    [House Hearing, 116 Congress]
    [From the U.S. Government Publishing Office]

                          NASA'S AERONAUTICS MISSION:
                    ENABLING THE TRANSFORMATION OF AVIATION

    =======================================================================

                                    HEARING

                                   BEFORE THE

                     SUBCOMMITTEE ON SPACE AND AERONAUTICS

                                     OF THE

                          COMMITTEE ON SCIENCE, SPACE,
                                 AND TECHNOLOGY
                            HOUSE OF REPRESENTATIVES

                         ONE HUNDRED SIXTEENTH CONGRESS

                                 FIRST SESSION

                                   __________

                                 JUNE 26, 2019

                                   __________

                               Serial No. 116-33

                                   __________

     Printed for the use of the Committee on Science, Space, and Technology

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

           Available via the World Wide Web: http://science.house.gov

                                ______

                  U.S. GOVERNMENT PUBLISHING OFFICE
     36-797PDF              WASHINGTON : 2020

                  COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY

                 HON. EDDIE BERNICE JOHNSON, Texas, Chairwoman
    ZOE LOFGREN, California              FRANK D. LUCAS, Oklahoma,
    DANIEL LIPINSKI, Illinois                Ranking Member
    SUZANNE BONAMICI, Oregon             MO BROOKS, Alabama
    AMI BERA, California,                BILL POSEY, Florida
        Vice Chair                       RANDY WEBER, Texas
    CONOR LAMB, Pennsylvania             BRIAN BABIN, Texas
    LIZZIE FLETCHER, Texas               ANDY BIGGS, Arizona
    HALEY STEVENS, Michigan              ROGER MARSHALL, Kansas
    KENDRA HORN, Oklahoma                RALPH NORMAN, South Carolina
    MIKIE SHERRILL, New Jersey           MICHAEL CLOUD, Texas
    BRAD SHERMAN, California             TROY BALDERSON, Ohio
    STEVE COHEN, Tennessee               PETE OLSON, Texas
    JERRY McNERNEY, California           ANTHONY GONZALEZ, Ohio
    ED PERLMUTTER, Colorado              MICHAEL WALTZ, Florida
    PAUL TONKO, New York                 JIM BAIRD, Indiana
    BILL FOSTER, Illinois                JAIME HERRERA BEUTLER, Washington
    DON BEYER, Virginia                  JENNIFFER GONZALEZ-COLON, Puerto
    CHARLIE CRIST, Florida                   Rico
    SEAN CASTEN, Illinois                VACANCY
    KATIE HILL, California
    BEN McADAMS, Utah
    JENNIFER WEXTON, Virginia
                                     ------

                     Subcommittee on Space and Aeronautics

                     HON. KENDRA HORN, Oklahoma, Chairwoman
    ZOE LOFGREN, California              BRIAN BABIN, Texas, Ranking Member
    AMI BERA, California                 MO BROOKS, Alabama
    ED PERLMUTTER, Colorado              BILL POSEY, Florida
    DON BEYER, Virginia                  PETE OLSON, Texas
    CHARLIE CRIST, Florida               MICHAEL WALTZ, Florida
    KATIE HILL, California
    JENNIFER WEXTON, Virginia

                             C  O  N  T  E  N  T  S

                                 June 26, 2019

                                                                       Page

    Hearing Charter..................................................     2

                               Opening Statements

    Statement by Representative Kendra Horn, Chairwoman, Subcommittee
      on Space and Aeronautics, Committee on Science, Space, and
      Technology, U.S. House of Representatives......................     9
        Written Statement............................................    10

    Statement by Representative Brian Babin, Ranking Member,
      Subcommittee on Space and Aeronautics, Committee on Science,
      Space, and Technology, U.S. House of Representatives...........    11
        Written Statement............................................    12

    Written statement by Representative Eddie Bernice Johnson,
      Chairwoman, Committee on Science, Space, and Technology, U.S.
      House of Representatives.......................................    13

                                   Witnesses:

    Dr. Jaiwon Shin, Associate Administrator, Aeronautics Research
      Mission Directorate, NASA
        Oral Statement...............................................    15
        Written Statement............................................    17

    Dr. Alan H. Epstein, R.C. Maclaurin Professor Emeritus of
      Aeronautics and Astronautics, MIT; Chair, Aeronautics and Space
      Engineering Board, National Academies of Sciences, Engineering,
      and Medicine
        Oral Statement...............................................    25
        Written Statement............................................    27

    Dr. Ilan Kroo, Professor of Aeronautics and Astronautics,
      Stanford University
        Oral Statement...............................................    32
        Written Statement............................................    34

    Dr. Mark Lewis, Director, IDA Science & Technology Policy
      Institute; Professor Emeritus of Aerospace Engineering,
      University of Maryland
        Oral Statement...............................................    37
        Written Statement............................................    40

    Discussion.......................................................    43

                 Appendix I: Answers to Post-Hearing Questions

    Dr. Jaiwon Shin, Associate Administrator, Aeronautics Research
      Mission Directorate, NASA......................................    58

    Dr. Alan H. Epstein, R.C. Maclaurin Professor Emeritus of
      Aeronautics and Astronautics, MIT; Chair, Aeronautics and Space
      Engineering Board, National Academies of Sciences, Engineering,
      and Medicine...................................................    73

    Dr. Mark Lewis, Director, IDA Science & Technology Policy
      Institute; Professor Emeritus of Aerospace Engineering,
      University of Maryland.........................................    84

                Appendix II: Additional Material for the Record

    Letter submitted by Representative Kendra Horn, Chairwoman,
      Subcommittee on Space and Aeronautics, Committee on Science,
      Space, and Technology, U.S. House of Representatives...........    88

    Article submitted by Representative Brian Babin, Ranking Member,
      Subcommittee on Space and Aeronautics, Committee on Science,
      Space, and Technology, U.S. House of Representatives...........    91

                          NASA'S AERONAUTICS MISSION:

                          ENABLING THE TRANSFORMATION

                                  OF AVIATION

                                  ----------

                            WEDNESDAY, JUNE 26, 2019

                      House of Representatives,
                 Subcommittee on Space and Aeronautics,
                   Committee on Science, Space, and Technology,
                                                       Washington, D.C.

        The Subcommittee met, pursuant to notice, at 3:16 p.m., in
    room 2318 of the Rayburn House Office Building, Hon. Kendra
    Horn [Chairwoman of the Subcommittee] presiding.

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

        Chairwoman Horn. This hearing will come to order. Without
    objection, the Chair is authorized to declare recess at any
    time. Good afternoon, and welcome. I'm especially pleased to
    welcome our distinguished group of witnesses today, and want to
    thank you all for being here, and for your patience as we were
    on the floor with votes.
        We are on the cusp of transformational changes in aviation.
    Not only is the commercial aviation market robust with global
    passenger air transport, but is projected to double by 2040.
    Emerging new markets and innovative technologies are also
    literally changing what we see on the horizon. These
    innovations are not just about the novelty of pizza and package
    deliveries to your door by flying drones, or the flying cars
    that we've always envisioned from the Jetsons era. They're
    about economic impact, competitiveness, and American jobs.
        One estimate projects that the integration of unmanned
    aircraft systems into the airspace could lead to 100,000 jobs
    and $82 billion in economic activity. Market projections for
    urban air mobility are also in the billions of dollars. Our
    U.S. economy stands to gain significantly from these emerging
    aviation markets. Yet, when combined with the current impact of
    civil aviation, which in 2014 provided over 10 million jobs,
    and represented $1.6 trillion of total U.S. economic activity,
    and accounted for 5.1 percent of U.S. GDP, the importance of
    commercial aviation to our Nation's economic growth is
    magnified. In my own State of Oklahoma, aviation and aerospace
    represent the second largest employment sector across the
    State, a fact that many people don't know. According to a study
    by the Oklahoma Aeronautics Commission, aviation, aerospace,
    and associated activities provide for over 200,000 jobs, and
    about $44 billion in economic impact.
        While there is much to celebrate in the success of U.S.
    commercial air transportation, our competitiveness on the
    global market is increasingly harder to maintain. The
    International Aviation and Transportation Association predicts
    that by the mid-2020s China will displace the United States as
    the world's largest aviation market. That's why Federal
    research investments to transform this industry are important,
    and why we are here today to examine NASA's (National
    Aeronautics and Space Administration's) Aeronautics mission and
    enabling role. Because maintaining our success, and realizing
    the opportunities before us, means overcoming challenges.
    Airplane noise complaints to the FAA (Federal Aviation
    Administration) have seen sharp increases; growth in air
    transportation is stretching the capacity of our national
    airspace system, and new entrants, including drones and urban
    air vehicles, add complexity to the airspace that must be
    safely managed if we are to be successful.
        Perhaps the most pressing of all is the impact of air
    transportation on the environment. Not only does commercial
    aviation account for about 2 percent of human-induced global
    carbon emissions, the jet fuel that produces those emissions
    represents a significant portion of commercial airline costs.
    With expected compound annual growth rates of about 3.5 percent
    in air passengers, the problem will only get worse.
    Sustainability is not only critical to the environment, it's
    becoming a competitive advantage.
        At this year's Paris Air Show, which ended just days ago,
    Chief Technical Officers (CTOs) of seven of the world's leading
    aviation manufacturers came together in an unprecedented union
    to commit to a sustainable future for commercial air
    transportation. I am submitting a copy of their statement for
    the record. And that's where NASA's aeronautic research plays a
    vital role, carrying out fundamental research to improve
    efficiencies, enabling the safe integration of new entrants
    into the airspace, testing new aircraft systems and designs,
    and developing enabling technologies and techniques to mitigate
    the environmental impacts of aviation.
        The question before us today is, are we, in Congress, and
    the Federal Government, doing enough? Are we making the
    necessary investments to help realize the full potential of
    emerging markets that have significant implications for U.S.
    competitiveness and economic growth? Do we have the workforce
    facilities to support NASA's aeronautics R&D (research and
    development), and the growing industries, and will our R&D
    efforts help keep us on track to meet goals for commercial
    aviation, to achieve carbon neutral growth in 2020, and reduce
    CO2 emissions by 50 percent of what they were in
    2005 by 2050?
        In closing, I'd like to say this: The proposal for
    aeronautical research and technology in NASA's Fiscal Year 1994
    budget request was 2-1/2 times the 2019 year dollars than the
    Administration's proposed investment in FY 2020 NASA
    Aeronautics' research programs. Recognizing the magnitude of
    the economic impact of U.S. commercial aviation today, and the
    challenges and opportunities ahead, the question is, is that
    sufficient? Thank you.
        [The prepared statement of Chairwoman Horn follows:]

        Good afternoon, and welcome. I'm especially pleased to
    welcome our distinguished group of witnesses. Thank you for
    being here.
        We're on the cusp of transformational changes in aviation.
    Not only is the commercial aviation market robust with global
    passenger air transport projected to double by about 2040,
    emerging new markets and innovative technologies are literally
    changing what we see on the horizon. These innovations are not
    just about the novelty of pizza and package deliveries to your
    door by drones or the ``flying cars'' of the Jetsons cartoon,
    they're about economic impact, competitiveness, and American
    jobs. One estimate projects that the integration of unmanned
    aircraft systems into the airspace could lead to 100,000 jobs
    and $82 billion in economic activity. Market projections for
    urban air mobility are in the billions of dollars.
        Our U.S. economy stands to gain significantly from these
    emerging aviation markets. Yet, when combined with the current
    impact of civil aviation, which in 2014, provided over 10
    million jobs, represented $1.6 trillion of total U.S. economic
    activity, and accounted for 5.1 percent of U.S. GDP, the
    importance of commercial aviation to our nation's economic
    growth is magnified. In my own state of Oklahoma, aviation and
    aerospace represent the second largest employment sector.
    According to a study by the Oklahoma Aeronautics Commission,
    aviation, aerospace, and associated activities provide for over
    200,000 jobs and about $44 billion in economic impact.
        While there is much to celebrate in the success of U.S.
    commercial air transportation, our competitiveness on the
    global market is increasingly harder to maintain. The
    International Aviation Transportation Association predicts that
    by the mid-2020s, ``China will displace the United States as
    the world's largest aviation market.'' That's why Federal
    research investments to transform this industry matter, and why
    we're here today to examine NASA's Aeronautics mission and
    enabling role. Because maintaining our success and realizing
    the opportunities before us means overcoming challenges.
        Airplane noise complaints to the FAA have seen sharp
    increases. Growth in air transportation is stretching the
    capacity of our national airspace system, and new entrants,
    including drones and urban air vehicles, add complexity to the
    airspace that must be safely managed if they are to be
    successful. Perhaps most pressing of all is the impact of air
    transportation on the environment. Not only does commercial
    aviation account for about 2% of human-induced global carbon
    emissions, the jet fuel that produces those emissions
    represents a significant portion of commercial airline costs.
    With expected compound annual growth rates of about 3.5 percent
    in air passengers, the problem will only get worse.
    Sustainability is not only critical to the environment; it's
    becoming a competitive advantage.
        At this year's Paris Air Show, which ended just days ago,
    Chief Technical Officers of 7 of the world's leading aviation
    manufactures came together in an unprecedented union to commit
    to a sustainable future for commercial air transportation. I'm
    submitting a copy of their statement to the record. And that's
    where NASA's aeronautics research plays a vital role-carrying
    out fundamental research to improve efficiencies, enabling the
    safe integration of new entrants into the air space, testing
    new aircraft systems and designs, and developing enabling
    technologies and techniques to mitigate the environmental
    impacts of aviation.
        The question before us today is: are we in Congress and the
    Federal government doing enough? Are we making the necessary
    investments to help realize the full potential of emerging
    markets that have significant implications for U.S.
    competitiveness and economic growth? Do we have the workforce
    and facilities to support NASA's aeronautics R&D and the
    growing industries? And will our R&D efforts help keep us on
    track to meet goals for commercial aviation to achieve carbon
    neutral growth in 2020 and reduce CO2 emissions by
    50 percent of what they were in 2005 by 2050?
        In closing, I'd like say this: the proposal for
    aeronautical research and technology in NASA's fiscal year 1994
    budget request was 2 and a half times more in 2019-year dollars
    than the Administration's proposed investment for NASA's
    Aeronautics research programs in the fiscal year 2020 budget
    request. Recognizing the magnitude of the economic impact of
    U.S. commercial aviation today, and the challenges and
    opportunities ahead, is it sufficient?
        Thank you.

        Chairwoman Horn. The Chair now recognizes Ranking Member
    Babin for an opening statement.
        Mr. Babin. Thank you, Madam Chair, and thank you,
    witnesses, for being here today. I'm looking forward to hearing
    what you have to say.
        Modern day aeronautics was founded by American ingenuity.
    And while flying machines were proposed by great minds like
    DaVinci, and balloons and gliders preceded aircraft, it was two
    bicycle makers from Ohio that proved, in 1903, that dreams are
    more than just imagination. They were the first to demonstrate
    an aircraft with powered flight in Kitty Hawk, North Carolina,
    which propelled America to the forefront of a new technological
    revolution. Many were engaged in solving the riddle of flight
    at the time. Some, like Samuel Langley, were supported by
    significant government funding, and the backing of established
    institutions like the Smithsonian. But it was the industrious
    tinkerers, backed by nothing but their own curiosity, who made
    the impossible possible.
        Wilbur and Orville Wright, as well as many others, went on
    to proselytize the potential of aviation, and participate in
    the Nation's first government aviation organization, the
    National Advisory Committee for Aeronautics, or NACA. Founded
    in 1915 to supervise and direct the scientific study of the
    problems of flight, with a view to their practical solution,
    NACA's roots in aviation formed the foundation for NASA. Those
    proud traditions continue today in the Aeronautics Mission
    Directorate.
        NASA is currently tackling several technological
    challenges. They're developing the low boom flight demonstrator
    to enable commercial supersonic flight that will drastically
    reduce flight times. They're building off of the success of the
    X-15, the X-43, and the X-51 to continue research and
    development into hypersonic flight, which could revolutionize
    space flight, enable faster transportation, and also promote
    national security. And while the U.S. has been at the forefront
    of hypersonic research for decades, Russia and China are making
    significant progress in this field, which threatens our own
    national security.
        NASA is also supporting urban air mobility, electric
    aircraft, and air traffic management research to promote
    innovation, and enable more efficient use of our air space.
    These are all fascinating fields of study. One aspect of
    aeronautics research that we must diligently monitor is
    international competitiveness. And while the U.S. has
    historically led the world in aeronautics and aviation, this
    lead cannot be taken for granted.
        Other nations are investing significant resources to
    challenge our leadership, but many of those countries embrace a
    strategy based on subsidies and government-sponsored monopolies
    that run counter to the American free-market spirit. And before
    we adopt policies similar to our international competitors, we
    should consider whether some technological challenges are best
    left to the market to solve. After all, it was the Wright
    brothers' curiosity and drive that made them successful, not
    government subsidies or political favoritism.
        Similarly, when we compare investments in aeronautics made
    by countries like China to NASA, or the U.S. government's
    investment, we must realize that virtually all of China's
    investments are made by the public sector, whereas here in
    America we have a vibrant private sector that is also investing
    in our Nation's aeronautics future. Aeronautics and aviation
    make up a significant portion of our nation's economy.
    Preserving our leadership role is something that we can all
    agree on.
        I look forward to working with my colleagues on this
    Committee, and with the Senate, and with the Administration to
    ensure the future of our aviation economy is just as bright as
    the past. And I yield back.
        [The prepared statement of Mr. Babin follows:]

        Modern-day aeronautics was founded by American ingenuity.
    While flying machines were proposed by great minds like da
    Vinci, and balloons and gliders preceded aircraft, it was two
    bicycle makers from Ohio that proved in 1903 that dreams are
    more than just imagination. They were the first to demonstrate
    an aircraft with powered flight in Kitty Hawk North Carolina,
    which propelled America to the forefront of a new technological
    revolution. Many were engaged in solving the riddle of flight
    at the time. Some, like Samuel Langley, were supported by
    significant government funding and the backing of established
    institutions like the Smithsonian. But it was the industrious
    tinkerers, backed by nothing but their own curiosity, who made
    the impossible possible.
        Wilbur and Orville Wright, as well as many others, went on
    to proselytize the potential of aviation and participate in the
    nation's first government aviation organization - the National
    Advisory Committee for Aeronautics (NACA). Founded in 1915 to
    ``supervise and direct the scientific study of the problems of
    flight, with a view to their practical solution,'' NACA's roots
    in aviation formed the foundation for NASA. Those proud
    traditions continue today in the Aeronautics Mission
    Directorate.
        NASA is currently tackling several technological
    challenges. They are developing the Low Boom Flight
    Demonstrator to enable commercial supersonic flight that will
    drastically reduce flight times. They are building off of the
    success of the X-15, X-43, and X-51 to continue research and
    development into hypersonic flight which could revolutionize
    spaceflight, enable faster transportation, and promote national
    security. While the U.S. has been at the forefront of
    hypersonics research for decades, Russia and China are making
    significant progress in the field, which threatens our national
    security. NASA is also supporting Urban Air Mobility, Electric
    Aircraft, and Air Traffic Management research to promote
    innovation and enable more efficient use of our air space.
    These are all fascinating fields of study.
        One aspect of aeronautics research that we must diligently
    monitor is international competitiveness. While the U.S. has
    historically led the world in aeronautics and aviation, this
    lead cannot be taken for granted.
        Other nations are investing significant resources to
    challenge our leadership. But many of those countries embrace a
    strategy based on subsidies and government sponsored monopolies
    that run counter to the American free market spirit. Before we
    adopt policies similar to our international competitors, we
    should consider whether some technological challenges are best
    left to the market to solve. After all, it was the Wright
    Brother's curiosity and drive that made them successful, not
    government subsidies or political favoritism. Similarly, when
    we compare investments in aeronautics made by countries like
    China to NASA or the U.S. government's investment, we must
    realize that virtually all of China's investments are made by
    the public sector, whereas here in America we have a vibrant
    private sector that is also investing in our nation's
    aeronautics future.
        Aeronautics and aviation make up a significant portion of
    our nation's economy. Preserving our leadership role is
    something we can all agree on. I look forward to working with
    my colleagues in this Committee, with the Senate, and with the
    Administration to ensure the future of our aviation economy is
    just as bright as the past.

        Chairwoman Horn. Thank you very much, Mr. Babin. It's a
    pleasure to work with you on this Committee, and we're very
    happy to have such a distinguished panel. And--give us just one
    moment. Excuse me. OK. Looks like we're waiting on a few people
    to arrive. If there are Members who wish to submit additional
    opening statements, your statements will be added to the record
    at this point.
        [The prepared statement of Chairwoman Johnson follows:]

        Thank you, Madame Chair, for holding this hearing on NASA's
    aeronautics mission and the activities of the Aeronautics
    Research Mission Directorate.
        As most of us in this room know, Aeronautics is the first
    ``A'' in NASA. NASA's very origins grew out of the National
    Advisory Committee for Aeronautics (NACA), which was
    established nearly 105 years ago to advise the nation during
    World War I and to advance U.S. aviation in light of Europe's
    rapid advancements. NACA's foundational research, experiments,
    flight tests and simulations not only established the U.S.
    aviation industry, it made possible the nation's early work in
    aeronautics and spaceflight.
        Today, over 100 years later, the importance of aeronautics
    to the nation has only grown. As Chairwoman Horn noted in her
    opening statement, the economic value of both existing
    commercial air transportation and emerging markets is
    significant, as are the innovative technologies and new
    operations on the horizon. This innovation is happening around
    my own District in Dallas, which will be one of the cities in
    which urban air mobility is to be tested.
        Yet there are many challenges in realizing opportunities
    such as urban air mobility. Noise, public acceptance, safety,
    and the integration of new, and eventually autonomous, systems
    into the national airspace are just a few. Research is needed
    to address these challenges, reduce risks, and enable the
    industry to lead in these emerging areas of civil aviation.
        Our investments in NASA's Aeronautics Research Mission
    Directorate have already returned handily in the infusion of
    NASA Aeronautics research into commercial and military
    aircraft, and in demonstrating tools for more efficient air
    traffic management that are being transitioned to the FAA for
    operational use, for example.
        While the economic impact of civil and commercial aviation
    is truly impressive, we can't take for granted the fact that
    other nations are becoming increasingly capable. The global
    market is competitive. Our ability to sustain our leadership
    and realize future opportunities in civil and commercial
    aviation require R&D investments and people.
        As Chairwoman Horn noted, in Fiscal Year 1994, the
    Administration's request for aeronautics research would be the
    equivalent of $1.76 billion in 2019-year dollars, after
    accounting for inflation. That's 2-1/2 times more than the
    Fiscal Year 2020 budget request for NASA's research aeronautics
    activities. And while the comparison may not be exact in the
    programmatic content included, the contrast is nonetheless very
    concerning. If we under-invest in research that supports one of
    the only industries in the nation that has a positive trade
    balance, provides for high-paying, skilled jobs, and has an
    economic impact for the U.S. economy of more than a trillion
    dollars, we risk losing the very tax base and national revenue
    that will help us support NASA and the broader R&D activities
    in our Federal government.
        I look forward to working with the Chairwoman and Ranking
    Member of the Subcommittee, the Ranking Member of the Full
    Committee, NASA, industry, and academia in considering the
    investments needed to ensure that NASA's aeronautics research,
    facilities, and workforce are positioned to enable the
    transformation in aviation that we are discussing today.
        Thank you, and I yield back.

        Chairwoman Horn. And now I would like to take a moment to
    introduce our witnesses today.
        Our first witness is Dr. Jaiwon Shin, Associate
    Administrator of NASA's Aeronautics Research Mission
    Directorate, where he has the responsibility for the strategic
    direction and management of NASA's aeronautics research
    portfolio. Dr. Shin also co-chairs the National Science and
    Technology Council's Aeronautics, Science, and Technology
    Subcommittee. Dr. Shin has served on many--in many positions in
    NASA, including as Chief of Aeronautics Projects Office at
    NASA's Glenn Research Center. Dr. Shin received a bachelor's
    degree from Yonsei University in South Korea, and a master's
    degree from California State University, Long Beach, and a
    doctorate in Mechanical Engineering from Virginia Polytechnic
    Institute and State University. Welcome, Dr. Shin.
        Our second witness is Dr. Alan Epstein. Dr. Epstein is the
    R.C. Maclaurin Professor of Aeronautics and Astronautics
    Emeritus, and is the former Director of Gas Turbine Laboratory
    at the Massachusetts Institute of Technology (MIT). Previously
    Dr. Epstein was the Vice President of Technology and
    Environment at Pratt and Whitney, an aerospace manufacturing
    company. Dr. Epstein is the Chair of the National Academies of
    Aeronautics and Space Engineering Board, and is a member of the
    NASA Advisory Council. Dr. Epstein is a member of the U.S.
    National Academy of Engineering, and past Chair of its
    aerospace section. Dr. Epstein received his bachelor's,
    master's, and doctorate degrees from the Massachusetts
    Institute of Technology. Welcome, Dr. Epstein.
        Our third witness today is Dr. Ilan Kroo, the Thomas V.
    Jones Professor of Aeronautics and Astronautics, and Director
    of the Aircraft, Aerodynamics, and Design Group at Stanford
    University. Previously Dr. Kroo served as the founding CEO of
    Zee.Aero, now Kittyhawk, and E-VTOL--did I do that right? I
    didn't do it quite right. You can correct me later--
    Manufacturing Company. Dr. Kroo is currently a member of the
    National Academies of Aeronautics and Space Engineering Board,
    and is on the American Institute of Aeronautics and
    Astronautics, Aircraft Design Technical Committee. Dr. Kroo is
    a member of the U.S. National Academy of Engineering, and
    received his bachelor's, master's, and doctorate degrees from
    Stanford University. Welcome, Dr. Kroo.
        Our fourth and final witness is Dr. Mark Lewis. Dr. Lewis
    is the Director of the IDA Science and Technology Policy
    Institute. Dr. Lewis also served as the Willis Young, Junior
    Professor and Chair of the Department of Aerospace Engineering
    at the University of Maryland. Previously Dr. Lewis was
    President of the American Institute of Aeronautics and
    Astronautics, and served as an advisor in the Air Force. Dr.
    Lewis is a member of the National Academies of Aeronautics and
    Space Engineering Board. He received his bachelor's, master's,
    and doctorate degrees from the Massachusetts Institute of
    Technology. Welcome, Dr. Lewis. You'd think that MIT might know
    a thing or two about aerospace, aeronautics, based on this.
        As our witnesses, you should know that you each have 5
    minutes for your spoken testimony. Your written testimony will
    be included in the record for the hearing. And when you've
    completed your spoken testimony, we'll begin with questions.
    Each Member will have 5 minutes to question the panel. And we
    will start today with Dr. Shin. Dr. Shin, you're recognized for
    5 minutes.

                      TESTIMONY OF DR. JAIWON SHIN,

              ASSOCIATE ADMINISTRATOR, AERONAUTICS RESEARCH

                        MISSION DIRECTORATE, NASA

        Dr. Shin. Thank you, Madam Chair, Ranking Member Babin, and
    Members of the Subcommittee. I really appreciate to have this
    opportunity to discuss FY 2020 budget request for NASA
    Aeronautics Research Mission Directorate. I would like to thank
    you for your continued support of the groundbreaking work good
    women and men in NASA Aeronautics are performing. Aviation is
    fundamental to the future of U.S. economy. NASA's cutting-edge
    aeronautics research is delivering new concepts and
    technologies, boosting U.S. global leadership, and creating
    high-quality jobs. Growing consumer demand, combined with
    innovative technologies and disruptive thinking, is
    transforming aviation in ways we could hardly imagine just a
    few years ago.
        Since 1973, commercial supersonic flight has been banned
    over land in the U.S. and around the world due to concerns of
    sonic boom. Over the past 10 years or so, NASA has developed
    technologies that will greatly reduce sonic boom noise. With
    support from the Congress, NASA is now building a quiet
    supersonic experimental aircraft, X-59 Quest, with a commitment
    for first flight by Fiscal Year 2022. Once built, NASA will
    measure public response to the sonic boom noise, and deliver
    the data to the FAA and the International Civil Aviation
    Organization to enable new rules allowing commercial supersonic
    flight over land, which will spark U.S. aviation industry's
    innovation and investment to take the global leadership
    position in developing future commercial supersonic airplanes.
        Subsonic aircraft will still carry the majority of
    passengers in the foreseeable future, but demands for reduced
    fuel burns, noise, and emissions are growing rapidly. NASA is
    collaborating with U.S. industry to develop innovative
    technologies, such as efficient wing designs, electric
    propulsion, and transformative materials and structures. Hybrid
    electric, or all electric propulsion, is being explored by
    aviation industry to bring dramatic reductions in fuel burns
    and emissions for future aircraft. NASA has been--NASA has
    begun a multi-year effort to enable one megawatt power electric
    propulsion system, which defines a critical technological
    milestone for electrification of aircraft, stirring notable
    international competition. Realizing an aviation grade one
    megawatt propulsion system has never been accomplished. NASA
    has built a world-leading ground test facility called NASA
    Electric Aircraft Test Facility, or NEAT, and we are already
    conducting a test of a high power electric propulsion system
    with our industry partner.
        The change to the aviation system also requires changing
    the way air traffic is managed. NASA has been developing
    innovative technologies to enable highly efficient air traffic
    management systems, while maintaining safety by collaborating
    with the FAA, airlines, and airport operators. Once such
    example is a new integrated surface management capability NASA
    is developing which will enable aircraft to move from the gate
    to take off without stops--any stops and waits. Our
    collaboration with FAA and operators at Charlotte International
    Airport has already saved 1.6 million pounds of fuel, and
    reduced emissions equivalent to over 57,700 trees in just the
    first 15 months of trials. FAA plans to deploy this technology
    to 27 of the Nations' biggest airports beginning in 2021.
        Increased use of autonomous systems is opening up
    completely new markets, such as commercial drone industry.
    NASA's research into UAS (unmanned aircraft systems)--
    communication and air traffic management has served as a
    critical enabler of the industry that did not exist only a few
    years ago. For example, under NASA's leadership, the most
    complex demonstration of the UAS traffic management, or UTM
    system in downtown Reno, Nevada, is scheduled to end the 10-day
    flight test tomorrow with great success. NASA has conducted
    four major capability demonstrations, including this one, in
    the last 4 years, which provided to be critically important
    steps toward enabling safe, efficient commercial flights of
    small UAS in dense urban environments. Just as a brand new
    drone industry is blossoming, another exciting industry called
    urban air mobility, or UAM, is emerging. Without NASA's only
    work in small UAS, a vision to open the skies over our
    communities, to move people and cargo safely, would not have
    been even conceivable. NASA is closely working with new
    industry--this new industry to rapidly develop key
    capabilities, such as reducing noise, and ensuring safety of
    our vehicles.
        The global aviation system of mid-21st century is emerging
    today. NASA Aeronautics strengthen the foundation of U.S.
    global leadership by working with traditional and emerging
    market players to bring exciting future for aviation. Thank you
    for this opportunity to testify today, and I look forward to
    answering any questions you may have.
        [The prepared statement of Dr. Shin follows:]

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        Chairwoman Horn. Thank you, Dr. Shin. Dr. Epstein?

                    TESTIMONY OF DR. ALAN H. EPSTEIN,

                  R.C. MACLAURIN PROFESSOR EMERITUS OF

                 AERONAUTICS AND ASTRONAUTICS, MIT, AND

             CHAIR, AERONAUTICS AND SPACE ENGINEERING BOARD,

              NATIONAL ACADEMIES OF SCIENCES, ENGINEERING,

                              AND MEDICINE

        Dr. Epstein. Madam Chair, Ranking Member Babin, Members of
    the Subcommittee, I am please to address NASA's role in
    aviation. I believe that we are living in the most exciting era
    for aviation in the last 50 years. Opportunities include ultra-
    quiet flight, true air taxi service, and low boom supersonic
    travel. Challenges include environmental concerns, rising
    foreign competition, and, of course, safety. Adding to the
    excitement are new entrants backed by venture capital, many of
    whom are outside the U.S.
        Government should care because the U.S. owns 49 percent of
    the world's $800 billion-a-year aerospace business. Other
    countries understand the importance of this market, and are
    making concerted attacks. First Europe with Airbus, and now
    China. To no small degree, NASA Aeronautics holds stewardship
    of this Nation's aeronautical future. Let me point out that
    shortly after the turn of the century the Aeronautics budget
    was cut by more than half in terms of operational funds. So,
    for the past 2 decades, Aeronautics has made due with
    relatively modest resources.
        I would now like to touch a few areas in which NASA can
    have significant impact. For example, the X-59 airplane will
    validate the concept that airplane shape can dramatically
    reduce sonic boom. This aircraft will then generate data from
    cooperating communities on peoples' tolerance for low intensity
    booms. This will provide a foundation to the FAA to re-examine
    its ban on over-land supersonic flight, and help them work with
    the international community to set certification standards for
    supersonic aircraft.
        A second is urban air mobility. Air taxis have been a dream
    since the 19th century. Such vehicles are now technically
    feasible. Public acceptance requires very low noise, and close
    to accident-free operation, areas of NASA's strength. More
    challenging is the need to safely integrate large numbers of
    these new vehicles into our crowded airways. NASA has an
    important technology role to play here as well.
        Now I'd like to touch on a topic for which I'm passionate,
    airplane noise. As we all know, community noise is a major
    irritant. People simply don't want airport noise. Progress in
    noise reduction has now reached the point where I believe we
    can envision aircraft so quiet that they would not be noticed
    in an urban environment. Virtually silent airliners would bring
    enormous relief to communities, and stimulate an expansion of
    air travel. With aggressive NASA action, I believe that such
    ultra-quiet airliner technology could be ready by the end of
    the next decade.
        Last, I would like to address climate change's threat to
    aviation. Some have misidentified aviation as a major factor in
    global warming, and so even attack the idea of flying. For
    example, the Bishop of London declared vacation flying a sin,
    and flight shaming is growing in Scandinavia. In fact, modern
    airplanes produce less CO2 per passenger mile than
    do cars and trains in this country. Nevertheless, the threat is
    real. In response, industry leaders pledge to halve aviation
    CO2 by 2050. Such progress requires reducing the
    energy needed for flight, and the fossil carbon of that energy.
    More than 98 percent of aviation CO2 comes from
    large aircraft flying distances more than 500 miles, so
    significant reduction requires focusing on airliners, not
    general aviation or small regional aircraft.
        Also, we now understand that aviation can't follow the auto
    industry in moving toward battery-powered vehicles. There's no
    battery technology on the horizon suitable for large electric
    airliners. Even if a breakthrough enabled battery power, it
    would make things worse rather than better, because modern
    engines produce less CO2 per unit of power than does
    the Nation's power grid, and will likely do so for the next
    several decades. NASA's work on energy reduction should focus
    on efficient aircraft and engines.
        In summary, this is an extraordinarily exciting time for
    aviation. Civil aeronautics is a major economic strength of the
    United States, and a strong NASA Aeronautics is needed to
    maintain that strength. The leadership and support that NASA
    provides is important at all levels. Supporting students in
    basic university research, stimulating new concepts, and
    exploring technology at larger scales, as with X planes. Thank
    you.
        [The prepared statement of Dr. Epstein follows:]

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

        Chairwoman Horn. Thank you, Dr. Epstein. Dr. Kroo?

                       TESTIMONY OF DR. ILAN KROO,

               PROFESSOR OF AERONAUTICS AND ASTRONAUTICS,

                           STANFORD UNIVERSITY

        Dr. Kroo. Madam Chair, Ranking Member Babin, and Members of
    the Committee, thank you for the opportunity to speak today. My
    remarks will deal with NASA's continuing contributions to
    aeronautics research and development. They represent my
    personal views, not those of any organization, although they
    were informed by many years of working with startup companies,
    government agencies, and university students. All of these
    groups, and indeed the general public, are aware of the many
    technology advances that promise to transform aviation not just
    in the distant future, but in the next decade, and perhaps in
    the next few years.
        So, when I was asked to talk today I looked on my desk, and
    found that there were all these magazines that discussed just
    that. And, in fact, headlines from multiple national and
    international magazines dated this month, and, as the Chair has
    pointed out, even some dated this week, talk exactly about
    those things, and they talk--they tout the technologies, and
    imminent advantage--advances in aeronautics that may result
    from new technology development. These technologies include
    many in NASA's research profile. Autonomy, as Dr. Shin
    mentioned, and includes machine learning, improved flight
    sensors and actuators. New control theory allows increasingly
    capable and reliable autonomous systems for aircraft, and it
    will reduce the cost of commercial air transport, enable on
    demand aerial delivery of various goods, and increase the
    safety of both piloted and unpiloted aircraft. Another
    technology that's talked about in these magazines is new fuels,
    and efficient high-power electric systems. These will make
    possible a new generation of environmentally sustainable
    propulsion, and more efficient aircraft.
        So these technology elements are being combined with
    advanced methods for aero and structural modeling and design to
    create entirely new types of vehicles from, as you've heard,
    small subsonic aircraft, with dramatically reduced noise and
    emissions, to atmospheric satellites that fly without pilots at
    altitudes above passenger aircraft. This is why an
    unprecedented number of students are enrolling in aerospace
    courses and clubs. Why computer science, despite the fact that
    Stanford, unlike MIT, is a liberal arts school, and they study
    philosophy, and economics, and things like that, but--the
    biggest department that graduates the most students is computer
    science. Still, many of our students are interns at companies
    that did not exist just a few years ago, and are studying a
    wide range of these things that will be of use to them in the
    future. It is certainly one of the most interesting periods in
    the development of civil aviation.
        But many students, and most aviation-related startups, and
    even many aeronautical researchers, have little idea of what
    NASA is doing in these technology areas, which is interesting.
    Articles in the popular press deal with flying cars, and
    electric airplanes, on demand delivery, and new companies
    working on supersonic prototypes. But in many of these
    articles, NASA goes unmentioned. So we have some of these
    magazines talking about 10 different technologies that are
    currently under development. Some of them tout how we're going
    to be delivering blood to Rwanda to help citizens there, and
    there are these compelling images of small aircraft without
    pilots delivering things where they are needed. But those small
    airplanes don't have NASA logos on them. Why is that? It's--it
    is the case also that many of these companies have to deliver
    convincing demonstrations to some of the--their investors
    before NASA has a chance to do the research that's required to
    make them go to the next level.
        [The prepared statement of Dr. Kroo follows:]

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

        Chairwoman Horn. Thank you, Dr. Kroo. We look forward to
    hearing more from you when we begin the questions----
        Dr. Kroo. Very good.
        Chairwoman Horn [continuing]. So thank you very much. Dr.
    Lewis?

                      TESTIMONY OF DR. MARK LEWIS,

               DIRECTOR, IDA SCIENCE AND TECHNOLOGY POLICY

             INSTITUTE, AND PROFESSOR EMERITUS OF AEROSPACE

                   ENGINEERING, UNIVERSITY OF MARYLAND

        Dr. Lewis. Madam Chair, Ranking Member Babin, distinguished
    Members of the Committee, thank you for the opportunity to
    testify today. I'm going to focus my remarks on NASA's role in
    hypersonics research, a field that holds the potential--what I
    think are truly transformative accomplishments in aeronautics.
    As I'm sure you all know, hypersonics is a broad area of
    inquiry. It generally refers to flight in excess of about 5
    times the speed of sound, that's Mach 5. An aircraft traveling
    at Mach 5 is traveling about a mile per second, so that means
    that an airplane flying from Dulles Airport to London, Heathrow
    at hypersonic speeds could get there in less than an hour, so
    talk about transformative.
        We've actually been flying hypersonic vehicles of one sort
    or another since the late 1940s. This is not a new field, but
    there are still many fundamental problems left to be solved.
    One of them is propulsion. Conventional jet engines won't work
    at hypersonic speeds, and that means you have to use either
    rockets, or what we call advanced air breathing engines, such
    as scram jets. Also, at high speeds, friction with the air
    makes the surface temperatures really hot. That means you
    stress the limits of materials, and so it calls for advances in
    high temperature materials. Control of a hypersonic vehicle is
    also an issue, as is the overall design of a hypersonic
    configuration that's fully integrated with its engines and
    airframe, and NASA has significant expertise in each of these
    areas.
        So historically NASA Aeronautics and its precursor, the
    NACA, that Ranking Member Babin referenced, have made notable
    contributions to the evolution of hypersonic flight, including
    our basic understanding of the physics of re-entering
    spacecraft, traveling, in some cases, at 40 times the speed of
    sound. That work continues today. NASA engineers study the
    problems associated with decelerating large spacecraft in the
    thin atmosphere of Mars. They've developed new high-temperature
    materials, including the material that's going to shield the
    SpaceX Dragon capsule. That's material that was invented by a
    team at the NASA Ames Research Center.
        That scramjet engine that I mentioned a moment ago was
    invented by NACA researchers working what is now the NASA Glenn
    Research Center. They did that work in the late 1950s, and 46
    years later engineers at NASA Langley, working with NASA
    Dryden, now Armstrong, flew the first operational scramjets on
    the X-43 experimental vehicle, once at nearly Mach 7, 7 times
    the speed of sound, and again at Mach 10. NASA also did key
    computational experimental work in support of the Air Force's
    own unmanned X-51 flights that flew between 2010, 2013. NASA
    even provided the chase planes that monitored the X-51 craft,
    gathered essential flight data.
        NASA propulsion engineers and materials experts are playing
    key roles in several programs, including DARPA (Defense
    Advanced Research Projects Agency) activities, the U.S./
    Australia high fire flight program. And I'll point out when
    engineers at the U.S. Air Force's Hyper Velocity Tunnel Number
    Nine, that's the Nation's premiere high-speed wind tunnel,
    needed a new way to measure model temperatures, they turned to
    their colleagues at NASA Langley to do that. NASA has developed
    many of the standard hypersonic aerodynamics models that we
    use. The agency also operates test facilities, including the
    Langley 8-foot-high temperature tunnel that has gathered data
    on nearly every significant air breathing hypersonic engine,
    including those that powered X-43, X-51, and the upcoming DARPA
    Hawk designs. Tunnel--the 8-foot tunnel is an irreplaceable
    national asset, and not just the tunnel itself, but the NASA
    test engineers and technicians who operate it.
        Research into hypersonic flight may someday lead to ultra-
    fast commercial aircraft, may lead to new ways to reach Earth
    orbit with airplane-like launch vehicles, and these are wholly
    appropriate, I would argue, for NASA Aeronautics research. But
    the proverbial elephant in the room is that the likely--is the
    likely military use of hypersonics, including ultra-fast,
    nearly unstoppable missiles and reconnaissance craft. In 2016,
    I chaired a National Academies study that reported that both
    Russia and China were advancing quickly in the field, and
    moving to operational deployment. We are in a race, and I
    believe that NASA must help our national address this threat. I
    further believe that role is completely consistent with NASA's
    mission, as codified under the Space Act. NASA has the
    capabilities and hypersonics that no other Federal agency can
    employ.
        Now, NASA's hypersonics investments began to languish,
    starting in 2012, when a roughly $60 million portfolio was
    allowed to drop to less than $10 million within about 2 years.
    More recently, NASA's hypersonics funding levels have been on
    the rise, just as our national programs are hitting limits of
    capacity and workforce, though they're still at only about half
    their levels in pre-2012. NASA's re-investment has included
    much needed maintenance on the Langley 8-foot tunnel, without
    which some of our national programs would come to a screeching
    halt. That's a promising start, but for our Nation to lead the
    world in hypersonics, I argue we must create a challenging
    future vision.
        The future success of hypersonics ultimately hinges on our
    ability to integrate computational and experimental
    capabilities. NASA is the ideal agency to lead such an effort.
    World-class research requires world-class researchers. We must
    have access to affordable, flexible, world-class modeling and
    test capabilities, and to do this we need to sustain and expand
    NASA's hypersonic test infrastructure, including the possible
    re-commissioning of the hypersonic test facility at NASA's Ohio
    Plumbrook campus. And, of course, we cannot relinquish our
    investments in fundamental research, both inside NASA and in
    the university community that NASA sponsors. With the promise
    of flying higher and faster, hypersonics is a great way to
    attract the best and the brightest to careers in aerospace.
        In conclusion, I'm convinced that NASA Aeronautics has a
    critical role to play in pursuing hypersonics research that
    will transform our civil commercial, and national security
    activities, and inspire the next generation. In its mission to
    transform aviation, I know of no worthier investment in the
    NASA Aeronautics portfolio. Thank you very much.
        [The prepared statement of Dr. Lewis follows:]

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

        Chairwoman Horn. Thank you very much, Dr. Lewis, and we'll
    observe any future back and forth between the Stanford and the
    MIT crowd out there. We'll keep an eye on you. At this point
    we'll begin our first round of questions, and the Chair
    recognizes herself for 5 minutes.
        Doctors Epstein, Kroo, and Lewis, this Committee will be
    working to reauthorize NASA this year, and I've got a number of
    questions. Just briefly, what are your top three priorities for
    aeronautics for NASA authorization, and why? We can just go
    down the----
        Dr. Epstein. OK. Well, my personal passion is for anti-
    noise. More accurately, NASA research to dramatically reduce
    the noise impact on our communities. I think that same sort of
    research also helps make much more efficient airplanes. So high
    on the priority would be a--enough funding to start an X
    airplane for subsonic commercial travel, with enormously
    reduced noise, and much reduced CO2.
        The second would be everything associated with UAM, which
    is an enormous potential market, a transformer of society, and
    I think we're at the most risk internationally of--we don't
    have a lead yet. We'll see if we end up with one. Thank you.
        Dr. Kroo. So I believe that many of these new companies, as
    well as the old companies, very much need help from NASA, and
    one has to figure out how it is that NASA can work with the
    many new players, the many new participants, in this field who
    are going to make some of these things happen, and I think that
    that is not clear yet how that will be done, but it's important
    to make sure it happens.
        Dr. Lewis. Well, of course I'm going to say hypersonics.
        Chairwoman Horn. I would never have guessed.
        Dr. Lewis. That's shocking. And not just facilities, but
    also workforce and fundamental research. Number two, I would
    say the X plane program, and the X-59 is a particularly
    exciting example. We need to fly things, we need to get
    experience in flight, and we need to be pushing the flight
    envelope. And then three, I'd say fundamental research, and I
    would take my hat off to the NASA Aeronautics Research mission
    director. I think they've led the way at NASA in fundamental
    research in support of universities and students, and feeding
    into our workforce.
        Chairwoman Horn. Thank you. And, as I noted in my opening
    statement, the CTOs--the Chief Technology Officers--of those
    seven companies came together at the air show to talk about how
    the aeronautics industry can work to reduce emissions and--in a
    sustainable way for aviation, which is important for us to
    address both. And the joint statement, which I submitted for
    the record has a three-prong strategy. One, improving aircraft
    and engine design and technology to improve fuel efficiency and
    reduce CO2 emissions; two, supporting sustainable
    alternate aviation fuels; and three, developing a new aircraft
    propulsion technology to enable a third generation of aviation.
        Dr. Epstein, given your experience in this industry, how
    important is a clear strategy for the industry's ability to
    plan for future technology and workforce needs? I think you
    touched on it a moment ago, but if you want to expand?
        Dr. Epstein. The industry reminds me of the comment by
    Benjamin Franklin, we hang together, or we hang separately, and
    the attack around the world on aviation affects all of us. In
    terms of climate change impacts on CO2, the
    sustainable alternative jet fuel is enormously important, and
    how that affects the agricultural economy in this country I
    think is equally important. And so, for example, ethanol is a
    big factor in much of the country. The auto industry doesn't
    want it. Aviation would embrace it. So getting not just the
    purview of this Committee on Science and Technology, but Energy
    and Agriculture as well to focus on a lot of this is, I think
    economically important.
        Chairwoman Horn. And for the rest of the panel, I would
    love to hear which of the three prongs of this strategy you
    think NASA can get the most bang for the buck, as it were, to
    move forward for investment on the NASA side.
        Dr. Kroo. Well, I must say I agree with many of these
    comments, and they will get a lot of mileage out of these
    investments. I do think that, in the near term, things such as
    alternative fuels, and increased efficiency, are much more
    important than the longer-term advances, and many of these
    longer-term concepts require very new ideas in both fuels and
    propulsion systems.
        Chairwoman Horn. Dr. Lewis?
        Dr. Lewis. And I would agree as well. I argue that an
    aerospace system is fundamentally an energy conversion system.
    As aerospace engineers, we do everything we can to get every
    last bit of energy out of our available fuel--out of our
    available energy supply. So aerospace has a lot of lessons to
    propagate to other parts of engineering disciplines on how to
    be energy efficient, how to use fuels effectively, how do to
    alternate fuels, how to do alternate energy sources, and I
    think NASA has a very important role to play in that.
        Chairwoman Horn. Thank you. Dr. Shin, would you care to
    comment briefly?
        Dr. Shin. Yes. I think, as the other witnesses summarized,
    and--in terms of priorities in near-term, and mid-term, and
    longer-term contributions, we--I want to say that NASA has been
    working on all those areas, improving the fuel efficiency and
    reducing emission from the engine research. And also we have
    done a major flight test of the alternative fuels with,
    actually, international partners from Germany, and Canada, and
    Japan. So--and then we're also working on lighter, stronger
    structures, so reducing the weight of aircraft will require
    less fuel burns. So, all those things need to be coming
    together. And, as other witnesses say, that it's not one magic
    bullet, or it's not one big gun that we can use to reduce these
    fuel burns.
        And, in fact, if I may add, in fact, I was at Paris Air
    Show last week, and I actually met with these industry CTOs.
    After the news conference they had, they meet regularly, and I
    was invited to join that meeting, so we did amply talk about
    this, and they were very appreciative of what NASA has been
    doing.
        Chairwoman Horn. Thank you, Dr. Shin. I've exceeded my
    time. Dr. Babin?
        Mr. Babin. No problem. Thank you, Madam Chair. Dr. Lewis--
    let's see, where was that article. OK, yes. A recent New York
    Times article, which I would like to ask to be put into the
    record, if you don't mind, if there's no objection----
        Chairwoman Horn. No objection.
        Mr. Babin [continuing]. Highlighted the current state of
    hypersonic research in the world, and it laid out the threat
    posed by hypersonic weapons being developed by China and
    Russia. General John Hyten, Commander of the U.S. Strategic
    Command, told the Senate Armed Services Committee in March
    2018, ``We don't have any defense that could deny the
    employment of such a weapon against us.'' Your testimony lays
    out how NASA's infrastructure and expertise enable our Nation's
    overall hypersonic program. Is greater coordination between
    NASA and other government agencies necessary to ensure American
    leadership and national security?
        Dr. Lewis. Thank you, Congressman. Well, first, I would say
    that NASA is doing a very fine job of coordinating with
    Department of Defense (DOD), and they've become a critical
    player in some of the work that's underway. I will give you an
    example. In my testimony I mentioned the 8-foot tunnel at NASA
    Langley.
        Mr. Babin. Right.
        Dr. Lewis. That's one of only two locations in the United
    States where you can do a full-scale hypersonic engine test.
    Right now the other location is not available, it's down for
    maintenance. So NASA is absolutely critical for much of the
    work that we're doing. But I think it goes beyond that. If
    you--I mentioned some of the contributions of NASA engineers,
    everything from material science, to controls, to understanding
    of propulsion technologies. NASA has been, and continues to be,
    critical players in each of those aspects, and supporting the
    national efforts, including Air Force--efforts with the Air
    Force, efforts with DARPA, and even some fundamental research
    efforts that were funded by the Department of Defense. So yes,
    I think they're absolutely critical.
        Mr. Babin. OK. Thank you, Dr. Lewis. The next question is
    for Dr. Shin and Dr. Lewis. NASA conducts aeronautics research
    on urban air mobility, and is developing the X-57 Maxwell, an
    electric aircraft that will demonstrate technologies to reduce
    fuel, noise, and emissions. I presume there are market demands
    for such technologies from either commercial aviation, general
    aviation, or both. From the dawn of aviation we've seen that
    top down, centrally planned research and development approaches
    are often eclipsed by free market responses to technological
    challenges. In face of other nations significantly subsidizing
    their aeronautics and aviation sectors, how should NASA
    approach this challenge of supporting free market principles,
    while also maintaining long-term aeronautics leadership? Dr.
    Shin, if you would first?
        Dr. Shin. Yes. Thanks for the question. In terms of urban
    air mobility, just like your emphasis on the free market
    economy that our Nation holds, we believe in that, so we are
    not--as an example, NASA, as a government entity, we are not
    investing to duplicate vehicle designs in this new industry
    because there are, last time I checked, over 150 entities
    working on these various design concepts, and billions of
    dollars are being invested from private sectors. So what we are
    working on is how do we enable these private investment to
    become the real, viable, and scalable market by working on
    system-level issues, community-wide issues, such as noise
    reduction and safety--ensuring safety, and how do we actually
    expedite, and cost-effective certification can be allowed for
    these vehicle designers. So, working with FAA, I think we have
    found a really nice government role, again, closely working
    with industry, but that's the way we believe how we enable this
    exciting future.
        Mr. Babin. OK. All right. Thank you. And, Dr. Lewis?
        Dr. Lewis. So I would argue that NASA's primary role is
    investing in areas that industry won't, or doesn't have the
    wherewithal, or that it's too far term. And I--again I would
    congratulate the NASA portfolio, because I think they've done a
    fine job of identifying key investments, key areas. If you look
    at some of the work that NASA's done, for example, on our
    advanced configurations for commercial airliners, they've done
    things that, frankly, I can't see an industry partner doing
    right now because it's really too speculative. In propulsion,
    the work that NASA has done looking at very advanced
    propulsion, again, wholly appropriate, because I don't see it
    as something that the industry necessarily would have the
    resources or the wherewithal to invest until NASA has proven
    the concept, and then handed it off to industry. I think we've
    got many examples of technologies that NASA has helped develop,
    and, once they developed it, were able to hand off to industry
    very successfully.
        Mr. Babin. OK. Thank you very much. And I've got more
    questions, but I'm out of time, so I'll yield back.
        Chairwoman Horn. Thank you, Mr. Babin. The Chair recognizes
    Mr. Olson for 5 minutes of questions.
        Mr. Olson. I thank the Chair, and welcome to our four
    expert witnesses. I'll open with an observation. Much has been
    said about Stanford and Harvard. Those are great, great schools
    to be sure, but, as a graduate of Rice University in Houston,
    Texas, we call those schools the Rice of the West Coast and the
    Rice of the East Coast, and that's just the way it is.
        My first question for you, Dr. Shin and Dr. Lewis, as a
    former Naval aviator, I have a great interest in the low boom
    flight demonstration projects. As was mentioned by I think Dr.
    Epstein, we have not allowed supersonic flights over America
    since 1973. My district is home to Ellington Joint Reserve
    Base. As you all may know, last year NASA test pilots flew
    modified F-18s out of Ellington to do some series of tests of
    low noise level sonic booms. It was called QSF-18. If possible,
    can you all update me on this project, especially if these test
    flights can help with supersonic travel in the future? Dr.
    Shin?
        Dr. Shin. Yes. I want to say up front, many things to that
    community, and also we tested that low boom through the
    customized maneuver because we don't have a low boom supersonic
    airplane as yet. We're building it, in collaboration with
    Lockheed Martin. But in the city of Galveston, we actually flew
    that F-18 that you mentioned, and--with tremendous support from
    Ellington and Johnson Space Center. And the community response
    has been actually very positive, that they actually liked
    being--participating in that flight test, measuring the
    community response.
        So the best measure of success, in my view, is the city of
    Galveston asked us, NASA people, to please come back when you
    actually have X-59 completed, and do this again in our
    community, because this is exciting. And this is exciting
    because we are trying to help flying public, general flying
    public, not the rich people only, but flying public to enjoy
    the supersonic flight, commercial supersonic----
        Mr. Olson. I'll pass those comments on to Mr. Weber,
    because Galveston is in his district. As you mentioned, too,
    they were so excited because, for the first time ever, the
    Johnson Space Center participated in operations in the Earth's
    atmosphere, not in the vacuum of space. Dr. Lewis?
        Dr. Lewis. So I share, I think, a frustration that you
    alluded to, that we are not flying at supersonic speeds today.
    It's been over 15 years since we had commercial supersonic
    travel in the U.S. And, of course, you know, in the 1960s the
    U.S. had its own plan to build a supersonic transport, NASA had
    a subsequent program in the 1990s, and yet we're still flying
    at about the same speed we flew in the 1950s, so I would love
    to see supersonic travel.
        Last month I and some of my colleagues were--had the
    privilege of visiting NASA Armstrong, and to climb on--look at
    the work that's being done on the X-59, and I have to tell you,
    it's absolutely phenomenal progress. It's a program that's
    basically getting NASA back into the flight test business. We
    got to fly the simulator, I got to crash the simulator, and
    it's--I think it's going to be an important milestone not in
    helping us re-introduce supersonic flight, but also getting
    NASA back into the flight test rhythm that is so critical to
    our industry.
        Mr. Olson. Thank you. Final question for Dr. Shin. In your
    testimony you mentioned that there'll be excessive growth in
    aviation in the future, and a shortage of pilots to fly these
    future aircraft. As you probably know, Ellington Field has been
    selected as a commercial spaceport. It's been approved. Their
    plan is for space tourism, basically following the same profile
    that Alan Shepherd followed on the first Mercury launch. Take
    off horizontally, go vertical, go into space for maybe 10, 15
    minutes and come back and land. They're going to need pilots.
    Our current aviation needs pilots. So how can NASA help
    recruit, develop, and train our future pilots, especially ones
    that are going into space?
        Dr. Shin. Yes. Whether we stay in the air or go into space,
    as you mentioned, the pilot shortage could become a real issue,
    so we've been working with our industry to bring more autonomy
    in the cockpit. I'm not suggesting that we are going to reduce
    the number of pilots in the cockpit, but by introducing safe,
    and efficient, and cost-effective autonomous systems, on top of
    what we already have, could probably reduce the workload of the
    pilots, and pilots' roles could be changing in the future. So
    some of these measures need to be introduced with care, of
    course, but some of these measures need to be researched for
    the longer term. It's not a--solution, or it's not something
    that we're going to just do it in a hurry. So that's what--we
    are working with industry.
        Mr. Olson. I yield back. Thank you very much.
        Chairwoman Horn. Thank you. The Chair now recognizes Mr.
    Posey for 5 minutes.
        Mr. Posey. Thank you, Madam Chair, for holding this
    Committee, and thank the witnesses, very impressive, for
    attending today and sharing your knowledge with us. In keeping
    with today's subject, NASA's aeronautics mission, enabling the
    transformation of aviation, it was interesting to hear Dr.
    Lewis say he thinks NASA's mission is essentially doing those
    things that private industry cannot do, which I pretty much
    think is the role of government, you do for the people what the
    people cannot do individually, you do collectively for them.
        And, Dr. Shin, I heard your reference to working with FAA,
    and having some good experiences, but it brings to mind some
    very bad experiences that I've seen with FAA, a terrible waste
    of resources. You may recall--you're all old enough to recall
    when the United States basically controlled 100 percent of the
    world's commercial launch market for satellites, commercial
    satellites, and, through overregulation of Federal bureaucrats,
    we parlayed that into about 15 percent, almost completely
    choked the golden goose, and created the competition that we
    have today for the commercial launches in other countries.
        You mentioned space support vehicles earlier. We have a
    contractor in my district, Space Support Vehicle. They've done
    years and years' worth of parabolic missions for NASA. It's so
    much easier to put an experimental of an F-104 with a pilot
    that's flown a zillion hours, and test the gravitational effect
    of the payload than it is to launch a dispensable rocket, or
    whatever. And, you know, that's one little company. They
    decided, you know, we'd like to take people up too for this,
    there's an interest in doing that, so they applied to license
    to the FAA. And the FAA said, well, you know, you're not a jet
    to go from Washington, D.C. to Orlando 50 times a day, and
    you're not Virgin Galactic, that we licensed before they ever
    put the first vehicle in the air, so we're not going to give
    you a license. I mean, they could get this license in any other
    country in the world, be delighted to have that business, but
    the unelected, unaccountable bureaucrats at the FAA couldn't
    get off center.
        So during the last session then Majority Leader McCarthy,
    with the support of a lot of co-sponsors passed legislation and
    said, you will be creating a licensing category for the space
    support vehicles, whereupon they have kind of refused to do
    that. And I'm wondering if you have other areas where you have
    observed this same kind of counterproductive behavior. I'd like
    to hear about it. Anyone.
        Dr. Shin. I'm sorry that you have had a lot of those
    examples, but from where I sit, I think, in the aviation side,
    FAA leadership, and our management and technical people, have
    really stepped up in trying to be proactive in opening up
    these--a lot of exciting markets that----
        Mr. Posey. OK, so you haven't experienced the downside.
    Anybody else experienced the downside, or am I supposed to take
    this personal? I'll take it personal, and work on their budget
    accordingly.
        Dr. Shin and Dr. Lewis, other agencies fund hypersonics at
    much higher levels than we do, however, NASA has unique
    facilities and expertise in that field, you know? Is there an
    opportunity for NASA to conduct work on a reimbursable basis
    for other agencies?
        Dr. Shin. I think that is entirely possible. And, as Dr.
    Lewis mentioned in his testimony, we have been cultivating a
    really robust, and very symbiotic mutually beneficial
    relationship with DOD in particular. But I think we can
    certainly increase the partnerships with other government
    agencies, and--because we have that core capability--technical
    capability both in workforce and in the facility as well.
        Mr. Posey. OK, Dr. Lewis?
        Dr. Lewis. So, as I mentioned, NASA's budget in hypersonics
    is a tiny fraction, frankly, of what the DOD is spending. But
    what they bring to the table is incredibly impressive. They've
    got depth of knowledge, they've got expertise. They understand
    aspects of the fundamentals that no other part of the
    government, which I'm aware, has. And I can cite success story
    after success story where NASA worked with the DOD in the
    hypersonic realm.
        One I'll give you right off the top of my head was when the
    Air Force was doing the X-51 program. So, we tested the engine
    for X-51 in the NASA facility. Then we had NASA engineers
    working on the X-51 program. We had NASA engineers in the
    control room the day of the first flight of X-51. I'm here to
    tell you if we didn't have those--that support, I don't think
    the program would have been as successful. It's absolutely
    critical.
        Mr. Posey. That's awesome. Madam Chair, I yield back. Thank
    you.
        Chairwoman Horn. Thank you, Mr. Posey.
        The Chair now recognizes Mr. Foster for 5 minutes.
        Mr. Foster. Thank you, Madam Chair, and thank you to our
    witnesses.
        Let's see. I've been musing about this low sonic boom
    technique, and I was wondering if any of you were willing to
    try to take a stab at telling a physicist how--you know, what
    are the actual breakthroughs that make it different than my
    memories as a toddler, listening to the sonic booms from the
    military jets operating out of Truax Air Field? What is new in
    the physics or in the design space makes this feasible?
        Dr. Shin. I'll give a stab at it, and--sure the witnesses
    are far more qualified to answer that.
        Certainly, we cannot change the physics or alter the
    physics, but what we were able to do is breaking the intensity
    of the shocks. So, rather than having the one big bow shock
    from the nose or the back end of the aircraft that shows the
    typical N-shape shockwaves, we break into smaller shocks and
    then they don't coalesce. They don't coalesce----
        Mr. Foster. Right, you just phase them so they partially
    cancel? Is that the basic plan?
        Dr. Shin. That's one technology we developed.
        Mr. Foster. Yes, sure, Dr. Kroo?
        Dr. Kroo. I think that is absolutely right. We could do
    some of that many years ago, and the additional technologies
    and breakthroughs that have happened have to do with improving
    computational capabilities for predicting these things before
    having to take so long to build them.
        Mr. Foster. And so, this will typically only work at one
    velocity to get the cancellation between all the wakes?
        Dr. Kroo. It actually works over a range of speeds, but
    over a smaller range, you can cancel out more of it.
        Dr. Epstein. I'll add something else. One is this was
    actually a theory developed by NASA, so no, it isn't new
    physics. It's understanding physics and exploiting your
    understanding. And because much of the action is in the far
    field, far away from the airplane, it's inadequate to test it
    just in a wind tunnel. That's why--we will fly a vehicle like
    this. Of course, it ends up as a strange looking long, skinny
    vehicle, but that's what the physics demands. And I certainly
    expect the X-59 to validate that.
        Mr. Foster. All right, that's interesting.
        Now, for a long time, I've wondered if there was some
    analog of noise canceling earphones that could be applied to
    the end of jet engines. I take it most of the takeoff noise is
    just turbulence in the back end of the engines, if I understand
    things correctly. What has ever been looked at, and is that
    still a fertile field to plow?
        Dr. Epstein. Airplane noise has been worked on for decades.
    It used to be rock bands were as loud as airplanes, so don't go
    to the rock concert. Rock concerts are still just as loud, but
    the airplanes have gone from about 125 dB down to 85.
        Mr. Foster. Um-hum.
        Dr. Epstein. And on the newest airplanes, the exhaust jet
    is not the major noise source, the fan is. And so, it doesn't
    matter whether you turn the fan with an electric motor, it's
    producing most of the noise. On the latest ones, on approach,
    if you shut the engines down, you wouldn't hear it on the
    ground because it's the airframe making most of the noise.
        Mr. Foster. On approach, but that's not----
        Dr. Epstein. Well----
        Mr. Foster. The complaints come from takeoff. At least
    around O'Hare, they come from takeoff.
        Dr. Epstein. Well actually, I addressed the O'Hare noise
    group. The complaints come from everywhere, I think.
        But strictly speaking, the noise is the fan noise. People
    have looked at active cancellation. You use some of it now. You
    do acoustic cutoff in the ducts by design of the physical
    acoustics. As we move to bigger fans, they're subsonic and it's
    a whole new world. So, I think there can be enormous progress
    in noise reduction. Because we've reached a cusp in our
    understanding.
        Mr. Foster. Yes. If I can go back to the low boom scenario.
    What is the range of velocities that you're reasonably hopeful
    that will work commercially? Are you still in the situation
    where the fuel consumption per mile is very non-linear as you
    keep increasing it? And so, what is the range of velocities
    that you really eventually hope that will operate over, in a
    commercially viable way?
        Dr. Kroo. There is a range. Probably the commercial
    viability is more related to the efficiency of these designs,
    but certainly in the Mach 1.-something to 2.-small number,
    these technologies can reduce the boom on the ground.
        Mr. Foster. OK. Thank you, and it looks like my time is up
    and I yield back the remainder.
        Chairwoman Horn. Thank you very much, Dr. Foster.
        I'm going to ask another round of questions. I think the
    Ranking Member will be back shortly. Since we had to move it
    around, I think we've lost a number of our Subcommittee Members
    today.
        Dr. Shin, I want to go back to one of the points we started
    with about workforce development, and the importance of
    aviation and aeronautics to the Nation and our economy, and
    what that means also for NASA.
        In my opening statement, I raised the question of whether
    or not we will have the workforce to realize the opportunities
    that we're working toward. So, along those lines, the NASA
    Advisory Council's Aeronautics Committee found that the next
    generation of aviation workers will need a different set of
    skills than the current generation, including artificial
    intelligence, cybersecurity--the cutting-edge issues in
    research that NASA is doing in order to handle the new
    technology, such as urban air mobility, drones, clearly
    hypersonics is another area that is important, and the nature
    of autonomy.
        So, how is NASA helping to prepare the workforce of this
    rapidly approaching future in aviation systems?
        Dr. Shin. Thank you. I think Madam Chair's observation and
    points are spot on. The aviation--not only aviation, but the
    entire 21st century industrial sector is changing because of
    the digital transformation to even new technologies, and the
    new ways of doing business.
        So, aviation industry as a whole, I think, it is
    experiencing and will experience--continue to experience
    competition of the top talents with more IT or those
    industries.
        So, what NASA--what we believe is we have to provide
    exciting missions. We are celebrating 50th anniversary of Moon
    landing this year, and I am the product of Apollo 13--11 Moon
    landing. So, we believe that providing that exciting missions
    so that the younger generation can actually look up to what
    they can do and what they can accomplish in aviation, be it
    really the key.
        Chairwoman Horn. Thank you, Dr. Shin.
        A short question. What, if any, additional hiring
    authorities might NASA need to attract that workforce?
        Dr. Shin. Our Human Capital Management office has been
    working really hard to figure out whether we can get more
    flexibility. So, I'm certainly not an expert in answering the
    question, but I think our agency, Human Capital Management can
    provide more details.
        Chairwoman Horn. If you want to take that for the record
    and come back to us, that's great.
        So, another question, turning a little bit toward some of
    the points that Dr. Lewis--that you made, especially around the
    importance of NASA and government investment in those cutting-
    edge technologies before they're ready to move onto the
    commercial sector.
        I noted in my opening statement the shift in budget, and
    looking forward with the important research and development
    that NASA needs to do in hypersonics, in urban air mobility, in
    noise, and other things. We are looking toward a likely
    decrease of funding for Fiscal Years 2023 and 2024.
        So, my question for each one of you quickly is how would
    such decreases of up to 12 percent affect the development of
    innovative capabilities such as supersonics, hypersonics, urban
    air mobility, and in aeronautics research, and then the follow
    on transition to commercialization?
        Dr. Kroo. In many of these areas, not developing these
    technologies will mean many of the possible airplanes that
    companies would develop are just not going to get developed.
    This is really NASA's role, as Dr. Shin has mentioned, and
    they're doing a very good job of it to decrease that rather
    than increasing that at a time when so many new possibilities
    are on the horizon is probably not the right thing to do.
        Dr. Epstein. If I can add to that, it isn't that they may
    not be developed. They won't be developed in the United States.
    Actually, I could identify 300 people working on air mobility
    or stating they've done that, and most of them are not U.S.-
    based.
        And so, it really is a point not of replacing an industry,
    telling industry what it may do, but enabling industry to make
    an investment that's reasonably prudent by providing a
    technology base.
        Dr. Lewis. And if I can build on that, I'll offer a
    historical example. NASA flew their X-43 for the last time in
    2004. There was a 6-year gap between the time NASA flew its
    vehicle and the Air Force flew X-51, which is essentially a
    logical follow on to X-43. That 6 years, I believe, was one of
    the reasons that foreign competitors were able to gain an
    advance in the hypersonics field.
        We did the homework for them, and then they were able to
    build on that investment and move forward at a pace that was
    faster than ours.
        Chairwoman Horn. Dr. Shin, would you care to add anything?
        Dr. Shin. Yes, I think other witnesses have very graciously
    offered the supporting comments. But I think what we have been
    really improving is within the given budget, how most
    effectively and efficiently we can use that precious funding
    toward the most compelling and impactful technologies. Then I
    think by working with industry and other government agencies in
    very close relationship for the past 10 years or so, we have
    really maximized return on investment.
        Chairwoman Horn. Thank you, Dr. Shin. I'm hearing from all
    of you it's a matter of U.S. leadership in aeronautics and
    aviation.
        Dr. Babin?
        Mr. Babin. Yes, ma'am. Thank you.
        This question is similar to the one that Mr. Olson had
    asked a while ago, but there is a little twist on it.
        Dr. Shin, NASA is developing a low boom demonstrator
    mission, the X-59, to develop new technologies to lower the
    noise associated with supersonic flight. NASA recently
    conducted a series of quiet supersonic research flights off the
    coast of Texas near Galveston to test ways to measure the
    community's response to the unique acoustic experience.
        And just a few weeks ago, the FAA announced that it is
    developing regulations to enable the resurgence of supersonic
    flight. How are these efforts coordinated?
        Dr. Shin. We're very, very much coordinating our efforts
    between FAA and NASA. As a matter of fact, I actually even met
    with the acting administrator of FAA yesterday to just talk
    about this.
        So, there are two challenges at the moment. Very quickly,
    one is certainly trying to influence regulatory agencies around
    the world so that this ban on supersonic flight over land is
    changed or lifted. So, that's what NASA X-59 will do. And then
    there's another challenge that is landing and takeoff noise
    from supersonic airplanes, should there be any commercial
    supersonic airplanes.
        So, that's what FAA is leading.
        Mr. Babin. Yes.
        Dr. Shin. So, we are collaborating with FAA to provide
    technical support for them to come out with regulatory
    standards.
        Mr. Babin. I understand. Thank you.
        You know, also this next one, Dr. Shin. NASA's recent
    budget request proposes reorganizing the management of
    aeronautics test facilities. This comes on the heels of a
    similar reorganization several years ago. What was the
    rationale for this restructuring?
        Dr. Shin. The main rationale is these are national asset-
    level wind tunnels, and certainly aeronautics--my mission
    directorate has been the custodian and keeper of those major
    wind tunnels for the agency and for the customers and
    participants as well.
        But other mission directorates also use these wind tunnels,
    so it is truly agency-level activity and agency-level issues.
    So, the agency has moved that to agency-level management, not
    just from the Aeronautics research mission directorate.
        So, that's all there is to it. There's no content
    reduction. There's no budget reduction, anything.
        Mr. Babin. I understand.
        OK. That takes care of me. Thank you. I yield back.
        Chairwoman Horn. Thank you very much, Mr. Babin.
        The Chair recognizes Mr. Foster for 5 minutes.
        Mr. Foster. Thank you, Madam Chair.
        You know, one of the obviously enabling technologies for
    electric airplanes is the energy density of batteries. I
    represent Argonne National Lab, which is the central lab
    organizing a national collaboration, with the goal of something
    like 5 times higher energy density than current lithium ion.
    And if you look at the feasibility in different areas, you
    know, what sort of energy density improvement do you really
    need to get, you know, commercial airliners versus, you know,
    local delivery drones, you know, all the different--which, you
    know, I guess these applications turn on one at a time as your
    batteries get more capable. I was wondering what the milestones
    there we should aim for are?
        Dr. Epstein. Well, different answers for different
    airplanes.
        So, the drones are almost good enough now. So, a factor of
    two in density would help a lot in a commercial sense,
    especially--so, it's a cost issue as well as that.
        Jet fuel burned in a modern engine is 100 times the energy
    density of the batteries, so should the batteries get 10 times
    better than the current batteries, the airliner could taxi out
    to the end of the runway, and then would have to turn around
    and go back to the terminal because you need a 45-minute
    reserve before you take off in case you can't land immediately.
    So, for airliners, it's a long, long way.
        The urban air mobility vehicles, however, these are things
    that only need ranges of 20, 50, 80 miles, they're factor of 5
    improvement with the associated economics would be very useful,
    and also that might allow you to optimize larger airplanes
    better. But it doesn't let you--electric power----
        Mr. Foster. You're not going to cross the Pacific----
        Dr. Epstein. Not without----
        Mr. Foster. A factor of 100 is what you said, or 50 at
    least?
        Dr. Epstein. Not without a very long extension cord.
        Mr. Foster. You know, I have expressed the opinion in this
    room many times that I think that NASA doesn't spend enough on
    potentially transformative technologies to get things into low-
    Earth orbit for cheap. You know, there are a large number of
    concepts for this, you know, everything from space elevators to
    electromagnetic launch to laser-assisted launch.
        We were able to get to bump up the budget in just the last
    couple weeks of the NASA Advanced Innovative Concept, NAIC, but
    it's still tiny. We bumped it up from about 8 to roughly $15
    million, if it survives the Senate. And so, some of these
    concepts have little to do with aeronautics, and some of them
    do. I was wondering what you think the most promising, you
    know, to be explored areas there that might really have a shot
    at dramatically lowering the cost of getting things into low
    Earth orbit?
        Dr. Epstein. Well, to steal Dr. Lewis' thunder, a combined
    cycle hypersonic propulsion system would let--as the Nation
    tried to do with the National Aerospace Plane in the 1980s, and
    that was a bridge too far for our technology at the time. That
    was national defense. That was probably the best chance of
    regularizing things.
        But in today's Wall Street Journal online, there's an
    article which shows what's going on in space in terms of
    activity. And one of its graphs shows that the cost of a pound
    to orbit was $34,000 on the shuttle. On a Falcon X Heavy, it's
    $640. So, the cost has come down considerably, and if the new
    entrants are successful, I expect it to be much less expensive
    as well.
        Mr. Foster. Dr. Lewis?
        Dr. Lewis. So, one of the challenges is that a modern
    rocket engine is really an amazing piece of equipment. It
    delivers efficiencies--energy efficiencies higher than almost
    any other machine I can think of on the planet. And so, trying
    to do better than a rocket engine is really quite a challenge.
        Mr. Foster. You know, what disturbs me is when you look at
    these missions to Mars, there's very little on them that would
    not be completely understandable to Wernher Von Braun.
        Dr. Lewis. Correct.
        Mr. Foster. You know, you very rapidly went to the
    asymptote for the performance of chemical rockets, and I really
    think it's time to step back and put more effort into something
    that has, you know, transformative potential.
        Dr. Lewis. Yes, I would agree completely.
        Mr. Foster. Things like laser-assisted launches, for
    example, you know, where you're beaming some of the power.
        And so, what is your view of the most promising things
    there, if we have to place some bets on speculative
    technologies?
        Dr. Lewis. So, I actually do think, as Professor Epstein
    mentioned, air breathing to orbit. And the reason is it's not
    science fiction. We know how to build those engines, although
    we haven't gotten them quite up to the Mach numbers yet. And
    essentially, if you're air breathing to orbit, that means
    you're swallowing oxygen as you go, it simply means you're not
    carrying the oxygen in a tank onboard the vehicle. You don't
    have the massive tank. And there's several approaches you might
    try. One is the scramjet engines that I mentioned. The other,
    what are called liquid air cycle engines where you have a
    cryogenic fuel, very cold fuel. You condense air as you go,
    collect it, separate out the oxygen, and then burn that in a
    relatively conventional engine. I think that's quite promising
    as well.
        I can go through the list of all the other options----
        Mr. Foster. If you could just, you know, contact my office
    and if there's some reasonable number of pages to read on this,
    because we have to throw deep, deeper than we've been throwing,
    because you know, we don't want to have the ghost of Wernher
    Von Braun meeting us another 25 years from now.
        Dr. Lewis. I agree. If I may, you know, I think it was a
    Robert Heinlein quote that low Earth orbit is halfway to
    anywhere, and if we can get the cost down to low Earth orbit
    and make it more regular, possibly through aeronautic
    solutions, and I think it opens up tremendous things for space
    exploration as well.
        Mr. Foster. All right. He had the physics right in the
    1950s, I guess.
        And so anyway, I'm out of time here, and thank you to all
    of the witnesses here, and I yield back.
        Chairwoman Horn. Thank you, Mr. Foster, and thank you to
    all of our witnesses for being here today and for your
    testimony and insight.
        Before we officially close the hearing, I want to say how
    much I appreciate the work that you're doing and your
    willingness to be here today as we move toward a NASA
    reauthorization, looking at the importance of the work that
    NASA Aeronautics is doing.
        The record will remain open for 2 weeks for additional
    statements from the Members and for any additional questions
    the Committee may ask of the witnesses. The witnesses are
    excused and the hearing is now adjourned.
        [Whereupon, at 4:39 p.m., the Subcommittee was adjourned.]

                                   Appendix I

                                  ----------

                       Answers to Post-Hearing Questions

                       Answers to Post-Hearing Questions
    Responses by Dr. Jaiwon Shin

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

    Responses by Dr. Alan H. Epstein

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

    Responses by Dr. Mark Lewis

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

                                  Appendix II

                                  ----------

                       Additional Material for the Record

                 Letter submitted by Representative Kendra Horn

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

                Article submitted by Representative Brian Babin

    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]