Keynote Address*
Total Page:16
File Type:pdf, Size:1020Kb
Keynote Address* DR. S. FRED SINGER Professor of Physics, University of Maryland INTRODUCTION G. C. TEWI:\KEL, Past President, .ISP Our Convention is honored this year in having as its guest speaker Dr. S. Fred Singer, Professor of Physics, University of Maryland. [ rnld that his work has been associated with such nebulous topics as: The Upper Atmosphere; High Altitude Sounding Rookets; Geophysical Re search with Artificial Satellites; Primary Cosmic Rays and their Origin; Environment in Space Vehicles; Orbits of Rockets and Space Vehicles; Theory of Relativity; Origin of Meteorites; [on 0 spheric Currents; Magnetic Storms and Aurora; and R.adiation Belts. Dr. Singer has earned for himself distinction as one of the most brilliant of our space scientists. He designed satellites before there were any. He pre dicted the existence of radiation belts which later were discovered by Dr. Van Allen. Dr. Singer was commended by President Eisen hower for outstanding achievement in the develop ment of satellites for scientific purposes. He was the recipient of the Distinguished Alumnus DR. S. FRED SINGER :\ward by Ohio State University in 1958. He was selected as olle of the Ten Outstanding Young excltI11g problems that exist in outer space, Men of 1959 by the U. S. Jr. Chamber of Com merce. particularly in connection with the planets. It is my pleasure and honor to present to you lI·hat their scientific importance is, and why Professor Singer of the University of Maryland. it is so vital that measurements be made. The start "'ill be the Moon-our nearest INTERESTING PROBLEMS IN neighbor-sometimes called a satellite of the OUTER SPACE Earth, because it in fact revolves around the RESlDEKT Tewinkel, President Karo, Earth. But sometimes it is also called a twin P Ladies and Gen tlemen of the Consecu ti ve planet of the Earth. Meeting, r am very pleased and honored to The origin of the Moon is unknown. There be invited to deliver thir Keynote Address are generally two types of theories. One is that today. the Moon was captured by the Earth but was After spending consideyable time in think formed independently. The other is that the ing about the subject I decided that since very Moon was formed close to the Earth, within soon you will have finished explori ng the its gravitational lield. Later I will tell you Earth, there then will be only one place to go, how careful measurements of the features of and that is out into space. Therefore, I will the Moon make possible deciding between touch on some of the interesting problems these two. possibilities. For historical reasons that exist in outer space for photogramme it should be men tioned that there are also trists, surveyors, cartographers and mappers; theories which claim that the Moon came out in other words, for people who have the back of the Earth after it had been formed; I fear ~round and professional interest "'hich you those theories do not stand up very well under have. the lall's of physics. I am not an expert in many of the new in rt seems fair to start with the problem of struments and new techniques. but [ can talk t he back side of the i\loon-the hidden side about what I personally think are some of the because therein lies theonl)' photogrammetric * Presented at the !\SP-l\CSi\1 Gellcral .\ssenlhly, The Shoreham Ilotel, Washing-Lon, D. C, i\larch 22, 1%I. 371 372 PI1UTU(;H.\~1 ~[ETR[l' ENGINEEHING achievement made in space so far. As you Unfortunately their techniques were not know, it was made by a Russian scientific perfect. In the first place, from reading over group in one of the lunik rockets, October 7, their original paper, it appears that the nega 1959. They were able to photograph the back tives themselves were not particularly good; side of the Moon using a camera with two there were little imperfections in the film; focal-lengths, 200 and 500 millimeters. They the development may not have been carried were able to obtain pictures of 10 millimeters on properly; the contrasts were not always and 25 millimeters in diameter, which they right. took on 35 millimeter film. Secondly, there was radio interference. It is a very important achievement. But While pictures were transmitted several from a technical point of view, the measure times from the probe to the Earth, there was ments were not ideal. In the first place, the radio interference; as a result noise was intro distance to the Moon was quite large--of the duced into the picture. order of 65,000 kilometers-during the time I think it extremely interesting how they that the camera was operating. And secondly finally reduced the data which they received -and this is probably the most serious on the Earth. I will spend a little time on that, they made their observations when the back because I am sure the action will interest side of the Moon was fully illuminated by the you. Sun. Therefore,- no shadows could be ob They took the precaution of having the served. it is extremely difficult to observe analysis made by three separate, independ any surface detail of the Moon when it is ent groups-one in Leningrad, one in Mos viewed under full illumination. cow, one in Kharkov. These groups did not The spectacular lunar pictures which you communicate with each other. They only always see are those taken during half-moon, compared their final results. This is quite im because then the craters and the mountains portant in order to get a completely unbiased throw shadows, and the relief stands out picture. particularly well. In fact, the most successful I mentioned before that not much surface picturing of the Moon that I know of is a detail is visible because the Sun was shining composite, the two halves of the Moon taken full on the Moon. They could however see with the Sun first on one side, and then on the surface detail very well near the edge-actu other side. When joined together, the whole ally the northwest rim-where many of the of the Moon surface is seen in relief. lunar features were already known. In spite of the fact that these pictures were You are probably aware of the fact that taken under fairly unfavorable conditions, the Moon "librates," so that we can see a they did achieve some results which they little around one edge of the Moon when it is analyzed. I should briefly discuss the tech turned one way, and then around the other nique because it has not been too well ex edge when turned the other way. They were pounded. It has only recently been released able to observe the edge features of the Moon by the Russians in a Russian journal. Also, quite well, and showed that the features it was discussed at a conference which the continued around into its hidden side. Russians organized last December in Lenin But then they ran up against the following grad. problem. There are on the Moon, roughly As I mentioned, the pictures were taken on speaking. two types of features. These are the 35 millimeter film. They were developed in so-called maria. the oceans-of course they the vehicle itself using very much standard are not really oceans. but are so-named-and types of processing techniques. The negatives the mountains. The contrast between them is were dried, and then scanned with a slow quite large. They have different reflecting television type of scanner. This has the ad powers. Furthermore, there are also small vantage of getting the resolution of the photo features on the Moon which have a rather graphic process without having to recover the low contrast. pictures. You can transmit them to the Their first problem was reducing the ex ground by telemetering. A further advantage treme contrast without destroying the moder is that you can take your time about trans ate contrast. They went about this in a very mission. Because you can scan as slowly as fine way. Essentially the need is a dynamic you like, you can get fairly high resolution. compression of the picture. They pre In other words, the resolution of the tele pared what is called a photographic mask. vision system, while of course not as good as The technique is quite new to me; per the photographic resolution, is better than haps it has been used by others, but I suspect televising directly. not. They then constructed a positive which KEYNUTE ADDRESS 373 was washed out, and purposely blurred it by But perhaps I should make clear that printing out-of-focus. They made it with very all of the back side of the Moon has not yet low con trast. Then they superimposed this been photographed. There is still an u nex positive on the negative and produced plored region which has not yet been seen. another print. In this way they were able There is still tremendous need for looki ng at to reduce the dynamic range-the con the back side of the Moon with much better trast range of the picture. They could reduce resolution and at a time when the Sun is so the extreme contrast without destroying the si tuated that one can see the relief and the moderate contrast. details much better than in the past. This technique worked well but unfor Leaving this problem for a moment, I tunately they had other problems. would like to discuss another one, concerned I mentioned the noise ,in the transmission.