- NASA before CCDs used Vidicons but they sucked at ground resolution. They nonetheless did wonders all the way from Mariner 2 to Voyager.
37 Development program37.1 IntroductionIn the 25- minute film, produced by General Dynamics/ Astronautics, to summarize the results of the first EMPIRE Study in 1962/63, [snip]
0:28 Study NAS 8-5026 Jun-Dec 19623:06 Phopro/Deipro concept art and image6:20 How to plan a mission17:30 Project management charts and explanation19:00 .... for first Lunar base20:30 launch with post Saturn vehicle (NEXUS-like )23:30 Advanced NERVA, Phoebus, Metal Carbide reactor, etc26:00 Using Saturn C-5 ELV for Venus (and without fancy post-Saturn nuclear stuff as simpler alternative trip)
Quote from: libra on 09/05/2022 12:32 pm- NASA before CCDs used Vidicons but they sucked at ground resolution. They nonetheless did wonders all the way from Mariner 2 to Voyager.Mariner 2 (& 5) lacked a camera. Mariner 4 used film read-out. I'd have thought the Voyagers had CCDs.
Quote from: Proponent on 09/05/2022 08:20 pmQuote from: libra on 09/05/2022 12:32 pm- NASA before CCDs used Vidicons but they sucked at ground resolution. They nonetheless did wonders all the way from Mariner 2 to Voyager.Mariner 2 (& 5) lacked a camera. Mariner 4 used film read-out. I'd have thought the Voyagers had CCDs.I checked, Voyager was the last to use Vidicon.
The successful performance of scientific measurements by the Mariner IV spacecraft of Mars and the successful transmission of these data over some 135 million miles, has demonstrated the capability of highly integrated and mechanical equipment to perform unmanned exploration of the planets. The spacecraft was fully attitude stabilized, using the Sun end Canopus as reference objects. Power was derived from the Sun, using photovoltaic cells mounted on panels having a body-fixed orientation. The primary objective of the Mariner IV mission was to obtain scientific measurements of the planet during the brief encounter period. One such measurement was the acquisition of photographic data from the planet's surface. The photographic system was to perform preliminary topographic reconnaissance of portions of the surface in two color bands. The use of vidicon television system as spacecraft scientific instrument presentes a number of new problems with respect to test and calibration. First of all, the camera must qualify environmentally for a spacecraft mission. Further picture processing consists of restoring the high frequencies, removing non-linearities of the photoconductor surface, and spatial filtering using both digital computer and optical techniques.
And I must admit I thought Mariner 4 was vidicon.
Quote from: libra on 09/10/2022 08:46 amAnd I must admit I thought Mariner 4 was vidicon. See for example this film explaining how it was done:https://archive.org/details/xd-45534-close-up-of-mars-vwrand a contmporary "instrument paper"https://www.sciencedirect.com/science/article/abs/pii/S0065253908612573iltering using both digital computer and optical techniques.
And I must admit I thought Mariner 4 was vidicon. See for example this film explaining how it was done:https://archive.org/details/xd-45534-close-up-of-mars-vwrand a contmporary "instrument paper"https://www.sciencedirect.com/science/article/abs/pii/S0065253908612573iltering using both digital computer and optical techniques.
The reason I thought Mariner 4 used a photographic system was that I recall reading that it could return only a set number of images. Am I wrong about that too, or did such a limit apply to the vidicon system for some reason?
While I enjoy all the insights and discussion, Mariner IV is probably better discussed at its dedicated thread
Re: EMPIRE Photographic mapping of Mars and overlap with 1960s Earth reconnaissance satellite optics such as CORONA et al?The JBIS EMPIRE summary articles discussed upthread mentions the photographic mapping of Mars as one of the goals, for science as well as reconnaissance for a future human landing. The GD/A and Lockheed reports go into considerable detail. The whole discussion on high resolution optics, analog film vs digital storage, data transmission, storage is strikingly similar to 1960s optical reconnaissance satellites in Earth orbit. There is a memo at NASM  where the GD/A team discusses with Perkin-Elmer (from Hubble optics) on the Mars mapping optics and design. Hence, I am curious on what overlap there was, if any, with the KH-x programs on optics, mapping, and telescope design. 1) General Dynamics/Astronautics (GD/A)[...]Next, I thought it is interesting that a Laser communication between Mars Mapper and EMPIRE Crew Vehicle was considered for power and bandwidth reasons (page 1, point (c), and page 5). While we know of Perkin-Elmer involvement with Hubble, I do not recall seeing similar proposals for Laser communications with reconnaissance satellites in Earth orbits in this 1960s timeframe, or anywhere else. Am curious about the state of Laser communication at that time as LASER was only invented in 1960. Maybe the team figured that by the 1970s this would be feasible? Their quotes below sound like straight out of SpaceX Starlink laser links (ISL) which surprised me.Quote(c) Data transmission is accomplished with a laser high intensity narrow light beam which originates at the Crew vehicle and is reflected at the Mapper back to the Crew vehicle. In the reflection, map data are added by a modulation of the light beam. Thus no high power transmitter is required on the MapperandQuoteLaser development. Dr. Scott stated that suitable Laser light sources have already been developed. Two necessary elements of the proposed system are not yet available but should be developed by 1967 - 1968:
(c) Data transmission is accomplished with a laser high intensity narrow light beam which originates at the Crew vehicle and is reflected at the Mapper back to the Crew vehicle. In the reflection, map data are added by a modulation of the light beam. Thus no high power transmitter is required on the Mapper
Laser development. Dr. Scott stated that suitable Laser light sources have already been developed. Two necessary elements of the proposed system are not yet available but should be developed by 1967 - 1968:
Assistant Recorder, Geophysical Division, Texas Company, 1949-1950; Research Fellow, California Institute of Technology, 1959-60.In 1951 Dr. Vernon joined the Microwave Laboratory at Hughes Aircraft Company as a Member of the Technical Staff and remained there until 1961 at which time he was Head of the Microwave Physics Section.
In 1961 he joined The Aerospace Corporation as a Member of the Technical Staff in the Electronics Research Laboratory. Since that time he has been Head of the Low Temperature Section, the Solid State Electronics Department, and the Physical Electronics Department all within the Electronics Research Laboratory. Currently, he has the position of Senior Scientist in the Photonics Technology Department, Electronics and Photonics Laboratory. At present his primary responsibility is directing the laser beacon activity which, in turn, supports the Air Force surveillance satellite programs.
Except for classified projects, much of the technical work with which he has been involved is obvious from his publications. [...] The activity that has occupied much of his time is development of a technique for using ground-based lasers to calibrate on-orbit surveillance satellites and to assist in troubleshooting in the case of malfunction. In fact, there are numerous additional uses for this system depending on the characteristics of the particular satellite being tested. [...] At the same time the beacon activity has been under development (since 1971) his group was fortunate to be able to carry out a number of other interesting investigations. These include: (a) High frequency and millimeter wave properties of superconducting point contacts, thin film tunneling junctions and squids (11 papers since 1970).(b) Cosmic Background Radiation at 3.3 mm. This was the second independent measurement which showed that the radiation followed the Planck distribution rather than the Rayleigh-Jeans curve.(c) Irradiation of the Delta Star satellite (low orbiting) using a ground-based laser. This was performed using one of the optical beam director telescopes at Malabar, Fla. (d) Development of a diode-pumped 1-W continuous wave Er:YAG 3 micron laser. This is one of the laser sources developed for beacon applications.(e) Studies of satellite-to-satellite laser communication.(f) Studies of two-way laser communication between satellite and ground.(g) Measurements of the radiation sensitivity of Nd:YAG and LiNbO3.(h) Studies of brilliant pebbles lasercom.(i) Studies of loss mechanisms for guided waves in a nominally loss-free medium. (theoretical) (j) Presently, his group is conducting studies into coupling high power (approx. 3 W) of CW SWIR radiation at a wavelength of 3 microns from the output of an OPO [i.e. one of these https://en.wikipedia.org/wiki/Optical_parametric_oscillator] into a single mode fiber.
A quick note that I am still reading EMPIRE documents, final reports and follow-ons. The large volume of materials means it will be while before any new insights bubble up. Physically, the stack of papers was about 5 inches high or so. As examples, I hope to find more on the FORTRAN software, the EMPIRE space station, artificial gravity solutions, etc. If you are interested in a particular aspect, I'll take requests To be continued.
Bromberg:Shall we go now to Arizona and that Optical Science Center. I’m really interested to know how it was set up and by whom. And why there was so much applied work… free- electron lasers and X-ray lasers and so forth.Scully:Yeah. Gyroscopes. As I mentioned earlier, I was at MIT and Arizona called me. The main contact that I had there was a physicist named Steve Jacobs. Steve Jacobs was a very interesting character. He was a good scientist and optical person; worked with Gordon Gould. And was involved in making the first, I think it was, sodium laser, back in the early days when nothing much but ruby had lased. Maybe the second laser, maybe the third. He went then to Arizona and invited me to come out. So I went out for a visit, enjoyed my interactions, and went back to MIT. Then he went to MIT, and suggested we go down to Washington, and talk to people in Washington about this new Optical Science Center. Aden Meinel was the one who had made the Optical Sciences Center work. He was an astronomer, discovered the Meinel bands of nitrogen, and built Kitt Peak, by the way. He then was contacted by the Air Force and they asked him if he would work on the problem of optical resolution. Well, back in those days, satellite reconnaissance was developing and it was very difficult to get scientists who knew enough optics to help the Air Force in their mission. And so the thought was, perhaps we should have another Rochester. Rochester was based on optics coming from Kodak i.e. a very different perspective. What if we had a group that was focused on big optics. Big telescopes for astronomy and perhaps big systems for satellite applications. So Aden got the money together to build the Optical Science Center. Adam was a very inventive guy. You couldn’t use government contract money to build a building. Therefore what he did was to go to bank and borrow X million dollars to build a building at the University of Arizona, with the agreement with the Air Force that they would lease that building, and the lease could be structured so that in a few years, it would pay off the loan. That’s the kind of guy he was. Then after my visit, Jacob came to MIT and said, “Let’s go down to Washington and talk to people and see if we can get some support.”Bromberg:Was that the Air Force Office of Scientific Research?Scully:That’s right. After we were there for a while and were about to leave, I said, “Why don’t we go over to the NSF and see if we can get a million dollars.” And Jacobs said, “That’s what I like about you, Scully. You think big.” I said, “I thought you liked me because of my personality!” He said “No” and he was serious. So at that point I realized that he was a quality person. He was so straightforward. So I took a leave of absence from MIT for a year and went to Arizona.
Quote from: leovinus on 10/18/2022 03:42 pmA quick note that I am still reading EMPIRE documents, final reports and follow-ons. The large volume of materials means it will be while before any new insights bubble up. Physically, the stack of papers was about 5 inches high or so. As examples, I hope to find more on the FORTRAN software, the EMPIRE space station, artificial gravity solutions, etc. If you are interested in a particular aspect, I'll take requests To be continued.Well I'd love you to keep a (well shielded) eye out for any laser related stuff. Have been fascinated by some AIP oral histories I've recently read, [snip]
The first laser was built in 1960 so it’s not obvious they’d have picked that for communications in 1962.
Quote from: Robotbeat on 11/02/2022 02:52 pmThe first laser was built in 1960 so it’s not obvious they’d have picked that for communications in 1962.I know which is why I wrote about it earlier in this thread post #37, section 2 titled "2) GD/A with Perkin-Elmer discussion" dated 7 November 1962 and asked what y'all think about such forward thinking in 1962.
In 1950, Townes was appointed professor at Columbia University. He served as executive director of the Columbia Radiation Laboratory from 1950 to 1952. He was Chairman of the Physics Department from 1952 to 1955.In 1951, Townes conceived a new way to create intense, precise beams of coherent radiation, for which he invented the acronym maser (for Microwave Amplification by Stimulated Emission of Radiation). When the same principle was applied to higher frequencies, the term laser was used (the word "light" substituting for the word "microwave").During 1953, Townes, James P. Gordon, and Herbert J. Zeiger built the first ammonia maser at Columbia University. This device used stimulated emission in a stream of energized ammonia molecules to produce amplification of microwaves at a frequency of about 24.0 gigahertz.From 1959 to 1961, he was on leave of absence from Columbia University to serve as vice president and director of research of the Institute for Defense Analyses in Washington, D.C., a nonprofit organization, which advised the U.S. government and was operated by eleven universities. Between 1961 and 1967, Townes served as both provost and professor of physics at the Massachusetts Institute of Technology.
Why was "laser coms" discussed in the days of AAP yet only happened 40 years later, in the early 2000's ?