[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:]
    
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    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:]
    
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    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:]
    
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    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

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                   Answers to Post-Hearing Questions




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

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Responses by Dr. Alan H. Epstein

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Responses by Dr. Mark Lewis

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                              Appendix II

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                   Additional Material for the Record



             Letter submitted by Representative Kendra Horn
             
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            Article submitted by Representative Brian Babin
            
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