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AAS Electronic Notification Service - Announcement #5 9/94

  1. NASA Cuts Delta Class Explorer Missions; FUSE to be restructured.
  2. NASA Announces Opportunity for Five Year Space Astrophysics Proposals
  3. AURA Considers Future Instruments; Seeks Community Comments
  4. Observing Opportunity - Penticton Synthesis Telescope
  5. Observing Opportunity - Haystack Observatory
  6. Meeting - Luminosity Functions 5-7/Jan/1995 (honoring M. Schmidt)

The AAS electronic announcements will be mailed about the 10th of every month, or more often if news items are deemed by the Executive Officer to be sufficiently important.

Items for possible inclusion in this announcement series should be sent to Keep announcements short and refer readers to sources of additional information.

Comments to

1. Delta Class Explorer Missions Cut - FUSE Restructured

We received the following letters with the request that we distribute them to the AAS membership. The AAS Executive Committee has reviewed the letters and we are forwarding them without comment on the issues raised. We plan to include further updates on this situation in future AAS Newsletters.
Peter B. Boyce, AAS Executive Officer

Dear Colleague:

This letter is to advise you of the decision at NASA Headquarters to restructure the Explorer program for astrophysics and space physics missions. The Explorer program is intended to provide these communities with a continuing program of small, low-cost, high-flight-rate, discipline-sustaining missions. The Explorer program currently includes the Small Explorers (SMEX), with launches scheduled approximately once per year, and the Delta class Explorers, for which launches had been planned for 1995 (X-ray Timing Explorer-XTE), 1997 (Advanced Composition Explorer-ACE) and 2000 (Far Ultraviolet Spectroscopic Explorer-FUSE).

Both the astrophysics and space physics communities have expressed the need for more frequent flight opportunities. The current plan for the Explorer program including the large Delta class missions was developed more than 3 years ago in a time of growth in space science when it was anticipated that a lower cost Medium Explorers (MIDEX) series of missions, which could be flown at a more frequent rate than the larger Delta-class, could be started through anticipated augmentations to the Explorer budget. These anticipated augmentations have not materialized and it now appears certain that funding for the Explorer program will remain flat for the foreseeable future. As the flight opportunities planned within the current baseline are insufficient to meet the demands of the astrophysics and space physics communities, the only remaining option for increasing the number of missions is to restructure the program by eliminating one or more of the large Delta class Explorers to release funds for more frequent, smaller MIDEX class missions.

As a consequence of these constraints, we have reached the very difficult decision to conclude the Delta class Explorers with the ACE mission and not to start a Delta-class FUSE mission in FY95. The $250M anticipated cost for the FUSE mission is simply too large for the current Explorer line budget. Terminating the Delta-class with ACE will therefore make it possible to initiate the MIDEX series and allow for more flight opportunities at lower cost, with the goal of one flight per year. It is now anticipated that an Announcement of Opportunity for MIDEX will be available early in calendar 1995. With the introduction of the MIDEX series, the Explorer program would be able to provide one SMEX and one MIDEX flight each year.

This decision has been made with the intention of optimizing the scientific return within the entire Explorer program. Nevertheless, it is acknowledged that the science proposed for FUSE has been ranked among the highest priorities in astrophysics and that many dedicated scientists have devoted years to planning for this mission. Consequently, we will give special effort to accomplishing far ultraviolet spectroscopy within plans developed for the MIDEX missions.


Wesley T. Huntress, Jr.
NASA Associate Administrator for
Space Science



The changes in the Explorer Program described in the accompanying letter from Wes Huntress will result in a major restructuring of the FUSE project. Both NASA Headquarters and the FUSE team have as a primary goal the preservation of as many of the FUSE science goals as possible, consistent with the budgetary restrictions upon NASA.

After discussions with NASA Headquarters the FUSE team is redesigning the mission for a very much lower cost. In 90 days we will present to NASA headquarters a new design that will fit within the new cost guidelines and be ready for launch in late 1998, and we will also present an assessment of which of the FUSE science goals can be saved with this low cost approach, and which will be lost. Our approach will necessarily include higher risk, shorter development time, and lower management overhead than is normally followed by the large Explorers.

We will report to the community on our progress in an upcoming AAS Newsletter.

Warren Moos, FUSE P.I.
Johns Hopkins University


by Guenter Riegler, Astrophysics Division, NASA Headquarters

The NASA Research Announcement (NRA) for the Long-Term Space Astrophysics Program (NRA 94-OSS-12) will be released on July 26, 1994; proposals are due by October 25, 1994. The purpose of this program is to enhance research in space astrophysics by providing a stable long-term source of support, typically for five years. The LTSA program solicits proposals for research in astrophysics whose dominant emphasis is the analysis and interpretation of data from past, current, and future space astrophysics missions. In support of that activity,
but as a secondary emphasis, the proposed research may include theoretical research, numerical modeling, use of existing data from ground-based or suborbital observations, and laboratory astrophysics measurements.

The NRA appendices are available through anonymous file-transfer-protocol (ftp) from Internet host ASCII and Postscript files for all Appendices and required forms are located in the directory "nras/ltsa." For further information, please e-mail to, or contact Dr. Guenter Riegler or Darrell New, Astrophysics Division, Code SZ, National Aeronautics and Space Administration, Washington DC 20546.

3. NASA and AURA Consider Future Missions

Dear AAS member:

I'm writing on behalf of the 'HST and Beyond' Committee, which has been appointed by AURA with NASA support, 'to study possible missions and programs for Optical-UV astronomy in space for the first decades of the 21st century' .... and to 'initiate a process which will produce a new consensus vision of the long term goals of this scientific enterprise. A list of the members of this committee is appended to this letter.

We held the first of what should probably be three meetings in April, at Goddard Space Flight Center, at which time we discussed such things as the health of HST, the social contract between science and society, and, of course, some of the scientific programs that we thought would be most important a decade from now. We began to discuss the conclusions of previous studies of a similar kind, like the committee led by Garth Illingworth on behalf of the Bahcall Decade Survey Report on astronomy.  We have decided to use these previous studies as the basis for our work, reasoning that they were broadly representative of the thinking of the community.

However, there are clearly shifts in the political climate, the possibilities for funding, and additional insight on scientific and technical matters that need to be mixed and evaluated with the earlier reports. We are undertaking to do so, but we would like to ask your help in our efforts. We are very interested in the community's scientific aspirations with regard to optical-UV space astronomy beyond the era of HST. (Optical, in this context, certainly includes up to 2-microns; extension further into the thermal infrared is one of the issues our committee is weighing.) To make this easy, we have set up an email address: Messages sent to this address will be distributed to the entire committee. You can, of course, also communicate with any member of the committee directly. 

To help put your thoughts in context, the following provides information about topics discussed at our first meeting. Your comments on any of these points would be very valuable.

We are inclined to organize our report around a few grand goals, like "mission to the early universe" and "search for other planets" that we think would have broad appeal to the public and still serve as a honest umbrella to many of the programs that are perceived to be important to our community. In other words, we think it is important to be able to communicate our scientific ambitions to the lay public more clearly than we have done before.

The Illingworth committee thought a likely successor to HST to be a 6-m reflector in high-earth orbit. Even if we ignore for the time being the difficulty in starting on such an ambitious project in the circumstances of NASA's current budget restraints, we should still ask whether this is the kind of project that best suits our community's scientific interests. For example, given a fixed budget, we could ask whether a general-purpose, long-lived observatory is more cost effective for our science than a string of COBE-size missions with well-set and limited scientific goals, or even greater number of still smaller missions, like the Explorer series.

We heard a presentation on AIM, a NASA development program that seeks to develop a space platform for astrometric interferometry that would give  positions of stars down to 17th magnitude or fainter to an accuracy of better than 10 micro-arcseconds. Is this a different kind of successor to HST that we should consider? Does the promise of "a distance to any star in the Milky Way galaxy" hold enough scientific bounty that we could forego, for a decade or more, the general capability to point at a particular object and take a picture or take an ultraviolet spectrum with the 0.1 arcsecond resolution we will have become accustomed to thanks to HST? More generally, what is the tradeoff between aperture, resolution, and coverage of the UV and IR spectral
regions and the u-v plane.

We also heard a presentation on Adapt, a Lockheed-Itek proposal to the Ballistic Missile Defense Office to fly a 4-meter diffraction limited "demonstrator" to low earth orbit within 3 years on a Proton rocket, at relatively low cost. The proposers seek astronomical involvement to establish "dual use" and would release the telescope to astronomers for the final 4 years of a projected 5 year lifetime. The obvious drawbacks are the poor performance below 4000 angstroms, a very limited instrumental complement, and the lack of support for operations and data handling from the proposers or BMDO.

These missions involve genuinely new technology. This seems to hold greater attraction to NASA than an enhancement of scientific capabilities, even considering the substantial scientific payoffs of a more powerful version of HST. Should we acknowledge this and work with it or press our scientific agenda as the overall priority? This relationship of the astronomical community with NASA has already become and will continue to be a point of discussion for our committee. NASA's admitted goal is "to build hardware and fly it" while our goal is to do science. Are the aspirations of the astronomical community in secure hands in such a situation? Is there any real alternative? We have also been asked to suggest how the conclusions of our committee
can be evolved in a process that could lead to a next step for OUV astronomy.

We are working on a fairly short timeline. We will meet in late August at the University of Michigan, and intend to hold a public meeting at the January AAS meeting. We hope to issue a report by late spring 1995.  We look forward to hearing from you.


Alan Dressler, for the HST and Beyond Committee



Alan Dressler, Chair, Carnegie Observatories
Robert A. Brown, STScI
France A. Cordova, NASA (ex officio)
Arthur F. Davidsen, Johns Hopkins University
Richard S. Ellis, Cambridge University
Wendy L. Freedman, Carnegie Observatories
Richard F. Green, NOAO
Michael Hauser, NASA/GSFC
Robert P. Kirshner, Harvard University
Shrivas Kulkarni, Caltech
Simon J. Lilly, University of Toronto
Bruce H. Margon, University of Washington
Carolyn C. Porco, University of Arizona
Douglas O. Richstone, University of Michigan
Hervey (Peter) Stockman, STScI
Harley A. Thronson, University of Wyoming
John L. Tonry, MIT
James Truran, University of Chicago
Edward J. Weiler, NASA (ex officio)



Proposal Deadline for 1995 January - June semester is October 15

The seven-element Synthesis Telescope at the Dominion Radio Astrophysical Observatory (Penticton, Canada) is a unique wide-field imaging instrument providing simultaneous observations in 256 channels of the HI 21-cm line and in two continuum bands at 1420 MHz and 408 MHz. Angular resolution at 1420 MHz is 1' within a 2-degree field and, at 408 MHz, 3.5' within a 7-degree field. The telescope is ideally suited to comprehensive studies of the ISM, of extended Galactic nebulae and star-forming regions, and of nearby galaxies.

Additional telescope information and application cover sheets can be obtained through anonymous ftp ( within the sub-directory ./pub or by World Wide Web with URL of Specific questions can be addressed to

The telescope is operated as an open facility by the Herzberg Institute of the National Research Council of Canada.

Robert Roger

Internet :
Postal address: Dominion Radio Astrophysical Observatory,
PO Box 248, Penticton, BC, Canada V2A 6K3
Observatory phone : (604) 493-2277 Fax: (604) 493-7767
Direct dial to rsr : (604) 490-4305


Due: 1 October 1994

Haystack Observatory invites proposals for the use of the 37m radio telescope for observations in the 3mm-wavelength band (85-115 GHz), as well as in the 7mm (35-49 GHz) and 1.3 cm (21-25 GHz) bands. Priority in the winter 1994-95 season will be given to observations at 3mm, with other wavelengths covered in the Fall and Spring months. All available time for radio astronomy will be allocated on the basis of scientific merit and suitability to the instrumentation, and visitors will be expected to operate the telescope for their observations.

Information about the capabilities and operations of the Haystack telescope, and procedures for proposal submission and time requests, are available through the World Wide Web/NCSA MOSAIC on the Haystack Observatory home page:

or by e-mail request to

Deadlines for submission of proposals are:
1 October 1994 (all frequencies)
1 January 1995 (85-115 GHz only)
1 April 1995 (21-25 GHz and 35-49 GHz)


A celebration of Maarten Schmidt's contributions to astronomy

One of the conceptually simplest operations in observational astronomy is counting the number of sources of a particular type as a function of brightness. Yet the derived frequency distribution, the luminosity function, is amongst the most powerful diagnostics available to astrophysicists, affording insight into mass distributions, evolutionary lifetimes and formation mechanisms.

Maarten Schmidt has been intimately involved in luminosity function analyses for more than 35 years, with research spanning the range from low-mass stars in the disk and halo of our Galaxy to quasars and gamma-ray sources. As a celebration of his considerable achievements in these and in other diverse areas of astronomy, the California Institute of Technology is holding a conference on the general topic of astronomical luminosity functions. Other sponsors include the National Optical Astronomy Observatories and the Association of Universities for
Research in Astronomy.

The conference will be held on January 5-7, 1995, and will consist of a series of invited reviews on the following topics:

white dwarfs - J. Liebert (Univ. of Arizona);
the halo star luminosity function - J. R. Mould (MSSSO);
disk main-sequence stars - I. N. Reid (CIT);
MACHOS - G. Preston (OCIW);
Galactic molecular clouds - R. Wilson (AT&T) (tentative);
Gamma-ray bursters - J. C. Higdon (Claremont Colleges);
field galaxies - B. Peterson (MSSSO);
galaxies in voids - D. Weistrop (UNLV);
emission-line galaxies - I. Horowitz (BYU);
Seyferts - R. Edelson (tentative);
QSOs - P. Osmer (OSU);
extragalactic radio sources - K. Kellerman (NRAO);
BL Lacs - L. Woltjer (Observatoire d'Haute Provence);
X-ray sources - R. Giacconi (ESO);
broad-absorption line QSOs - R. Weymann (OCIW);
black holes - D. Richstone (Michigan);
clusters of galaxies - N. Bahcall (Princeton);
the future
of the VLA - A.C. S. Readhead (CIT);
of X-ray astronomy - J. Truemper (MPE, Garching)
of the Gemini project - R. Green (NOAO);
of HST - J. Bahcall (Princeton);
of the Sloan Digital Sky Survey - D. Schneider (Penn State);
of Keck - W. L. W. Sargent (CIT);
Summary - J. E. Gunn (Princeton).

Although there will be no short talks, poster papers are invited. There will be no published proceedings.

For further details, contact: Diane Fujitani,  Astronomy Department 105-24, Caltech, Pasadena CA 91125. (email:; FAX: 818 568 9352)

R. Blandford, R. Green Co-Chairs SOC; W. L. W. Sargent Chair LOC