[dramatic percussion music]
- HI, AND WELCOME TO "NASA LAUNCHPAD."
I'M YOUR HOST, JUSTIN GARCIA.
INNOVATION IS INCREDIBLY IMPORTANT TO NEW DISCOVERIES.
BUT YOU'VE PROBABLY HEARD THE OLD SAYING
"IF IT AIN'T BROKE, DON'T FIX IT."
SO JUST HOW DO YOU KNOW WHEN TO USE WHAT YOU ALREADY HAVE
AND WHEN TO START WITH SOMETHING NEW?
WELL, A TEAM AT NASA HAS THE ANSWER,
AT LEAST WHEN IT COMES TO A SERIES
OF VERY SUCCESSFUL EARTH-OBSERVING INSTRUMENTS.
SAGE, OR THE STRATOSPHERIC AEROSOL AND GAS EXPERIMENT,
IS AN INSTRUMENT THAT SCIENTISTS HAVE USED
SEVERAL TIMES SINCE THE 1970s
TO LEARN ABOUT EARTH'S ATMOSPHERE.
OF COURSE, THE ENGINEERS ARE CONSTANTLY MODIFYING THE DESIGN
AND UPDATING THE TECHNOLOGY.
BUT THE SAME BASIC INSTRUMENT HAS BEEN USED ALL THESE YEARS.
YOU SEE, MORE THAN 30 YEARS AGO,
SCIENTISTS REALIZED THERE WAS A PROBLEM
WITH THE EARTH'S PROTECTIVE COAT OF OZONE.
IT WAS THINNING.
THE SAGE FAMILY OF INSTRUMENTS WAS PIVOTAL
IN MAKING ACCURATE MEASUREMENTS OF THE AMOUNT OF OZONE LOSS
IN EARTH'S ATMOSPHERE.
AND THEN, WHEN INTERNATIONAL REGULATIONS
TO REVERSE THE LOSS OF OZONE WERE ENACTED,
SAGE ALSO PLAYED A KEY ROLE IN MEASURING THE OZONE RECOVERY.
OVER THE LAST 30 YEARS,
SAGE TECHNOLOGY HAS SHED LIGHT ON HOW AEROSOLS, WATER VAPORS,
AND OTHER GASES INTERACT WITH AND AFFECT OUR ATMOSPHERE.
TODAY SAGE IS STILL THE BEST FOR THE JOB,
AND NASA SCIENTISTS ARE PREPARING TO SEND
THE THIRD GENERATION OF THE INSTRUMENT INTO SPACE.
HOWEVER, NOT JUST ANY SPACECRAFT WILL DO FOR SAGE III.
SCIENTISTS HAVE BEEN KEEPING IT SAFE,
WAITING FOR THE DAY THAT IT COULD GO
WHERE NO CONTINUOUS EARTH-OBSERVING INSTRUMENT
HAS GONE BEFORE:
THE INTERNATIONAL SPACE STATION.
- WELL, FOR THE SCIENTISTS, IT'S GREAT,
BECAUSE THE ORBIT THAT IT'S IN ALLOWS US TO TAKE SCIENCE
BETWEEN AROUND MINUS 60 TO PLUS 60 DEGREES.
SO THAT'S QUITE A MAJOR RANGE OF DATA
THAT THE SCIENTISTS CAN GET, ESPECIALLY IN THE EQUATOR,
WHICH IS GREAT FOR THE SCIENTISTS.
OPERATIONAL-WISE, IT'S GREAT FOR US
BECAUSE WE'RE ALLOWED TO TALK--
OR COMMUNICATE WITH THE PAYLOAD ALMOST CONTINUOUSLY,
WHICH YOU GENERALLY CAN'T DO FOR MOST SATELLITES.
- THE SPACE STATION IN ORBIT
HAS A SPECIFIC DIRECTION THAT IT POINTS.
THEY CALL IT THE YAW, PITCH, AND ROLL,
SO THE THREE DIRECTIONS THAT MOVE.
BECAUSE IT'S SUCH A LARGE STRUCTURE
AND IT'S GOT A LOT OF THINGS THAT IT'S TRYING TO ACCOMPLISH,
THAT ATTITUDE, THOSE YAW, PITCH, AND ROLL NUMBERS
CHANGE OVER THE COURSE OF WEEKS, MONTHS, AND YEARS.
SO BECAUSE OURS WAS DESIGNED TO POINT AT THE EARTH
THE WHOLE TIME, WE NEEDED SOME WAY
TO BE ABLE TO CORRECT THAT, THOSE CHANGES
AND GET OUR INSTRUMENT POINTED BACK
IN THE WAY IT'S SUPPOSED TO BE.
- YOU'RE ORIENTED SO THAT THIS IS FACING EARTH.
AND OUR SCAN HEAD CAN ACCOUNT FOR THIS DIRECTION,
BUT IF THERE ARE ANY DISCREPANCIES
IN HOW THE ISS IS ORIENTED,
THE HEXAPOD, WHICH IS THIS GUY IN THE BLUE,
CAN HELP ORIENT YOUR SCAN HEAD IN AZIMUTH AND ELEVATION
SO YOU'RE POINTING IN THE RIGHT DIRECTION.
- SAGE III WILL BE THE FIRST CONTINUOUS
EARTH-OBSERVING INSTRUMENT EVER TO GRACE THE ISS.
BUT SOMETHING ELSE MAKES THIS SAGE
DIFFERENT THAN THE REST:
ITS USE OF THE MOON.
- YOU TAKE OBSERVATIONS WITH SUN--
WITH SOLAR OCCULTATION
ONLY WHERE YOU SEE SUNRISE AND SUNSET,
SO NOW IF YOU CAN TAKE MOONRISE AND MOONSET,
YOU'VE BASICALLY, IN SOME SENSE,
KIND OF DOUBLED YOUR MEASUREMENT CAPABILITY.
BUT YOU CAN ALSO PROBE DIFFERENT PLACES
IN DIFFERENT TIMES.
THE LUNAR OCCULTATIONS ONLY OCCUR
AT A LOCAL NIGHTTIME CONDITION,
SO WITH THE SUNRISE/SUNSET WITH SOLAR OCCULTATION,
YOU'RE SEEING IT AT SUNRISE AND SUNSET.
WITH LUNAR OCCULTATION, YOU CAN SEE IT IN THE NIGHTTIME.
AND MANY OF THE GASES IN THE STRATOSPHERE
HAVE CYCLES TO THEM.
FOR EXAMPLE, NITROGEN TRIOXIDE, NO3,
IS ONLY PRESENT REALLY IN CONCENTRATIONS AT NIGHTTIME,
BUT YOU NEED TO UNDERSTAND THAT
TO UNDERSTAND THE CHEMICAL BALANCES GOING ON.
- SAGE IS ONE OF NASA'S LONGEST-RUNNING
EARTH-OBSERVING PROGRAMS.
AND WE KNOW THAT LONG-TERM COLLECTION OF THIS TYPE OF DATA
IS NECESSARY TO TRULY UNDERSTAND
BOTH THE FRAGILITY AND COMPLEXITY
OF OUR ATMOSPHERE.
TAKE A LOOK AT THIS PHOTO.
THAT THIN BLUE LINE, THAT'S EARTH'S ATMOSPHERE.
THIS IMAGE REALLY SHOWS JUST HOW DELICATE OUR ATMOSPHERE IS.
NOT ONLY WILL SAGE III HELP US UNDERSTAND MORE
ABOUT OUR TENUOUS ATMOSPHERE AND OZONE,
BUT IT CAN ALSO HELP US UNDERSTAND THE IMPACT
THAT HUMAN ACTIVITIES HAVE ON EARTH'S ATMOSPHERE,
INFORMATION THAT MAY PROVE VITAL
AS WE LOOK TO SOLVE THE CHALLENGES
OF EARTH'S CHANGING CLIMATE.
UNTIL NEXT TIME, I'M JUSTIN GARCIA.
THANKS FOR WATCHING.