WEBVTT

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[dramatic percussion music]

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- HI THERE,
AND WELCOME TO "NASA LAUNCHPAD."

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I'M YOUR HOST, MOLLY.

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WHAT DO YOU KNOW ABOUT
RADIOISOTOPE POWER SYSTEMS?

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[crickets chirping]

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NOT EVEN SURE WHAT AN R.P.S. IS?

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WELL, YOU MAY HAVE HEARD OF

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THE VOYAGER MISSION
TO THE OUTER PLANETS

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OR THE ONGOING
CASSINI MISSION TO SATURN.

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AND WE CAN'T LEAVE OUT
NEW HORIZONS,

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THE NASA SPACECRAFT

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THAT IS SPEEDING ON ITS WAY
TO PLUTO.

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ALL OF THESE
AMAZING NASA MISSIONS

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TO EXPLORE THE SOLAR SYSTEM

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HAVE BEEN MADE POSSIBLE

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BY THE USE OF RADIOISOTOPE
POWER SYSTEMS,

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OR R.P.S. FOR SHORT.

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AN R.P.S.
IS A UNIQUE POWER SYSTEM

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THAT PROVIDES ELECTRICITY

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USING HEAT
FROM THE NATURAL DECAY

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OF THE RADIOISOTOPE
PLUTONIUM-238.

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RADIOISOTOPE POWER
CAN SIGNIFICANTLY ENHANCE

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THE ABILITY OF SOLAR SYSTEM
EXPLORATION MISSIONS

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TO MEET THEIR SCIENTIFIC
AND OPERATIONAL GOALS.

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USUALLY THESE POWER SYSTEMS
ENABLE SPACE MISSIONS TO HAPPEN

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THAT JUST WOULDN'T WORK
WITHOUT THEM.

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IN PARTICULAR,
AN R.P.S. PROVIDES A CONTINUOUS,

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LONG-LIVED POWER SOURCE

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THAT'S IDEAL FOR MISSIONS
TO PLACES THAT ARE DARK, DUSTY,

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OR HAVE EXTREME
TEMPERATURE FLUCTUATIONS,

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WHERE SOLAR PANELS
OR BATTERIES ALONE

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MIGHT NOT BE THE BEST CHOICE.

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- WELL, RADIOISOTOPE
POWER SYSTEM TECHNOLOGY

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ALLOWS US TO GO TO THE FURTHEST
REACHES OF THE SOLAR SYSTEM

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AS WELL AS OTHER PLACES
IN THE SOLAR SYSTEM

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WHERE THE SUN'S ENERGY

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JUST CAN'T BE USED
FOR SPACECRAFT POWER.

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SO WE WANT TO BRING A DIFFERENT
ENERGY SOURCE WITH US.

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SO OUT IN THE JUPITER, SATURN,
URANUS, NEPTUNE RANGE,

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YOU WOULD WANT TO USE
RADIOISOTOPE POWER.

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- SO KNOWING THAT,

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YOU MIGHT NOT BE SURPRISED

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THAT WE HAVE BEEN USING
THIS TECHNOLOGY

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TO POWER SPACE PROBES
FOR 50 YEARS.

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- SPACECRAFT THAT ARE POWERED BY
RADIOISOTOPE POWER SYSTEMS

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HAVE BEEN AN INTEGRAL PART
OF OUR EXPLORATION

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SINCE THE VERY BEGINNING.

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AND THIS IS BECAUSE THEY PROVIDE
SUCH STEADY AND RELIABLE POWER

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OVER THE COURSE
OF AN ENTIRE MISSION,

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WHICH CAN GO BEYOND 30 YEARS.

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WE LIKE TO SEND SPACECRAFT
WITH RADIOISOTOPE POWER SYSTEMS

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INTO THE PLACES
OF THE SOLAR SYSTEM

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WHERE THERE'S VERY LOW LIGHT.

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WHEN WE WANT TO GO
FAR AWAY FROM THE SUN,

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THE SUNLIGHT
IS GONNA GET DIMMER AND DIMMER.

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IT'S JUST LIKE WHEN
YOU LEAVE YOUR HOUSE AT NIGHT,

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WHEN YOU SEE YOUR PORCH LIGHT

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AND IT GETS DIMMER AND DIMMER
AS YOU DRIVE AWAY.

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THAT'S JUST HOW IT IS
AS THE SPACECRAFT TAKES OFF

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TOWARDS JUPITER, SATURN, URANUS,
AND NEPTUNE.

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SO WE NEED
RADIOISOTOPE POWER SYSTEMS

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TO PROVIDE A RELIABLE,
STEADY SOURCE OF HEAT

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THAT WE THEN CONVERT
INTO ELECTRICITY

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THAT PROVIDES THE POWER
FOR THESE MISSIONS

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AS THEY GO
ON THEIR OUTWARD JOURNEY

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ACROSS THE SOLAR SYSTEM.

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- THE POWER SOURCE FOR AN R.P.S.
PRODUCES HEAT FOR A LONG TIME.

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THAT MEANS AN R.P.S.
CAN PROVIDE POWER

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FOR LONG-LASTING SPACE MISSIONS,

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LIKE THE VOYAGER SPACECRAFT.

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LAUNCHED BACK IN 1977,

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THE TWO VOYAGERS ARE THE LONGEST
CONTINUALLY OPERATING SPACECRAFT

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IN DEEP SPACE.

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AFTER TRAVELING AT TENS
OF THOUSANDS OF MILES PER HOUR

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FOR MORE THAN 30 YEARS,

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THEY'VE ACTUALLY REACHED, WELL,

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BASICALLY THE EDGE
OF OUR SOLAR SYSTEM.

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BOTH CRAFT
ARE STILL SENDING BACK DATA

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AS THEY HURTLE
TOWARD INTERSTELLAR SPACE--

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THE SPACE BETWEEN THE STARS.

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THESE SPACECRAFT
REALLY HAVE GONE

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WHERE NO ONE HAS GONE BEFORE.

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AND RIGHT NOW,
THEY'RE HELPING US

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LEARN MORE ABOUT
THE EDGES OF OUR SOLAR SYSTEM.

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NASA GROUND CONTROLLERS

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RECENTLY COMMANDED
ONE OF THE VOYAGERS

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TO ROTATE IN SPACE
FOR THE FIRST TIME IN 20 YEARS

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TO MAKE A CERTAIN KIND
OF SCIENTIFIC MEASUREMENT,

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AND THE SPACECRAFT
RESPONDED PERFECTLY.

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THE REASON THEY STILL HAVE POWER
IS THANKS TO R.P.S. TECHNOLOGY.

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TRY FINDING A BATTERY

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THAT'LL HOLD A CHARGE
AFTER THREE YEARS OF USE,

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LET ALONE THREE DECADES.

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VOYAGER 1 AND 2
ARE NOT THE FIRST SPACECRAFT

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TO USE R.P.S. TECHNOLOGY,

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NOR ARE THEY THE LAST.

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MORE THAN 20 NASA MISSIONS
HAVE USED THIS TECHNOLOGY.

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PIONEER 10 USED AN R.P.S.

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TO FLY THROUGH
THE ASTEROID BELT,

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MAKING OUR FIRST
DIRECT OBSERVATIONS OF JUPITER.

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AND GALILEO GAVE US

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OUR FIRST CLOSE-UP RENDEZVOUS
WITH AN ASTEROID

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AND WAS NEARBY TAKING PICTURES

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WHEN A COMET
SMASHED INTO JUPITER.

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THE ULYSSES MISSION
FLEW OVER THE SUN'S POLES

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TO HELP US LEARN MORE
ABOUT SOLAR FLARES.

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EVEN THE APOLLO ASTRONAUTS
USED R.P.S. TECHNOLOGY

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TO POWER SCIENCE EXPERIMENTS
THEY LEFT BEHIND

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ON THE SURFACE OF THE MOON.

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AT SATURN, THE CASSINI MISSION
ALSO MAKES USE OF R.P.S.

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AT SATURN'S DISTANCE
FROM THE SUN,

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WHICH IS TEN TIMES FARTHER AWAY
THAN EARTH,

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SOLAR POWER ISN'T A PRACTICAL
OPTION--AT LEAST NOT YET.

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BUT THANKS TO R.P.S. TECHNOLOGY,

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WE CAN CONTINUE TO RECEIVE
AMAZING IMAGES LIKE THESE.

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CASSINI'S INCREDIBLY SUCCESSFUL
MISSION HAS BEEN EXTENDED TWICE,

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AND IT STILL HAS POWER
TO EXPLORE.

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IT WILL HAVE OPERATED IN SPACE
FOR 20 YEARS

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BY THE TIME THE MISSION ENDS
IN 2017.

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THERE'S ANOTHER BENEFIT
TO USING R.P.S.

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SOME OF THE EXCESS HEAT
FROM THE POWER SYSTEM

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CAN BE USED TO KEEP VITAL PARTS
OF A SPACECRAFT WARM

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SO THEY CAN OPERATE
IN COLD PLACES LIKE DEEP SPACE

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OR THE FRIGID SURFACE
OF MARS.

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OF COURSE NASA WANTS TO USE
THE BEST POWER SYSTEM

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FOR ANY MISSION IT LAUNCHES,

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AND SAFETY IS THE FIRST
OF NASA'S CORE VALUES.

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RADIOISOTOPE POWER SYSTEMS

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ARE A TYPE
OF NUCLEAR TECHNOLOGY,

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SO HOW SAFE ARE THEY?

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- SAFETY IS A KEY FACTOR
IN THE DESIGN

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OF ALL RADIOISOTOPE
POWER SYSTEMS.

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WE DESIGN SAFETY
FROM THE INSIDE OUT

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AND THE OUTSIDE IN

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OF ALL
RADIOISOTOPE POWER SYSTEMS.

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WE BEGIN WITH
THE RADIOISOTOPE FUEL ITSELF,

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PLUTONIUM-238 DIOXIDE,

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WHICH IS A CERAMIC MATERIAL.

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IT'S INSOLUBLE AND BREAKS
INTO LARGE PIECES WHEN IMPACTED.

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NEXT,
WE HAVE THE IRIDIUM CLADDING,

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WHICH SURROUNDS
THE PLUTONIUM FUEL.

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THE IRIDIUM IS DUCTILE.

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IT'S VERY STRONG, AND IT HAS
A HIGH MELTING TEMPERATURE.

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SURROUNDING THE IRIDIUM
IS A CARBON MATERIAL.

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IT'S VERY TOUGH,

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AND IT ALSO PROTECTS
AGAINST FIRES

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AND THE HEAT OF REENTRY.

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THE DEPARTMENT OF ENERGY
AND ITS PREDECESSOR AGENCIES

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HAVE BEEN INVOLVED WITH--
FOR OVER 50 YEARS

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IN DEVELOPING SPACE R.P.S.
WITH NASA AND NAVY, AIR FORCE.

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- COMBINING TECHNOLOGY
WITH KNOW-HOW--

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AND THE RESULT IS AN R.P.S.

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THAT MAKES POWER USING THE HEAT
FROM ITS PLUTONIUM FUEL SOURCE,

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WORKS IN ALL KINDS
OF EXTREME ENVIRONMENTS,

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AND LASTS A REALLY LONG TIME.

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AND FOR SOME OF NASA'S
MOST POPULAR

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AND EXCITING SPACE MISSIONS,

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R.P.S. TECHNOLOGY
HAS BEEN AND REMAINS

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AN ABSOLUTE NECESSITY.

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- I THINK THE FUTURE FOR US

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IS VERY BRIGHT,
VERY INTERESTING.

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WE HAVE A LOT OF PLACES TO GO
IN THE SOLAR SYSTEM.

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WE NEED TO BRING
RADIOISOTOPE POWER SYSTEMS ALONG

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TO BE ABLE TO GO UNDERSTAND

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THE ICE SURFACE
OF JUPITER'S MOON EUROPA.

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WE'D LIKE TO GO OUT
TO THE ICY MOON OF SATURN

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THAT'S KNOWN AS ENCELADUS.

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WE WOULD THINK THAT WOULD BE
A FROZEN BALL OF ICE,

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BUT WE FIND IT'S ACTUALLY
GEOLOGICALLY ACTIVE

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AND THERE'S WATER AND VOLATILE
SPEWING OUT OF ITS SOUTH POLE.

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ALSO OUT AT SATURN
IS THE GIANT MOON TITAN,

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WHICH HAS A HAZY ATMOSPHERE
AND LIQUID HYDROCARBON LAKES.

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WE'D LIKE TO SEND
A SPACECRAFT THERE.

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AND THEN AS WE TRAVEL
EVEN FURTHER OUT,

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WE COME TO THE KUIPER BELT

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WHERE THERE'S A MYRIAD
OF SMALL BODIES

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THAT ARE VERY PRIMITIVE
LEFTOVER BUILDING BLOCKS

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FROM THE FORMATION
OF THE SOLAR SYSTEM.

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- SOME PAST NASA MISSIONS

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WOULD NOT HAVE BEEN
THE SUCCESS THEY WERE

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WITHOUT THE USE OF R.P.S.

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IN FACT WITHOUT IT,

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WE WOULDN'T HAVE HAD
THIS REVEALING PICTURE

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OF MARS' SURFACE IN 1976

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OR THIS PANORAMIC VIEW
FROM THE FAR SIDE OF SATURN

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OR EVEN THIS GLIMPSE OF EARTH
FROM 4 BILLION MILES AWAY

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OR ANY OF THESE
DOZENS OF IMAGES.

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WE WOULDN'T HAVE ANY OF THESE
WITHOUT R.P.S.

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SO RADIOISOTOPE POWER SYSTEMS
LEAD TO ANOTHER KIND OF R.P.S.,

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REALLY PRODUCTIVE SPACECRAFT.

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THAT'S IT FOR THIS EPISODE.

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THANKS FOR WATCHING.

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I'M MOLLY,

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