[dramatic percussion music]
- HI, AND WELCOME TO "NASA LAUNCHPAD."
I'M YOUR HOST, ISAAC.
MICRO-PULSE, MULTI-BEAM,
PHOTON COUNTING.
SOUNDS COMPLICATED, DOESN'T IT?
BUT IF YOU'VE EVER PLAYED WITH A GREEN LASER POINTER,
YOU MAY ALREADY HAVE A JUMP ON THE ADVANCED TECHNOLOGY
THAT NASA IS USING
FOR ITS NEWEST ICE MONITORING SATELLITE,
ICE SAT-2.
THE ORIGINAL ICE SAT MISSION
OPERATED FROM 2003 TO 2009
AND HELPED NASA SCIENTISTS STUDY SEA ICE AND ICE SHEETS,
DETECTING SOME DRAMATIC CHANGES IN EARTH'S CRYOSPHERE.
BUT WHY STUDY ICE, ANYWAY?
ICE CAN ACTUALLY HAVE AN ENORMOUS IMPACT
ON WEATHER AND ON GLOBAL CLIMATE.
SEA ICE KEEPS THE POLAR REGIONS COOL
AND HELPS MODERATE GLOBAL CLIMATE.
SEA ICE HAS A BRIGHT SURFACE,
SO MUCH OF THE SUNLIGHT THAT STRIKES IT--
ABOUT 80% OF THE LIGHT, IN FACT--
IS REFLECTED BACK INTO SPACE.
AS A RESULT, AREAS COVERED BY ICE
DON'T ABSORB MUCH SOLAR ENERGY,
SO THE TEMPERATURES REMAIN RELATIVELY LOW.
AS SEA ICE MELTS IN THE SUMMER,
DARKER OCEAN SURFACES ABSORB THE SUNLIGHT,
THE OCEANS HEAT UP, WHICH, IN TURN,
HEATS UP THE SURROUNDING ATMOSPHERE,
CAUSING ARCTIC TEMPERATURES TO INCREASE EVEN MORE.
EVEN A SMALL INCREASE IN TEMPERATURE
CAN LEAD TO GREATER WARMING OVER TIME,
MAKING EARTH'S POLAR REGIONS THE MOST SENSITIVE AREAS
TO CLIMATE CHANGE.
SO IT'S REALLY IMPORTANT
THAT WE KEEP A CLOSE EYE ON WHAT'S GOING ON
IN THESE ICY REGIONS NEAR THE NORTH AND SOUTH POLES,
AND THAT'S JUST WHAT ICE SAT HELPS SCIENTISTS DO.
- ICE SAT WAS NASA'S FIRST LASER ALTIMETER IN SPACE.
AND ICE SAT STANDS FOR
THE ICE, CLOUD, AND LAND ELEVATION SATELLITE.
ICE SAT WAS A BENCHMARK MISSION
FOR NASA'S EARTH OBSERVING SYSTEM FLEET OF SATELLITES,
AND IT PROVIDED A REFERENCE POINT
FOR ICE SHEET MASS BALANCE,
SEA ICE THICKNESS,
VEGETATION BIOMASS,
AND CLOUD STRUCTURE.
SOME OF THE MAJOR FINDINGS OF THE ICE SAT MISSION WERE
THAT THE GREENLAND ICE SHEET IS LOSING A LOT OF ICE EVERY YEAR.
WE TAKE ALL THAT ICE AND PUT IT INTO THE OCEAN--
THAT'S ENOUGH TO RAISE THE OCEAN SEA LEVEL
ALL OVER THE WORLD BY A FEW MILLIMETERS,
AND THAT HAPPENS EVERY YEAR.
- AFTER THE ICE SAT MISSION CAME TO AN END,
ENGINEERS WENT TO WORK ON A NEW DESIGN
TO GET BETTER COVERAGE OF THE EARTH.
NOW, ICE SAT-2 IS ALL ABOUT MEASURING ELEVATION,
BUT EXACTLY HOW DOES IT DO THAT,
AND HOW DOES THIS NEW DESIGN OVERCOME LIMITATIONS
OF THE FIRST SATELLITE?
- THERE WERE THREE COMPONENTS TO FIGURING OUT
THE ELEVATION MEASUREMENT.
WE NEED TO KNOW
WHERE THE SATELLITE IS VERY ACCURATELY,
WE NEED TO KNOW THE DIRECTION THAT THE LASER IS POINTING,
AND WE NEED TO KNOW HOW FAR THE LASER PULSE TRAVELED
WHEN IT WENT FROM THE SATELLITE TO THE SURFACE OF THE EARTH.
WITH THOSE THREE PIECES,
WE CAN ACTUALLY CALCULATE THE HEIGHT, THE ELEVATION
OF A PARTICULAR SPOT ON THE SURFACE OF THE EARTH.
- ICE SAT WOULD SEND OUT SMALL PULSES OF LIGHT
AND TIME VERY PRECISELY HOW LONG THAT LIGHT TOOK
TO GO FROM THE SATELLITE, BOUNCE OFF THE EARTH'S SURFACE,
AND BACK TO THE SATELLITE AGAIN.
BY MEASURING THAT TRAVEL TIME,
WE COULD LEARN ABOUT THE HEIGHT OF THE EARTH
BENEATH THE SATELLITE.
AND OVER TIME, WE WERE ABLE TO BUILD UP MAPS
OF THE SHAPE OF THE ICE SHEETS,
THE THICKNESS OF SEA ICE,
AND THE HEIGHT OF FORESTS ALL OVER THE WORLD.
NOW, THE DETECTORS ON ICE SAT-2 ARE SO SENSITIVE
THAT THEY CAN DETECT INDIVIDUAL PHOTONS OF LIGHT.
THAT'S THE SMALLEST UNIT OF LIGHT THAT WE HAVE.
SO ICE SAT-2 WILL SEND OUT MILLIONS OF PHOTONS,
AND OF THOSE MILLIONS IT SENDS OUT IN EACH PULSE,
WE'LL RECORD FIVE, SIX, TEN SIGNAL PHOTONS,
AND THOSE FIVE OR TEN PHOTONS
ARE WHAT WE USE TO MAKE OUR ELEVATION MEASUREMENT.
WE KNOW PRECISELY WHEN THEY LEFT,
AND WE KNOW PRECISELY WHEN THEY CAME BACK AGAIN.
- ICE SAT CARRIED THREE LASERS THAT OPERATED ONE AT A TIME.
JUST LIKE ICE SAT,
ICE SAT-2 HAS MULTIPLE LASERS TO ENSURE LONG-TERM OPERATION.
THE LASERS SHOOT A SINGLE LASER PULSE.
THE PULSE THEN SPLITS INTO SIX SEPARATE BEAMS.
WHAT'S THE ADVANTAGE OF THIS HIGH BEAM TECHNOLOGY?
LET'S TURN TO THE EXPERTS TO FIND OUT.
- SO WHEN WE TALK ABOUT ICE SAT-1,
ICE SAT-2 IS THE FOLLOW ON MISSION
TO ICE SAT-1.
AND WHENEVER WE DO THINGS AT NASA,
WE LIKE TO IMPROVE UPON THE TECHNOLOGY
THAT WE'VE DEVELOPED IN PREVIOUS MISSIONS.
- WITH ICE SAT-2, WE'RE USING A MUCH SMALLER BEAM
THAT ILLUMINATES AN AREA ABOUT TEN METER CIRCLE,
SO IT'S A MUCH FINER PRECISION MEASUREMENT.
IN ADDITION, ICE SAT-2 FIRES ITS LASER MUCH MORE FREQUENTLY.
SO INSTEAD OF ONE MEASUREMENT EVERY 150 METERS
AS THE SATELLITE FLIES,
ICE SAT-2 WILL GIVE US ONE MEASUREMENT
EVERY 70 CENTIMETERS
AS ICE SAT-2 FLIES.
SO IT'S MUCH SMALLER FOOTPRINT
AND MUCH MORE DENSE SPATIAL SAMPLING.
- THE STATISTICS COLLECTED ABOUT THE CRYOSPHERE BY ICE SAT-2
WILL BE ORGANIZED INTO DATA PROFILES
AND STUDIED BY SCIENTISTS ALL OVER THE GLOBE.
BUT WHAT IS IT THEY HOPE TO UNDERSTAND?
- SO ICE SAT-2 IS MEASURING HEIGHT.
IT'S AN ALTIMETER.
SO YOU'RE GONNA GET VERY HIGH RESOLUTION,
VERY SPECIFIC LEVELS IN TERMS OF DATA.
AND SO WE HAVE RESEARCHERS, WE HAVE SCIENTISTS
THAT ARE LOOKING AT THE LEVEL OF WATER IN A RESERVOIR.
THAT IS SOMETHING THAT YOU WOULDN'T NECESSARILY THINK OF
RIGHT OFF THE CUFF WHEN YOU SEE THE NAME ICE SAT-2,
BECAUSE YOU AUTOMATICALLY THINK "ICE."
BUT IT HAS DIFFERENT APPLICATIONS BEYOND THAT
OF THE CRYOSPHERE,
SO YOU HAVE RESERVOIR HEIGHTS,
YOU'LL HAVE VEGETATION CANOPY HEIGHTS,
THEN YOU HAVE, AGAIN, YOUR SEA ICE THICKNESS
AND THEN YOUR LAND ICE.
I THINK YOU CAN REALLY BE CREATIVE
IN TERMS OF HOW YOU USE THE DATA,
WHICH IS WHY WE GO OUTSIDE OF THE SCIENTIFIC COMMUNITY
AND LOOK AT DIFFERENT WAYS OPERATIONAL USERS
COULD REALLY VALUE ALTIMETER DATA,
BECAUSE IT'S NOT JUST WHAT'S IN OUR HEAD.
IT'S REALLY COMBINING WHAT'S IN OTHER PEOPLE'S HEADS,
AND I THINK ONCE YOU GET ALL THESE, YOU KNOW,
CREATIVE MINDS WORKING,
YOU CAN FIND DIFFERENT WAYS OF APPLYING THE DATA.
- SO THAT'S IT.
WITH ICE SAT-2,
NASA'S STAYING ON TOP OF TECHNOLOGY
AND ADVANCED CRYOSPHERIC RESEARCH.
AND WITH EACH PULSE OF LIGHT,
ICE SAT-2 IS PUTTING EARTH IN PERSPECTIVE.
THANKS FOR WATCHING.
I'M ISAAC,
AND WE'LL CATCH YOU NEXT TIME ON "NASA LAUNCHPAD."