Many folks would like to see us back on the Moon and developing its resources.

Monday, April 24, 2006

Space trailblazer Eberhardt Rechtin passed away at the age of 80 on Friday, 14 April 2006.

Once again, my thanks to Larry Klaes for keeping me informed.

He passed a notification of the death of Eberhardt Rechtin who passed away at the age of 80 on Friday, 14 April 2006. (See below)

You can read the notices below but what I want, is for you to take the time to read and digest and ponder the Oral History Interview with Eberhardt Rechtin that is posted on the IEEE web site.

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http://www.ieee.org/organizations/history_center/oral_histories/transcripts/rechtin.html

Interviewee:
Eberhardt Rechtin
Interviewer:
Frederick Nebeker
Date:
February 23, 1995

Copyright Statement

This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the IEEE History Center. No part of the manuscript may be quoted for publication without the written permission of the Director of IEEE History Center.

Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, Rutgers - the State University, 39 Union Street, New Brunswick, NJ 08901-8538 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Eberhardt Rechtin, Electrical Engineer, an oral history conducted in
1995 by Frederik Nebeker, IEEE History Center, Rutgers University, New Brunswick, NJ, USA.
-------------------------------------------------------------

After reading the above copyright notice I will probably get in trouble for including these few paragraphs but I really want you to read the interview.

Then go remind those that are organizing our "To the Moon, Mars, and Beyond"
quest to do some "architecting".
- LRK -

-------------------------------------------------------------
Snip
Nebeker: I remember Bill Baker telling me that I don't know this story well, but at some point Bell Labs was recognizing that what you are dealing with is a large system and that engineers have to be trained in taking in the big picture.

Rechtin: That came about easily in World War II and maybe before because Boda could not have written his book on feedback systems unless they had a system concept, because it was not just an idea of "Put it in the front it comes out the other end." That was a new idea of feedback and the difference between positive and negative feedback. They had already run into problems of stability, because when they put in the wrong kind of feedback, the damn thing oscillated and blew up. So they had clearly seen that when you connected all these parts together, you could produce something. You could get rid of a lot of the problems on the forward link, particularly on the linearities, if you had a feedback loop. That led to control theory, which tended to branch away from the Bell System. It also led to switching theory, which is the core of the Bell System. That became obvious when they found out that there weren't enough telephone operators in the world to pick up all the number of connections they were going to have to make. In terms of where all of this came from, I made no claims at all that either systems or architecture were my inventions. When you put them together you then define the function of building architectures as architecting. I don't know if I would even call it that word but I was one of the first to use it consistently. I use "architecting" so that people focus on the process that an architect does. If I just use "architecture" it means too many different things, so I invented another word. Some people want to call it "architecturing" but that could be more complicated than we want. I wanted to focus on system architecting as a process. That also avoids another process as to who does it, because there is nothing that says a system engineer can't do architecting, and nothing says a system architect can't do systems engineering. If you are missing that function, then you have a problem. The Bell System didn't confront the problem too seriously because their whole basic architecture from the beginning was essentially the same.

Snip
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Because I am afraid you won't go read the whole interview, let me include a few more paragraphs and really get me in trouble.

What do you do when you flunk a required course for your degree?

What do you do when you are told you cannot communicate with a space probe that is going to go outside the Solar system?
- LRK -

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Nebeker: This is a graduate course.

Rechtin: This is a graduate barrier course to a Ph.D. I flunked it, absolutely cold out, and it was as I recall a three quarter course--you had three parts to it. Well, that meant no Ph.D., but Cal Tech always said one can have a second try at it and if one can get your average above the necessary C or whatever it was, well all right. Very few people ever made it the second time if they couldn't figure it out the first time. So I spent the summer going through every problem in Symthe's book. It got awfully tedious after a while and suddenly the light hit; I saw the key to the lock.
I hadn't seen it before and nobody would tell you, least of all Smythe. For every one of his problems, and later I learned for a lot of the world's problems, there is a simple way of getting the answer and the standard way of getting the answer. The standard way takes a lot of time and a lot of grinding, and a lot of work. The simple way you get by sitting back and thinking, "Are there whole chunks of this problem that have already been solved?" For example, did some famous mathematician solve a certain kind of equation? Absolutely, and it is expressed in terms of Bessel functions. I didn't know that; I didn't know a Bessel function from a rock on the ground when I began this thing. Anyway, they are solutions to boundary conditions and if you express them in Bessel functions, they essentially work out what all the mathematical answers are. It suddenly occurred to me that all of these problems were all of the same type.

Nebeker: So he designed these all to have a simpler way?

Rechtin: There was always a simple way. His course consisted of a set of problems in an exam session where they were always four problems. If you solved them in the simple clear way that Smythe was aiming for, which he never told you, naturally, you could do the whole thing in maybe half or three quarters of an hour, well within the one hour time limit, with absolutely no problem. If you didn't you were lucky to get past two of them.
Well, I had been struggling the hard way, not understanding what the message was. So I then went back and said, "I want to take the first semester over again and at the end of the first semester, I want to take the whole course by exam." Smythe thought, "This guy is a lunatic," because he told me so.
Well, I took the semester and cracked it with a straight A. Then I went in to take the whole course by exam, and he looked a bit pitying me in the end, I guess. I sat down for as I recall, a four hour exam, a whole slew of problems. In about an hour and a half I finished them all and I walked into his office and said, "This is what I can do." He looked up thinking, "This guy has flunked." Well, he said he would look at it and looked at it and saw that they were all done. All of them were clean, perfect, straightforward, so I got an A for the course as a whole on top of that. That taught me a number of things. One of the things that I found out was that there are was that there are what I call the three line solutions. In many problems you can show what the proof is in just very few lines or a few points in logic worked carefully through. There is a clean, clear way of doing it. That had a profound influence on the rest of my life, which is the reason I told the story in detail. When I first went to the Jet Propulsion Laboratory, I went there before I got my Ph.D. I was at JPL for the final year and that was because I was wiped out on my Ph.D. exam by Bell Labs solving my problem before I could solve it so I had to start all over again but that's a different story. Anyway, I went to JPL to work on problems of jamming, and anti-jamming of signals because the defense department was still very active. Even after the second world war, the Korean War started up.

Nebeker: What sort of signals?

Rechtin: These were primarily guide missile signals because JPL was working on guided missiles at the time. They were using radio guidance and they were concerned about these things being jammed. A group of us, including Saul Galan, who is now a professor at USC and a member of the National Academy.
Eva Turby, a professor who went on to found a lot of companies, which have done very well, also worked in my group and went on to become a member of the National Academy. Dante Yula went to Brooklyn Poly Tech became a professor, member of the National Academy; Walt Victor who was essentially the chief engineer on the architectural things that we came up with, and the principal reason the deep space network and communications actually worked went on to become a member of the National Academy. Of the seven-person group I had at the time, six were members of the National Academy because of what we did. How did we start? We started out by thinking, "Well, we ought to do some self-learning here." One of the things that we had to learn about was Wiener's famous "yellow peril." That was a thesis-like thing which Norbert Wiener put together; it was called the "yellow peril" because it came out in a yellow-covered book. It was a proof of how you could extract the signal from noise essentially using spectral techniques. By spectral I mean you look at the spectrum of the signal that you anticipate and you look at the spectrum of the noise. You look at the two and you run through all the mathematics and integral equations and lots of complicated things. It will then show you what the transfer function of your box ought to be in order to get the most signal for the least noise. At least on statistical average.

This "yellow peril" started out with the statement of the problem and started to go through forming an analysis. It went on and on. In the middle there was this elaborate integral equation. It kept going on and on and then at the end of the book it said QED. Well, what was it saying? The equation didn't look familiar to anybody; it was a strange-looking thing. Well, it turned out that in Pickering's course the one I mentioned on Gardener and Barnes, we had to learn the Laplace transforms. It suddenly occurred to me that all this stuff that Wiener had been going through was because of a property of the Fourier transforms which is very difficult to take into account. That is, the Fourier transform assumes that the signal has started at minus infinity and is going to plus infinity. All of the difficulties that Wiener had gone into were because of that characteristic. It occurred to me that maybe I could prove it in three lines with the Laplace transform.
The Laplace has an interesting characteristic, a built-in damping function, so the assumption is by the time you get to infinity it will be negligibly small--complex variables will show you the same sort of thing.

Well in three lines I showed not only how to get that integral equation but also how to state it in Fourier terms. I transformed it by complex algebra into a very simple algebraic thing that you could do. Then I realized it was true not only for a simple sine wave going through noise, which is what he had analyzed, but for any signal form in a closed loop control system. I could design control systems confronted with heavy noise, and no one knew how to do that when we started. We had to study Cromaire's book on statistics; we had to study all kinds of things just to make sure that we'd end up on some [unintelligible passage] But it led in turn to what people now call the phase locked loop. I showed the underlying theory of what a phase locked loop would be confronted with noise, and most importantly that was the best you could do. You could not do any better, there's a remarkable proof that we had but you had to state it in engineering terms that people could use and apply to any desired application.

Why did that turn out to be important? Because later on in the career of JPL, we were confronted with the problem of communicating to the edge of the solar system. I was told by Nobel Prize winners that it would not be possible really to communicate to the edge of the solar system. If you could, you couldn't send back enough interesting information. You would have to have band widths of your receiving system wide enough to account for the Doppler shifts. If you did that you had to send megawatts of power back from enormous antennas at the edge of the solar system. Nobody knew how to do that with any finite wait; any worthwhile wait anyway. Well, I sat down and figured out, "Wait a minute. We could track the Doppler. There is no reason we have to have a band width equivalent to the maximum spread that you hear on the train going by." All you had to know was more or less where it started. The rest of it was controlled completely by simple mechanics because Newton's Laws were going to tell you what you were going to do and you could compute what the Doppler was going to be. The filter band width you needed was only enough to find out that single parameter. The amount of information in that single parameter as to what's the Doppler frequency is very small. The only way it can change in the gravitational field is through acceleration, which is another simple parameter to find. If you could find the position and the velocity and the acceleration, the total number of bits that you were looking for in finding the carrier signal was very small.

So we built phase lock receiving systems which had the equivalent band width at ten gigahertz of ten cycles. That meant we had what was then called a Q of 108, unheard of at the ratio of bandwidth to the total signal. There is so such thing; there is no mechanical thick filter that you could build in a Q of that sort. That meant we could detect very small signals. As you know, it is about ten watts with a ten foot antenna at roughly ten billion miles that is picked up routinely. Given that, when the problems came up that NASA had, we came up first with the system called Microlock. I don't remember the military equivalent system, which was called Codorac. It included ranging, velocity, command and everything else. We found that you could determine where you were in the solar system relevant to the planets with extraordinary accuracy by using radio systems far better than you could with anything else. The precision with which you could near an outer planet was going to be within about a hundred miles at roughly ten billion and that was not going to be all that difficult to do. Now, nobody believed all this when we started but I knew what to do; I was the architect. I figured out that it was possible to do, and we began to demonstrate it. In due course, JPL wound up building the deep space network and we wound up determining all of the velocity position angular stuff for navigation in the solar system. We had worked out what kinds of commands you could send. We collaborated with MIT-Lincoln, my good friend Bill Davenport, working out how you treat different kinds of systems which are coded, using essentially some of Shannon's ideas, and with all of that we came up with a completely integrated coded phase lock system. It was a completely different architecture from anything I have ever seen before.

Nebeker: When was this?

Rechtin: That was 1957. We made proposals on how to do all this in the early part of 1958, and everything came up to the surface.

Snip
-------------------------------------------------------------

Phase locked loops, solving in three lines, thinking the problem through, taking the time to do the "architecting", hope that makes sense.
Enjoyed the read.
- LRK -

Thanks for looking up with me.

Larry Kellogg

Web Site: http://lkellogg.vttoth.com/LarryRussellKellogg/
BlogSpot: http://kelloggserialreports.blogspot.com/
RSS link: http://kelloggserialreports.blogspot.com/atom.xml
Newsltr.: https://news.altair.com/mailman/listinfo/lunar-update

=============================================================
LARRY KLAES passed this information on the death of Eberhardt Rechtin.
- LRK -
-------------------------------------------------------------

>From: "Craig B. Waff"
>Reply-To: History of Astronomy Discussion Group
>
>To: HASTRO-L@LISTSERV.WVU.EDU
>Subject: [HASTRO-L] Eberhardt Rechtin
>Date: Sat, 22 Apr 2006 17:09:02 +0000
>
>Members of this list may be interested in learning of the sad news that
>Eberhardt Rechtin, who in the late 1950s and early 1960s led the team
>at the Jet Propulsion Laboratory that developed NASA's Deep Space
>Network communications system for communicating with space probes,
>passed away at the age of 80 on Friday, 14 April 2006. Rechtin was
>also a director of the Defense Advanced Research Projects Agency, an
>Assistant Secretary of Defense for telecommunications, chief engineer
>at Hewlett Packard, chief executive officer of the Aerospace
>Corporation, and a professor at the University of Southern California.
>While conducting research for a history of the Deep Space Network, I
>had the pleasure of interviewing Dr. Rechtin several times.
>
>Obituaries written for the Los Angeles Times and the Pasadena Star-News
>can be found online at
>
>
http://www.latimes.com/news/obituaries/la-me-rechtin18apr18,1,1635196.story?coll=la-news-obituaries
>
> http://www.pasadenastarnews.com/news/ci_3725423
>
>
>Craig B. Waff
>Historian, 89th Airlift Wing
>Andrews AFB, Maryland

=============================================================
http://www.nasawatch.com/archives/2006/04/eberhardt_recht.html
Eberhardt Rechtin Has Died

Space trailblazer Rechtin dies, Pasadena Star News

"Eberhardt Rechtin, a pioneer in deep space research and former assistant director of the Jet Propulsion Laboratory, died Friday after a long illness.
He was 80."
http://www.pasadenastarnews.com/news/ci_3725423

=============================================================
http://www.legacy.com/Obituaries.asp?Page=APStory&Id=11040

>From the Associated Press
Eberhardt Rechtin
TORRANCE, California (AP) - Eberhardt Rechtin, an engineer who played a key role in the development of space technology during the Cold War, has died.
He was 80.

Rechtin died Friday at Torrance Memorial Hospital after lengthy battles with several illnesses, his family said in a statement.

His technical accomplishments included the creation of the Deep Space Network, a system developed at the Jet Propulsion Laboratory in California that captures communications from distant planetary spacecraft.

Although it may seem routine now to see photos from the surface of Mars, the network required the solution of huge technical problems in the 1960s. Not only were signals extraordinarily weak after traveling millions of miles (kilometers) through space, but they also had to be captured by a series of receiving stations as the Earth rotated. Ultimately, the network became a critical part of U.S. breakthroughs in planetary science.

Rechtin also helped develop electronics systems for the nation's first space probe, Explorer, said Albert Wheelon, a close friend and fellow aerospace industry leader.

"He felt his time in public service had been a privilege," Wheelon said.
"There was never a careerist view of his work. He was a selfless person."

Rechtin studied engineering at the California Institute of Technology during World War II and received a Ph.D. there in 1950. He worked at Jet Propulsion Laboratory until 1967, when he was named director of the Pentagon's Defense Advanced Research Projects Agency. One of his first decisions was to cancel a program to develop a mechanical elephant intended to fight in the jungles during the Vietnam War. He later was named an assistant secretary of Defense, helping to oversee defense intelligence operations.


Copyright © 2006 The Associated Press
=============================================================
http://www.pasadenastarnews.com/news/ci_3725423

Article Launched: 4/19/2006 12:00 AM
Space trailblazer Rechtin dies

Pasadena Star-News

LA CA√ĎADA FLINTRIDGE - Eberhardt Rechtin, a pioneer in deep space research and former assistant director of the Jet Propulsion Laboratory, died Friday after a long illness. He was 80.

In the early years of the United States space race with the Soviet Union, Rechtin was a key player in putting together JPL's Deep Space Network, which tracks objects in Earth's orbit and beyond.

Rechtin helped create the Goldstone tracking dishes in the Mojave Desert, as well as similar projects in Australia and South Africa, responsible for providing the tracking, telemetry, and command for all space flight from the Ranger program onward.

In 1967, Rechtin was named director of the Defense Advanced Research Projects Agency (DARPA), the Department of Defense's laboratory for new technology. While at the DoD, Rechtin was also named principal deputy director of research and engineering, then assistant secretary of defense for telecommunications.

In 1973, Rechtin left the DoD to become chief engineer of Hewlett-Packard Corp.

After four years in the private sector, Rechtin became CEO of The Aerospace Corp., the El Segundo-based nonprofit corporation that provides engineering and architectural services for the Air Force's space program.

During Rechtin's tenure, Aerospace placed the first GPS satellites in orbit, was involved in the Strategic Defense Initiative and was instrumental in testing the first anti-satellite weaponry. In that era, Aerospace sales nearly tripled, rising to $323 million in 1986 from $126 million in 1977.
Under Rechtin, Aerospace also made major strides in advancing the roles of minority and women engineers.

After he retired from Aerospace, Rechtin focused on engineering theory. He became a professor at USC, teaching graduate students the concept of systems involved in large-scale engineering projects. Rechtin's vision of systems architecting is now taught worldwide. He retired from USC in 1994 as professor emeritus.

Rechtin authored several books: "Looking Ahead 1977-1987"; "Systems
Architecting: The Creating and Building of Complex Systems"; "The Art of Systems Architecting" and "The Architecting of Organizations: Why Eagles Can't Swim."

During his career, Rechtin was the recipient of numerous awards from professional organizations, including the National Academy of Engineering, the Institute of Radio Engineers, American Institute of Aeronautics and Astronautics (von Karman lectureship and Robert H. Goddard Award), the American Association for the Advancement of Science, the International Council on Systems Engineering, Institute of Electrical and Electronic Engineers (the Alexander Graham Bell Award), Department of Defense, the NASA medal for exceptional scientific achievement and a Caltech distinguished alumni award. He was awarded an honorary doctorate from USC in 2005.

Rechtin received his B.S. with honors and Ph.D. degrees in electrical engineering from Caltech in 1946 and 1950, respectively. Born in Orange, N.J., Rechtin grew up in Palos Verdes and attended Redondo Union High School.

Rechtin was an accomplished violinist, pianist and classical guitarist. An avid hiker, Rechtin enjoyed exploring the backcountry around Mammoth Lakes with his family.

Rechtin is survived by his wife of 55 years, Deedee; their five children, Andrea Rechtin, Nina Meierding, Julie Rechtin, Erica Bauermeister and Mark Rechtin; four grandchildren; and his sister, Joan Lincoln.

A memorial service is planned for 2 p.m. Sunday at The Neighborhood Church in Palos Verdes Estates. In lieu of flowers, the family requests a donation be made to the scholarship fund for graduate students at Caltech in honor of Eberhardt Rechtin.

=============================================================
http://www.ieee.org/organizations/history_center/oral_histories/transcripts/rechtin.html
Interviewee:
Eberhardt Rechtin
Interviewer:
Frederick Nebeker
Date:
February 23, 1995

Copyright Statement

This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the IEEE History Center. No part of the manuscript may be quoted for publication without the written permission of the Director of IEEE History Center.

Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, Rutgers - the State University, 39 Union Street, New Brunswick, NJ 08901-8538 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Eberhardt Rechtin, Electrical Engineer, an oral history conducted in
1995 by Frederik Nebeker, IEEE History Center, Rutgers University, New Brunswick, NJ, USA.

Snip

[Please do read the above interview. - LRK -] =============================================================
http://www.ieee.org/organizations/history_center/
IEEE History Center
Preserving, Researching and Promoting the Legacy of Electrical Engineering and Computing
-------------------------------------------------------------
Monday, 24 April, 2006.

"MIT achieved the first satellite relay of a television signal, between Camps Parks, CA and Westford, MA, on this day in 1962."

Snip
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WHAT THE MIND CAN CONCEIVE, AND BELIEVE, IT WILL ACHIEVE - LRK

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