WEBVTT FILE

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(on-screen text) Landsat 9: Continuing the Legacy

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Matt Bromley: Absolutely. As a native Nevadan,

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we're aware of the value of water.

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(on-screen text) Episode Two: Designing for the Future

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Narrator: This is Matt Bromley.

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Understanding water scarcity? That's his second nature.

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He's one of the key players tracking water usage

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in Nevada and the western United States from space.

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Matt Bromley: Everything from public service commercials

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telling you to turn off your faucet while you're brushing your teeth

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to knowing which days you're allowed to water your lawn

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based off of whether or not you have an odd or even address. 

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There's years where the water in the river is very, very low,

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and then there's years where it's really plentiful.

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And so we're really tied into that variability from year to year.

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Narrator: For a state like Nevada, somewhere between

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70 and 80% of the water in the state is used for agriculture. 

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Matt Bromley: And so if we can do better with managing irrigation water

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agricultural water, it goes a long way with water conservation.  

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Narrator: The Landsat program has had its eyes in the sky for almost 50 years.

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Remember how USGS and NASA teamed up,

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made a revolutionary satellite and launched into space? 

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Yeah, that was great.

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The point is, Landsat's success is due in large part

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to its forwarding-thinking tech.

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Each new generation produces better and better measurements.

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And you can't conserve what you can't measure.

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Phil Dabney: Just in agriculture, the ability to

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look at the consumption of water...

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the economic value of Landsat to agriculture alone

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is several times the cost, or a few times the cost, of the entire system.

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And that's pretty significant.

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Narrator: That's Phil Dabney.

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A self proclaimed dinosaur, Phil has worked for Landsat

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since Landsat 7 back in the nineties.

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Phil Dabney: It's always been about the detector,

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I actually had a bumper sticker that people tease me

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that only, uh, the nerds at NASA would understand.

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And that was "it's the detector stupid!"

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And that's been our limitation.

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Narrator: The detector that Phil is talking about

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is basically the most important piece of technology on the entire satellite.

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It's where light gets turned into data.

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In the early days, the detector was made out of just silicon,

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the same material you'd find in your smartphone camera today.

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Technological limitations prevented Landsat

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from seeing anything too far beyond the visible light spectrum. 

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Fast forward to today, when our detectors span infrared frequencies.

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Landsat 8's thermal sensor is so sensitive,

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scientists can calculate Earth's temperatures down to a fraction of a degree. 

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Phil Dabney: The addition of thermal is a major addition.

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And then things came out of that like evapotransporation,

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the ability to estimate how much water the plants are taking out of the ground

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based on how well they can cool themselves by sweating essentially.

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And, and that's been used a lot in agriculture water managment.

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Narrator: This detector seems to be a pretty big deal.

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But what does it do?

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I'm so glad you asked.

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There are two instruments aboard Landsat 9.

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So that means there are different detectors.

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Let's start with OLI.

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When you're building hardware for space flight,

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you have to keep it in a clean room to protect it from any dust that might block light

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…and OLI is all about light.

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Once in orbit, OLI collects sunlight reflected off Earth's surface.

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The reflected light bounces between a few mirrors

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to focus the beam on a plane of detectors, all lined up in a row.

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The light passes through a set of filters,

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to separate out nine specific wavelength bands,

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in visible and infrared frequencies.

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Each band provides different pieces of information about the land cover.

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The second instrument aboard Landsat 9, called TIRS, is a little different.

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It collects the thermal infrared wavelengths,

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or "temperature signatures" emitted by the Earth itself.

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But to accurately calculate the temperature,

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the detector needs to be much colder than what it is measuring from Earth.

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So along with the lenses and the detectors,

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TIRS carries a condenser that cools the detectors down to 43 Kelvin.

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That's -382 degrees Fahrenheit!

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To put it all together, let's go to an engineer.

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Melody Djam: The spacecraft is not just a piece of structure

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that holds this instrument.

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The spacecraft responsibility is to provide the juice or information

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or power that the instrument needs in order to function.

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Narrator: Melody's right. The detector may be the most important part of the spacecraft,

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but it's far from being only tech on board.

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As the TIRS-2 Deputy Project Manager and systems engineer by trade,

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she understands first hand what kinds of life-support systems are required

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to keep these two instruments operational.

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Picture this: The entire satellite stands about 15 feet tall

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and is the length of a school bus.

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TIRS-2 and OLI-2 occupy about this much space.

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The rest is occupied by other critical systems

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that power the satellite, cool the instruments down, package the data,

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send it back to Earth, along with many other duties.

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Melody Djam: And looking at the data and seeing the smile from the scientists

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that they're getting the right data,

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that by itself is great, a great experience.

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Matt Bromley: Yeah, so I don't know if you noticed,

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but I get kind of a smile when I start thinking of this Landsat data,

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because it is very unique.

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It's very special and it feels good to be part of work like this.

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Phil Dabney: Yeah, it's being surrounded by people that can do,

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you know, failure is not an option, which is a famous NASA phrase.

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We can do that. We'll make it happen. [chuckles]

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Narrator: It's clear that Landsat tech is delivering on its promise to provide game-changing data.

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Landsat 9 represents the best of what NASA has to offer.

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But what happens when your satellite works so well

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that keeping up with all the information it's sending back to Earth

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becomes its own monumental challenge?

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(on-screen text) Coming Next…

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Jeff Masek: You're seeing before your eyes, you know,

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how the environment of forest change, how agriculture changes,

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urban expansion, the whole, the whole thing,

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how the planet has changed over 50 years.

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So it's, to me, it's that historical perspective that I find really fascinating.

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(on-screen text) Episode Three: More Than Just a Pretty Picture

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Landsat is a joint program of NASA and USGS