WEBVTT

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[dramatic percussion music]

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- HI, AND WELCOME
TO "NASA LAUNCHPAD."

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I'M YOUR HOST, ISAAC.

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MICRO-PULSE,
MULTI-BEAM,

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PHOTON COUNTING.

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SOUNDS COMPLICATED,
DOESN'T IT?

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BUT IF YOU'VE EVER PLAYED
WITH A GREEN LASER POINTER,

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YOU MAY ALREADY HAVE A JUMP
ON THE ADVANCED TECHNOLOGY

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THAT NASA IS USING

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FOR ITS NEWEST
ICE MONITORING SATELLITE,

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ICE SAT-2.

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THE ORIGINAL ICE SAT MISSION

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OPERATED FROM 2003 TO 2009

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AND HELPED NASA SCIENTISTS
STUDY SEA ICE AND ICE SHEETS,

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DETECTING SOME DRAMATIC CHANGES
IN EARTH'S CRYOSPHERE.

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BUT WHY STUDY ICE, ANYWAY?

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ICE CAN ACTUALLY HAVE
AN ENORMOUS IMPACT

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ON WEATHER
AND ON GLOBAL CLIMATE.

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SEA ICE KEEPS
THE POLAR REGIONS COOL

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AND HELPS MODERATE
GLOBAL CLIMATE.

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SEA ICE HAS A BRIGHT SURFACE,

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SO MUCH OF THE SUNLIGHT
THAT STRIKES IT--

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ABOUT 80% OF THE LIGHT,
IN FACT--

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IS REFLECTED BACK
INTO SPACE.

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AS A RESULT,
AREAS COVERED BY ICE

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DON'T ABSORB MUCH SOLAR ENERGY,

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SO THE TEMPERATURES REMAIN
RELATIVELY LOW.

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AS SEA ICE MELTS
IN THE SUMMER,

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DARKER OCEAN SURFACES
ABSORB THE SUNLIGHT,

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THE OCEANS HEAT UP,
WHICH, IN TURN,

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HEATS UP
THE SURROUNDING ATMOSPHERE,

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CAUSING ARCTIC TEMPERATURES
TO INCREASE EVEN MORE.

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EVEN A SMALL INCREASE
IN TEMPERATURE

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CAN LEAD TO GREATER WARMING
OVER TIME,

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MAKING EARTH'S POLAR REGIONS
THE MOST SENSITIVE AREAS

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TO CLIMATE CHANGE.

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SO IT'S REALLY IMPORTANT

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THAT WE KEEP A CLOSE EYE
ON WHAT'S GOING ON

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IN THESE ICY REGIONS
NEAR THE NORTH AND SOUTH POLES,

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AND THAT'S JUST WHAT
ICE SAT HELPS SCIENTISTS DO.

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- ICE SAT WAS NASA'S FIRST
LASER ALTIMETER IN SPACE.

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AND ICE SAT STANDS FOR

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THE ICE, CLOUD,
AND LAND ELEVATION SATELLITE.

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ICE SAT WAS A BENCHMARK MISSION

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FOR NASA'S EARTH OBSERVING
SYSTEM FLEET OF SATELLITES,

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AND IT PROVIDED
A REFERENCE POINT

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FOR ICE SHEET MASS BALANCE,

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SEA ICE THICKNESS,

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VEGETATION BIOMASS,

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AND CLOUD STRUCTURE.

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SOME OF THE MAJOR FINDINGS
OF THE ICE SAT MISSION WERE

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THAT THE GREENLAND ICE SHEET IS
LOSING A LOT OF ICE EVERY YEAR.

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WE TAKE ALL THAT ICE
AND PUT IT INTO THE OCEAN--

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THAT'S ENOUGH TO RAISE
THE OCEAN SEA LEVEL

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ALL OVER THE WORLD
BY A FEW MILLIMETERS,

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AND THAT HAPPENS EVERY YEAR.

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- AFTER THE ICE SAT MISSION
CAME TO AN END,

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ENGINEERS WENT TO WORK
ON A NEW DESIGN

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TO GET BETTER COVERAGE
OF THE EARTH.

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NOW, ICE SAT-2 IS
ALL ABOUT MEASURING ELEVATION,

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BUT EXACTLY HOW DOES IT DO THAT,

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AND HOW DOES THIS NEW DESIGN
OVERCOME LIMITATIONS

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OF THE FIRST SATELLITE?

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- THERE WERE THREE COMPONENTS
TO FIGURING OUT

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THE ELEVATION MEASUREMENT.

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WE NEED TO KNOW

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WHERE THE SATELLITE IS
VERY ACCURATELY,

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WE NEED TO KNOW THE DIRECTION
THAT THE LASER IS POINTING,

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AND WE NEED TO KNOW HOW FAR
THE LASER PULSE TRAVELED

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WHEN IT WENT FROM THE SATELLITE
TO THE SURFACE OF THE EARTH.

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WITH THOSE THREE PIECES,

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WE CAN ACTUALLY CALCULATE
THE HEIGHT, THE ELEVATION

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OF A PARTICULAR SPOT
ON THE SURFACE OF THE EARTH.

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- ICE SAT WOULD SEND OUT
SMALL PULSES OF LIGHT

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AND TIME VERY PRECISELY HOW LONG
THAT LIGHT TOOK

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TO GO FROM THE SATELLITE,
BOUNCE OFF THE EARTH'S SURFACE,

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AND BACK TO THE SATELLITE AGAIN.

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BY MEASURING THAT TRAVEL TIME,

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WE COULD LEARN ABOUT THE HEIGHT
OF THE EARTH

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BENEATH THE SATELLITE.

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AND OVER TIME, WE WERE ABLE
TO BUILD UP MAPS

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OF THE SHAPE OF THE ICE SHEETS,

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THE THICKNESS OF SEA ICE,

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AND THE HEIGHT OF FORESTS
ALL OVER THE WORLD.

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NOW, THE DETECTORS
ON ICE SAT-2 ARE SO SENSITIVE

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THAT THEY CAN DETECT
INDIVIDUAL PHOTONS OF LIGHT.

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THAT'S THE SMALLEST UNIT
OF LIGHT THAT WE HAVE.

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SO ICE SAT-2 WILL SEND OUT
MILLIONS OF PHOTONS,

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AND OF THOSE MILLIONS
IT SENDS OUT IN EACH PULSE,

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WE'LL RECORD FIVE, SIX,
TEN SIGNAL PHOTONS,

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AND THOSE FIVE OR TEN PHOTONS

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ARE WHAT WE USE TO MAKE
OUR ELEVATION MEASUREMENT.

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WE KNOW PRECISELY
WHEN THEY LEFT,

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AND WE KNOW PRECISELY
WHEN THEY CAME BACK AGAIN.

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- ICE SAT CARRIED THREE LASERS
THAT OPERATED ONE AT A TIME.

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JUST LIKE ICE SAT,

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ICE SAT-2 HAS MULTIPLE LASERS
TO ENSURE LONG-TERM OPERATION.

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THE LASERS SHOOT
A SINGLE LASER PULSE.

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THE PULSE THEN SPLITS
INTO SIX SEPARATE BEAMS.

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WHAT'S THE ADVANTAGE
OF THIS HIGH BEAM TECHNOLOGY?

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LET'S TURN TO THE EXPERTS
TO FIND OUT.

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- SO WHEN WE TALK ABOUT
ICE SAT-1,

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ICE SAT-2 IS
THE FOLLOW ON MISSION

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TO ICE SAT-1.

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AND WHENEVER WE DO THINGS
AT NASA,

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WE LIKE TO IMPROVE UPON
THE TECHNOLOGY

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THAT WE'VE DEVELOPED
IN PREVIOUS MISSIONS.

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- WITH ICE SAT-2,
WE'RE USING A MUCH SMALLER BEAM

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THAT ILLUMINATES AN AREA
ABOUT TEN METER CIRCLE,

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SO IT'S A MUCH FINER
PRECISION MEASUREMENT.

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IN ADDITION, ICE SAT-2 FIRES
ITS LASER MUCH MORE FREQUENTLY.

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SO INSTEAD OF ONE MEASUREMENT
EVERY 150 METERS

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AS THE SATELLITE FLIES,

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ICE SAT-2 WILL GIVE US
ONE MEASUREMENT

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EVERY 70 CENTIMETERS

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AS ICE SAT-2 FLIES.

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SO IT'S MUCH SMALLER FOOTPRINT

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AND MUCH MORE DENSE
SPATIAL SAMPLING.

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- THE STATISTICS COLLECTED ABOUT
THE CRYOSPHERE BY ICE SAT-2

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WILL BE ORGANIZED
INTO DATA PROFILES

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AND STUDIED BY SCIENTISTS
ALL OVER THE GLOBE.

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BUT WHAT IS IT THEY HOPE
TO UNDERSTAND?

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- SO ICE SAT-2 IS
MEASURING HEIGHT.

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IT'S AN ALTIMETER.

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SO YOU'RE GONNA GET
VERY HIGH RESOLUTION,

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VERY SPECIFIC LEVELS
IN TERMS OF DATA.

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AND SO WE HAVE RESEARCHERS,
WE HAVE SCIENTISTS

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THAT ARE LOOKING AT THE LEVEL
OF WATER IN A RESERVOIR.

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THAT IS SOMETHING THAT YOU
WOULDN'T NECESSARILY THINK OF

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RIGHT OFF THE CUFF
WHEN YOU SEE THE NAME ICE SAT-2,

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BECAUSE YOU AUTOMATICALLY
THINK "ICE."

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BUT IT HAS DIFFERENT
APPLICATIONS BEYOND THAT

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OF THE CRYOSPHERE,

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SO YOU HAVE RESERVOIR HEIGHTS,

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YOU'LL HAVE
VEGETATION CANOPY HEIGHTS,

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THEN YOU HAVE, AGAIN,
YOUR SEA ICE THICKNESS

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AND THEN YOUR LAND ICE.

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I THINK YOU CAN
REALLY BE CREATIVE

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IN TERMS OF HOW
YOU USE THE DATA,

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WHICH IS WHY WE GO OUTSIDE
OF THE SCIENTIFIC COMMUNITY

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AND LOOK AT DIFFERENT WAYS
OPERATIONAL USERS

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COULD REALLY VALUE
ALTIMETER DATA,

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BECAUSE IT'S NOT JUST
WHAT'S IN OUR HEAD.

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IT'S REALLY COMBINING WHAT'S
IN OTHER PEOPLE'S HEADS,

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AND I THINK ONCE YOU GET
ALL THESE, YOU KNOW,

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CREATIVE MINDS WORKING,

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YOU CAN FIND DIFFERENT WAYS
OF APPLYING THE DATA.

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- SO THAT'S IT.

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WITH ICE SAT-2,

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NASA'S STAYING ON TOP
OF TECHNOLOGY

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AND ADVANCED
CRYOSPHERIC RESEARCH.

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AND WITH EACH PULSE OF LIGHT,

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ICE SAT-2 IS PUTTING EARTH
IN PERSPECTIVE.

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THANKS FOR WATCHING.

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I'M ISAAC,

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AND WE'LL CATCH YOU NEXT TIME
ON "NASA LAUNCHPAD."