Joseph H. Taylor, Jr.
Member, Board on Physics and Astronomy
Cochair, Astronomy and Astrophysics Survey Committee
National Research Council
and
Dean of the Faculty
James S. McDonnell Distinguished University Professor of Physics
Princeton University
Before the
Subcommittee on Space and Aeronautics
Committee on Science
U.S. House of Representatives
The State of NASA’s Space Science Enterprise
Wednesday, September 11, 2000
Mr. Chairman, Ranking Minority Member, and members of the subcommittee: I am Joseph Taylor, Dean of the Faculty at Princeton University. I am a
physicist and a radio astronomer, best known for my observations of the effects on a binary star system of the gravitational radiation predicted by Einstein’s
General Theory of Relativity. Together with my colleague Christopher McKee of the University of California at Berkeley, I co-chaired a committee of the
National Academy of Sciences that prepared a report on the status of astronomy and astrophysics and that proposed priorities for large projects such as a new
space telescope. I am also a member of the Academy’s Board on Physics and Astronomy, which sponsored the report in cooperation with the Space Studies
Board.
Your letter inviting me to testify today asked that I focus on the survey of astronomy and astrophysics and its implications for space science programs at the
National Aeronautics and Space Administration. Let me begin by giving some background on the survey and follow that with some of its principal
recommendations.
The report, entitled Astronomy and Astrophysics in the New Millennium, carries on the astronomy community’s tradition of preparing surveys of the field
every 10 years, starting in the 1950s. The New Millennium report sets out a science strategy that covers both ground- and space-based astronomy and
astrophysics, providing a unified perspective on the science. The report details the priorities across the discipline for initiatives, missions, and programs. It
makes recommendations concerning astronomy and astrophysics policy, including education, international cooperation, and technology development.
The committee worked with nine sub-panels and involved a significant fraction of the practicing astronomy and astrophysics community, including pertinent
professional societies and prominent international astronomers. Several hundred U.S. astronomers were involved either in the panels or as consultants.
Seven of the nine panels dealt with sub-disciplinary areas and each prepared a report that identified the most important scientific goals in their respective
areas, prioritized new initiatives needed to achieve those goals, recommended proposals for technology development, considered the possibilities for
international collaboration, and discussed relevant policy issues.
The committee’s report discusses scientific priorities that are central to astronomy and astrophysics. The high-priority problems include
determining the large scale properties of the universe;
studying the dawn of the modern universe;
understanding the formation and evolution of black holes of all sizes;
studying the formation of stars and their planetary systems, including the birth and evolution of giant and terrestrial planets; and
understanding how the astronomical environment affects Earth.
The report notes that astrophysical theorists can help guide the choice of instruments and the interpretation of data, and it recommends that one or more
“Theory Challenges” be integrated into most major initiatives to focus attention on the scientific objectives of the project. It also recommends that the
National Aeronautics and Space Administration enhance its Astrophysics Theory Program. The report promotes a number of broad objectives:
balancing new initiatives with ongoing programs recommended in the previous ten-year survey report (such the Space Infrared Telescope Facility, the Space
Interferometry Mission, and the Atacama Large Millimeter Array),
strengthening ground-based astronomy and astrophysics,
ensuring the diversity of NASA missions, ranging from large to small (such as the successful Explorer program),
coordinating programs among federal agencies (including NASA, NSF, and DOE), and
collaborating with international partners.
Education is a major focus of the report. Recommendations in this area include:
improve the opportunities for astronomers to engage in outreach to the K-12 community,
establish astronomy and education department partnerships at a few universities,
develop exemplary science courses for pre-service teachers,
improve coordination among federal programs funding educational initiatives in astronomy, and
improve public understanding of the achievements of all NSF-funded science and facilities.
The priorities for major space missions, in order, are the
Next Generation Space Telescope, the successor to the Hubble Space Telescope, followed by
Constellation-X, a multi-satellite x-ray telescope,
Terrestrial Planet Finder (TPF), an ambitious mission that could begin at the end of the decade, and
Single-Aperture Far Infrared Observatory (SAFIR), an 8-meter class far infrared telescope that leverages NGST technology.
Each of these missions offers powerful and unique capabilities. The best available estimate of cost to the federal government for this category over the next
decade is $2.1 billion, which includes full costs for all initiatives (except TPF and SAFIR, for which only estimates of costs through 2010 are included).
In the moderate scale category, the top-ranked mission is the
Gamma-ray Large Area Space Telescope, which will study extremely energetic phenomena, followed by the
Laser Interferometer Space Antenna, a gravitational-wave detector of unprecedented sensitivity.
Study of the Sun, which is important both scientifically and economically, will be carried out by the Solar Dynamics Observatory, part of NASA’s
“living with a star” initiative. Next are the Energetic X-ray Imaging Survey Telescope and a mission to conduct Advanced Radio Interferometry between
Space and Earth, both of which will provide high-resolution images at their respective wavelengths. The estimate of costs for this category is $1.35 billion.
In the small program category, the top priority is the creation of a National Virtual Observatory (NVO). The NVO will integrate major astronomical
data archives into a database accessible via the internet with standards and tools for data exploration. Other small program priorities are the Advanced
Cosmic-ray Composition Experiment for the Space Station, augmentation of the NASA Astrophysics Theory Program, the Laboratory Astrophysics Program,
the National Theory Postdoctoral Program, and the Ultra-Long-Duration Balloon Program. The estimate of costs for the small program category is $264
million. The estimated total for these space-based initiatives, excluding technology development, is $3.714 billion.
NASA’s Office of Space Science will necessarily play a central role in implementing the priorities of the astronomy survey because many of the major
initiatives are space-based, including the overall top priority—the Next Generation Space Telescope. The space environment is crucial in astronomy because
the Earth’s atmosphere is opaque to many of the essential wavelengths, and it blurs the formation of images at other wavelengths. But the role of OSS goes
well beyond creating the big space-based instruments prioritized by the survey. The Astrophysics Theory Program is a principal component of the U.S.
astrophysics effort. Theory plays a critical and inexpensive role in defining the scientific objectives of major projects and in analyzing, interpreting, and
understanding the data to shed new light on the remarkable phenomena that we can now observe. Research supported by NASA both generally and in
connection with missions has become essential in addressing fundamental questions in astronomy and astrophysics.
In making these remarks, I would be remiss not to note that ground-based facilities and research supported by the National Science Foundation and the
Department of Energy also play crucial roles complementary to that of OSS. In this regard, I might mention that in my own field, radio astronomy, the
outstanding priority is the Atacama Large Millimeter Array, a recommendation of the previous survey committee. ALMA is a project with international
partners that will yield images with unprecedented resolution of the formation of stars and galaxies, and maps of the formation regions of planetary systems
in our galaxy.
My Survey Committee colleagues and I foresee a decade of unprecedented achievement for this field of science if the priorities identified in our report
can be realized and implemented. The top priorities address some of the most exciting and profound questions that mankind can pose about the origin and
fate of the universe. These questions engage the interest of the public, they define the a frontier of the scientific enterprise, and they fascinate the students
who will be leading citizens and scientists of tomorrow.
A copy of the Executive Summary of the survey report is included with my written statement.
Thank you, Mr. Chairman, for inviting me to address the Committee and to convey to you the excitement that astronomers and astrophysicists feel about
the future of our field.