coming from

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McMurdo, which is a nice seaside town right at sea level, and South Pole is

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what, about 10,000 feet. And yeah, you notice it pretty quickly. The

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temperature is a lot colder than in McMurdo. It's probably 30 degrees

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40 degrees colder and 10.000 feet higher. Walking from the

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camp to where we're putting in an array for example, would be a ten minute walk maybe,

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five minutes. A couple of breaks on the way, you know, it's still pretty

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high.
Brunt: The plan is to repeat this traverse for the

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next three years. So four years of data total, and that

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would last the mission lifetime--the mission requirement lifetime--

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for ICESat-2.
Neumann: ICESat-2 has 1,387 orbits

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and so it's cruising around the world, and it's got these unique tracks that repeat every

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91 days. And all those tracks converge at 88-South. and

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so our route crossed, what, twenty percent of them. So we can

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calibrate data from twenty percent of our tracks with this

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stretch that we drove. And by repeating it every year about the same time

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of year, we'll overlap it exactly the same time, but we'll also be able

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to figure out what's going on in between. Because we'll measure it in 2017,

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and then again in 2018, and you can see how it changes from year to year. So that will be pretty

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cool, too. It will quickly become the best-surveyed piece of

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either of the ice sheets.
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