Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from corsica.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Mon, 7 Aug 89 05:17:22 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 7 Aug 89 05:17:14 -0400 (EDT) Subject: SPACE Digest V9 #589 SPACE Digest Volume 9 : Issue 589 Today's Topics: Electronic Journal of the ASA, Vol. I, No. I (part 2) ---------------------------------------------------------------------- Date: 22 Jul 89 18:22:59 GMT From: eedsp!chara!don@gatech.edu (Donald J. Barry) Subject: Electronic Journal of the ASA, Vol. I, No. I (part 2) -------------------begin part 2------------------ THE ONE DREAM MAN: ROBERT H. GODDARD, ROCKET PIONEER Copyright (c) Larry Klaes When telescopes were introduced into astronomy during Europe's Renaissance, they revolutionized humanity's oldest science. Earth's Moon was shown to be no longer a smooth, reflective disk as once believed, but a crater-scarred, mountainous world not far removed in constitution from the planet it orbits. The other planets, once no more than bright points of light in the night sky, were now shown to be worlds themselves, all displaying discernible disks, some with phases, others with surface features, and even possessing retinues of moons. But as good as Earth-based telescopes have become, they still cannot present to us the truly close-up, detailed views of the other planets in the Solar System, neither can they give us direct samplings of these worlds' atmospheres and minerals, nor can they bring humans themselves to these places for exploration and colonization. Such abilities required the advent of the rocket to place our astronomical instruments and people in space. All this came about due to a rather private, driven, frequently ill New Englander in the first half of the Twentieth Century. Robert Hutchings Goddard (1882-1945) is looked upon as one of the three main founders of modern rocketry, along with Konstantin Tsiolkovsky (1857-1935) of the Soviet Union, and Hermann Oberth (born 1894) of Germany. What makes Goddard stand out is that he went beyond just theorizing about various rocket designs and actually built working models. In fact, Goddard launched the first liquid-fueled rocket (the forerunner of most rockets used in today's various space programs) in Auburn, Massachusetts, on March 16, 1926. The flight lasted just 2.5 seconds, reaching an altitude of 12.3 meters (41 feet) and landing (crashing, actually) 55.2 meters (184 feet) from the launch site in his Aunt Effie's cabbage patch. Today the launch site is commemorated with a small monument surrounded by a busy street and numerous stores, including the Auburn Mall. Goddard belonged to the league of misunderstood geniuses who was most certainly ahead of his time. As a teenager growing up in Worcester, Massachusetts (about eighty kilometers/fifty miles west of Boston) he dreamed of sending spacecraft to orbit and photograph the planet Mars at a time when many people didn't even know what Mars was; and sadly this is still true in some cases today. Goddard attended and eventually graduated from Clark University in Worcester, where he earned a degree in mechanical engineering. Later he taught physics at Clark and began to assemble, from among his students, those who would work with him later on. Goddard sustained his rocketry work with grants from the Smithsonian Institution in Washington, D.C.. He always preferred to think of rockets in terms of space exploration. However, to stay viable, he also attempted to sell the idea of rocket-borne weapons to the United States Army. In 1920, the Smithsonian Institution published Goddard's paper on rocket concepts, "A Method of Reaching Extreme Altitudes", in the Smithsonian's Miscellaneous Collections (Volume 71, Number 2). Always concerned about being rejected as an "outlandish misfit", Goddard tried to protect his meager funding by remaining very conservative in print. After discussing some rocket fundamentals, he described the rocket's potential for exploring Earth's upper atmosphere directly. Towards the end of his article, Goddard began to hint at his thoughts for the future by detailing his plans for launching a small, unmanned rocket that would be sent to Earth's Moon, wherein it would strike the surface and explode its payload of flash powder, so that observers with telescopes could see where the rocket had landed. Goddard was cautious not to mention flights to Mars or any other planet, as any celestial object beyond the Moon was considered by many scientists at that time to be too far away from Earth to ever be reached by humans, and general opinion on journeys to the Moon fared little better. Although published in a journal virtually unknown to the general public, "A Method of Reaching Extreme Altitudes" did not go unnoticed, but it brought about the kind of attention Goddard did not want at all: Regular daily newspapers grabbed his ideas and practically announced that the Massachusetts scientist would be sending a manned expedition to the Moon within a few years! The prestigious NEW YORK TIMES dismissed Goddard's ideas and said that he didn't even possess an elementary knowledge of physics. The TIMES' editor incorrectly thought that rockets could not work in space. He thought the exhaust from the vehicle would have nothing to push against; he did not realize that the rocket exhaust would be acting against the inner walls of the rocket itself, thus creating the required reaction (The TIMES did not make a retraction of this error on their part until the day APOLLO 11 landed Neil Armstrong and Edwin Aldrin on the Moon in July of 1969!). Mary Pickford, the famous silent screen film actress, asked if she could put a letter in the non-existant Moon rocket; one man insisted that if Goddard paid ten thousand dollars for the insurance, he would fly to either the Moon or Mars without any other provisions. Goddard was a very private man. This overblown attention was one of his worst fears come true. He was also justly concerned of rivals stealing his ideas and claiming them for their own. Goddard later commented that he should have written about his plans for a Mars mission, as then it would have been deemed ridiculous and he would have been left in peace. Although it came close to causing him to lose his funding, eventually the publicity would reach the right people who would help Goddard finance his dream of rocket research. In 1929, a particularly loud rocket test in Auburn, Massachusetts had neighbors believing an airplane had crashed, so they called the police and fire department, who - along with the press - rushed to the scene, only to find Goddard and his assistants gathering up the pieces of a wrecked rocket and putting out small grass fires. Even though the incident was really a test with the crash of the rocket fully expected by Goddard and his team, the press had a different point of view and played it much differently: One of the most painful headlines told about Goddard's rocket missing the Moon by "only 238,799 1/2 miles!" After this event, Goddard was asked by the local authorities not to fly rockets in the area again, as it was deemed far too dangerous, particularly in a residential area (this was a legitimate concern). Goddard reluctantly took his project to Hell Pond, a desolate federal artillery range at Camp (now Fort) Devens in Ayer, Massachusetts, where he conducted a number of static firing tests for several months. Fortunately for Goddard, he did not have to dwell at the range for long: Aviator Charles Lindberg - who had become quite famous for crossing the Atlantic Ocean on his own in an airplane two years earlier - took an interest in Goddard's concepts and decided to help finance his work on rockets. As an interesting note, Lindberg was introduced to Goddard by one of the rocket pioneer's own students and a former associate of the Wright Brothers: Edwin Aldrin, Sr., father of Edwin "Buzz" Aldrin, Jr., the astronaut who landed on the Moon with Neil Armstrong in APOLLO 11 on July 20, 1969, and became the second human being to directly explore another world. Lindberg also convinced philanthropist Daniel Guggenheim to help fund Goddard and move his entire operation to Eden Valley near Roswell, New Mexico. There Goddard could test his new developments in the comparative safety and peace of the wide open desert. Goddard's research would be a prelude to the thousands of rocket tests which would be conducted in that part of the United States in the decades to follow, all descended from the launch of that primitive liquid- fueled rocket on a farm in Auburn in 1926. Here in the desert, Goddard did some of his best work, testing parachute systems to recover rockets and their payloads, constructing stabilizing fins and gyroscopes to keep rockets flying straight, and even putting simple meteorological instruments aboard some flights to study the weather. During this entire time, Goddard's staff never numbered more than seven people: Five machinists (some of whom hadn't even graduated from high school), his wife Esther (who took the photographs and extinguished fires), and Goddard himself. The man who wrote about rockets to the Moon never got any of his rockets higher than 2,250 meters (7,500 feet), though distance was only one of many important aspects of his rocket development. Despite all this work, Goddard and his rockets were generally unknown to the American public, and many of his ideas went unrecognized until several decades after his death in 1945. Ironically, his ideas did not go unnoticed by the Germans, particularly Wernher von Braun, who took Goddard's plans from various journals and incorporated them into building the A-4 series of rockets - better known as the V-2 - which constantly struck at Europe in the last two years of World War Two. The Army also adopted only one major and direct facet of Goddard's concepts in his lifetime, the antitank weapon known as the bazooka. Eventually, the United States Patent Office would posthumously recognize 214 patents in all for various rocket designs invented by Goddard. Goddard was visionary in his dreams for space travel: Nuclear and ion-powered rockets, solar-powered satellites, solar sails, even methods for communicating with extraterrestrial intelligences. The proposed (but never built) American probe to Comet Halley in 1986 had incorporated in two of its design plans ion power and solar sails as possible methods of propulsion to reach the comet. Goddard even felt that rockets would also pave the way to save the human race in the far distant future when Earth's Sun will begin to expand into a red giant star and envelope Earth, vaporizing it along with Mercury and Venus. He proposed that humanity use its no doubt advanced skills to construct habitats inside large planetoids (less correctly known as asteroids) and then propel them out of the Solar System using some distant descendants of his primitive rockets to other, still viable star systems, where humans could find new planets to live on and continue the existence of the species. Today, Goddard's designs and dreams have either become realities or at least well-used plot concepts in science fiction. Because of his work, we have been able to study lunar minerals first hand, search Mars for signs of life, find active volcanoes and frozen oceans on the moons of Jupiter, and view the Milky Way and other galaxies with a clarity unavailable within the turbulent atmosphere of Earth. As rocket expert Jerome Hunsaker said of the man from Worcester, "Every liquid-fueled rocket that flies is a Goddard rocket." Some recommended reading: Anne Perkins Dewey, ROBERT GODDARD: SPACE PIONEER, Little, Brown and Company, Boston, 1962, Library of Congress Catalog Card Number 62-8309 (hardcover). Milton Lehman's 1963 biography on Goddard, THIS HIGH MAN, was reprinted in 1988 by Da Capo Press, New York, with the title ROBERT H. GODDARD: PIONEER OF SPACE RESEARCH, ISBN 0-306-80331-3 (paperback). Another book (actually a multi-volume work) on Goddard's work is THE PAPERS OF ROBERT H. GODDARD, edited by G. Edward Pendray and Esther C. Goddard, McGraw-Hill, New York, 1970. THE CHARA MULTI-TELESCOPE TELESCOPE by Hal McAlister Astronomers at Georgia State University's (GSU) Center for High Angular Resolution Astronomy (CHARA) have developed a novel approach to the design of inexpensive telescopes having significant light collecting power. The new design concept calls for nine 32.75-centimeter (13.1-inch) diameter parabolic mirrors to be arranged in a 3x3 configuration. All nine mirrors are carried on a common mount, but each mirror directs its collected light to a separate focus - hence the name Multi-Telescope Telescope, or MTT. At each of the nine foci is located an optical fiber to carry the collected light to a spectrograph, or other instrument, located indoors away from the telescope. Because the nine optical fibers feed the same instrument, the MTT acts as if it were a larger single-mirror telescope. A standard telescope with equivalent light collecting power would cost $500,000, but because of the low cost and weight of small mirrors, the CHARA MTT, including spectrograph, solid state detector system, and shelter is estimated to cost about one-tenth that amount. The MTT design was originated by CHARA astronomer William G. Bagnuolo. With the collaboration of Georgia Tech faculty members William Russell of the College of Architecture and John Dorsey of the School of Electrical Engineering, a design concept combining rigid light weight mechanical support structures with inexpensive real-time electronic control systems has been developed. Dr. Bagnuolo's interest in telescope design grew out of the CHARA Array project, in which considerable effort was expended to take advantage of modern technology to develop inexpensive telescopes. CHARA members Douglas Gies, Ingemar Furenlid, and Don Barry, all members of the Society, are also participants in the project, which has been proposed for funding to the National Science Foundation (NSF). Accompanying the telescope would be a dedicated spectrograph similar to one designed by Dr. Furenlid and built for use with the 210-centimeter (84-inch) telescope operated by the Mexican government in Sonora, Mexico. The MTT with its spectrograph will give CHARA a powerful new capability for carrying out programs of high signal-to- noise stellar spectroscopy. Planned research programs include the accurate measurement of Doppler velocity orbital motions in binary star systems that are also under scrutiny in CHARA's programs of speckle interferometry and the study of emission features arising in the spectra of so-called Be stars in order to determine whether pulsations in the stellar atmosphere are responsible for the disk-like gaseous envelopes surrounding the stars. Because of the minimal obscuration of light by the fiber support structure and the ability to use very high reflectivity coatings on the 32.75-centimeter (13.1-inch) mirrors, the MTT, when used for spectroscopy, will have the effective light gathering power of a 135-centimeter (54-inch) telescope. The CHARA MTT will thus be the largest telescope in the southeastern U.S. It is hoped that the new facility can be operational before the end of 1990. A VIEW FROM TAIWAN: WEAN-SHUN TSAY An interview by Edmund G. Dombrowski Editor's Note: Wean-Shun Tsay recently completed his thesis work for his Ph.D. in astronomy, the first such degree to be bestowed in the history of Georgia. Society member Wean-Shun Tsay is an astrophysics graduate student at Georgia State University under the direction of Dr. Harold A. McAlister of CHARA. He entered the GSU Ph.D. program in the fall of 1986 after obtaining a Masters degree from Yale. Currently completing his doctoral dissertation, Wean will soon graduate, and then return to his homeland of Taiwan to continue research in astrophysics. I interviewed Wean on the morning of June 15, 1989: Ed: I guess a good place to start is your educational background. You obtained a bachelor's degree in physics from the National Central University in Taiwan. Then you came over to the United States to attend Yale University at which you earned your Masters degree. What was that transition like, first of all, coming from Taiwan to the U.S.? Wean: There was a big difference, because during the first half of the year when I arrived the language was a big problem; but it was fortunate that I had a couple of classmates who really helped me a lot. Ed: How was your experience at Yale University and the Department of Astronomy there? Wean: Yale was my first exposure to the U.S. It was quite different from what I expected before I came. As you know, the Yale Astronomy Department has a very strong background in galactic and globular cluster research, and I believe half of the students are working on theoretical research. Most of them are Pierre Demarque's students. [Editor's Note: Pierre Demarque is a well known astrophysicist who has contributed much to the field of stellar dynamics and evolution]. Ed: So you were concentrating more on the experimental. Wean: Yes, it's a big difference. I wasn't expecting to do much theoretical work when I went there. Ed: Whom did you end up working with for your degree? And what was your master's research? Wean: van Altena, [Dr. William van Altena]. Most of the research I was working on dealt with a PDS machine. I studied there two years and after I graduated I worked for Van Altena for one year, working on the PDS, scanning 21 or 22 4-meter plates, from Kitt Peak. Ed: What is the PDS machine? Wean: The PDS machine was designed by van Altena; he improved the commercial type of PDS machine created by the Perkin Elmer company. The original design allowed hospitals to scan x-ray pictures. The machine scans a 20x20 inch (50x50 centimeter) area. van Altena purchased this one in order to do proper motion studies on big plates. Since the original accuracy of this machine is only 5 microns, he tried to improve it. The first step involved using a micrometer which had a micron separation between each mark, so the best accuracy with the older device was 0.8 micron after several scans. Later he used a laser interferometer to improve this machine. I went to Yale just at this time, so I did a lot with the laser interferometer, making many adjustments, scanning data, and later on improving the machine to about the limitation of the grain noise of the plate, which is about 0.2 to 0.3 micron. Ed: By a photographic plate, I suppose you mean the machine scans over the plate and detects a dark, exposed source. What specifically are you recording? Wean: The plates I was working on were 8x10 inches in size. The active area was about 8 inches in diameter, and each plate contained more than a million star images. The brightest stars were about twelfth magnitude, and went down to magnitude 21-22. The first step of analysis uses a fast scanning mode to search through the whole plate to create a scanning catalogue. After this, the results were added to the original catalogue which holds about 20,000 stars. If you go down much fainter than 21 or 22 magnitudes, you get many more stars, but the signal to noise of these are poor. Then you take out the brighter objects and fit them to two-dimensional profiles, because experience shows that this method gives the most accurate positions compared with other types. Maybe other types of fitting can do better, but they can't offer higher accuracy on the position. van Altena was interested in astrometry, or accurately fitting the positions of these stars. Ed: While you were working for him, how many stars do you think you personally measured? Wean: After the first scan I reduced the search catalogue to about 9,000 stars. I used the first five plates for trigonometric purposes. For this you need to take one picture every half year. For best results you must take five pictures every half year over two and one half years to get five points of data. This data gives you the parallax information. That's the basic idea, and I took the best plates on each epoch, and scanned through those for 9,000 stars and ran them through the parallax program. From this information, I deleted some more data which were poor spots. The final catalogue is around 5,000 stars on a small plate. It's only half a degree in the sky over the whole region. Ed: After this, you eventually got your Master's degree from Yale and came down to Georgia to attend GSU. It's a big enough move from Taiwan to the U.S., but now you had to move from a northern state to a southern state. What was that like? Did you notice a different life style between the North and the South? Wean: The big difference between GSU and Yale is that Yale is a big university town. GSU has only a few buildings and is a smaller place. That was a big difference for me. You have to rent off campus here, and use transportation. The weather is also quite different between the North and the South. Ed: Which do you like better? Wean: I like both, but Atlanta has weather which is much like my home country. Ed: Yes, I can see how that would be easier to get used to. Could you describe basically your work at GSU which has led to your thesis under Hal McAlister. Wean: Right now, my topic for dissertation is trying to find a site for the future CHARA interferometer array. That's the basic purpose. This is also very interesting to me because I am working with various instruments and technical equipment. I especially like the CCD camera work. Even though I used a commercial one, with high resolution and low price, I still learned a lot about CCD cameras. Also since I am planning to go back to my home country, I believe this site survey project is very useful for me for my later research in Taiwan. Ed: Your writing your thesis now, and finishing your dissertation. You are expecting to graduate by the end of this summer. I know you have a wife and son, and they have both constantly moved back and forth between here and Taiwan: How has this been for them? Wean: For the first two years when my wife came to the US while we were still at Yale, she was not very comfortable with the environment there, because she has a very large family in Taiwan, and here there were only her and myself, before we had our baby; but when we moved down here, her brother joined us. He is studying here at GSU. In Atlanta, there are more Chinese people and there is the Chinese Community Center, and the Farmer's Market where we can buy authentic Chinese food. Ed: It was more difficult in Connecticut? Wean: Yes, because we had to drive one and a half hours to New York City or two and a half hours to Boston. Ed: Was the cost of living that different? Wean: We paid more rent up there than here, but the transportation is more expensive here than there. Ed: You mentioned that there's a big Chinese community down here in Atlanta, and there are a lot of Chinese students here. In light of what's happened recently in China, do you think that that's going to put a damper on Chinese students coming over here to the United States? Wean: I think in the near future the students who have already applied and have been approved will have some problems coming in, or maybe unfortunately they have already died. Ed: Do you think we'll probably see a withdrawal of the Chinese student population for a while? Wean: I hope that this will be finished in about half of a year. Ed: Do you think things will improve now? Wean: I don't know, because the Communists are trying to disconnect all the information to the free world. Ed: What do you think Taiwan's role will be in any of this in the future. Do you think they'll have more of a role than they have now? Wean: I think Taiwan will keep going on like right now. As you know, currently, Taiwan doesn't officially support the students at Tinianmen Square, and most of the supplies go through the Red Cross association, through the patient's branch. So most of the work is done through the government. The Taiwan government is trying to keep some distance from the situation to somehow avoid the problems between China and Taiwan. Ed: It could still be a very tense situation when you return. When you do go back to Taiwan, you'll have your Ph.D. in Astrophysics. Where will you be working? Wean: I'll be working at my home university, the National Central University. I'll be going in as an Associate Professor in Astronomy. The system is different from the university system here. In the coming two years, however, the university law will change, and we'll adapt some kind of system like in the US. Ed: What kind of work do you plan to do in astronomy? Wean: I think I will continue the site surveying because in Taiwan we only have a 24-inch (60-centimeter) telescope for research and education. The site is very close to the city, about 30 miles (48 kilometers) south from Taipei. The population there is probably 30,000 people at the site, so there are lots of city lights and light pollution there. Ed: So you'll take your knowledge from here and apply it there? What essentially were you doing here? What was your setup like? Wean: The seeing monitor was designed by Nat White of Lowell Observatory, and Bill Bagnuolo here at CHARA. The basic idea is to use a CCD camera attached on a C-14 telescope and then take the star image at a fast speed. This kind of technology lets one directly take the image profile from the CCD array and find the width to determine the seeing during the moment. Ed: To describe it, you're taking a star image and looking at the image profile you get which is highly dependent on the turbulence in the atmosphere. And so, based on fitting Gaussian profiles to these you can tell what the seeing is like at that time. I guess a good description of the seeing would be how the star images vary over a certain period of time. Wean: Yes. For this kind of seeing test you have two or three ways of doing this. The first way is the direct image profile measurement, which involves trying to fit the profile to a Gaussian or some other kind of model profile, and to determine the full width at half maximum. The other two ways use the image motion to describe how the atmospheric turbulence affects the plane wave when the light passes through it, that is, how the light is disturbed. Ed: A lot of readers are observers in this area. Recently I was looking at a chart Bill Bagnuolo prepared for the Georgia area which showed a plot of mean cloud cover versus time. The mean cloud cover looks almost the same as the plot for Arizona, with Arizona being better by only 20 percent. At a site such as the Hard Labor Creek observatory, what do you think the prospects are for seeing and good observing? Wean: I think in the future before I go back to Taiwan, and after I have done my dissertation, I may spend some time doing some tests there. It looks like a pretty good site. I expect good results. Ed: After you go back to Taiwan, you'll do more site surveys. Do you think you'll ever travel back to the US? Wean: I think so. Presently, the National Central University has very generous funding. They have 400,000 dollars for setting up an instrument there. I think I have a very good chance to get some money to do this particular research. I would like to cooperate with CHARA to do some kind of site testing both here and in Taiwan. Maybe we will need help from the CHARA group. I would also like to invite the amateur astronomers here to visit Taiwan because Taiwan is about two- thirds mountainous area, and more than 16 mountains are higher than 10,000 feet (3,000 meters). I have seen some pictures that amateur astronomers took from these areas and they show pretty good seeing. Ed: Speaking of amateurs, are there many groups over there that are really interested in astronomy? Wean: Most of them are in the university astronomy club. Ed: But, in general, is there a big interest in astronomy in Taiwan? Wean: Right now the economics in Taiwan is much better than ten or twenty years ago, and the young people are playing with their personal computers because right now Taiwan is one of the most important suppliers of personal computers. Many people also have the money to purchase telescopes. Ed: At one time China was one of the dominant civilizations contributing to astronomy. It was a distinct part of the Chinese culture and folklore. Do you think that presently astronomy is making a resurgence in both China and Taiwan? Wean: Yes. That's another reason I'm going back to Taiwan, because most of the money at the university is from the government, and the Education Administration is trying to develop the astronomy program. They are well aware that the Chinese have about 4,000 or 5,000 years of recorded history of celestial objects. Many people are also interested in astrology, but people still confuse this with astronomy. That may be another purpose for developing an astronomy program, so that we can educate people with more astronomical common sense. Ed: That's good. You're trying to get across the idea that there is a big difference between astrology and astronomy, and bring the science up to where it should be. Well, I'm sure you'll do well no matter what pursuit you tackle first. Thank you very much for your time and we wish you all the luck and good fortune when you return to Taiwan. Wean: Thank you. THE ELECTRONIC JOURNAL OF THE ASTRONOMICAL SOCIETY OF THE ATLANTIC August 1989 - Vol. 1, No. 1. Copyright (c) 1989 - ASA -- Donald J. Barry (404) 651-2932 | don%chara@gatech.edu Center for High Angular Resolution Astronomy | President, Astronomical Georgia State University, Atlanta, GA 30303 | Society of the Atlantic ------------------------------ End of SPACE Digest V9 #589 *******************