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NASA
Destination Tomorrow
#DEST11
Caption File Transcript
Captioning provided by N.E.C. Foundation of America. COMING
UP ON DESTINATION TOMORROW: SEE HOW SOLAR SAILS ARE BEING DEVELOPED FOR
DEEP-SPACE EXPLORATION. WE'LL ALSO SEE HOW NASA TECHNOLOGY IS BEING USED
TO HELP PROTECT SOME OF AMERICA'S MOST IMPORTANT DOCUMENTS. PLUS WE'LL
TAKE A LOOK AT HOW THE NEXT GENERATION OF REUSABLE LAUNCH VEHICLES IS
BEING DEVELOPED; AND JOHNNY ALONSO FINDS OUT EXACTLY HOW G.P.S. WORKS.
ALL THIS AND MORE, NEXT ON DESTINATION TOMORROW. HELLO, EVERYONE. I'M
STEELE McGONEGAL. AND I'M KERA O'BRYON. WELCOME TO DESTINATION TOMORROW.
THIS PROGRAM WILL UNCOVER HOW PAST, PRESENT, AND FUTURE RESEARCH IS CREATING
TODAY'S KNOWLEDGE TO ANSWER THE QUESTIONS AND SOLVE THE CHALLENGES OF
TOMORROW. UP FIRST, WE LOOK AT A NEW WAY FOR SPACECRAFT TO TRAVEL TO DISTANT
DESTINATIONS. NEW LIGHTWEIGHT SOLAR SAILS MIGHT SOON BECOME THE STANDARD
MECHANISM TO POWER SPACECRAFT. THESE REFLECTIVE STRUCTURES USE ENERGY
FROM THE SUN RATHER THAN ROCKET POWER TO MOVE THROUGH SPACE. THESE SAILS
ARE NOT ONLY LESS EXPENSIVE THAN CURRENT ROCKET-POWERED SPACECRAFT BUT
CAN POTENTIALLY BE FOUR TO SIX TIMES FASTER. THIS INCREASED SPEED AND
COST SAVINGS COULD CHANGE THE WAY WE STUDY DEEP SPACE. JENNIFER PULLEY
SPOKE WITH DR. KEITH BELVIN AT NASA LANGLEY RESEARCH CENTER TO FIND OUT
MORE. THROUGHOUT HUMANKIND'S EARLY HISTORY, THE QUEST FOR GREATER KNOWLEDGE
AND UNDERSTANDING FUELED THE NEED FOR EXPLORATION. FOR CENTURIES, THE
VEHICLE MOST EARLY EXPLORERS USED TO ACHIEVE THIS EXPLORATION WAS A SHIP
WITH SAILS. BUT BECAUSE THESE SHIPS DEPENDED ON WIND PUSHING AGAINST THE
SAILS FOR FORWARD MOTION, THEY WERE GENERALLY VERY SLOW, UNPREDICTABLE,
AND OFTEN VERY DANGEROUS. TODAY, WITH THE MULTITUDE OF WAYS THAT HUMANS
NOW POSSESS TO TRAVEL, THE SAIL, WITH ALL OF ITS LIMITATIONS, HAS BEEN
RELEGATED TO RECREATIONAL STATUS RATHER THAN A SERIOUS TOOL FOR EXPLORATION.
BUT A NEW IDEA MIGHT CHANGE THE WAY WE THINK ABOUT SAILS. NASA RESEARCHERS
ARE ACTUALLY DEVELOPING A NEW TYPE OF SAIL THAT WILL USE THE SUN'S LIGHT
TO PROPEL SPACECRAFT DEEP INTO SPACE. THESE SOLAR SAILS ARE SO PROMISING
THAT SOMEDAY THEY MAY REPLACE SLOWER, MORE COSTLY PROPULSION SYSTEMS FOR
DEEP-SPACE EXPLORATION. I SPOKE WITH DR. KEITH BELVIN AT NASA LANGLEY
RESEARCH CENTER TO FIND OUT MORE. WELL, THE IDEA FOR SOLAR SAILS HAS BEEN
AROUND FOR A VERY LONG TIME. MAXWELL, BACK IN 1873, PREDICTED THE EXISTENCE
OF SOLAR PRESSURE--LIGHT-- SO WE'VE KNOWN ABOUT SOLAR PRESSURE FOR A LONG
TIME, BUT IT WASN'T UNTIL RECENTLY THAT WE WERE ABLE TO BUILD SOLAR SAILS
WITH THE LIGHTWEIGHT MATERIALS AND STRUCTURES THAT ARE NEEDED. TELL ME
ABOUT THESE LIGHTWEIGHT MATERIALS AND STRUCTURES. HOW ARE THEY BEING USED?
WELL, THE KEY TO BUILDING A SOLAR SAIL IS, OF COURSE, TO MAKE IT VERY
LARGE AND VERY LIGHTWEIGHT. FOR A USEFUL SOLAR SAIL, IT HAS TO HAVE A
WEIGHT OF LESS THAN 10 GRAMS PER SQUARE METER. FOR EXAMPLE, COPIER PAPER
HAS A WEIGHT OF 70 GRAMS PER SQUARE METER, SO WE'RE TALKING ABOUT SOME
MATERIALS THAT ARE MUCH LIGHTER THAN THAT. ONE OF THE THINGS THAT NASA'S
DONE OVER THE LAST DECADE IS TO WORK ON MATERIALS THAT CAN BE PROCESSED
TO JUST A COUPLE MICRONS. THAT'S A COUPLE MILLIONTHS OF A METER THICK.
AND THESE LIGHTWEIGHT, THIN MATERIALS THEN ARE MADE SPACE-DURABLE SO THEY
CAN WITHSTAND THE RADIATION AND TEMPERATURES OF SPACE. DR. BELVIN, TELL
ME HOW A SOLAR SAIL WORKS. THE BASIC PRINCIPLE IS MUCH LIKE A SHIP ON
THE SEA THAT USES SAILS TO CAPTURE THE WIND. THE SUN IS CONSTANTLY EMITTING
LIGHT, OR PHOTONS, IN ALL DIRECTIONS. SINCE THE PHOTONS HAVE MASS AND
ARE IN MOTION, THEIR MOMENTUM PRODUCES A PRESSURE WHEN REFLECTED BY A
SURFACE. WHEN A SPACECRAFT USES A SOLAR SAIL FOR PROPULSION, THE SAIL'S
REFLECTIVE SURFACE TRANSFERS A CONTINUOUS FORCE FROM THE PHOTONS TO PROPEL
THE CRAFT THROUGH SPACE, MUCH LIKE A SAILING SHIP USES WIND TO PUSH IT
ACROSS THE WATER. SINCE THE PRESSURE BEING EMITTED FROM THE PHOTONS IS
VERY LOW, THE FORCE IS SMALL. BUT BECAUSE THE SAIL WILL HAVE A CONSTANT
SOURCE OF ENERGY, IT IS CONTINUOUSLY ACCELERATING AND CAN REACH SPEEDS
UPWARDS OF 155,000 MILES PER HOUR. THIS SPEED COULD CUT YEARS OFF TRAVEL
TIME DURING LONG-DURATION INTERSTELLAR FLIGHTS. IN ADDITION, THE CONSTANT
PROPULSIVE FORCE PROVIDED BY THE SUN'S LIGHT ALLOWS THE SPACECRAFT TO
TRAVEL IN ORBITS THAT ARE NOT AFFORDABLE USING CONVENTIONAL PROPULSION.
SO CAN SOLAR SAILS BE USED ON ALL TYPES OF MISSIONS? WELL, IN ADDITION
TO SOLAR SAILS HAVING TO BE LIGHTWEIGHT FOR VARIOUS MISSIONS, THE SPACECRAFT
THEY'RE PROPELLING HAS TO BE VERY LIGHTWEIGHT. BUT THERE ARE MANY MISSIONS
WHERE, WITH THE MINIATURIZATION OF ELECTRONICS, THAT THE SPACECRAFT'S
SCIENCE SENSORS ARE VERY SMALL AND LIGHTWEIGHT, AND THOSE SYSTEMS ARE
VERY AMENABLE TO BEING PROPELLED BY A SOLAR SAIL. FOR EXAMPLE, WE'RE LOOKING
AT MISSIONS IN THE FUTURE WHERE WE DO INTERSTELLAR TRANSFER OF SCIENCE
INSTRUMENTS USING SOLAR SAILS. SO DO WE SEE SOLAR SAILS ONLY BEING USED
IN DEEP SPACE? WELL, THERE ARE MISSIONS WHERE SOLAR SAILS CAN BE USED
CLOSE TO THE EARTH'S ORBIT. THEY DON'T ALL HAVE TO BE LONG-DURATION,
INTERSTELLAR-TYPE MISSIONS. THE CONSTANT ACCELERATION THAT A SOLAR SAIL
PRODUCES GIVES AN ORBIT TRAJECTORY THAT IS NOT ACHIEVABLE BY SOME OTHER
MEANS. FOR EXAMPLE, WE CAN FLY A SCIENCE PAYLOAD TO MEASURE THE MAGNETIC
STORMS EMANATING FROM THE SUN. HOW DO YOU DEPLOY SUCH A LARGE STRUCTURE
INTO SPACE? TO DEPLOY A SOLAR SAIL IN SPACE IS QUITE A CHALLENGE. FIRST
OF ALL, THE SAIL HAS TO BE PACKAGED IN A SMALL SIZE TO FIT INTO THE LAUNCH
VEHICLES. NEAR-TERM SAIL MISSIONS ARE ON THE ORDER OF 70 METERS UP TO
150 METERS IN SIZE, AND SO IT'S A REAL CHALLENGE TO PACKAGE THOSE TIGHTLY
AND THEN DEPLOY IN SPACE. TWO ASPECTS PROBABLY ARE MOST IMPORTANT FOR
DEPLOYING A SOLAR SAIL. THE FIRST IS DEPLOYING THE BOOMS THAT HOLD THE
MEMBRANES IN PLACE. WE'RE USING INFLATION TO PUSH THE BOOMS OUT INTO THE
RIGHT LOCATION, AND THEN WE COOL THE BOOMS TO RIGIDIZE THEM. THE SECOND
ASPECT IS DEPLOYING THE SAIL, THE THIN-FILM MEMBRANES THAT WE'VE TALKED
ABOUT. THOSE WILL INCORPORATE RIPSTOP SO THAT IF THERE'S A SMALL TEAR,
IT DOESN'T PROPAGATE VERY FAR. IN ADDITION, WE HAVE TO DEPLOY THOSE SO
THAT WE DON'T AFFECT THE SAIL'S REFLECTIVE PERFORMANCE, AND SO SPECIAL
MEASURES ARE TAKEN TO MAINTAIN THE INTEGRITY OF THAT SAIL. WHAT IS THE
FUTURE OF THIS PROGRAM? I WOULD SAY WITHIN THE NEXT DOZEN YEARS OR SO,
SOLAR SAILS WILL BE USED ROUTINELY TO PROPEL SPACECRAFT. CONTINUAL IMPROVEMENTS
IN THE SAIL TECHNOLOGY WILL ALLOW THEM TO BE USED FOR EXTREME ENVIRONMENTS,
LIKE NEAR-SUN MISSIONS. OVER THE NEXT 20 YEARS, MOST IMPORTANTLY, WE'LL
HAVE THE TECHNOLOGY IN HAND TO DO INTERSTELLAR MISSIONS. THESE ARE KILOMETER-SIZE
SOLAR SAILS THAT WEIGH ONLY ONE TO TWO GRAMS PER SQUARE METER. THE TECHNOLOGY
BEING DEVELOPED TODAY AT NASA IS GOING TO ENABLE US TO UNLOCK A LOT OF
THE SECRETS OF THE UNIVERSE. NOT ONLY WILL WE BE ABLE TO LOOK AT DISTANT
PLACES USING TELESCOPES; WE'LL ACTUALLY BE ABLE TO SEND SCIENCE INSTRUMENTS
TO SOME OF THOSE LOCATIONS USING SOLAR SAILS. RESEARCHERS AT NASA ARE
CONTINUING TO IMPROVE THE MATERIALS USED FOR SOLAR SAILS EVERY DAY, MAKING
THEM STRONGER AND LIGHTER. COMING UP, WE FIND OUT HOW SOME NASA DETECTIVE
WORK HELPED PRESERVE THE DECLARATION OF INDEPENDENCE, THE BILL OF RIGHTS,
AND THE CONSTITUTION. BUT FIRST, DID YOU KNOW THAT THE INSPIRATION FOR
SOLAR-SAIL TECHNOLOGY CAME FROM THE 17th-CENTURY ASTRONOMER JOHANNES KEPLER?
KEPLER DEDUCED THAT WINDS BLEW OBJECTS AROUND IN SPACE AFTER HE OBSERVED
COMET TAILS BLOWN BY WHAT APPEARED TO BE A SOLAR BREEZE. KEPLER SUGGESTED
THAT EVENTUALLY SHIPS MIGHT NAVIGATE THROUGH SPACE USING SAILS THAT COULD
CATCH THIS WIND. THE CONSTITUTION, THE BILL OF RIGHTS, AND THE DECLARATION
OF INDEPENDENCE, ALSO KNOWN AS THE CHARTERS OF FREEDOM, ARE OBVIOUSLY
THREE OF THE MOST IMPORTANT AMERICAN DOCUMENTS EVER WRITTEN. THEY NOT
ONLY GUIDE AND GUARANTEE LIBERTIES FOR ALL AMERICANS BUT HAVE ALSO BEEN
MODELED BY DOZENS OF OTHER COUNTRIES AROUND THE WORLD. SO WHEN SIGNS OF
PREMATURE DETERIORATION BEGAN TO SHOW ON THE DOCUMENTS, CONSERVATORS BECAME
VERY ALARMED. TO HELP FIND OUT WHAT WAS CAUSING THE DETERIORATION AND
HOW IT COULD BE STOPPED, THE NATIONAL ARCHIVES TURNED TO NASA RESEARCHERS
FOR AN ANSWER. TONYA ST. ROMAIN FINDS OUT MORE. (. ) IN THE LATE 1700s,
THREE OF THE WORLD'S MOST IMPORTANT DOCUMENTS WERE WRITTEN HERE IN THE
UNITED STATES. NOW CALLED THE CHARTERS OF FREEDOM, THE DECLARATION OF
INDEPENDENCE, THE CONSTITUTION, AND THE BILL OF RIGHTS WERE CONCEIVED
AND WRITTEN BY EARLY AMERICANS WHO BELIEVED THAT TYRANNICAL RULE AND OPPRESSION
SHOULD BE REPLACED BY INDIVIDUAL LIBERTIES AND FREEDOM. UNTIL THE MID-20th
CENTURY, THESE DOCUMENTS WERE PROUDLY DISPLAYED FOR THE GENERAL PUBLIC,
BUT THE YEARS OF INADEQUATE PRESERVATION LEFT THEM A BIT FADED AND BRITTLE.
THIS ALL CHANGED IN 1951, WHEN THE DOCUMENTS WERE PLACED IN SPECIALLY
ADAPTED ENCASEMENTS WHICH WERE DESIGNED TO SLOW DOWN THE DETERIORATION
PROCESS. THESE GLASS ENCASEMENTS WERE FILLED WITH INERT HELIUM, WHICH
WOULD PROTECT THE DOCUMENTS FROM THE HARMFUL CHEMICALLY CORROSIVE EFFECTS
OF AIR, KEEPING THEM SAFE FOR GENERATIONS TO COME. BUT IN THE LATE 1990s,
CONSERVATORS BEGAN NOTICING THAT THE DOCUMENTS WERE IN FACT STILL SHOWING
SIGNS OF DETERIORATION. MYSTERIOUS SMALL WHITE SPOTS WERE APPEARING INSIDE
THE ENCASEMENTS AND ON THE DOCUMENTS. TO HELP DETERMINE THE CAUSE OF THE
DETERIORATION AND HOW TO FIX THE PROBLEM, THE NATIONAL ARCHIVES ASKED
RESEARCHERS AT NASA TO PERFORM A SERIES OF TESTS ON THE ATMOSPHERE INSIDE
THE ENCASEMENTS. I SPOKE WITH DR. JOEL LEVINE AT NASA LANGLEY RESEARCH
CENTER TO FIND OUT MORE. IN 1951, THE NATIONAL BUREAU OF STANDARDS, WHICH
IS NOW NIST, THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, WAS ASKED
BY THE NATIONAL ARCHIVES TO PRESERVE THESE VERY IMPORTANT DOCUMENTS: THE
DECLARATION OF INDEPENDENCE, THE U.S. CONSTITUTION, AND THE BILL OF RIGHTS.
IT BECAME APPARENT SEVERAL YEARS PRIOR TO 1998 THAT SOME MYSTERIOUS WHITE
SPOTS APPEARED IN ALL ENCASEMENTS, AND OVER TIME-- OVER SEVERAL YEARS--
THEY INCREASED IN NUMBER. THE NATIONAL ARCHIVE CONSERVATORS WANTED TO
KNOW IF WE HAD TECHNOLOGY THAT COULD DETERMINE THE CHEMICAL
COMPOSITION OF THE ENCASEMENTS NONINVASIVELY. NONINVASIVELY MEANS WITHOUT
EXTRACTING AIR. WE DIDN'T WANT TO TOUCH THE AIR. WE DIDN'T WANT TO TOUCH
THE ENCASEMENT. WE WANTED TO COME UP WITH SOME TECHNIQUE THAT COULD TELL
US THE ANSWER WITHOUT DISTURBING THE CONTENTS OF THE ENCASEMENT, BOTH
THE DOCUMENTS AND THE ATMOSPHERE. AFTER CONSIDERABLE DISCUSSION, WE DECIDED
WE SHOULD USE A TECHNIQUE CALLED LASER SPECTROSCOPY. WHAT THE LASER DID
IS PROVIDE ENERGY AT THE VERY WAVELENGTH THAT WATER VAPOR ABSORBS, AND
AS WE LOOKED AT THE ABSORPTION, WE COULD DETERMINE WHAT THE BACKGROUND
GAS WAS. WE WERE INTERESTED IN NOT THE DOCUMENT BUT THE ATMOSPHERE IN
THE ENCASEMENT THAT'S PROTECTING THE DOCUMENT. WHAT WE FOUND IS THAT THE
GAS THAT WAS SEALED 50 YEARS AGO WAS STILL THERE. WHEN THE LASER STUDIES
WERE DONE, NASA RESEARCHERS CONCLUSIVELY DETERMINED THAT HELIUM IN THE
ENCASEMENTS HAD NOT LEAKED OUT. THIS DETERMINATION ONLY INCREASED CONCERNS
OVER THE ORIGIN OF THE MYSTERIOUS WHITE SPOTS. MOST CONSERVATORS BELIEVED
THAT CHEMICALLY CORROSIVE AIR HAD LEAKED INTO THE ENCASEMENTS, CAUSING
THE DAMAGE. WITH THIS BELIEF DISPELLED, THE PUZZLE ONLY INTENSIFIED. SO
IN SOME INSTANCE, WE ACTUALLY WENT BACK TO STEP ONE BECAUSE WE STILL HAD
THE PROBLEM. THE PROBLEM IS, WHAT IS RESPONSIBLE FOR THESE WHITE SPOTS?
WE ELIMINATED AIR AS THE CORROSIVE AGENT. AND THE NEXT THING THE NATIONAL
ARCHIVES ASKED US IS, COULD WE TELL THEM NONINVASIVELY HOW MUCH WATER
VAPOR WAS IN THE ENCASEMENT? BECAUSE THE DOCUMENTS WERE WRITTEN ON SHEEPSKIN,
WHICH REQUIRES A SMALL AMOUNT OF WATER VAPOR FOR STABILITY, THE RELATIVE
HUMIDITY INSIDE THE ENCASEMENTS WAS ORIGINALLY SET BETWEEN 25% AND 35%.
TO DETERMINE IF THE HUMIDITY LEVELS HAD CHANGED, THE NASA RESEARCHERS
NEEDED TO MEASURE THE RELATIVE HUMIDITY INSIDE THE SEALED ENCASEMENT.
THE FIRST TECHNIQUE CONSIDERED INVOLVED PLACING THE ENCASEMENTS IN A FREEZER
TO CAUSE THE CONDENSATION OF GASEOUS WATER VAPOR TO LIQUID WATER DROPLETS.
THIS IDEA WAS REJECTED, DUE TO THE DISTINCT POSSIBILITY THAT THE DOCUMENTS
INSIDE COULD BE DAMAGED BY THE CONDENSED WATER. IT WAS LATER DECIDED THAT
THE HUMIDITY COULD BE CHECKED BY USING A VERY INEXPENSIVE DEVICE CALLED
A THERMAL ELECTRO COOLER. THIS DEVICE WOULD SAMPLE ONLY A SMALL AREA OF
THE ENCASEMENTS, KEEPING THE DOCUMENTS INSIDE SAFE. I CALLED UP THE ARCHIVES,
AND I SAID, "WE JUST HAVE TO FREEZE A SMALL PART OF IT AT THE EDGE,
"WHERE THERE'S NO DOCUMENT, NO INK, AND WE CAN SOLVE YOUR PROBLEM."
(. ) WHEN THE HUMIDITY LEVELS WERE CHECKED, IT WAS FOUND THAT THE LEVELS
INSIDE THE ENCASEMENT WERE 60% TO 65%, TWICE THE EXPECTED RELATIVE HUMIDITY.
THIS IS BECAUSE WHEN THE DOCUMENTS WERE ORIGINALLY SEALED IN 1951, THE
RELATIVE HUMIDITY IN WASHINGTON, D.C., WAS VERY HIGH. THE BACKING PAPER
THAT THE DOCUMENTS WERE LAID UPON HAD ACTUALLY SOAKED UP WATER VAPOR LIKE
A SPONGE. ONCE THE DOCUMENTS WERE ENCASED, THE WATER VAPOR INSIDE THE
BACKING PAPER COULD NOT ESCAPE, SO IT REMAINED IN THE ENCASEMENT'S ATMOSPHERE,
CAUSING THE HUMIDITY TO RISE. THE WHITE SPOTS WERE BASIC OR ALKALINE CHEMICALS
THAT WERE PULLED OUT OF THE GLASS BECAUSE OF THE PRESENCE OF HIGH LEVELS
OF WATER VAPOR. AND NOW, WHEN THE NATIONAL ARCHIVES OPENS WITH ITS NEW
ENCASEMENTS, WE ALL SURE THAT THE DOCUMENTS WILL BE STABLE FOR MANY CENTURIES.
AND IN SOME SMALL PART, NASA SCIENTISTS AND NASA TECHNOLOGY HELPED PRESERVE
THESE DOCUMENTS FOR MANY GENERATIONS TO COME. TO BETTER UNDERSTAND AERODYNAMIC
FORCES, EARLY PILOTS AND ENGINEERS PUSHED AIRCRAFT TOLERANCES TO THE LIMIT.
BUT BY PUSHING THE LIMITS, SOME PILOTS EXPERIENCED A VERY FRIGHTENING
AERODYNAMIC PHENOMENON CALLED A FLAT SPIN. IN AN EFFORT TO BETTER UNDERSTAND
THIS PHENOMENON, NASA'S PREDECESSOR, NACA, DEVELOPED A UNIQUE WIND TUNNEL
CALLED THE 20-FOOT VERTICAL SPIN TUNNEL. THIS TUNNEL WAS DESIGNED TO NOT
ONLY STUDY THE UNIQUE FLIGHT CONDITIONS OF AN AIRCRAFT IN SPIN BUT ALSO
TEACH PILOTS RECOVERY TECHNIQUES TO AVOID A FATAL CRASH. THE RESEARCH
PERFORMED AT THIS TUNNEL WOULD HAVE A DIRECT IMPACT ON VIRTUALLY EVERY
AMERICAN FIGHTER AIRCRAFT FROM WORLD WAR II THROUGH TODAY. EARLY IN 1941,
THE NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS, OR NACA, COMPLETED ITS
NEW 20-FOOT VERTICAL SPIN TUNNEL. THIS TUNNEL TESTED A VERY DIFFERENT
TYPE OF FLIGHT SITUATION THAN THE TUNNELS RESEARCHERS WERE ACCUSTOMED
TO USING. THE TRADITIONAL WAY TO TEST AIRCRAFT IN A WIND TUNNEL IS BY
MOUNTING AN AIRCRAFT IN THE WIND STREAM TO EVALUATE THE AIRCRAFT'S FLIGHT
CHARACTERISTICS. THIS TYPE OF TESTING IS VERY EFFECTIVE WHEN TESTING AN
AIRCRAFT IN NORMAL FLIGHT SITUATIONS. BUT DATA FROM A TRADITIONAL WIND
TUNNEL COULD NOT ADEQUATELY ACCOUNT FOR UNUSUAL FLIGHT CONDITIONS, LIKE
A FLAT SPIN. AS A PLANE ENTERS A FLAT SPIN, AIR IS NOT MOVING OVER THE
CONTROL SURFACES AS IT SHOULD, WHICH RENDERS THE PLANE'S CONTROLS VIRTUALLY
USELESS. TO HELP FIND WAYS FOR AIRCRAFT TO RECOVER FROM THESE DANGEROUS
SPINS, RESEARCHERS TEST SMALL-SCALE MODELS IN THE SPIN TUNNEL. THE IDEA
BEHIND THE SPIN TUNNEL IS SIMPLE. A LARGE FAN PULLS A COLUMN OF AIR UP
THROUGH THE MIDDLE OF THE TUNNEL. THEN A RESEARCHER LAUNCHES AN AIRPLANE
MODEL
DIRECTLY INTO THE AIRFLOW BY HAND. AS THE MODEL SPINS DOWNWARD, THE OPERATOR
INCREASES WIND SPEEDS UNTIL THE MODEL'S FALL IS JUST BALANCED BY THE UPRUSHING
AIR. THEN THE CONTROL SURFACES OF THE MODEL ARE SYSTEMATICALLY ACTIVATED
ELECTROMAGNETICALLY TO FIND OUT WHICH ONES ALLOW THE MODEL TO RECOVER
FROM THE SPIN. THIS SAME BASIC TECHNIQUE THAT WAS USED IN 1941 IS STILL
BEING USED TODAY, BUT RESEARCHERS NOW USE COMPUTERS TO TRACK UNIQUE MARKERS
ON THE BOTTOM OF THE PLANE TO MEASURE THE AIRCRAFT'S SPIN CHARACTERISTICS.
WITH THESE MEASUREMENTS, RESEARCHERS CAN DETERMINE DESIGN MODIFICATIONS
AND PILOT TRAINING PROCEDURES WHICH CAN HELP PULL A PLANE OUT OF A SPIN,
SAVING THE PLANE AND THE PILOT FROM A CATASTROPHIC ACCIDENT. THIS SIMPLE
SYSTEM HAS WORKED ESPECIALLY WELL OVER THE YEARS. DURING WORLD WAR II,
EVERY FIGHTER, LIGHT BOMBER, ATTACK PLANE, AND TRAINER-- OVER 300 DESIGNS
IN ALL-- WERE TESTED IN THE SPIN TUNNEL. SUBSEQUENTLY, OVER HALF OF THESE
AIRCRAFT WERE MODIFIED IN SOME WAY TO ENSURE THAT THEIR CONTROLS WOULD
BE ABLE TO PULL THEM OUT OF A SPIN. TODAY, THE SPIN TUNNEL IS STILL TESTING
MANY DIFFERENT TYPES OF DESIGNS, FROM SMALL GENERAL AVIATION PLANES TO
THE MARS SAMPLE RETURN CAPSULES. SINCE IT OPENED FOR BUSINESS IN 1941,
NEARLY EVERY AMERICAN MILITARY FIGHTER HAS BEEN TESTED IN THIS TUNNEL.
HOWEVER, WITH 10% OF ALL MILITARY AIR ACCIDENTS STILL OCCURRING DUE TO
THE FLAT SPIN, THE NASA LANGLEY 20-FOOT VERTICAL SPIN TUNNEL WILL UNDOUBTEDLY
CONTINUE TO SAVE LIVES FOR MANY YEARS TO COME. BEFORE THE SPIN TUNNEL
WAS BUILT, RESEARCHERS SOMETIMES TESTED AIRCRAFT SPIN CHARACTERISTICS
BY SIMPLY DROPPING AIRPLANE MODELS FROM HIGH BUILDINGS. COMING UP, WE
FIND OUT ABOUT THE NEXT GENERATION OF REUSABLE LAUNCH VEHICLES. BUT FIRST:
DID YOU KNOW THAT LIEUTENANT FRANCIS EVANS BECAME ONE OF THE FIRST AVIATORS
TO DEVELOP AN EFFECTIVE SPIN RECOVERY TECHNIQUE? IN 1917, WHILE ATTEMPTING
TO GET HIS PONTOON PLANE INTO A LOOP, LIEUTENANT EVANS INADVERTENTLY WENT
INTO A SPIN. AS HE MANEUVERED OUT OF THE SPIN, HE REALIZED THAT HE HAD
UNWITTINGLY DISCOVERED AN EFFECTIVE SPIN RECOVERY MANEUVER. HE WAS AWARDED
THE DISTINGUISHED FLYING CROSS NEARLY 20 YEARS LATER FOR HIS LIFE-SAVING
DISCOVERY. REUSABLE LAUNCH VEHICLES LIKE THE SPACE SHUTTLE ARE A VITAL
TYPE OF SPACECRAFT FOR CLOSE-EARTH OPERATIONS. WITH THE INTERNATIONAL
SPACE STATION PROVIDING A PLATFORM FOR UNIQUE SCIENTIFIC EXPERIMENTS,
A RELIABLE MULTIUSE CRAFT LIKE THE SPACE SHUTTLE IS NEEDED. SINCE THE
EARLY '90s, RESEARCHERS AT NASA HAVE BEEN DEVELOPING NEW TYPES OF REUSABLE
LAUNCH VEHICLES WHICH WILL REPLACE THE AGING SPACE SHUTTLE. THESE NEW
SPACECRAFT WILL BE SAFER, LESS EXPENSIVE, AND MUCH MORE DURABLE. STEPHANIE
SY SPOKE WITH CHARLIE COCKRELL AT NASA LANGLEY RESEARCH CENTER TO FIND
OUT WHAT THE FUTURE HOLDS FOR THE NEXT GENERATION OF REUSABLE SPACECRAFT.
THE ABILITY TO TRAVEL INTO SPACE IS STILL A RELATIVELY RECENT EVENT IN
HUMAN HISTORY. TO GET TO SPACE, EARLY ASTRONAUTS TRAVELED IN VERY EXPENSIVE
SPACE CAPSULES WHICH WERE ONLY USED ONCE BEFORE BEING RETIRED. THESE SYSTEMS
WORKED WELL, BUT IT WAS REALIZED THAT A REUSABLE SYSTEM SHOULD BE IMPLEMENTED
OVER THE SINGLE-USE CAPSULE SYSTEM. SO IN THE EARLY 1980s, THE WORLD'S
FIRST AND ONLY REUSABLE LAUNCH VEHICLE, THE SPACE SHUTTLE, CAME INTO SERVICE.
WITH THE SHUTTLE IN SERVICE, SPACE FLIGHT BECAME MUCH MORE ACCESSIBLE
AND LESS EXPENSIVE, WHILE ALSO TRULY EXPANDING TECHNOLOGICAL AND SCIENTIFIC
EXPLORATION. BUT IN A CONTINUED EFFORT TO MAKE SPACE FLIGHT EVEN LESS
EXPENSIVE AND MUCH SAFER FOR ASTRONAUTS, NASA RESEARCHERS HAVE BEEN LOOKING
TOWARD THE NEXT GENERATION OF REUSABLE SPACE LAUNCH VEHICLES. TO HELP
DEVELOP THE NEXT GENERATION OF SPACECRAFT, NASA RESEARCHERS HAVE BEEN
DEVELOPING AND TESTING A LOT OF NEW VEHICLE TECHNOLOGIES. SOME OF THESE
NEW VEHICLES ARE SO REVOLUTIONARY THAT THEY MAY SOON CHANGE THE WAY WE
ALL THINK OF SPACE TRAVEL. I SPOKE WITH CHARLIE COCKRELL AT NASA LANGLEY
RESEARCH CENTER TO HELP EXPLAIN THE NEXT GENERATION OF SPACE VEHICLES.
NASA'S GOAL IS TO MAKE SPACE TRAVEL SAFER, MORE RELIABLE, AND MORE COST-EFFECTIVE.
ONE OF THE GOALS OF THE NEXT-GENERATION LAUNCH TECHNOLOGY PROGRAM IS TO
PROVIDE ROUTINE ACCESS TO THE INTERNATIONAL SPACE STATION, PROVIDE A SAFER
WAY FOR CREW RETURN FROM THE SPACE STATION, AND TO ALSO LOOK AT OTHER
OPPORTUNITIES IN SPACE AND BE ABLE TO DO THAT ON A ROUTINE BASIS. CHARLIE,
HOW ARE THESE NEW SPACECRAFT SO DIFFERENT FROM THE SPACE SHUTTLE WE'RE
USED TO SEEING? OUR VISION IS TO REALLY MOVE TOWARDS SPACECRAFT THAT LOOK
AND OPERATE MORE LIKE CONVENTIONAL AIRCRAFT, SO WE WANT TO DO THINGS LIKE
HAVE LESS TURNAROUND TIME IN BETWEEN MISSIONS. THEY'RE GOING TO BE MORE
RELIABLE TO OPERATE, LESS REPAIRS THAT WILL HAVE TO TAKE PLACE IN BETWEEN
MISSIONS. ONE OF THE CHIEF DIFFERENCES BETWEEN THE SPACE SHUTTLE AND THE
VEHICLES THAT YOU'RE GOING TO SEE IN THE FUTURE IS, WE'RE LOOKING AT MORE
ADVANCED TYPES OF PROPULSION SYSTEMS, SO THEY'RE GOING TO LOOK AND OPERATE
MUCH DIFFERENTLY THAN THE SHUTTLE. SO WHAT ARE SOME OF THE TECHNOLOGIES
YOU'RE USING TO DEVELOP THESE NEW VEHICLES? IN ADDITION TO ADVANCED PROPULSION
SYSTEMS, WE ARE DEVELOPING DIFFERENT VEHICLE TECHNOLOGIES THAT WILL BE
DIRECTLY APPLICABLE TO THE NEXT-GENERATION SET OF LAUNCH VEHICLES. ONE
OF NASA'S MAJOR REQUIREMENTS IS TO DEVELOP NEW TECHNOLOGIES AND VEHICLES
TO TRANSPORT CREWS AND CARGO TO AND FROM THE INTERNATIONAL SPACE STATION.
BECAUSE THE SPACE STATION IS RELATIVELY CLOSE TO EARTH AND NEEDS TO BE
RESUPPLIED FREQUENTLY, THE MOST LOGICAL CHOICE IS A REUSABLE SPACECRAFT.
ONE IDEA UNDER CONSIDERATION IS AN AIR-BREATHING CRAFT RATHER THAN A ROCKET-PROPELLED
SPACECRAFT. TO BREAK EARTH'S GRAVITATIONAL FIELD, A CRAFT NEEDS TO REACH
ABOUT 17,500 MILES PER HOUR. CURRENTLY, THIS IS BEING ACCOMPLISHED THROUGH
THE USE OF A SERIES OF ROCKETS. THESE ROCKETS NOT ONLY CARRY LARGE AMOUNTS
OF FUEL BUT MUST ALSO CARRY LIQUID OXYGEN TO MIX WITH THE FUEL FOR MAXIMUM
THRUST. ALTHOUGH THIS SYSTEM IS EFFECTIVE, IT IS VERY EXPENSIVE AND CAN
BE DANGEROUS. THE BENEFIT OF AN AIR-BREATHING CRAFT IS THAT IT WOULD NOT
NEED TO CARRY ITS OWN OXYGEN. IT WOULD SCOOP OXYGEN FROM THE EARTH'S ATMOSPHERE
INTO A SPECIAL ENGINE CALLED A SCRAMJET. THIS SYSTEM WOULD ALLOW THE CRAFT
TO REACH THE SPEED REQUIRED TO BREAK THE PULL OF THE GRAVITATION FIELD,
SENDING IT INTO SPACE. BECAUSE THE CRAFT IS NOT CARRYING ITS OWN OXYGEN,
THE WEIGHT WILL BE REDUCED BY UP TO 50%. THIS COULD REDUCE SPACE FLIGHT
COSTS BY A FACTOR OF 10, BRINGING CURRENT PAYLOAD COSTS FROM ABOUT $10,000
PER POUND TO ABOUT $1,000 PER POUND. SO IS SCRAMJET TECHNOLOGY THE ONLY
CONCEPT YOU'RE LOOKING AT? NO, WE'RE ACTUALLY STUDYING A WIDE RANGE OF
TECHNOLOGIES THAT INCLUDE DIFFERENT CONFIGURATION SHAPES, DIFFERENT NUMBERS
OF STAGES IN THE VEHICLE, DIFFERENT TYPES OF PROPULSION SYSTEMS. MOST
OF THE LONGER-TERM APPLICATIONS DO USE SCRAMJETS, BUT WE'RE ALSO LOOKING
AT SOMETHING THAT WE WOULD CALL COMBINED CYCLE PROPULSION, WHICH WOULD
ACTUALLY TAKE ELEMENTS OF ROCKET PROPULSION, SCRAMJETS, HIGH-SPEED TURBOJET
ENGINES, AND MAYBE OTHER ADVANCED PROPULSION CYCLES SO THAT WE CAN USE
THE BENEFITS OF THOSE AT DIFFERENT POINTS IN THE FLIGHT. SO WHERE WILL
THIS PROGRAM BE IN THE NEXT 10, 15, 20 YEARS? I THINK WE'RE GONNA BE WELL
ON OUR WAY TO DEVELOPING A NEXT-GENERATION REUSABLE LAUNCH VEHICLE SYSTEM.
WHETHER OR NOT WE WILL ACTUALLY HAVE AN OPERATIONAL SYSTEM IN THE NEXT
10 TO 15 YEARS IS GOING TO BE DEPENDENT ON WHAT THE NATION'S NEEDS ARE
AND HOW WE ADDRESS THAT AS AN OVERALL STRATEGY. BUT WE ARE DEVELOPING
TECHNOLOGIES THAT CAN NOT ONLY BE INCLUDED IN A VEHICLE THAT WOULD BE
DEVELOPED IN, SAY, THE NEXT 10 TO 15 YEARS, BUT WE'RE ALSO DEVELOPING
A LOT MORE ADVANCED TECHNOLOGIES THAT WOULD BE GOOD FOR VEHICLES THAT
ARE GONNA BE DEVELOPED IN, SAY, THE NEXT 20 TO 30 YEARS. AND WE'RE DOING
ALL OF THAT BY UTILIZING ALL OF THE UNIQUE CAPABILITIES THAT WE HAVE AT
OUR NASA FIELD CENTERS ACROSS THE COUNTRY. ONE OF THE MOST USEFUL DEVELOPMENTS
FOR PROFESSIONAL PILOTS, DRIVERS, AND SEAMEN IN RECENT YEARS HAS BEEN
THE G.P.S. RECEIVER. THESE RECEIVERS ARE ALSO BEING USED BY HIKERS, GOLFERS,
AND FISHERMEN FOR RECREATIONAL PURPOSES. HOWEVER, MANY PEOPLE WHO USE
THIS TECHNOLOGY STILL DON'T KNOW EXACTLY HOW IT WORKS. OUR OWN JOHNNY
ALONSO FINDS OUT HOW THIS COMPLEX SYSTEM HELPS KEEP MANY OF US ON TRACK
AND ON SCHEDULE. TRYING TO FIGURE OUT WHERE YOU ARE AND WHERE YOU'RE GOING
HAS ALWAYS BEEN A CHALLENGE. NAVIGATION AND POSITIONING ARE CRUCIAL TO
SO MANY ACTIVITIES, AND YET THE PROCESS HAS NOT ALWAYS BEEN EASY. THANKFULLY,
THE DAYS OF NAVIGATING BY CELESTIAL MEANS OR LANDMARKS ARE LONG GONE SINCE
THE INTRODUCTION OF G.P.S., OR THE GLOBAL POSITIONING SYSTEM. SO WHAT
IS G.P.S.? FOR SOME ANSWERS, I SPOKE WITH DR. KEVIN DUTTON AT NASA LANGLEY
TO FIND OUT HOW IT WORKS. G.P.S. STANDS FOR THE GLOBAL POSITIONING SYSTEM,
AND LIKE THE NAME SUGGESTS, IT'S A SYSTEM TO FIND YOUR LOCATION ANYWHERE
ON THE EARTH OR NEAR THE EARTH'S SURFACE. AND THE WAY IT DOES THAT IS
BY USING RADIO FREQUENCY BROADCASTS FROM ORBITING SATELLITES. CAN YOU
TELL ME WHY G.P.S. WAS ORIGINALLY DEVELOPED? IT WAS DEVELOPED BY THE DEFENSE
DEPARTMENT TO MEET ALL OF THEIR NAVIGATIONAL NEEDS, FOR EXAMPLE, AIRCRAFT
AND SHIPS AT SEA. AND NOW, EVEN INDIVIDUAL SOLDIERS CARRY LITTLE RECEIVERS
LIKE THIS IN THE FIELD TO FIND OUT WHERE THEY ARE. THE GLOBAL POSITIONING
SYSTEM CONSISTS OF A CONSTELLATION OF 24 SATELLITES AND THEIR GROUND STATIONS
WORKING TOGETHER. G.P.S. USES THESE MAN-MADE STARS AS REFERENCE POINTS
TO CALCULATE POSITIONS ACCURATE TO A MATTER OF METERS AND IN SOME CASES,
CENTIMETERS. AS LONG AS YOU HAVE A G.P.S. RECEIVER AND A CLEAR VIEW OF
THE SKY AND A MAP, YOU'LL NEVER BE LOST AGAIN. TODAY, G.P.S. IS FINDING
ITS WAY INTO CARS, BOATS, PLANES, CONSTRUCTION EQUIPMENT, FARM MACHINERY,
EVEN LAPTOP COMPUTERS. SO HOW DOES THE SYSTEM WORK? LET'S SAY YOU'RE BACKPACKING,
AND YOU HAVE A RECEIVER WITH YOU. YOU'RE GONNA TURN ON THAT RECEIVER.
NOW, THE G.P.S. SATELLITES ARE CONSTANTLY BROADCASTING A SIGNAL, ALL 24
OF THEM, BUT ABOVE YOU AT ANY ONE TIME, THERE'S ONLY 12 AVAILABLE, AND
THEN THE OTHER 12 ARE ON THE OTHER SIDE OF THE EARTH. SO YOUR RECEIVER
IS GOING TO LISTEN AND TRY TO FIND AT LEAST FOUR OF THESE SATELLITES DIRECTLY
ABOVE YOU, AND THEN IT'S GOING TO DETERMINE A RANGE TO EACH SATELLITE,
AND IT'S GOING TO USE THOSE RANGES AND THE KNOWN LOCATIONS OF THE SATELLITES,
AND IT'S GOING TO DO SOME MATHEMATICAL CALCULATIONS AND A PROCESS CALLED
TRILATERATION, AND IT'S GOING TO FIGURE OUT WHERE THAT G.P.S. RECEIVER
IS. THAT'LL ALSO GIVE YOU ALTITUDE, AND IT'LL GIVE YOU SPEED AND THE DIRECTION
THAT YOU'RE TRAVELING. A STANDARD G.P.S. RECEIVER WILL NOT ONLY PLACE
YOU ON A MAP AT ANY PARTICULAR LOCATION BUT WILL ALSO TRACE YOUR PATH
ACROSS A MAP AS YOU MOVE. IF YOU LEAVE YOUR RECEIVER ON, IT CAN STAY IN
CONSTANT COMMUNICATION WITH G.P.S. SATELLITES TO SEE HOW YOUR LOCATION
IS CHANGING. WITH THIS INFORMATION AND ITS BUILT-IN CLOCK, THE RECEIVER
CAN GIVE YOU SEVERAL PIECES OF VALUABLE INFORMATION, LIKE: ALSO THE ESTIMATED
TIME OF ARRIVAL AT YOUR DESTINATION IF YOU MAINTAIN YOUR CURRENT SPEED.
THERE'S A LOT OF USES THAT THEY HADN'T REALLY THOUGHT ABOUT WHEN THEY
DEVELOPED THIS SYSTEM. FOR EXAMPLE, LATER ON, IT WAS DISCOVERED THAT IF
YOU PUT MULTIPLE ANTENNAS ON A VEHICLE, LIKE AN AIRCRAFT, FOR INSTANCE,
YOU COULD ACTUALLY GET ATTITUDE. YOU COULD FIGURE OUT ITS ORIENTATION
AND WHETHER IT WAS ROLLING OR PITCHING OR YAWING. OTHER THINGS THAT THEY
DIDN'T REALIZE IT COULD REALLY DO WERE, FOR INSTANCE: SEISMOLOGISTS USE
IT FOR EARTHQUAKE DETECTION AND TO FIND OUT WHEN TECTONIC PLATES ARE ACTUALLY
SHIFTING APART. IT'S THAT GOOD. IT'S SOMETHING ELSE. YEAH, VERY INTERESTING.
SURE. SO THAT'S HOW IT WORKS. SO THE NEXT TIME YOU WANT TO KNOW WHERE
YOU ARE OR WHERE YOU'RE GOING, DON'T REACH FOR A MAP. REACH FOR YOUR G.P.S.
NOW, WHICH BUTTON IS IT HERE TO PRESS FOR A DATE FOR TONIGHT'S GATHERING
AT THE... THAT'S ALL FOR THIS EDITION OF DESTINATION TOMORROW. THANK YOU
FOR JOINING US. I'M STEELE McGONEGAL. AND I'M KERA O'BRYON. FOR ALL OF
US HERE AT NASA, WE'LL SEE YOU NEXT TIME. Captioning provided by N.E.C.
Foundation of America. Captioning by CaptionMax www.captionmax.com T-minus
ten, nine, eight. The clock is operating. Tranquility Base here. Endeavour,
go at throttle-up. IF IT'S CUTTING-EDGE TECHNOLOGY, MEDICAL BREAKTHROUGHS,
OR ADVANCED AERODYNAMIC RESEARCH, NASA'S DESTINATION TOMORROW WILL BRING
IT TO YOU FIRST. NASA'S DESTINATION TOMORROW, A SIGNATURE BROADCAST FOR
NASA LANGLEY RESEARCH CENTER FOR DISTANCE LEARNING, IS PIONEERING A NEW
APPROACH TO EDUCATIONAL PROGRAMMING. EACH EXCITING PROGRAM PRESENTS THE
HIGHEST-QUALITY REPORTING, INVESTIGATIVE FEATURES, OR, STEP BACK IN TIME
AND RELIVE NASA'S PAST ACHIEVEMENTS, WITH RETROSPECTIVE. VIEWERS LOOK
BEHIND THE SCENES TO INVESTIGATE HOW TOMORROW'S TECHNOLOGY IS BEING DEVELOPED
TODAY. THE PROGRAM BRINGS AMERICANS IN-DEPTH COVERAGE OF NEW AND PAST
ADVANCEMENTS IN AERODYNAMICS, ACHIEVEMENTS IN SPACE, AND MEDICAL BREAKTHROUGHS
THAT ARE TAKING PLACE RIGHT HERE ON EARTH. WATCH NASA'S DESTINATION TOMORROW
AND BRING THE FUTURE INTO FOCUS.
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