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hello and welcome to future path I'm

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amreeka forsteri director of external

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affairs at the NASA Lewis Research

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Center in Cleveland Ohio in NASA's goal

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is to try to fly higher further and

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faster new materials and structures are

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required to meet these goals in today's

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segment we're going to look at some of

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the things being done in our structures

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division structures for flight

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propulsion I think you'll find it

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interesting let's watch flight in the

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air or in space requires propulsion

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systems able to withstand extremes of

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mechanical stress vibration and

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temperatures designing these structures

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and matching available materials to the

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job has always been a complicated

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business and is becoming more so

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requiring safety and reliability from

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structures needing minimum maintenance

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having the least possible weight poses a

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basic contradiction which can be

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resolved only by the most sophisticated

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analytic methods the Lewis research

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structures division is dedicated to

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advancing the state of the art of

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structures technology or aeronautical

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space and terrestrial applications the

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principal product of the division is the

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development of validated analytic

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methods to predict the behavior of

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structural components and systems or

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aerospace propulsion and power machinery

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division provides not only solutions to

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problems encountered in current

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applications but also leadership in

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setting new directions for structures

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engineering to solve tomorrow's problems

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today the purpose of the structures

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division at Lewis research center is to

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develop advanced credible design tools

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these tools can then be used by

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designers

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to design advanced concepts for future

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missions both in aeronautics and in

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space we develop these methods for use

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on high-speed computers and they are

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validated with the state-of-the-art

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laboratory equipment we can predict the

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life that is the number of missions that

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can be flown by the advanced concept and

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we can optimize the design both from the

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point of view of minimum weight or from

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breakthroughs in flight usually follow

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developments in propulsion systems in

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the early days of flight structures

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design was a combination of art and

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trial and error if you are developing a

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rocket you built an engine derived from

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earlier designs to be sure it didn't

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fail you made it sturdier heavy as

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technology advanced lighter stronger

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materials and improve manufacturing

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methods made the impossible possible but

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mistakes were still made and the results

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were spectacular and costly failures the

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job of the structures division is to

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make sure such accidents will no longer

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occur they do this by applying the

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latest scientific analysis possible and

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by using the most up-to-date testing

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equipment and methods available to do

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this the staff of scientists engineers

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and technicians of the division perform

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work in structural mechanics structural

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dynamics fatigue fracture and on

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projects and applications some of the

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work in structural mechanics includes

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characterizing the properties of metals

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used in propulsion systems by subjecting

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specimens to stress and varying

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temperatures researchers can predict

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maximum loading and operating

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temperatures and testing is performed at

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very high temperatures on materials that

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will be used at places like the leading

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edge of the National aerospace plane

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the work in structural dynamics focuses

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on the forces affecting bodies in motion

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when the turbine in a jet engine loses a

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blade or even during a very hard landing

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the vibrations that occur can cause a

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propulsion system to fail tests in

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dynamics can simulate a blade boss

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condition to provide test data to

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compare with simulation models any

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rotating machine will tend to vibrate at

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certain critical speeds and since modern

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rotating equipment is required to

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operate at ever higher speeds this

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problem is increasingly important

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research in the division is developing

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methods for both active feedback and

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passive suppression to permit operation

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of equipment above critical speeds and

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to reduce bearing wear high-speed

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computer simulation is required for the

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full dynamic analysis of rotating

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machinery parallel computing developed

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in the division is making this possible

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by combining a large number of

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processors in one transfuser

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computations can be performed rapidly

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enough to study high speed vibrations of

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you

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studies in fatigue and fracture analysis

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are performed in many of the structures

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divisions labs both destructive and

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non-destructive methods are used to

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evaluate and characterize new materials

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and sometimes a combination of both are

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used to improve the analytical process

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much of this work is directed toward

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characterizing and understanding

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advanced material systems as an example

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researchers in the division sonic map a

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ceramic disc and send the data to a

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computer the computer outputs a color

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simulation showing variations in density

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defining areas where fractures should

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occur later the disc is placed in a

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hydrostatic chamber and fractured the

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actual fracture disk is then compared to

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the computer model for verification

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division researchers also test advanced

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fiber reinforced composite materials

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under varied loads expected in aerospace

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applications data collected from these

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tests are used to verify mathematical

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models which describe the material

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behavior these models are then

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incorporated into NASA computer codes

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used to predict the performance of

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composite structures in a variety of

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applications beyond solving the problems

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which can lead to failures the division

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provides leadership in developing new

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concepts and integrating information

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from many sources for application in

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areas ranging from windmills to the

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Space Shuttle main engines from

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fuel-efficient propellers to computer

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codes for production design and

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propulsion systems simulations the work

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of the division provides verified

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mathematical models and computer codes

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that are key elements of today's

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computer based design analyses for

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flight propulsion systems as well as

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many other systems with similar problems

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using the products of the structures

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division designers can better predict

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the life of a component by constructing

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it on the computer thereby saving time

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and material while

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venting costly failure future aerospace

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systems will require advanced capability

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on board computation and real-time

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sensors will combine to make it possible

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to monitor the health of advanced

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systems active elements could be

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included to make it possible to suppress

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dynamic instabilities structural

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tailoring to account for local stresses

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and local hot spots may be the only way

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to take advantage of the new lightweight

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high temperature yet very brittle

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materials computational simulation will

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allow designers to make rapid affordable

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and feasible designs probabilistic

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methods will allow designers to quantify

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risk and make trade-offs between

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performance and life combination these

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capabilities will allow those designers

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to operate and design closer to the

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limits such capability will allow us to

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build systems that we couldn't build

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before to carry out missions that

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conceivably couldn't be carried out with

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the development of these capabilities

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the structures division hopes to play a

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major part in bringing them about a

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special combination of experienced

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in-house staff and facilities in the

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Lewis research structures division has

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been tailored to meet the challenges and

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needs of a new age of spaceflight and

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aviation the work of the division

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continues to evolve technology and will

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take us into the next generations of

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flight our second segment is about a

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process developed at Lewis that we're

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very proud of an engineer in our

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materials division developed a process

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called arc sprayed mono tape let's find

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unfazed by extreme fire not temperatures

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possessing amazing strength a strength

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beyond belief its creation one of

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outstanding engineering achievement the

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new the ultra advanced composite

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materials being developed by NASA Lewis

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Research Center in Cleveland Ohio to

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understand this fascinating field we

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must start with basics and determine

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exactly what is a composite material

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possibly the easiest way to visualize a

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composite material is to offer the

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example of a tennis racquet the arm and

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frame part of the rocket is made by

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combining two distinct materials

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graphite fibers which give it strength

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and a low-temperature glue or binder

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which hold the fibers together that

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allows it to be fashioned into shape

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this is a composite material to

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different parts each with a different

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function research in this area began

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about 25 years ago when minut whiskers

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were discovered growing on electrical

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devices the whiskers were found to be

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single grain crystals that when tested

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proved to be very strong in later

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research work the whiskers were used in

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the making of bulk materials today

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instead of whiskers fibers like silicon

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carbide tungsten and graphite are used

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with a glue or binder to make such

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things as engineering and sports

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products there are some products though

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that need to be able to withstand higher

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temperatures

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at the same time it's also necessary

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that they be lightweight and stiff which

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incidentally are very important

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requirements for just about anything

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intended for use in space to meet the

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more demanding requirements a glue or

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binders such as aluminum or titanium may

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be used for other products that need to

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be heat-resistant at even higher

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temperatures a nickel or iron base alloy

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is combined with even certain carbide

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fibers or tungsten fibers there are

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several ways to do this and one of them

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is the arc spray process this method was

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developed right here at NASA but one of

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our engineers Leonard Westfall he works

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in the advanced metallic branch of

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NASA's materials division recently mr.

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Westfall described exactly how the arc

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process works the process works like

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this we have an arc spray gun which is

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attached to a large vacuum chamber

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inside the vacuum chamber is a drum that

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has our real strong fibers found on the

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surface at a very regular spacing the

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arc spray gun works by having two metal

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wires coming into the gun an electric

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arc is struck between the tips of the

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wires the electric arc is sufficient

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intensity to cause the water tips to

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melt I pressure stream of neutral gas

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and will usually use our gun very clean

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argon is sprayed on this molten on the

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mold and wire tips causing the molten

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metal to dislodge from the from the

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wires and to be vaporized into very very

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fine particles in sprayed and we aim it

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right on this drum surface

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thin sheet that's formed can be as big

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as two drum surface the thin sheet mr.

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Westfall was talking about is called a

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mono tape it comes off the drum very

285
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easily because a teflon spray is applied

286
00:13:44,070 --> 00:13:41,680
first the spray allows the material to

287
00:13:49,080 --> 00:13:44,080
get hard and yet not stick to the drum

288
00:13:51,540 --> 00:13:49,090
it simply peels off composite mono tapes

289
00:13:53,850 --> 00:13:51,550
are used to make composite shapes which

290
00:13:57,090 --> 00:13:53,860
are rather complex structures requiring

291
00:13:59,490 --> 00:13:57,100
extremely high strength in order to make

292
00:14:01,740 --> 00:13:59,500
the structure as strong as possible the

293
00:14:05,400 --> 00:14:01,750
mono tapes must be positioned in certain

294
00:14:07,860 --> 00:14:05,410
directions to do this the mono tape is

295
00:14:10,980 --> 00:14:07,870
cut into small pieces and stacked one on

296
00:14:14,010 --> 00:14:10,990
top of the other on the first piece all

297
00:14:16,530 --> 00:14:14,020
fibers are placed in one direction on

298
00:14:18,630 --> 00:14:16,540
the next piece the fibers are put in the

299
00:14:21,390 --> 00:14:18,640
opposite direction of those on the first

300
00:14:23,850 --> 00:14:21,400
piece this alternation of the fibers

301
00:14:25,980 --> 00:14:23,860
direction is continued on the pieces in

302
00:14:29,640 --> 00:14:25,990
order to maximize the structure strength

303
00:14:32,490 --> 00:14:29,650
in different directions the small pieces

304
00:14:35,270 --> 00:14:32,500
of composite mono tape usually are glued

305
00:14:38,040 --> 00:14:35,280
together by a method called hot pressing

306
00:14:39,960 --> 00:14:38,050
very heavy pressure is applied to the

307
00:14:42,150 --> 00:14:39,970
stack while it is subjected to a

308
00:14:45,420 --> 00:14:42,160
temperature of almost 2,000 degrees

309
00:14:48,120 --> 00:14:45,430
Fahrenheit as the metal gets squeezed

310
00:14:50,280 --> 00:14:48,130
together any small imperfections in the

311
00:14:52,770 --> 00:14:50,290
mono tape disappeared and the metal

312
00:14:56,250 --> 00:14:52,780
pieces blend together resulting in a

313
00:14:58,290 --> 00:14:56,260
perfectly solid plate cut into thin

314
00:15:02,010 --> 00:14:58,300
strips the plates are used extensively

315
00:15:04,260 --> 00:15:02,020
at NASA for testing purposes engineers

316
00:15:06,840 --> 00:15:04,270
have been able to make large tubes by

317
00:15:08,790 --> 00:15:06,850
using a pressing guide to shape it they

318
00:15:11,880 --> 00:15:08,800
have made demonstration turbine blades

319
00:15:14,400 --> 00:15:11,890
for jet engines these blades are located

320
00:15:17,250 --> 00:15:14,410
very close to the place where air mixed

321
00:15:19,980 --> 00:15:17,260
with fuel is burned as combustion takes

322
00:15:23,250 --> 00:15:19,990
place the expanding gases hit the blade

323
00:15:24,960 --> 00:15:23,260
causing it to turn it's easy to see why

324
00:15:29,070 --> 00:15:24,970
the blades must be able to withstand

325
00:15:31,650 --> 00:15:29,080
extremely high temperatures presently

326
00:15:34,920 --> 00:15:31,660
there are five NASA programs in which

327
00:15:38,220 --> 00:15:34,930
arc spray mono tape plays a major role

328
00:15:41,250 --> 00:15:38,230
our two programs deal specifically with

329
00:15:43,050 --> 00:15:41,260
the space shuttles main engine since the

330
00:15:45,139 --> 00:15:43,060
material now used to make the main

331
00:15:48,600 --> 00:15:45,149
engine is cracking due to thermal shock

332
00:15:51,240 --> 00:15:48,610
NASA is working with tungsten reinforced

333
00:15:54,210 --> 00:15:51,250
super alloys to replace it these

334
00:15:56,850 --> 00:15:54,220
composites in tests so far have proven

335
00:15:58,800 --> 00:15:56,860
to be more shock resistant stronger and

336
00:16:02,730 --> 00:15:58,810
able to withstand higher temperatures

337
00:16:05,100 --> 00:16:02,740
than the present material the second

338
00:16:07,340 --> 00:16:05,110
program deals with the reinforcement of

339
00:16:11,190 --> 00:16:07,350
a combustion liner in the space shuttle

340
00:16:19,019 --> 00:16:11,200
mr. Westfall explains a combustion liner

341
00:16:22,110 --> 00:16:19,029
is a contoured shape that is Hydra

342
00:16:24,300 --> 00:16:22,120
liquid hydrogen cold and it's the vessel

343
00:16:29,040 --> 00:16:24,310
that the liquid oxygen and liquid

344
00:16:31,400 --> 00:16:29,050
hydrogen burned in and you have very

345
00:16:33,810 --> 00:16:31,410
very high temperatures inside this

346
00:16:37,230 --> 00:16:33,820
combustion liner and typically it's made

347
00:16:39,210 --> 00:16:37,240
out of copper or strong copper alloy the

348
00:16:42,440 --> 00:16:39,220
problem this combustion liner is

349
00:16:45,960 --> 00:16:42,450
experiencing is the copper alloy is

350
00:16:48,019 --> 00:16:45,970
deforming due to the very high

351
00:16:50,970 --> 00:16:48,029
temperatures and the stresses that are

352
00:16:53,370 --> 00:16:50,980
generated in the thin inner wall causing

353
00:16:55,110 --> 00:16:53,380
in a while to deform and actually

354
00:16:57,900 --> 00:16:55,120
correct and the liquid hydrogen is

355
00:17:01,620 --> 00:16:57,910
leaking out we are putting tungsten

356
00:17:03,360 --> 00:17:01,630
fibers in the inside layer of the

357
00:17:05,460 --> 00:17:03,370
combustion liner to strengthen to

358
00:17:08,069 --> 00:17:05,470
selectively strengthen the inner wall of

359
00:17:11,520 --> 00:17:08,079
the combustion liner this is an example

360
00:17:13,860 --> 00:17:11,530
of one of the test specimens that we

361
00:17:16,620 --> 00:17:13,870
make and we have tungsten fibers

362
00:17:20,160 --> 00:17:16,630
reinforcing the inside surface of this

363
00:17:23,699 --> 00:17:20,170
specimen alright this specimen then will

364
00:17:25,470 --> 00:17:23,709
be tested in a rocket test chamber under

365
00:17:27,290 --> 00:17:25,480
conditions very very similar to the

366
00:17:32,490 --> 00:17:27,300
Space Shuttle main engine and the

367
00:17:34,919 --> 00:17:32,500
material will be tested to to failure we

368
00:17:36,870 --> 00:17:34,929
predict a much longer life with our

369
00:17:40,380 --> 00:17:36,880
tungsten reinforce copper than the

370
00:17:42,750 --> 00:17:40,390
current copper alloy that's being flown

371
00:17:45,200 --> 00:17:42,760
in space shuttle today also regarding

372
00:17:47,299 --> 00:17:45,210
space the third program has

373
00:17:49,820 --> 00:17:47,309
with the creation and development of

374
00:17:52,269 --> 00:17:49,830
very strong tools to hold liquid metals

375
00:17:54,980 --> 00:17:52,279
and heat pipes for nuclear reactors

376
00:17:57,169 --> 00:17:54,990
because of the tremendous pressure the

377
00:17:59,120 --> 00:17:57,179
tubes will have to withstand a new

378
00:18:02,600 --> 00:17:59,130
material is needed that is much stronger

379
00:18:05,269 --> 00:18:02,610
than the one now used using the

380
00:18:07,159 --> 00:18:05,279
composite process engineers are adding

381
00:18:11,090 --> 00:18:07,169
tungsten fibers to the present material

382
00:18:13,610 --> 00:18:11,100
to strengthen it and again in support of

383
00:18:16,190 --> 00:18:13,620
space power the next program is working

384
00:18:18,019 --> 00:18:16,200
to develop a specific container and will

385
00:18:20,180 --> 00:18:18,029
be able to take high temperatures and

386
00:18:23,419 --> 00:18:20,190
amounts of pressure which the current

387
00:18:25,340 --> 00:18:23,429
container cannot in this case the power

388
00:18:29,029 --> 00:18:25,350
being generated would be for a space

389
00:18:31,010 --> 00:18:29,039
station the composite material that has

390
00:18:34,130 --> 00:18:31,020
been developed is three to four times

391
00:18:35,930 --> 00:18:34,140
stronger than the present one surpassing

392
00:18:37,940 --> 00:18:35,940
the program's goal of finding a

393
00:18:40,490 --> 00:18:37,950
substitute container for present

394
00:18:42,889 --> 00:18:40,500
temperature and pressure levels the

395
00:18:45,049 --> 00:18:42,899
engineers at NASA have created one that

396
00:18:49,310 --> 00:18:45,059
can be used as power demands go up in

397
00:18:51,380 --> 00:18:49,320
the future the final program developing

398
00:18:54,039 --> 00:18:51,390
composite materials for use in space

399
00:18:57,139 --> 00:18:54,049
deals with the improvement of radiators

400
00:18:59,690 --> 00:18:57,149
again NASA engineer Leonard Westfall

401
00:19:03,740 --> 00:18:59,700
explains these tubes I talked about

402
00:19:06,399 --> 00:19:03,750
before have radiator panels hooked on on

403
00:19:10,970 --> 00:19:06,409
the back of them to get rid of the heat

404
00:19:14,299 --> 00:19:10,980
all right we're developing fiber

405
00:19:17,750 --> 00:19:14,309
reinforced radiator panels that are made

406
00:19:19,669 --> 00:19:17,760
out of graphite fibers that I have very

407
00:19:21,980 --> 00:19:19,679
very high thermal conductivity and

408
00:19:25,149 --> 00:19:21,990
thermal conductivity is the materials

409
00:19:27,440 --> 00:19:25,159
ability to conduct heat very quickly

410
00:19:30,320 --> 00:19:27,450
alright these fibers conduct heat

411
00:19:34,970 --> 00:19:30,330
extremely fast and we put them in and

412
00:19:37,419 --> 00:19:34,980
copper as a high-temperature glue copper

413
00:19:40,909 --> 00:19:37,429
also has very high thermal conductivity

414
00:19:44,240 --> 00:19:40,919
and so what we end up with is a

415
00:19:47,090 --> 00:19:44,250
structure that has higher thermal

416
00:19:52,519 --> 00:19:47,100
conductivity than copper is very very

417
00:19:54,500 --> 00:19:52,529
stiff and light and this saves weight it

418
00:19:56,870 --> 00:19:54,510
increases the efficiency of the radiator

419
00:19:59,010 --> 00:19:56,880
panels and makes the whole cooling

420
00:20:01,710 --> 00:19:59,020
scheme work much

421
00:20:04,170 --> 00:20:01,720
much better at NASA there is also very

422
00:20:07,290 --> 00:20:04,180
exciting work being done to support the

423
00:20:09,570 --> 00:20:07,300
national aerospace plane the plans for

424
00:20:11,670 --> 00:20:09,580
this remarkable plane call for it to

425
00:20:15,120 --> 00:20:11,680
take off from the ground and fly up

426
00:20:17,550 --> 00:20:15,130
right into orbit it would fly like an

427
00:20:19,920 --> 00:20:17,560
airplane but it's jet engine at higher

428
00:20:23,220 --> 00:20:19,930
altitudes and speeds would become like a

429
00:20:25,440 --> 00:20:23,230
rocket and boosted into space NASA's

430
00:20:27,600 --> 00:20:25,450
advanced metallics branch is working on

431
00:20:29,910 --> 00:20:27,610
developing a fiber-reinforced inner

432
00:20:33,060 --> 00:20:29,920
metallic material out of which to build

433
00:20:35,430 --> 00:20:33,070
the plane currently the plane severely

434
00:20:37,170 --> 00:20:35,440
lacks a suitable material there are

435
00:20:39,420 --> 00:20:37,180
three vital requirements that the

436
00:20:42,150 --> 00:20:39,430
material must have it must be

437
00:20:45,780 --> 00:20:42,160
lightweight highly resistant to extreme

438
00:20:48,120 --> 00:20:45,790
heat and very strong since it will be

439
00:20:50,520 --> 00:20:48,130
used primarily as a major structural

440
00:20:53,550 --> 00:20:50,530
component the composite material being

441
00:20:56,610 --> 00:20:53,560
tested and developed uses ceramic fibers

442
00:20:59,010 --> 00:20:56,620
the intermetallic matrix and ceramic

443
00:21:00,870 --> 00:20:59,020
fibers together form a material that

444
00:21:04,950 --> 00:21:00,880
could be the solution to one of the

445
00:21:07,860 --> 00:21:04,960
planes most pressing needs in all the

446
00:21:10,470 --> 00:21:07,870
research in all of these programs with

447
00:21:12,900 --> 00:21:10,480
all of the discoveries breakthroughs and

448
00:21:16,080 --> 00:21:12,910
amazing new products tested and those

449
00:21:19,110 --> 00:21:16,090
actually in use still according to mr.

450
00:21:21,060 --> 00:21:19,120
Westfall the present work is quote just

451
00:21:24,600 --> 00:21:21,070
scratching the surface in composite

452
00:21:26,910 --> 00:21:24,610
materials besides the fibers in

453
00:21:29,250 --> 00:21:26,920
existence today there are many many

454
00:21:33,540 --> 00:21:29,260
others with great potential that need to

455
00:21:35,730 --> 00:21:33,550
be developed and tested NASA's goal to

456
00:21:39,360 --> 00:21:35,740
develop even stronger fibers that can

457
00:21:41,070 --> 00:21:39,370
work at even higher temperatures some of

458
00:21:42,960 --> 00:21:41,080
the structures nASA has been working on

459
00:21:46,080 --> 00:21:42,970
will be used for the National aerospace

460
00:21:47,160 --> 00:21:46,090
plane or commonly known as nasp naspa

461
00:21:48,930 --> 00:21:47,170
when it is built will have a unique

462
00:21:50,670 --> 00:21:48,940
capability of taking off from any

463
00:22:03,840 --> 00:21:50,680
airport and fly directly into space

464
00:22:08,680 --> 00:22:06,160
imagine taking off from an airport

465
00:22:11,680 --> 00:22:08,690
runway flying at three to five times the

466
00:22:14,590 --> 00:22:11,690
speed of sound at altitudes of 20 miles

467
00:22:16,720 --> 00:22:14,600
or even higher a few short hours after

468
00:22:19,930 --> 00:22:16,730
departure you come to a stop halfway

469
00:22:21,850 --> 00:22:19,940
around the world or maybe you took off

470
00:22:24,250 --> 00:22:21,860
from a runway and flew directly into

471
00:22:26,080 --> 00:22:24,260
orbit to work in space and then you

472
00:22:29,890 --> 00:22:26,090
returned landing on a conventional

473
00:22:32,710 --> 00:22:29,900
Airport runway the National aerospace

474
00:22:35,920 --> 00:22:32,720
plane will try to make both scenarios a

475
00:22:38,440 --> 00:22:35,930
reality NASA and the Department of

476
00:22:41,950 --> 00:22:38,450
Defense have done research on hyper

477
00:22:44,710 --> 00:22:41,960
sonic technology for many years the NASP

478
00:22:47,710 --> 00:22:44,720
technology demonstrator will be a highly

479
00:22:50,170 --> 00:22:47,720
advanced explain a new member of the

480
00:22:54,160 --> 00:22:50,180
elite special research aircraft that

481
00:22:55,930 --> 00:22:54,170
includes the x1 which in 1947 was the

482
00:22:59,470 --> 00:22:55,940
first aircraft to break the speed of

483
00:23:02,470 --> 00:22:59,480
sound and fly supersonic in the early

484
00:23:05,830 --> 00:23:02,480
1960s the x-15 became one of the first

485
00:23:09,550 --> 00:23:05,840
manned hypersonic aircraft and reached

486
00:23:12,750 --> 00:23:09,560
speeds of Mach 7 for about 4,500 miles

487
00:23:16,930 --> 00:23:12,760
per hour one of the key technological

488
00:23:20,100 --> 00:23:16,940
developments of the x30 or NASA are in

489
00:23:22,600 --> 00:23:20,110
the propulsion area an air-breathing

490
00:23:27,280 --> 00:23:22,610
hydrogen-fueled supersonic combustion

491
00:23:29,410 --> 00:23:27,290
ramjet engine or scramjet engine is now

492
00:23:34,240 --> 00:23:29,420
being developed for speeds from about

493
00:23:36,910 --> 00:23:34,250
Mach 7 to Mach 25 the engine uses the

494
00:23:40,660 --> 00:23:36,920
velocity of the vehicle to compress air

495
00:23:42,730 --> 00:23:40,670
as it is rammed into the intake this

496
00:23:45,850 --> 00:23:42,740
compressed air is then mixed with

497
00:23:49,030 --> 00:23:45,860
gaseous hydrogen at this stage to

498
00:23:52,180 --> 00:23:49,040
generate high thrust a development on

499
00:23:54,290 --> 00:23:52,190
which we will focus is materials here to

500
00:23:56,780 --> 00:23:54,300
speak on that is Matt

501
00:24:00,710 --> 00:23:56,790
with the advent of the the aerospace

502
00:24:02,450 --> 00:24:00,720
plane there's become a need for a lot of

503
00:24:04,400 --> 00:24:02,460
new material development beyond a shadow

504
00:24:07,310 --> 00:24:04,410
of a doubt we need new materials all

505
00:24:09,620 --> 00:24:07,320
right and these new materials will most

506
00:24:12,800 --> 00:24:09,630
probably be composite materials but

507
00:24:16,700 --> 00:24:12,810
instead of using a metal matrix based

508
00:24:18,050 --> 00:24:16,710
composite will be using our epoxy based

509
00:24:21,430 --> 00:24:18,060
will be using a metal matrix based

510
00:24:23,930 --> 00:24:21,440
composite all right metal matrix being

511
00:24:26,390 --> 00:24:23,940
copper for instance one of the big

512
00:24:29,240 --> 00:24:26,400
problems NASA is facing with the advent

513
00:24:31,490 --> 00:24:29,250
of the National aerospace plane deals

514
00:24:34,550 --> 00:24:31,500
was not only finding the right materials

515
00:24:37,190 --> 00:24:34,560
to use but in cooling them as well we

516
00:24:38,930 --> 00:24:37,200
have to figure out some way of making a

517
00:24:40,280 --> 00:24:38,940
very strong material that's going to

518
00:24:43,190 --> 00:24:40,290
survive in a high temperature

519
00:24:46,460 --> 00:24:43,200
environment and what we're going to have

520
00:24:48,220 --> 00:24:46,470
to do is actively cool this material all

521
00:24:50,450 --> 00:24:48,230
right by putting some kind of a

522
00:24:52,130 --> 00:24:50,460
cryogenic fluid behind a gaseous

523
00:24:55,430 --> 00:24:52,140
hydrogen or liquid hydrogen which is

524
00:24:56,690 --> 00:24:55,440
very cold and X is a good heat transfer

525
00:25:00,260 --> 00:24:56,700
medium to take heat away from the

526
00:25:02,060 --> 00:25:00,270
leading edge so on on one side of the of

527
00:25:03,110 --> 00:25:02,070
the material on the inside of the wing

528
00:25:05,360 --> 00:25:03,120
for instance there'll be a lot of

529
00:25:07,220 --> 00:25:05,370
coolant rushing through to cool the

530
00:25:09,770 --> 00:25:07,230
inside down and on the outside you'll

531
00:25:11,390 --> 00:25:09,780
have a very hot surface and that is why

532
00:25:12,530 --> 00:25:11,400
we need the high heat conductivity with

533
00:25:14,750 --> 00:25:12,540
our instance you look at fighter jets

534
00:25:17,360 --> 00:25:14,760
that's travel Mach 1 or Mach 2 or even

535
00:25:18,950 --> 00:25:17,370
the Concorde which goes up to Mach 2 you

536
00:25:21,860 --> 00:25:18,960
see that their wings are very narrow at

537
00:25:23,270 --> 00:25:21,870
the leading edges okay and there's a

538
00:25:25,330 --> 00:25:23,280
problem with that because the smaller

539
00:25:28,400 --> 00:25:25,340
the leading edge gets the more difficult

540
00:25:30,950 --> 00:25:28,410
it is to cool and the hotter it gets

541
00:25:33,020 --> 00:25:30,960
because it's such a small it's just such

542
00:25:36,830 --> 00:25:33,030
a small point lying out there in the

543
00:25:39,770 --> 00:25:36,840
free stream that it gets it gets very

544
00:25:42,320 --> 00:25:39,780
warm very quickly the National aerospace

545
00:25:45,230 --> 00:25:42,330
plane is one of the projects being

546
00:25:48,290 --> 00:25:45,240
developed by NASA for future space use

547
00:25:50,810 --> 00:25:48,300
but we cannot expect it to do all of our

548
00:25:53,630 --> 00:25:50,820
work in space the National aerospace

549
00:25:57,710 --> 00:25:53,640
plane being something that will possibly

550
00:25:59,900 --> 00:25:57,720
be able to supplement the shuttle fleet

551
00:26:02,510 --> 00:25:59,910
or or maybe even replace it but

552
00:26:04,190 --> 00:26:02,520
obviously if you have an airplane that

553
00:26:07,010 --> 00:26:04,200
can take off from a runway and go to

554
00:26:08,510 --> 00:26:07,020
orbit with some people in it and go

555
00:26:11,780 --> 00:26:08,520
the space station for instance or

556
00:26:14,060 --> 00:26:11,790
something like that obviously it would

557
00:26:18,920 --> 00:26:14,070
have to be capable of shuttle type

558
00:26:20,600 --> 00:26:18,930
operations as far as payload goes I

559
00:26:22,580 --> 00:26:20,610
think moving big things like space

560
00:26:25,250 --> 00:26:22,590
station components or say for instance

561
00:26:26,600 --> 00:26:25,260
they want to go to Mars and they have to

562
00:26:28,220 --> 00:26:26,610
get some big boosters up there or

563
00:26:30,470 --> 00:26:28,230
something like that I don't see the

564
00:26:32,480 --> 00:26:30,480
national aerospace plane taking that

565
00:26:35,270 --> 00:26:32,490
kind of payload up there the National

566
00:26:37,790 --> 00:26:35,280
aerospace plane is expected to yield a

567
00:26:41,450 --> 00:26:37,800
high payoff for the United States in the

568
00:26:44,720 --> 00:26:41,460
early 21st century with reduced space

569
00:26:47,390 --> 00:26:44,730
launch costs vastly reduced transit time

570
00:26:49,700 --> 00:26:47,400
on long-haul air routes major

571
00:26:52,670 --> 00:26:49,710
investments by private enterprise in

572
00:26:56,090 --> 00:26:52,680
commercial space ventures and sustained

573
00:26:58,880 --> 00:26:56,100
us preeminence in aeronautics with all

574
00:27:02,270 --> 00:26:58,890
of the social and economic benefits that

575
00:27:03,680 --> 00:27:02,280
accompany it this is a Mariko forest

576
00:27:05,840 --> 00:27:03,690
area wishing you would buy and hope

577
00:27:07,880 --> 00:27:05,850
you've enjoyed our show I hope you walk

578
00:27:09,290 --> 00:27:07,890
along the future path again with me at