>> THIS IS THE CDR
AT, UH, 14.090.
SUBJECT IS M4-- 479 OPERATION,
FLAMMABILITY.
UH, SAMPLE NUMBER TWO
HAS BEEN, UH, INSERTED
INTO THE, UH, UH, FURNACE.
>> FLAMMABILITY IN ZERO-G
WITH NO CONVECTION WAS TESTED
AND PHOTOGRAPHED DURING
THE MISSION OF SKYLAB 4.
37 TESTS WERE COMPLETED
ON MISSION DAYS 81 AND 82.
IN PERFORMING THE EXPERIMENT,
COMMANDER JERRY CARR NOTED
AND PHOTOGRAPHED FOUR EVENTS.
FIRST, THE EXTENT OF SURFACE
FLAME PROPAGATION AND FLASH OVER
TO ADJACENT MATERIALS.
SECOND, THE RATES OF SURFACE
AND BOLD FLAME PROPAGATION.
THIRD, SELF EXTINGUISHMENT.
AND FOURTH, EXTINGUISHMENT
BY VACUUM.
SIMILAR EXPERIMENTS ACTUALLY
BEGAN OVER 10 YEARS AGO
USING A 10 INCH CHAMBER
AND A BUILT IN CAMERA.
ZERO-G WAS CREATED IN AIRCRAFT.
TEST TIMES VARIED
FROM FOUR TO TEN SECONDS.
HOWEVER, EACH TEST ENDED
ERRATICALLY DUE TO
THE JARRING RETURN TO 1G.
IN THE SKYLAB TESTS,
SIX TYPES OF MATERIALS
WERE TESTED.
EACH PIECE OF TEST MATERIAL
WAS MOUNTED WITH
A NICHROME HEATER WIRE
AND AN ELECTRIC SOCKET
TO SUPPORT THE MATERIAL
IN THE PROPER ORIENTATION.
THE HARDWARE, DESIGNED
AND BUILT BY
THE MARSHALL SPACE FLIGHT CENTER
CONSISTED OF THE IGNITION
CHAMBER, A BUILT-IN CAMERA,
INSTRUMENTATION,
STORAGE CABINETS,
AND VACUUM VENT LINE.
COMMANDER CARR DISPLAYS
THE SPECIMEN USED IN
TEST NUMBER TWO, A PIECE
OF SHEET NYLON, 1-INCH BY 1-INCH
BY 1/8TH INCH THICK.
HE INSTALLS THE SPECIMEN
IN THE CHAMBER.
THE COVER IS UP AND
AN INTERIOR WORK LIGHT IS ON.
ELECTRONIC CONTROLS
ARE TO THE RIGHT.
NEXT, COMMANDER CARR EXPLAINS
THE IGNITION TESTS
FOR POLYURETHANE AND PAPER.
>> WHAT I HAVE HERE IS
A, UH, PIECE OF, UH,
POLYURETHANE SPONGE,
OR POLYURETHANE FOAM, WHICH, UH,
I'VE DONE A FEW EXPERIMENTS ON
AND I FOUND THAT IT REALLY DOES,
UH, BURN QUITE BRIGHTLY.
SO I WANTED TO SHOW IT TO YOU
FOR A MINUTE HERE.
UH, IT HAS A LITTLE COIL HERE
ON THE END, IT'S THE LITTLE
WIRES THAT COME DOWN.
WHAT WE DO IS WE PUT
AN ELECTRICAL CURRENT
ACROSS THESE WIRES,
AND, UH, ESSENTIALLY IGNITE
THIS POLYURETHANE FOAM
WHILE IT'S IN, UH, SIDE
OF A LITTLE FURNACE.
WE HAVE A WINDOW,
AND SO WHEN I PUT THIS IN
AND GET READY TO IGNITE IT,
I'M GONNA SET THE TELEVISION
CAMERA UP AND, UH, ALLOW YOU
TO LOOK IN THE WINDOW AND SEE
WITH ME WHAT HAPPENS WHEN
THIS POLYURETHANE FOAM IGNITES.
I HAVE THE TELEVISION, UH,
CAMERA LOOKING INTO THE WINDOW
OF THE, UH, OF THE, UH,
PRESSURE WORKING CHAMBER.
I'M NOW GOING TO, UH, THROW
THE SWITCH ON THE PANEL WHICH
PUTS US IN THE READY POSITION
AND KILLS THE FLOODLIGHT INSIDE
THE, UH, THE WORK CHAMBER.
NOW WHEN I, UH...
THROW THE, UH, THE DATA START
SWITCH, YOU'RE GOING TO SEE
AN IGNITER START,
AND THEN YOU'RE GOING TO SEE
THE, UH, THE, UH,
POLYURETHANE FOAM FLARE UP.
AND AFTER IT BURNS ONE-THIRD,
I'M GOING TO OPEN UP
THE VACUUM VALVE, WHICH WILL,
UH, EXTINGUISH THE FLAME.
ALL RIGHT, HERE WE GO.
NOW, CAMERAS ARE RUNNING.
YOU SEE THE GLOW AND THE FLASH.
THERE, IT'S ABOUT A THIRD GONE.
YOU NOTICE HOW IT
FLARES UP AND GLOWS?
AS I DUMP IT, NOW IT'S OUT.
FANTASTIC.
NOW I JUST DON'T KNOW
IF YOU WERE ABLE TO SEE
ALL THAT OR NOT.
UH, THE TELEVISION CAMERA
HAS AN AUTOMATIC LIGHT CONTROL
IN IT, WHICH, UH, SETS
THE, UH, THE, UH, F-STOP IN IT
WHEN THE LIGHTS CHANGE.
IT MAY HAVE BEEN THE CHANGES
WERE TOO FAST, BUT I THOUGHT
I WOULD LEAD-LEAD THE EXPERIMENT
AND SEE IF WE COULD SEE THIS
ON TELEVISION.
>> NEXT, COMMANDER CARR WOULD
IGNITE BLEACHED CELLULOSE PAPER
AND TELL US ABOUT IT.
>> I'M GOING TO DO THE SAME
THING AS WE DID WITH
THE, UH, POLYURETHANE FOAM,
THAT IS WE'LL START THE--
GET IT IGNITED.
AND THEN, UH,
ONCE IT'S IGNITED,
WE WILL, UH, LET IT BURN
ABOUT ONE-THIRD, AND THEN, UH,
EVACUATE THE CHAMBER
AND SEE HOW IT QUENCHES
THE FIRE.
OKAY, WE'RE AT THE READY NOW.
HERE WE GO. STANDBY.
IGNITION.
YOU SEE THE GLOW, THE SMOKE,
LITTLE FLARE.
OKAY, YOU NOTICE THERE
THE ORANGE FLAME DIES OUT
AND JUST BECOMES SORT OF
A BLUE GLOW THAT EXTENDS
ALL THE WAY DOWN
THE WIDTH OF THE PAPER.
I CAN SEE THAT YOU'RE HAVING
DIFFICULTY SEEING IT.
ALL RIGHT, WE ARE NOW ONE-THIRD
OF THE WAY DOWN THE PAPER
GOING TO QUENCH NOW.
VERY BRIGHT BLUE.
NOW IT'S OUT.
>> THE PICTURES YOU WILL NOW
BE SEEING WERE TAKEN BY
THE BUILT-IN 16 mm FILM CAMERA.
THIS IS THE NEOPRENE COATED
NYLON TEST, WHICH YOU JUST SAW
THROUGH THE CHAMBER WINDOW.
THIS MATERIAL IGNITES EASILY
AND BURNS VIGOROUSLY.
AS IT IS HEATED,
IT CAUSES THE NYLON TO SHRINK,
WHICH IN TURN,
MAKES THE MATERIAL TEAR LOOSE
AND ROLL-UP.
THE FIRE GOES OUT
AS THE BURNING PORTION
IS COVERED BY
THE ROLLED PORTION.
NEXT, THE POLYURETHANE BURNS,
THEN THE DUMPING FLARE,
AND THE FRAME METAL HEATS UP.
THEN THE POST BURN CONDITION.
THIS IS A STILL SHOT
OF POLYURETHANE TEST
NUMBER 16.
NOTE THE 6 cm FLAME
EXTENDING AN INCH AND A QUARTER
FROM THE BURNING MATERIAL.
THE COMPANION STILL PICTURE
SHOWS THE POST-BURN CONDITION.
BUT THE FUSION IS SO VERY SLIGHT
THAT SMOKE PARTICLES
TELL US EXACTLY
WHERE THE FLAME WAS.
ANOTHER POLYURETHANE TEST,
NUMBER 10, IGNITES
AND BURNS UNDISTURBED.
RATHER THAN BEING
SELF-EXTINGUISHED
BY BLANKETING SMOKE PRODUCTS,
THE AGITATED MOLTEN
POLYURETHANE CAUSES
AN AIR DISTURBANCE
THAT ALLOWS OXYGEN
TO ENTER THE FLAME ZONE.
A VERY SMALL RESIDUE
OF MATERIAL IS NOTED
ON THE LEFT SIDE
OF THE SUPPORT FRAME.
THE NEXT POLYURETHANE TEST,
NUMBER 22,
HAS A SIMILAR EFFECT,
EXCEPT THAT WATER
IS DIRECTED TOWARD THE SPECIMEN
TO EVALUATE EXTINGUISHMENT.
HOWEVER A SYSTEM FAILURE
CAUSES LOW WATER PRESSURE
AND THE WATER MISSES THE FOAM.
THIS LAST POLYURETHANE TEST,
NUMBER 28, SHOWS A PARTIALLY
SUPPORTED SPECIMEN
REMAINING IN CONTACT
WITH THE FRAME AND IGNITER.
IT BURNS TO COMPLETION
WITH THE SAME
VIGOROUS AGITATION
OF THE MOLTEN BOILING FUEL.
AND NOW THE PAPER TEST,
NUMBER 17.
WE SEE IGNITION
WITH CONSIDERABLE LIGHT
AT THE IGNITER WIRE,
BUT AT ABOUT THE SAME TIME,
THE POWER IS CUT OFF.
THE FLAME DISAPPEARS
AFTER ABOUT THREE SECONDS.
THE METAL HEATS UP
WITH A SOFT RED COLORATION
AT THE TOP INDICATING
A FLAME TEMPERATURE
OF AT LEAST
650 DEGREES CELSIUS.
THEN AS THE AIR
IS DUMPED OVERBOARD,
THE FLAME INTENSIFIES.
IN TEST NUMBER 23,
ANOTHER PAPER SPECIMEN
IGNITES READILY
AND BURNS BRIEFLY.
WATER IS DIRECTED
OUT THE NOZZLE.
WHILE THE FIRE DID GO OUT,
IT IS NOT KNOWN AT THIS TIME
TO WHAT EXTENT THE WATER
CONTRIBUTED TO EXTINGUISHMENT.
THIS IS TEFLON FABRIC.
IN TEST NUMBER 18,
IT BURNS WHERE IT TOUCHES
THE HOT IGNITION WIRE,
BUT AS THE WIRE COOLS DOWN,
THE MATERIAL CANNOT SUPPORT
COMBUSTION IN THE 65% OXYGEN
ATMOSPHERE, AND SO IT GOES OUT.
SINCE THE IGNITER WIRE
IS NOT DAMAGED,
COMMANDER CARR RE-ACTIVATES
THE SYSTEM BUT IGNITION
DOES NOT OCCUR.
THIS IS TEST NUMBER 30,
INVOLVING TEFLON THAT IS ONLY
PARTIALLY SUPPORTED.
THIS IS WITH A HOLDER
THAT DOES NOT COVER
THE WHOLE SPECIMEN.
THE TEFLON IGNITES
AND IS FREE TO MOVE.
AS THE MATERIAL IS HEATED,
IT SHRINKS TOWARD THE SOURCE
OF HEAT.
THIS KEEPS THE FIRE GOING
AWHILE LONGER
THAN WAS THE CASE
IN THE PRECEDING TEFLON TEST,
BUT IT STILL
IS SELF-EXTINGUISHED.
NEXT, WE SEE ALUMINIZED MYLAR
IN TEST NUMBER ONE.
IT BURNS AT NEARLY
FOUR INCHES PER SECOND,
WITH A VERY BRIGHT FLAME
INDICATING THE ALUMINUM
IS BURNING ALONG
WITH THE MYLAR ITSELF.
THE MATERIAL IS VERY THIN,
ABOUT A THIRD OF A MIL
IN THICKNESS.
THE METAL IS ONLY
A FLASH-COATED VAPOR DEPOSITED
ALUMINUM, APPARENTLY
THIS MATERIAL IS IGNITED
AND BURNS IN ZERO G,
AT ABOUT THE SAME RATE
AS IT DOES IN 1G.
IN 1G,
THE BURNING IS SO FAST
THAT CONVECTIVE FORCES
CAN'T CONTRIBUTE ANYTHING.
SO WE HAVE THE SAME RAPID
BURNING IN ZERO G
AS IN 1G.
IN THE POST BURN CONDITION,
NOTE THE SMOKE DEBRIS
THAT DRIFTS OUT
AS THE VENT IS OPEN.
IN THIS ALUMINIZED MYLAR TEST,
NUMBER 13, WE NOTE
THE SAME RAPID FLAME RATE,
ALTHOUGH THE MATERIAL
DOES NOT BURN COMPLETELY.
THIS NEXT TEST, NUMBER 19,
BURNS ONLY A SHORT DISTANCE.
THE BURN IS SHORT-LIVED
AND INCOMPLETE.
AN ATTEMPT TO EXTINGUISH
WITH WATER WAS UNSUCCESSFUL.
THIS FINAL ALUMINIZED
MYLAR TEST, NUMBER 25,
INCORPORATES A SPECIMEN
HOLDING FRAME THAT DOES NOT
EXTEND THE FULL DISTANCE
OF THE MATERIAL.
IT WAS ANTICIPATED
THAT THE MATERIAL
MIGHT BECOME SEPARATED
AND DRIFT AWAY WHILE BURNING.
HOWEVER, IT DID NOT SEPARATE
IN THIS TEST.
NEXT, IS TEST NUMBER TWO,
USING NYLON MATERIAL,
WHICH COMMANDER CARR SHOWED US
EARLIER AS EXHIBITING
ONLY MINIMAL HEAT DAMAGE.
WIRES HEAT UP BUT THE NYLON
DOES NOT IGNITE.
THEN, A FINAL TRY,
STILL WITH NO FLAME NOTED.
PERHAPS THERE'S TOO MUCH
MATERIAL AROUND IT
THAT ACTS AS A HEAT SYNC.
THE NYLON TEST YOU ARE ABOUT
TO SEE WAS ONE OF THE MORE
INTERESTING TESTS.
THIS NYLON USES
THE IDENTICAL IGNITER
AS THE PREVIOUS NYLON TEST,
BUT IT HAS A DIFFERENT GEOMETRY.
THE IGNITER IS ACTIVATED
BUT IT DOES NOT PRODUCE
A FLAME.
HE ACTIVATES THE IGNITER
A SECOND TIME.
AND THIS TIME, WE SEE FIRE
AT THE TOP AND THE BOTTOM
WHERE THE SPECIMEN IS IN CONTACT
WITH THE IGNITER WIRE.
WE HAVE LESS MATERIAL
IN CONTACT WITH THE IGNITER,
APPARENTLY ALLOWING THE AIR
TO GET TO THE MATERIAL
AND KEEP IT BURNING.
THERE ARE TWO FLAMES
THAT ARE VERY, VERY SMALL,
CONSIDERING THE FACT
THAT THE MATERIAL IS ONLY
ONE INCH BY ONE INCH.
NOW THE FLAME AT THE BOTTOM
IS MORE ACTIVE
AND SOMEWHAT LARGER.
IT'S PULSING VERY RAPIDLY,
PERHAPS DUE TO MELTING NYLON,
WHICH IS BEGINNING TO BOIL
AND ISSUE FLAMMABLE GASES.
THE FLAME AT THE TOP
HAS DISAPPEARED
AND THE COLORATION
OF THE CERAMIC INSULATOR
HAS FADED.
THE OTHER INSULATOR, WHICH IS
IN CONTACT WITH THE FLAME
SEEMS TO BE HOLDING ITS HEAT
AS IT GLOWS
WITH AN ORANGE COLOR.
THE FLAME NOW HAS BURNED
FOR ABOUT 30 SECONDS,
AND EXTENDS FOR A QUARTER INCH.
THE TOP FLAME IS BEGINNING
TO APPEAR WITH ERRATIC FLASHES,
WHICH ARE LESS RAPID
THAN THE ONES AT THE BOTTOM.
FOR AWHILE,
THEY ARE MORE PRONOUNCED.
AND NOW THEY SEEM TO BE
PRACTICALLY INVISIBLE.
THIS IS AN INTERESTING TEST
BECAUSE WE ANTICIPATED
THAT THE MATERIAL
WOULD BE SELF-EXTINGUISHING
WITH THE GASEOUS PRODUCTS
OF COMBUSTION BLANKETING
THE OXYGEN FROM THE SYSTEM.
BUT INSTEAD OF PERFORMING
THAT WAY, THIS TEST BURNED
FOR 10 MINUTES, 43 SECONDS,
AT WHICH TIME, IT WAS PUT OUT
DELIBERATELY BY DUMPING
THE ATMOSPHERE OVERBOARD.
THIS IS JUST PRIOR TO DUMP.
THE FLAMES ARE COMING OUT
MORE RAPIDLY AND MUCH LARGER.
THEY EXTEND OUT OVER AN INCH,
AND THERE ARE VERY SHORT-LIVED
FLASHES OF LIGHT.
NOW AT VENTING,
THE INTENSIFICATION
IS QUITE SIGNIFICANT.
WE GOT ALMOST A WHITE-OUT
OF THE SCREEN BECAUSE
OF THE INCREASED BURNING.
NOW AS THE PRESSURE DROPS,
WE SEE A LESS DRAMATIC BURNING.
IT STILL HAS LARGE FLASHES
OF FLAME WHEN IT FLASHES,
BUT IT'S ONLY ABOUT
ONE PER SECOND AT THE MOMENT.
IT'S NOT POSSIBLE TO RECORD
THE PRESSURE AT WHICH IT DOES
GO OUT COMPLETELY,
BUT FROM SOME SIMILAR TESTS
ON EARTH,
WE KNOW THAT'S IT'S ABOUT
ONE-ONE HUNDREDTH
OF AN ATMOSPHERE PRESSURE
WHEN THE MATERIAL
STOPS BURNING.
THE 37 TESTS
CONDUCTED IN SKYLAB
HAVE RESULTED IN
THE FOLLOWING CONCLUSIONS:
IGNITION IN ZERO GRAVITY
APPEARS TO BE IDENTICAL
IN HEAT AND TIME
TO IGNITION IN 1G.
BURNING RATES GENERALLY
ARE SLOWER IN ZERO GRAVITY.
EXTINGUISHMENT BY VACUUM
IS EFFECTIVE, HOWEVER THE FLAME
INTENSIFICATION CAUSED BY
THE INITIAL AIRFLOW
IS A SIGNIFICANT SIDE EFFECT
THAT MUST BE CONSIDERED.
EXTINGUISHMENT BY WATER
APPARENTLY IS POSSIBLE
WITH ADEQUATE EQUIPMENT.
THE 37 TESTS WERE SUCCESSFUL
IN INCREASING OUR KNOWLEDGE
OF IGNITION, PROPAGATION
AND EXTINGUISHMENT
IN ZERO GRAVITY.