2
Back to the Past: An Update on the 1991 Decadal Report
The 1991 Decadal Report contained a compendium on the demographics of astronomy. In this chapter the CAA recalls that information with the aim of providing a quick overview and a historical perspective on the key indicators of the health and status of the field of astronomy.
For convenience, the committee's findings are presented in an order that parallels that of the 1991 Decadal Report.
2.1
THE DEMOGRAPHICS OF ASTRONOMY
The 1991 Decadal Report charted the growth in the number of astronomers from 1981 to 1989, an exercise that showed the field had grown by 42 percent during the decade of the 1980s. What has happened since 1989? Figure 2.1 shows the total, full, and junior membership of the American Astronomical Society (AAS) from 1984 to 1999. AAS full members represent active professionals in the field; about 18 percent of the AAS full members are at foreign institutions. The growth of the field has slowed since the last decade, and the growth in the number of active researchers —as measured by full members of the AAS—has slowed as well. However, the astronomical community is still growing significantly faster than the U.S. population as a whole. The demographics of the astronomical community are discussed further in Chapter 4.
The 1991 Decadal Report also commented on the percentages of women and minorities in the field. Women made up 8, 12, 13, and 16 percent of the astronomical community in 1973, 1987, 1990, and 1995, respectively, as measured by the fraction of AAS membership. This trend has followed increasing enrollment by women in graduate programs as tracked by the American Institute of Physics (AIP).
According to AAS information, the median age of astronomers in 1995 was about 41 for men and 34 for women. For all astronomers, the median age was about 40. There is no evidence of the “graying” of astronomy. However, there has been a major change in the age distribution of the field. Whereas in 1987 half of all astronomers were between the ages of 35 and 50, in 1995 the distribution of ages was somewhat broader, with about 40 percent of astronomers in the same age range.
2.2
THE FUNDING OF ASTRONOMY
At the time of the 1991 Decadal Report, the status of funding was reasonably clear: NSF provided the major share of funding for ground-based astronomy; NASA provided most of the funding for space astronomy; a significant component was provided by state and private funding (estimated at $190 million per year); and some support for special projects came from the Department of Energy, Department of Defense, and Smithsonian Institution. In 1989, in the Astrophysical Journal (ApJ), 34 percent of the articles acknowledged NSF funding, 39 percent acknowledged NASA funding, and 10 percent acknowledged other forms of federal funding. Has the balance of federal funding changed significantly? The committee found that in the 1995 ApJ, 42 percent of the papers published acknowledged NASA support, but only 24 percent acknowledged NSF.
Figure 2.2, an updated version of Figure B.2 of the 1991 Decadal Report, shows the overall funding of astronomy by NSF and NASA and the fraction of the agency budgets allocated to astronomical research. It makes clear that NASA dominates the total funding for astronomical research, as it has since at least 1981. This is due, of course, to the large amount of NASA funding going into space astronomy projects such as the HST; the Advanced X-ray Astronomy Facility (AXAF), now called the Chandra X-ray Observatory (hereinafter Chandra); and the Space Infrared Telescope Facility (SIRTF).
More interesting from the perspective of the current study is whether there has been a shift in the grant funding to individual researchers from NSF to NASA. Figure 2.3, Figure 2.4 through Figure 2.5 update the information presented in the 1991 Decadal Report.
2.2.1
Support from NSF
The 1991 Decadal Report documented a steady decline in the fraction of the total NSF research budget allocated to astronomy, from a historical level of more than 6 percent to about 5 percent by the end of the decade. A similar trend occurred in the 1990s. As Figure 2.2 indicates, the fraction of NSF funding going to astronomical research at the end of the decade was a little more than 5 percent of the NSF R&D budget. However, between 1990 and 1995, the funding level was higher, typically 7 to 8
percent of the budget, with an increase to almost 11 percent in 1991 due to the one-time increment in funding for the construction of the Green Bank Telescope (GBT).
Figure 2.3, an updated version of Figure B.3 in the 1991 Decadal Report, indicates where the increases come from. Funding for major research equipment (MRE) provided large increments in funding from 1990 to 1995. The MRE funding includes VLBA ($35 million between 1990 and 1993), Gemini ($95 million between 1991 and 1995), and the GBT ($81 million in 1991). All funding levels are given in FY 1997 dollars. Also shown in Figure 2.3 is the funding for astronomy and astrophysics from NSF's Physics Division. This includes funding for theory, atomic and molecular astrophysics-related research, and submillimeter and IR astronomy from the South Pole. Further details are given in Chapter 5. Funding levels for astrophysics programs from the Physics Division were not included in the 1982 Decadal Report (National Research Council, Astronomy and Astrophysics for the 1980's, National Academy Press, Washington, D.C., 1982). Inclusion of these programs would have resulted in astronomy and astrophysics support that was higher than that shown in Figure 2.2 and Figure 2.3. However, Figure 2.3 shows that the core funding of astronomy grants and facilities operation from NSF's Division of Astronomical Sciences has been relatively flat in constant FY 1997 dollars between 1990 and 1999. During the same period, the total NSF R&D budget rose by 26 percent.
Figure 2.4 is an update of Figure B.4 of the 1991 Decadal Report and provides a more detailed view of the trends in grant funding. The 1991 Decadal Report documented the disturbing trend of a decrease (by 50 percent) in the average NSF grant size. Since 1990, the average grant size appears to have stabilized. The 1991 Decadal Report made the further observation that the size of the average grant had dropped below the critical size required for support of a faculty summer salary plus a graduate student and travel. The consequence was that scientists often had to seek support from multiple grants, with a resultant increase in overhead for preparing, reviewing, and managing a larger number of smaller proposals. In the 1990s, astronomers appeared to turn increasingly toward NASA as a new source of funding to offset the dwindling size of NSF research grants.
2.2.2
Support from NASA
The 1991 Decadal Report stated clearly, “NASA is becoming the dominant agency in astronomy grant funding. In 1982, NSF provided about 60 percent of the federal support for individual grants” (p. 156). However, by the end of the 1980s, NASA had provided more grant money than had NSF, and the 1991 Decadal Report stated that “in the 1990s, NASA's grant support for data analysis is expected to increase even more.” This prediction was indeed correct. From 1989 to 1999, NASA's grant funding for astronomy increased by about a factor of two in constant dollars. During the same time, grant and
university observatory support from NSF remained flat; thus, the fraction of research grant funding supported by NSF continued to decrease during the 1990s. In a span of about 15 years, support for the field of astronomy made a major (and largely unplanned) transition from one federal agency to another.
Figure 2.5 details the portion of NASA funding going to various components of the astronomy program. For 1981 to 1985, the data are taken from the 1991 Decadal Report and show the breakdown of astronomy funding into two components: (1) large and medium missions and (2) small programs and grants. For the period beginning in 1986, more detailed and uniform information is available. The large-and medium-mission component is roughly replaced by two components: (1) flight programs and (2) mission operations and data analysis (MO&DA). The small programs and grants component is roughly replaced by two other components: (1) the research and analysis (R&A) program and (2) the suborbital program (primarily support for SOFIA). In both cases, the replacement is approximate, primarily because MO&DA includes support of programs that would fall under the category of small projects and grants in the classification used in the 2000 decadal survey. Note that the increase in MO&DA funding in 1990 is due to the HST program.
2.2.3
Trends in Astronomical Research
Lastly, it is important to point out some real and perceived changes in astronomical research. Three major changes are (1) the increase in international projects both in space (see the NRC report U.S.-European Collaboration in Space Science, National Academy Press, Washington, D.C., 1998) and on the
ground (Gemini, ALMA); (2) the increase in university-based consortia to build and operate midsized-to-large telescopes (Keck/California Association for Research in Astronomy [CARA]; Astronomical Research Corporation [ARC]; Berkeley-Illinois-Maryland Array [BIMA]; Wisconsin, Indiana, Yale, and NOAO [WIYN]; MDM Observatory [consortium of University of Michigan, Dartmouth College, Ohio State University, and Columbia University]; Southern Observatory for Astronomical Research [SOAR], etc.); and (3) the general increase in the size of research groups pursuing large and long-term programs. Examples of large astronomical scientific programs are the Sloan Digital Sky Survey (SDSS), the HST Key Projects on quasar absorption lines and the extragalactic distance scale, and the Two-Micron All-Sky Survey (2MASS).
Telescope consortia have generally increased preferential access to the community; as indicated below, the fraction of observational optical and infrared astronomers at institutions without moderate to large telescopes has dropped over the decade from about 58 to about 48 percent. As the field matures, many of the remaining scientific problems are of a scale and complexity that they can be approached only by large groups of researchers with varied expertise. These trends all reflect the natural evolution of the field.
To the great benefit of the community, much of the program outlined in the 1991 Decadal Report has been realized. With international collaborators, the 8-meter Gemini telescopes are nearing completion. Both SIRTF and the Millimeter Array (now ALMA) appear to be on track, although the new start for SIRTF was later than originally hoped for and ALMA construction still has to be approved by the National Science Board (NSB). The Far Ultraviolet Spectroscopic Explorer (FUSE) has been launched, the Stratospheric Observatory for Infrared Astronomy (SOFIA) is on track, and there has been significant progress in adaptive optics and laser guide stars. There are now working prototype optical-infrared interferometers, two shared 4-meter telescopes (ARC and WIYN) have been constructed, and one more (SOAR) is on the way. For the ground-based optical and infrared (OIR) community, (see the NRC report A Strategy for Ground-Based Optical and Infrared Astronomy, National Academy Press, Washington, D.C., 1995), several new 8-meter-class telescopes have been constructed or are well under way.
New fields of astronomy have opened up. The Hubble Space Telescope has transformed the way observational optical and near-ultraviolet astronomy is done, not only with the tremendous improvements attributable to getting above Earth's atmosphere but also with its Guest Investigator program. The Hubble Deep Fields have given researchers their best look yet at the early universe and whet our appetite for the additional data and theory necessary to understand the formation of galaxies and the first objects in the universe. The data are beginning to become available as large ground-based telescopes reveal an increasing number of galaxies with ages 90 percent of the way back to the beginning of the universe, and submillimeter instruments such as SCUBA are revealing a new component of dust-enshrouded galaxies at high redshift. The Cosmic Background Explorer (COBE) clearly observed fluctuations in the microwave background and, in doing so, has strongly confirmed the Hot Big Bang model. The BOOMERANG (Balloon Observatories of Millimetric Extragalactic Radiation and Geophysics) balloon experiment has resolved the fluctuations and has shown that we live in a “flat” universe. The newly launched Chandra X-ray Observatory is beginning to probe the synthesis of elements in supernovae and is uncovering new populations of active galaxies at high redshift. The combination of the Compton Gamma Ray Observatory (CGRO), BeppoSax, Keck, HST, the VLA, and other ground-based telescope observations has shown that gamma-ray bursts are powerful explosions at cosmological distances. However, the source of these explosions remains uncertain.
A new generation of ground-based high-energy and neutrino telescopes has come on line (Milagro, Super Kamiokande, Antarctic Muon and Neutrino Detector Array [AMANDA], Sudbury Neutrino Observatory [SNO], Fly 's Eye, etc.), significantly improving the ability to understand energetic astrophysics, but also bringing forth new puzzles. Studies of binary pulsars have provided exquisite tests of general relativity, and more are yet to come with NASA's Gravity Probe B, the NASA Laser Interferometer Space Antenna (LISA) mission, and NSF's Laser Interferometer Gravitational-wave
Observatory (LIGO). Extrasolar planets have been discovered, but not necessarily where they were expected to be in their stellar systems. Protoplanetary disks have been found around many young stars. What is the nature of the “dark matter” and “dark energy,” if any really exists? A complete theory of star formation still eludes our grasp and, with it, both a complete theory of galaxy formation and a complete theory for the formation of large-scale structures in the universe, although significant strides have been made in showing that gravitational instability is the dominant process.