In 1956 a Research Corporation representative visited Paul Engle of Pan American University to sample interest in a grant of seed money for a project in astronomy. Paul said that they would like to consider a large aperture telescope for the future of the Rio Grande Valley or for Northern Mexico in collaboration with Monterrey Technical Institute. A collaboration with MTI was established, which lasted four years. Research Corporation granted Pan American $5000 which made it possible for Corning Glass to pour the mirror blank. Paul Engle asked them to pour the largest blank possible for $5000, hoping that it would be larger than 40 inches. They were able to pour a 41-inch blank. The first two attempts were defective, so the present telescope is the result of the third attempt. The pour date was around 1960. Tinsley Laboratories was contracted to grind, polish, and figure the primary after another $5000 grant from Research Corporation was received.
Norman Cole from the Kitt Peak headquarters in Tucson, Arizona tested the primary mirror in Berkeley, California. It was better than one-tenth of a wavelength of sodium light. The completed primary mirror was then shipped to Tucson. Three NSF grants to Pan American were utilized to have Norman Cole make the three secondary mirrors, two Cassegrain and one Coudé. The f/8 Cassegrain secondary and the f/14.8 mirror were intended to be used for photoelectric photometry. An auto-collimation test of each secondary mirror with the primary was conducted at the Kitt Peak labs.
Phase II
Dr. Robert W. Gruebel
In 1968 an astronomy course, Physics 301, was introduced to provide background for teachers of Earth Science. The course was taught annually to about 50 students. The students in general were those with an interest in astronomy apart from their degree programs. The laboratory was taught by Dr. Gruebel with the assistance of amateur astronomers from the Nacogdoches area. A 6-inch Criterion reflector and a 3-inch refractor were the primary instruments and they were supplemented by the instruments of interested amateurs.
The Physics Department received an NSF COSIP Grant which included funds for a 10-inch reflector. President Steen authorized the department to commence a site search on university property. The Excess Property provisions of the COSIP Grant allowed us to obtain approximately $1.2 million worth of scientfic equipment in 1971. Astronomical instruments included in this acquisition were:
a. an 18-inch Cassegrain telescope; b. a 12-foot Observadome;
c. four 6-inch refractors capable d. six 8-9 inch Cassegrain reflectors;
of solar photography;
e. two 6-inch reflectors; f. sixty 3-inch, 30X spotting scopes;
g. an assortment of filter boxes,
adaptors, etc.
NSF approved transfer of equipment funds to purchase a 30-inch mirror blank in lieu of the 10-inch relector and other equipment.
Harlan Smith, Chairman of the Department of Astronomy at UT and Director of the McDonald Observatory, visited the department in 1972 to aid in site selection for an observatory to house the 18-inch Cassegrain and the proposed 30-inch Coudé/Cassegrain. The original site selection on the University farm located the observatory at the site of the proposed animal barn. President Steen told us that the site would be dedicated to the observatory if absolutely necessary, but asked us to search for an alternate site. A search produced an alternate site on the farm which had no significant access problems.
The Physics Department introduced Physics 105 (Introductory Astronomy) in 1973. The University provided $25,000 for observatory construction. Drs. Gruebel and Callaway surveyed the site and located polar north for both domes. The student viewing facility was constructed and the 18-inch telescope was installed in the small dome. A 24-foot Ash Dome was purchased for the 30-inch telescope. Construction of the large dome was delayed until 1977 by the default of the original construction firm.
On a 1974 visit to the Kitt Peak National Observatory, Dr. Tom Harrison of NTSU found the 41-inch mirrors of the Pan American project still in storage. He urged Universities in Texas to form a consortium to build an observatory to house the 41-inch telescope. Two years later Drs. Callaway and Gruebel attended the Astrophysical Society Meeting in Austin where the telescope consortium and the lack of interest were discussed. Dr. Gruebel suggested to Dean Glen Clayton that we upgrade our telescope plans and attempt to negotiate with Pan American University for the 41-inch optics in exchange for telescope time on the completed instrument. The agreement was successfully concluded in 1978. The large utility building was installed in that same year to serve as a shop and classroom.
Phase III
Dr. N. L. Markworth
I took over the position of Project Director for the new telescope from Dr. Gruebel in June 1982. I was convinced that to be successful in this endeavor, every available avenue of expertise needed to be explored and utilized. To this end I enlisted the services of John Gregory, who has been designing and building telescopes of all sizes for over thirty years. Likewise, we purchased the plans for the newly completed 40-inch telescope of the Lick Observatory, University of California, Santa Cruz. Although these plans required great modification, they represented an immense resource of fundamental engineering considerations for a telescope of this size. Finally, the assembled faculty and staff of the Physics Department here at SFA are a highly motivated, energetic group, representing an important resource for the solution of practical problems.
The new telescope would have a unique position in the astronomical community. Since large telescopes are heavily over-subscribed, our masters' degree students would not be permitted regular access to these instruments. We also have a history of providing research opportunities for interested, qualified undergraduate students. The 41-inch telescope still stands today as the only instrument of its size that provides substantial support to masters' level graduate research as well as undergraduate use. An instrument which could be used for all kinds of astronomical research was deemed inappropriate for our climate and anticipated support budget. A highly automated telescope, principally dedicated to photoelectric photometry, would, however, make important contributions to astronomy.
The academic year of 1982/83 was one of planning and organizing. The Lick Observatory plans were used (when applicable) or modified to our purpose. The details of the telescope operating system were refined. The academic year 1983/84 proved to be the watershed year for the project. Two events transpired that culminated in the project completion in August of that year. First, Dr. J.B. Rafert joined the Physics faculty. He had independently been pursuing the goal of telescope automation at Appalachian State U. Our combined efforts outdistanced what either one of us could have achieved on his own. Secondly, the Physics Department committed all of its capital equipment budget for the year ($20,000) to the completion of the 41-inch telescope project. We then pooled two grants from Research Corporation and one from the American Astronomical Society for a total of nearly $15,000 in equipment funds. As a measure of the growing awareness in the astronomical community of the significance of our facility in providing observing time to masters' level graduate students and interested undergraduates, Dr. Rafert and myself received a major grant from the National Science Foundation to fund undergraduate research just as the telescope was being commissioned. This two year grant was later renewed for an additional two years. We have had constant grant funding for research using the 41-inch telescope since "first light."
With funds in hand a carefully orchestrated plan was put into action to purchase material when necessary and build the bulk of the telescope in our shop. Mr. Bennett Montes, our staff machinist, did much of the machining required and Mr. Ed Michaels helped in the logistical planning. For a total capital outlay of $35,000, we constructed an $800,000 instrument. The cost to value ratio is a tribute to the entire department and is indicative of the philosophy we work toward.
Work on the NSF grant continued throughout 1985 and 1986, while at the same time hardware and software problems were corrected. The dome was placed under the control of the master computer in 1986. At this same time the Department changed its name to Physics and Astronomy. The anticipated improvement in observing efficiency was realized due to the automatic positioning capabilities, but the total number of observing hours remained low because of an unexpected problem. Inexperienced observers were spending large amounts of telescope time making sure that the target star had been found. Since a masters' degree student is in the program for typically two years, and the usual training period is about six to nine months, I am always training new students. Some way needed to be found to break this loop, or the goal of high telescope efficiency would be lost.
In 1986 I began to consider the problem of allowing the TV camera to work with the computer in automatically recognizing and centering the target star. After four years and two graduate theses on various aspects of the problem, we are nearing the goal outlined here. It has required a substantial improvement in the instrumentation of the telescope and a completely new software package.
Much of the funding for these improvements has come from a Texas Advanced Research grant by the Texas Higher Education Coordinating Board. In order to implement the pattern recognition process, the master computer would have to be considerably faster and more capable than the Commodore 64. The telescope software has been completely rewritten by Dr. Dennis and myself in Microsoft C. Two new CCD cameras have been obtained to digitize the telescope view, one for the finderscope, the other for the main optics. The new software and camera systems are being tested now. By August I hope to make the observer into an attendent. While some have argued that this removes the glamour of Astronomy, it will allow the students to concentrate on the science rather than the mechanics of their work.
New Directions for the SFA Observatory
The future of the Observatory is exceptionally bright. I have been actively involved with a group of astronomers, both professional and amateur, whose interest lie in the complete automation of observatories. Our goal is to link facilities world-wide by ordinary phone lines. As the Sun rises on one location, observations can be passed along to the next longitude zone. High priority observations could still be conducted even if clouds intervene. Students in Texas may even be able to "use" telescopes in New Zealand during an afternoon lab. The possibilities are bounded only by one's imagination. Our group has even approached NASA about the possibility of placing "Robotic Observatories" on the space station Freedom and at the Lunar Outpost. The SFA Observatory will be involved in the global network of telescopes even at the present stage of automation, but the 41-inch telescope can become a true robotic telescope with the following changes:
1. Retrofit the dome to allow for untended operation.
2. Provide a non-interruptable power supply.
3. Develop communications software so that the telescope may either be operated from a remote center or commanded during the day for the night's activities.
4. Provide a campus control center.
5. Improve the reliability of the phone service to the observatory.
6. Install a computer controled weather station at the Observatory.
7. Modify the software for untended operation.
In many ways the SFA Observatory is at the forefront of Astronomical facilities, not only among observatories in similar circumstances, but also among all facilities. Where we differ from the major observatories is in our lack of support personnel. Typically, an observatory requires a full time machinist and electronics technician. We share a machinist with the rest of the Department, which makes production of instrumentation a lengthy process. Presently, the machinist is producing a three- channel photometer. By the time it is ready to use, the total manufacturing time will have been two years. Our electronics technician is one we share with the entire school of Sciences and Mathematics. He is also a graduate student in Physics who is graduating soon. Because of the emphasis we place on computer control, the ET has become essential to our operation.
41-inch Telescope Dedication
I took over the position of Project Director for the new telescope from Dr. Gruebel in June 1982. The project had reached the critical turning point encountered in many ventures of this sort. The design and construction of a one-meter class telescope is a major undertaking. Many large telescopes have encountered months or years of agonizing redesign, as errors were uncovered in the original concept. The questions that were foremost in everyone's minds were 1) could we do it? and 2) to what use would the new telescope be put?
Our gathering here tonight tells us that the answer to the first question was "Yes." After many consultations with astronomical instrument specialists, I was convinced that to be successful in this endeavor, every available avenue of expertise needed to be explored and utilized. To this end I enlisted the services of Mr. John Gregory, who has been designing and building telescopes of all sizes for over thirty years. Likewise, we purchased the plans for the newly completed 40-inch telescope of the Lick Observatory, University of California, Santa Cruz. Although these plans required great modification, they represented an immense resource of fundamental engineering considerations for a telescope of this size. Finally, the assembled faculty and staff of the Physics Department here at SFA are a highly motivated, energetic group, representing an important resource for the solution of practical problems.
The answer to the second of our questions was equally clear. Large telescopes are used for their greater light gathering power, permitting astronomers to view fainter objects. The large telescope installations around the world are, however, heavily over-subscribed. No facility permits use of large telescopes by masters' degree students. We in the Physics Department also have placed emphasis on providing research opportunity for interested, qualified undergraduate students. In order that we meet our goals and still produce quality astronomical research, a local facility was the obvious choice. An instrument which could be used for all kinds of astronomical research was deemed inappropriate for our climate and anticipated support budget. A highly automated telescope, principally dedicated to photoelectric photometry, would, however, make important contributions to astronomy.
The academic year of 1982/83 was one of planning and organizing. The Lick Observatory plans were used (when applicable) or modified to our purpose. The details of the telescope operating system were refined. My experience in the area of computer control of telescopes was invaluable in creating a state-of-the-art telescope system. Computer control allowed us to use an unconventional "friction" drive system, which is not only more accurate, but also far less expensive than the more traditional gear drive. [slide] The drive system consists of a 48-inch diameter drive disk with a precision edge. Bearing against this disk is a small drive roller, which is mounted on the same shaft as a 7-inch worm gear. The worm gear turns a worm, which is connected to the stepping motor. The motors are controlled by Superior Electric drive electronics. The master computer (a Commodore-64) sends information on the length of move, move rate, direction, and acceleration to the drive electronics over an RS-232 channel. The drive electronics sequence the commands to the motors, so that the Commodore is free to go about its other tasks. [slide] The Commodore is quite busy during an observing run. In addition to issuing commands to the drive electronics, it must pulse auxiliary stepping motors that control 1) the filter and aperture wheels of a Starlight-1R pulse counting photometer, 2) the position of a TV camera (used to image the focal plane onto a monitor), and 3) the focus of the secondary mirror. This computer also reads the pulse counter of the photometer, senses WWV for timekeeping information, and reads the manual hand paddle. The original concept of a telescope which could be operated with precision from a remote control room has been achieved without compromise.
The academic year 1983/84 proved to be the watershed year for the project. Two events transpired that culminated in the project completion in August of this year. First, Dr. J.B. Rafert [slide] joined the Physics faculty. He had independently been pursuing the goal of telescope automation at Appalachian State U. Our combined efforts outdistanced what either one of us could have achieved on his own. Secondly, the Physics Department committed all of its capitol equipment budget for the year to the completion of the 41-inch telescope project. In addition several grants by myself and Dr. Rafert provided supplementary funds for equipment and subsequent research with the telescope. In particular I was awarded a grant from the Research Corporation, Dr. Rafert received a grant from the American Astronomical Society, and another joint grant from the Research Corporation was funded for a total of nearly $15,000 in equipment funds. As a measure of the growing awareness in the astronomical community of the significance of our facility in providing observing time to masters' level graduate students and interested undergraduates, Dr. Rafert and myself received notification of a major grant from the National Science Foundation to fund undergraduate research using the new telescope.
With funds in hand a carefully orchestrated plan was put into action to purchase material when necessary and build the bulk of the telescope in our shop. Mr. Bennett Montes, our staff machinist, did much of the machining required and Mr. Ed Michaels helped in the logistical planning. [slides]
Finally, I consider the new telescope to be much more than a new research tool for astronomy at SFA. The Observatory has always conducted public tours, and the addition of a large telescope will enhance the effectiveness of these tours. The new telescope places SFA on the world astronomical map, thereby acting as an aid in the recruitment of quality students to our campus. The new telescope speaks far louder than words can that quality research with state-of-the-art tools is not only possible, but is also flourishing at Stephen F. Austin State U.
Paul Engle's Recollections on the 41-inch Telescope Project
It all started probably just before the 1960 period. At that time I was teaching at Pan American University. In 1956 a Research Corporation representative (I can't remember his name) came to Pan American University and he inquired as to what kind of project I might be interested in dealing with astronomy, and wanted to give us some seed money. I said that we would like to consider a large aperture telescope for the future of the Rio Grande Valley or for Northern Mexico in collaboration with Monterrey Technical Institute. In fact, we worked four years with them. Research Corporation gave us five thousand dollars which made it possible for Corning to pour the blank. This is the third blank - the first two were defective. Corning never explained what happened on the two original blanks, but I asked them what was the largest blank they could give us for five thousand dollars. I told them I hoped it was larger than 36 inches and possibly even a little larger than 40 inches because of the publicity. They made it 41 inches, which is an odd size, but that is how it happened. They did their best for five thousand dollars. The pour date was around 1960.
We had Tinsley Laboratories take that blank and grind, polish, and figure the primary. If I remember correctly, the Research Corporation then gave us another five thousand dollars for that. So the primary was produced.
Norman Cole from the Kitt Peak headquarters in Tucson, Arizona made a special trip to Berkeley, California to run independent tests of the primary mirror and gave me a report on its accuracy. Norman's report was very favorable. As I recall it was better than one-tenth of a wavelength of sodium light. We then had the primary shipped to Tucson. From three of our NSF grants during that time, we received enough money to have Norman Cole make the three secondary mirrors, two Cassegrain and one Coudé. The f/8 Cassegrain mirror and the f/14.8 mirror were intended to be used for photoelectric photometry. That angle of beam we felt was ideal for photometry with the fabry lens, a photometer, the f/32 Coudé, and so forth. Norman produced the three secondary mirrors and ran the auto-collimation test with the primary at the Kitt Peak labs. Each secondary was corrected with the primary mirror. That finished the optics.