Subscribers to this newsletter should have already heard the news. Funding for the ADC and its activities has been eliminated by NASA. As a result, the ADC will close as of October 1, 2002. This ends 25 years of service by the Data Center. For the immediate future, the ADC's Web site will remain open, but with no further updates expected. Links to other organizations that offer services similar to those of the ADC will be posted on the ADC home page at adc.astro.umd.edu.
This will, therefore, be the last issue of this newsletter. If you'll allow me to inject a personal note, I'd like to say that it's been a privilege to be a member of the staff of the ADC. I've enjoyed the associations with coworkers and the interactions with colleagues and users through the years. The pending close of the Astronomical Data Center has brought a flood of memories of those times back again.
The announcement of the termination of the ADC is included in this issue. As this is the last newsletter, as well as the 25th anniversary of the ADC, I thought it fitting to take a bit of a look back at the Center. In 1997, Jaylee Mead wrote an article on the early days at ADC. It is reprinted here. I've included an article that recounts a few highlights from the technical efforts of the ADC throughout its history, lest those accomplishments be overlooked.
On behalf of the staff of the ADC, thanks for your support and our best wishes to you all.
NASA has determined that ADC services sufficiently overlap those provided by CDS and others to allow termination of the ADC. Therefore, effective immediately, NASA will route ADC users to the other sites that now perform these same services. We apologize if this causes you any inconvenience.
(Reprinted from the July 1997 issue of the ADC Electronic News)
Goddard Space Flight Center's Astronomical Data Center was built on developments made by astronomers who were forward-looking in anticipating the future needs of the field, particularly considering the requirements of space astronomy. As early as 1959, when I joined NASA, the agency was working with the Naval Research Laboratory to develop a computerized approach to the calibration of the Minitrack System for use in tracking the earliest satellites. This involved devising a method for computerized plate reductions using star catalog coverage of the entire sky. At that time only 14 small star catalogs were machine-readable. Astronomers at the US Naval Observatory and Yale Observatory were cooperating in key-punching of positional data for 250,000 additional stars from the Yale Zone and AGK2 catalogs. At Goddard we put this data on 9-track magnetic tape and wrote the software to provide automated plate reductions. Sixteen 12-inch tapes were required to load in all the stellar data!
This experience in the 1960's provided a logical basis for applications needed by upcoming space missions, such as the Orbiting Astronomical Observatory, the Goddard Experiment Package (which failed to reach orbit), and IUE. Additional astronomical catalogs were made machine-readable for use in these and later missions, primarily for planning observations, preparation of finding charts, telescope pointing requirements and later identification of field stars.
By the early 1970's astronomers in other countries were also foreseeing the need for computerized stellar and galactic databases. The French government was among the most farsighted when they announced in 1970 plans to establish the Strasbourg Stellar Data Center. The Goddard ADC has had strong cooperative ties with the French center since that time, when we exchanged copies of all of our machine-readable catalogs, a practice which continues today.
Many people contributed to the ADC in the early years. Among those who made the most significant inputs through hands-on efforts, funding, advice or other encouragement are William Cahill, Ray and Julie Duncombe, Dorrit Hoffleit, Theresa Nagy, Wayne Warren, Carlos Jaschek, Nancy Roman, Anne Underhill, Al Boggess, Gart Westerhout, and Jim Vette.
Throughout its 25 year existance, the ADC's mission was to support ongoing scientific research by providing computer-ready catalogs and journal tables to NASA projects and individual researchers. As an integral part of that mission, the ADC staff worked to improve the methods, technologies, and tools for ingesting and distributing such data. The history of the ADC shows that it was much more than a mere library of digital data sets. The efforts of the ADC have steadily improved access to and the usefulness of the published astronomical data.
In the beginning, many useful catalogs were only available in printed form. ADC staffers worked to acquire or prepare digital versions of these works. For the most comprehensive catalogs, ADC personnel developed new cross-index catalogs to make the job of intercomparing the data on similar catalogs easier.
In the 1980's and beyond, individuals from the ADC and its parent organization contributed to the development of the FITS standard. In the years that followed, some of these same individuals established and maintained the FITS Support Office, a clearinghouse for documents, software, and test data for users of FITS.
In 1991 Lee Brotzman, Susan Gessner, and Jaylee Mead produced the first in a series of CD-ROMs containing selected astronomical catalogs. Their goal was to use this medium to make the most useful catalogs available in an easily portable form for use offline. Other members of the staff produced three more volumes in this popular series, the last in 1997. In total, more than 9,200 copies of these CD-ROMs were distributed to astronomers world-wide.
Through their involvement with the STudy of Electronic Literature for Astronomical Research (STELAR), members of the ADC and its parent organization, the ADF, were among the first in NASA to develop information access sites on the brand new World Wide Web, including the first NASA-wide home page in 1993. It is not surprising then, that by 1994, the ADC had established its Web site as the preferred way for users to access its data holdings.
In 1994, Francois Ochsenbein of CDS developed a new documentation format for catalogs and journal tables that was more concise and maintainable than previous documents developed at CDS and ADC. This approach offered numerous advantages over the older journal article-style documentation. Francois collaborated with N. Paul Kuin of ADC to standardize this new documentation format. Internally known as the ReadMe, this flat ASCII document format is, with minor refinements, still in use 8 years later.
Since 1998, the ADC staff worked to apply the new XML technologies to the task of making tabular and other scientific data computer-readable, well documented, and readily searchable. The team defined document type definitions for both ADC tabular data and our eXtensible Data Format (XDF) for most scientific data types. This XML project evolved with the emerging XML and supporting standards. By the time of the closure of the ADC, more than one third of the ADC's archived collection had been converted to XML format. Public access to these data was established with an initial set of Web-based services offering enhanced search and retrieval.
As an major part of the ADC's XML effort, the staff developed an experimental pipeline to demonstrate the automatic preparation of computer-ready datasets in XML format directly from the University of Chicago Press' internal SGML format for ApJ, AJ, and PASP journal tables. Runs of this pipeline successfully demonstrated that this approach can be used to make much more of the published data readily usable with modest human intervention for quality assurance purposes.
In recent years, members of the ADC staff participated in the fledgling National Virtual Observatory effort. They contributed the experience gained in making the ADC's services interoperate with those of other astronomy data providers and their knowledge of emerging information technologies.
All the past members of the ADC staff can take pride in their accomplishments over the years. The steady growth in the use of the ADC and its services is proof of the success of their efforts.
Due to the closure of the ADC, no future issues of this newsletter are anticipated. Should there be further events of direct interest to current ADC users, the subscription list for this newsletter may be used to inform you of those events. Few, if any, such announcements are likely to be emailed.
If you would like to be removed from this list send E-mail to Majordomo@adc.astro.umd.edu and in the body of the message put in the command
UNSUBSCRIBE ADC-SUBSCRIBERS .
Questions or comments on the closure of the Astronomical Data Center can be sent to Space Science Data Operations Office Code 630 NASA Goddard Space Flight Center Greenbelt, Maryland 20771 USA Internet: webmaster@adc.astro.umd.edu