# Oral-History:Hugo Fruehauf

Hugo Fruehauf earned a degree in Electronic Engineering Technology from DeVry University, IL. Starting with his graduation in 1960 to 65, he was a Field Operations Test Engineer at Martin-Marietta, part of a team launching TM-76B Cruise Missiles at Cape Canaveral. Then, while at General Dynamics Astronautics, he was part of Atlas-Agena launches and Titan-I ICBM testing at Vandenberg Air Force Base. He joined Rockwell International (formally North American Rockwell) in 1965 at Mississippi Test Facility as a test/electronic engineer. He became Chief Test conductor for Rockwell’s second stage (the S-II) for the Saturn-V Apollo launch vehicle. After the Apollo program, while at Rockwell’s California division, Fruehauf was Chief Engineer for the design and development of the GPS Satellite from 1973 to 1978. As part of the satellite, he was also the team leader and major developer of the fully radiation hardened 20-yr life space-born Rubidium Vapor Atomic Clock. For the GPS system and the clocks, he, along with three other team members, were awarded the 2019 Queen Elizabeth Prize for Engineering; for the development of GPS system. Leaving Rockwell in 1978, Fruehauf served as President and CTO of both the German and US-based Ball-Efratom atomic oscillator company till 1995. He became Group Vice President and CTO at a Defense company, Alliant Techsystems (ATK), beginning 1995. In the ‘2000s, President/CEO/CTO of FEI-Zyfer Inc., a developer of GPS-aided time, frequency and telecon systems, till 2010. Before retiring, he earned an MBA (Presidential and Key Executive Program) in Global Business and Management from Pepperdine University, Malibu CA. In 2008 he set up the ‘Hugo Fruehauf Company’ (a sole proprietorship consulting firm) and since then is also an Adjunct Professor at the Pepperdine University Graduate School, teaching Global Economics and International business.

This oral history was made possible by support from Richard and Nancy Gowen.

HUGO FRUEHAUF: An Interview Conducted by Michael Geselowitz for the IEEE History Center, January 8, 2020.

Interview #842 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.

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

Hugo Fruehauf, an oral history conducted in 2020 by Michael Geselowitz, IEEE History Center, Piscataway, NJ, USA.

## Interview

INTERVIEWEE: Hugo Fruehauf

INTERVIEWER: Michael Geselowitz

DATE: 08 January 2020

PLACE: Laguna Niguel, California

Geselowitz:

This is Mike Geselowitz from the IEEE History Center. I'm in Laguna Niguel, California interviewing Hugo Fruehauf for our IEEE Oral History Collection. So, Hugo, we'd like to start at the beginning, if that's okay with you. Where were you born and educated and how did you come to technology and engineering as a career?

Fruehauf:

Okay. I was a World War II kid in Germany and was six years old when the war ended. As you can imagine, I spent a lot of time in bomb shelters and in one way or another found ways to entertain myself while waiting for the “all-clear” siren. We lived near Frankfurt in a small town to the east called Hanau. Unfortunately, there were several military facilities in the area that seemed to require destruction every other day. And of course, as you know, Hitler sold out his civilization by putting military facilities among people and commercial enterprise, resulting in 600,000 to a million civilian deaths from allied carpet bombings in an attempt to stop the war. Since German bomb shelters were basically indestructible (most are still in use today as taverns), there was no fear of getting hurt, so one was free to find ways to cope with the waiting, and kids seeking ways to entertain themselves. My favorite past time involved my ability to hypnotize myself, bringing me to a different world, absent of the sound of explosions and the shaking ground after a blast. I would wedge myself into a corner, as the effects of my self-hypnosis began. It was a sinking feeling, sinking deep, deep into the earth. It really frightened my mother, because I had my eyes open and would talk, but could not respond to her questions in any way. My mother gave up worrying after a while, seeing it was not doing me harm. My attempts to go to my other world did not always succeed, so I would wake myself and switch to my second form of entertainment – dismantling all kinds of things that I would bring to the bomb shelter and then putting them together again; all about finding out how things worked. My family seeing that I was always busy, nicknamed me Beaver.

Geselowitz:

Wie sagt Man “Beaver” auf Deutsch?...

Fruehauf:

“Biber”

Anyway, my father was in the war of course, drafted in 1939 when I was born. He saw what was going on from the early 30’s to 1939 and did not like what was happening in Germany. He must have talked too much about politics and his fears – most likely the reason he was sent to the most troubled part of the war-zone; Germany getting ready to invade Russia via Poland. I saw my father for the first time when things were still going reasonably well for Germany, home on ‘leave’ for about a week, early-1943. He brought with him a Russian prisoner of war named Paul. It was Hitler’s attempt to show his enemies how wonderful the Third Reich would become. My father had no concern about Paul escaping nor doing us harm. This was repeated, no doubt, 1000s of times with other German soldiers coming home for a break. The almost ‘every other day’ bombing started to take its toll, beginning late-1943. As amazing as it seems, we most always had faucet water, gas, and electricity, the result of good preplanning by Hitler – a lot of infrastructure was deep underground or easily fixed in hours. This led to repeated bombings to wear down the military facilities and civilians alike. Germans still went to the movies however, Kinos, so called. The shows would begin with the usual newsreels about the war, followed by much darker propaganda designed to show the cruelty of our adversaries (the allies, especially the Americans). One scene that still haunts me – a kitchen table, with four young children hanging off the table by their tongues nailed to the top of the table. There seemed to be no end to the savagery shown or displayed about our ‘so-called’ enemies. We lived near the main railroad tracks going to Frankfurt and occasionally my mother would wake my sister and me to watch a long train going by. The train would be slow, burdened by many emergency brakes pulled on the cattle cars. It would make the train wheels red-hot, like smoldering charcoal. My mother explained that the people in the cattle cars were “Juden” (Jews) being moved to prison camps. The pulled-brakes would slow the train so people could see what was happening to German citizens in broad daylight, rather than sneaking through Frankfurt in the dark of night. It took me awhile to recover after seeing the movie “Schindler’s List. I could not mistake the same scene – cattle cars with arms hanging out between the boards.

Things started falling apart; sinister messages from Hitler’s radio broadcasts. I remember being in a dark room in our home (a typical blackout night), the only thing I could see was a dimly lit radio dial. My aunt jumping up from the couch during one of the broadcasts shouting; “I will not be part of a “blank”, “blank” “Ein Schlafendes Deutschland”- ‘a sleeping Germany’!! (as Hitler put it) – meaning; “go out in style, mothers, commit suicide with your children”. Alarming for sure, but apparently the concept it did not take hold, ignored as Hitler’s desperation. Early 1944, my mother received all my father’s war medals, no paperwork attached. She knew what it meant – he was dead. About six months later, March 19, 1945 to be exact, (even a kid like me would never forget the date) - our area was devastated, probably because of a surviving Dunlap factory. It was our last run to one of Hitler’s indestructible bomb shelters. “We survived the war”, all five of us, unharmed. My mother Dora, my sister Gertrud, eleven years old, me, six years old, my mother’s sister Christal and her daughter Hildegard, 11 years old. It took hours to clear the debris in front of our air-lock exit door. When we were finally able to get out of the shelter, all we saw was a desert of bricks and chunks of cement; not a tree, nor a utility pole left standing. As for the bomb shelters? most are still standing tall, converted to taverns and ‘dives’ now. I should mention however, that Hitler’s magic bomb shelter designers did overlook one vulnerability – with hundreds of explosions happening at the same time during a bombing raid, the air-overpressure pushed the sewer water up the drains in the bomb shelters. During our last and final bomb shelter saga, we had about 1-foot of water in our shelter and feared it would go higher - thank God it did not.

For us living near Frankfurt, the war was essentially over, early April 1945, although not officially until Hitler committed suicide in May of that year. My mother could not come to grips with the fact that my father was not coming home. However, at times, my sister and me would hear her say while sleeping: “…he is alive, I see his eyes open!”. There was a constant reminder of my father’s absence, seeing many other German soldiers back from the war. Some held in minimum security facilities, others (for whatever reason) back with their families. As for the millions of women and children, whose father/spouses were dead or had not returned from the war, the Americans developed a brilliant plan. American soldiers, with the help of German city administrators, visited the farming countryside, compelling the farmers to host city families in every available spare room. This was possible because the farming countryside was generally spared the three-year bombing campaigns of the major cities. It was brilliant. Without this plan, the American forces would have faced an unparalleled disaster; 100s of 1000s of women and children dying from exposure and starvation in the city streets – it was after-all still winter. My mother, my sister, and me where assigned to a farm family in Raffolds Hausen, a suburb of Hanau. It was a three-hour walk north-east from our bomb shelter location.

My mother’s sister Christal had a gift falling from heaven – her husband Hans suddenly showed up, coming from the French-front; a funny scene – riding a bicycle with no tires. He was part of German General Kesselring’s army in France who saw no need for more killing, telling his soldiers to go home and find their families. Kesselring was probably shot. Hans and family, occupied a pre-war home still in one piece in Fechenheim, a suburb of Frankfurt, a train ride away from us in Raffolds Hausen. The home actually belonged to a German Officer with no family, asking Hans and his family to occupy his home until he returned from the war – he never did. We, my mother, my sister, and me remained in Raffolds Hausen for about two years. Living there was not as easy as we thought. The three of us could only eat what we gleaned from the fields and fruit trees. That meant an occasional potato and as for trees, not much was left to glean. We scoured the nearby woods for pine nuts, which we squeezed for oil and occasionally found some berries. The woods came with their own problems however – one might have survived the war, only to be killed by dramatized wild boars. I started school, first-grade there, mid-1945 and barely survived an appendix removal at a makeshift roadside hospital with no roof. Pretty good job for a nurse helping those with critical issues and injuries; I was six years old then.

Close to the end of the two years in Raffolds Hausen, an unbelievable event took place. My mother was right all these years – my father was alive, he showed up one morning, unannounced. I was in the outhouse that morning and of course, had no idea who belonged to that skeleton coming up the walkway. We had the room closest to the front door of the farmhouse, so my Mother opened the door and started to scream, scream, scream, and would not stop – she thought he was a ghost. It took about 30 minutes for things to calm down; neighbors coming to see what was going on. My father said he was dying and did not want to take a chance on the time it would take to make a gradual appearance and not shock everyone. He was captured in Kiev, Ukraine and shipped to a camp in the Ural mountain ranges in 1944, stripped of his medals that my mother received. The camp had 10s of 1000s of German prisoners and it became clear that if you got sick, you would be shot. My father got sick, but managed to escape somehow. With the help of Russian villagers, he made it back to Germany, looking for us. He was very sick, suffering from Darmschluss (intestinal closure at the outlet of his stomach). It meant that he was living on what nutrients his stomach could absorb and everything else would have to be thrown up. At about noon the same day, we were able to convince a local army captain to transport my father to the US Army Hospital in Frankfurt, where he surrendered to the military police there (the MPs). My father made up a story of sorts, that the American Headquarters in Frankfurt would want to talk to him about his late return home. After a two-hour ride, accompanied by my mother, it was hospital and operation first to save his life, then the MPs. My father was actually right, the MPs did want to investigate. Late returning soldiers meant one of two things; one, the Russian were violating the Armistice (which of course they were) or two, the German soldier had something to hide (especially those who had a significant Nazi post). The operation lasted many hours and was successful, telling my mother that this was the first successful operation of this kind. It required removal of more than 80% of his stomach (a tangerine-size stomach remaining) and several feet of intestines. We now know that the stomach regrows to normal size in 10 to 12 years, so my father was able to live a normal, healthy life – which he did. It took awhile to recover from the operation, but getting his full strength back took months. When he was reasonably recovered, he was brought to a minimum-security facility, interrogated by the Americans, and cleared after three weeks.

Geselowitz:

Wow. This was German doctors doing this or American?

Fruehauf:

They were probably American doctors, because they took over the hospitals after the war and rebuilt them to serve their needs as well as German civilians.

Geselowitz:

Right. That's what I thought.

Fruehauf:

My father and mother did not return to Raffolds Hausen, instead stayed with Hans and Christal in Fechenheim, helping to convert their home to a two-family dwelling. My sister and I gathered the little we had in Raffolds Hausen, thanked our two-year host with all our heart and got on a bus to Fechenheim. My sister was now about fourteen years old and I eight. We were together again, not five, but seven now, counting our two dads, having returned from hell. My father and Hans checked in with the local Army station and were assigned to a very large company in town called ‘AG-Faben’. They became part of the re-building and maintenance group. At that time, technically, both were still prisoners of war, but on an honor system, a category that disappeared after a while. Compared to our food supply in Raffolds Hausen, Fechensheim was so much better. American occupying forces mostly set up minimum security facilities; just wire fences with no barb wire. People like us, living near prison camps, would go to the fences, picking up food that the German prisoners threw over the fences, while the American guards looked the other way, going to their tents for lunch.

Patton ordered the release of prisoners within about three months of their return home. Of course, closing the camps threatened our food supply. To our amazement, “Care” packages started coming from the US – our next source of food. They came in two by two by two-foot packages, containing everything needed for a family to stay alive, including a one pound can of Maxwell House Coffee, which we sold for about 150 DM to buy shoes. This went on for more than a year or so, as I remember. I have only one complaint about how the American soldiers treated us after the war – they introduced us to ‘Hershey Bars’; that was great, but also chewing gum, not so great – the soldiers never told us to spit the chewing gum out. However, it seemed obvious that the Americans did not want prison camps, but also did not want the prisoners released too quickly either. One day I was standing on a street corner in Frankfurt with my cousin watching a convoy of American military trucks going by; one after another, the line seemed endless, We, along with dozens of others, stood speechless. Maybe a hundred or more trucks, each crammed with maybe 40 German prisoners. They were heading east on the Hanauer Haubtschtrasse (a main highway). The rumors were circling around in the group watching (and later the Frankfurt newspapers took note) that the prisoners were being shipped east and would eventually end up in Russia. Americans treated everybody so well, as I mentioned before and we could only conclude that the Americans were naive, not realizing the prisoners would never see their homeland again.

There was trouble with a small cadre of Polish forces in our area that were part of the American occupation forces. Polish soldiers coming from the Russian front (they and their families having suffered greatly from the Nazis) must have felt they were not finished yet with the Germans. To the horror of the Americans, they raped women, while the prisoners were confined in camps and local factories. To avoid political problems with the Poles, the Americans came up with a clever solution – randomly, they let out selected German prisoners in areas where the rapes were taking place. The prisoners would kill the rapists, then return to their assigned barracks. This way Americans had no direct part in this and I assume the polish leadership was not anxious to investigate. I personally as an 8-year old, watched one of the killings. The perpetrator ran to the nearby river Main (maybe a mile away) and started to swim across, only to be confronted by a group of prisoners on the other side. He lasted about an hour or so, then drowned (maybe himself); it was certainly an easier death. It did not take long for the rapes to stop and we no longer saw the black-uniformed Polish soldiers in our area.

In 1947, we became aware that the US was accepting immigration application from western European countries. It required someone (a sponsor), preferably family, who is willing to take care of the immigrant(s), so the state is not burdened in any way. My mother and her sister Christal had a brother who immigrated to the US, Chicago, in 1925. Initially, he (Carl) did not do well in the US. However, once discovering that his skills as a ‘Tool and Die Maker made him successful, things began to change. He married and with a friend, formed a company called Mel and Hoffmann in Chicago. They manufactured things like barbecues, garden-related tools, and is said to have invented the ‘folding card table’ which ended up the most successful product for the company. Carl, before the war, encouraged both of his sisters (my mother and Christal) to come to the US, because looking at Germany in the ‘30s was troubling for Americans, while at the same time, Germans were blind to what the world was seeing.

We all filed immigration papers in 1948. Hans, Christal, and daughter Hildegard received their papers after a one year wait and left for Chicago in 1949. We, however, waited four years and when called to the Consulate, were told that my mother, my sister and I could go, but my father was now polish, and not allowed to immigrate. So, how is it that one can change ‘his homeland’ status? Well, my father was born in the eastern part of Germany and at the end of WW-II the area was rezoned as part of Poland. This border had and still has a complicated history, which involved heated debates that included Stalin, Roosevelt, and Churchill. As I noted before, the Americans treated us well. We were asked to return to the Consulate to discuss a ‘a loophole’ that went like this – If a ‘father’ is needed to make life possible in the new world (what father wouldn’t be), then he would be put into a special class of immigrants, but this might add many more years of waiting. So, after about two weeks of family debate, we decided to chance it. We certainly could make it in the new world without my father, considering all the support we had. My uncle Carl bought us an apartment house; the second floor already occupied by Hans and family and third floor waiting for us to arrive. As for jobs, Hans was already working at uncle Carl’s company, Christal remained a homemaker, and Hildegard, then in her teens, was going to school in Frankfurt. We did not discuss the details of our support structure with the Consulate, we feared it might reduce the urgency of my father joining us in the US. The Consulate never asked how we would make it without my father, because they knew my mother’s brother had a company in the US.

We had unbelievable luck. My mother, my sister, and I left Germany in July 1952 on a ‘just established’ PanAm intercontinental flight arranged by my Mother’s brother Carl. The flight left Frankfurt to London, to Shannon, Newfoundland, ending at LaGuardia airport in in New York city. We fell asleep in the La Guardia terminal and boarded an AA flight to Chicago the next morning. Speaking of ‘luck(s)’ – (1) as for the flight, a rocky start, quite critical, but with no previous flight experience and lack of language skills, we missed what the commotion was all about. I was sitting on the right-side window and noted the outboard engine propeller was not rotating. Not to worry, I thought that’s how airplanes land, turning off their outboard engines – (2) after leaving Shannon, we ran into severe weather; very strong winds and rain, hearing a significant number of people throwing up into the little bags left on the backs of the seats. My mother was petrified; there was nothing I could do for her. The pilot told us we were low on fuel and would land in Newfoundland first to refuel before landing in NY. It was a rough landing in Newfoundland and I finally realized that things were not going well – (3) the best part however; if you were flying as an immigrant to the US, you did not have to go through Ellis Island, only if you come by ship. My uncle Carl picked us up at Midway Airport and drove us to our new home. As he was driving though the city streets, my first impression of Chicago was not very good. Lots of wooden houses with odd configurations. I did not know houses could be built with wood; minor issue in the scale of things – becoming an American overshadowed all these things. The greatest event of all – my father got his papers six months after we left for the US (not years) as we expected; and arrived on Christmas day, Dec. 25, 1952 – the seven were together again.

I was thirteen years old now and at 69 pounds, critically malnourished. My parents did everything they could while we were still in Germany, but that all changed after arriving in the US. In August 1952, I was enrolled as an 8th grader until my English skills improved to enter high school. Although I would have liked going to High School directly, 8th grade was the best thing that ever happened to me. While there, our science teacher, Ms. Carpenter, singlehandedly helped me formulate part of my lifelong career – electronics. She came to the classroom with a small wood base, a large nail, some metal from a tin can, wire, and a host of other things and before my very eyes made a primitive electric motor. She connected a battery, the armature she just made started spinning – I was blown away! I did poor to average in Lakeview High School, Chicago, but at home, thrived making electronic things for friends, like guitar amplifiers, radios, and the like. In those days, one could buy “Heath Kits” to build Oscilloscopes and other test equipment. My father saw my fascination with electronics and gave me the money for everything I needed; and am sure, they sacrificed some to do this. In parallel with electronics, I had an equal fascination with rocket after coming to America. A lot of things where going on with rockets in the mid-50s. Articles written about German Dr. Wernher von Braun working on the next generation liquid-fueled rockets. He and about 120 of his best team members where snatched away by the Americans at the end of WW-II from the would-be Russian-occupied territory and brought to the US. Braun and his team would become the center of US rocket development, at a place later known as Marshall Space Flight Center, Huntsville AL.

During the first few years in the US, my father and mother where trying hard to become successful in leading a typical American way of life. My mother got a job down the street from our apartment. My father worked for a while at uncle Carl’s factory, Mel and Hoffmann. He apparently had skills as a butcher before WW-II (don’t know anything about that), left Mel and Hoffmann and worked at a delicatessen-type butcher shop in Chicago, later becoming a partner with the Jewish owner. My father was good in English, personable, but spent most of his time in the back room, cutting meat and making every kind of sausage from scratch. He did well, later buying our own home in the north-west part of Chicago – “the American Dream”.

Geselowitz:

In Chicago?

Fruehauf:

In Chicago. It just doesn't get any better than this, right? Now back to my fascination with rockets, along with electronics. In those days, like today, one could buy products in containers that looked like large hairspray cans. Once empty, it was easy to weld a rocket nozzle to the spray-end of the can. Then I would fill it with my version of gunpowder (to make it burn slower) which I made myself and ‘walah’, I had a solid rocket motor. I would launch them safely in the near-by large park, coming down with a parachute. What makes this story funny is that in those days, one could go to a drugstore to buy medicines, but also basic chemicals, etc.

Geselowitz:

A pharmacy?

Fruehauf:

A pharmacy, right. And you could buy bags full of potassium nitrate, carbon, sulfur, and the like so I was able to make my own gun powder. However, potassium nitrate was also saltpeter, and you know what that was for, right?

Geselowitz:

Right.

Fruehauf:

It was used to reduce sex drive in the military, although this has never been proven to work. One day I was looking for two or three pounds of potassium nitrate, more than I usually bought and the druggist said, I really need to have a note from your father about this. He was probably thinking saltpeter, I'm thinking gunpowder, right. No problem, my father gave me a note saying, my son builds rockets using gunpowder. The druggist said ‘ok’, and from then on, I was able to buy all I wanted. So, my dad never really explained the pharmacist’s concern, I understood it all later on.

Geselowitz:

[Laughter.]

Fruehauf:

Can you imagine an event like this today? There would be ten armored vehicles around our house and the pharmacy. Amazingly, my father had trust in me that I was learning about explosives and rockets, even though he saw that our basement ceiling had a black spot. It was a ‘one-time’ event, during which I burned-off my eyebrows. But anyway, a long story short, I was in heaven, right? I'm doing stuff that I always wanted to do.

In the mid-50s Disney had a program on TV for teens called ‘The Mickey Mouse Club’. It featured Adventure Land, Tomorrow Land, etc., all related to the Disneyland Park in Anaheim CA. On one occasion for ‘Tomorrow Land’, they featured Wernher von Braun for about 45 minutes, explaining how we will fly to the moon in the future. He gave design details about the rocket’s first stage, which was massive, powered by about 25 or so engines (the Saturn-V first stage has five), the second stage, and the third stage, housing the Astronauts. I was speechless, the program grabbed me like nothing else before. And to top this off, could I ever have imagined that I would meet ‘von Braun’, him shaking my hand, twelve years later. Wow! combining rockets with electronics would seal my future work-life forever. I was now near high school graduation time and started looking for a school that would advance my next steps. Knowing nothing about colleges and the like, I found what I thought to be the perfect, accelerated program for me – DeVry Tech, Chicago. It featured six months of book study at home and having to send in test papers, followed by two years of resident study; 50 weeks a year, 5 days per week, 6 hours per day, focused on lectures and lab electronic studies. I started the six month pre-resident program while still in high school.

Geselowitz:

But you finished high school?

Fruehauf:

I finished high school, graduating in 1958.

Geselowitz:

And did you have an opportunity to do chemistry in high school?

Fruehauf:

I did, however I wasn't a very good student in high school and chemistry certainly did not grab me. I didn’t really flourish until I got out of high school.

Geselowitz:

Right.

Fruehauf:

In those days, graduating from any school of higher learning, there would be ten or more companies waiting in the school lunchroom prior to graduation, offering jobs; no job hunting required. I was very lucky - Martin Marietta Company in Baltimore, Maryland, needed test engineers, working at Cape Canaveral Florida launch pads. I must have impressed them; no one in my graduating class was in love with rockets – a ‘slam dunk’ for me.

Geselowitz:

So, you were only looking at aerospace companies making rockets or missiles, because of your interest?

Fruehauf:

Yes, I was lucky, because only one aerospace company came and as I mentioned, I showered rockets on them like no one in my class could. However, most of other companies that came were people from Chicago-wide IBM, looking for test people to take over the manufacturing, testing, repairing, and management of their new product lines; primitive computers and the like.

Geselowitz:

[Laughter.]

Fruehauf:

I graduated from DeVry, January 1960, and headed to Baltimore, the headquarters of Martin Marietta’s rocket and missile division. As promised, I spent a lot of time on the launch pads at the Cape, launching pre-production TM-76B cruise missiles that had a range of about 1,500 miles. I did well and became the leader of our test group. I married a beautiful Irish girl in July that same year – she was also an immigrant like me. In the early-60s, America was behind the Russians in the area of ICBM technology, which also translated to being behind in human space travel. The government put a lot of pressure on the aerospace industry to fix this problem. To keep the Russians at bay, we developed good shorter-range missiles and moved them closer to the Russian borders in hardened shelters; in countries such as Germany. During my first job after graduating, I began to realize I was born for this stuff. In 1961, after a year at Martin Marietta, I received an exciting job offer from General Dynamics Astronautics in San Diego. It would be our home-living base between Atlas-Agena launches at Vandenberg. The Agena payload was a spy package taking pictures, with a Kodak film recovery system. It was so classified that we had to have ‘beyond’ secret clearances. But with all the security precaution, people without the ‘beyond’ secret requirement where able to walk by the Agena assembly building and see garbage bins loaded with empty Kodak film boxes.

Geselowitz:

[Laughter.]

Fruehauf:

So much for security. In 1962, I received a job offer from Martin Marietta again (I think it was just Martin Co. then), but this time in Denver, doing the final work to make the Titan-I ICBM system fully operational. Along with the Atlas ICBM system, we finally reached par with the Russians. Martin just turned over the Titan-I system to the USAF, several weeks before all hell broke loose – the Cuban Missile crises, Oct. 1962. To make a long story short, the system was too new and the Airforce was just beginning to become familiar with it. To solve this problem, the USAF agreed to have Martin engineers in the Launch Control Centers of each Titan ICBM site, in case this crisis would become a nuclear exchange. Each control center served nine Titan-I missile silos, some distance apart. I was briefly assigned to a launch control console at a Titan Control Center some distance from Denver. While sitting at the console, USAF MPs with hand on their sidearm would be monitoring our every move. They had the same procedure in hand as we did. We had to move slowly to stay in sync with our MP partners. It was a scary time for everybody, but especially so for people working directly with the Atlas and Titan ICBM complexes. I remained with Martin- Denver till 1965, but in 1963 lived near San Bernardino Air Material Area, referred to (then) as SABAMA. As Martin’s representative, I assisted a Duarte, CA subcontractor in the design and build process of test equipment for the Titan-I missile ‘Rate-Gyro Control Package’, part of the missile guidance system.

In spring of 1965, I received a job offer from (then) North American Rockwell as a Systems Test Engineer at (then) Mississippi Test Facility (MTF), now called Stennis Space Center, located about seventy miles north-east of New Orleans. It was a huge facility (and still is) where both the first and second stages of the Apollo Saturn-V launch vehicle were ‘static fired’, strapped down in huge test stands – all part of the process of getting the vehicles ready for launch at the Kennedy Space Center, Cape Canaveral, FL. 1965 was a tough year for us at Rockwell; we were dangerously behind schedule and it worried NASA. An entire Saturn-V test vehicle was already stacked up in the Vertical Assembly Building at the Cape, where preliminary checkout of mechanical and electrical interfaces were being conducted. Since we had only one vehicle (the S-II ‘T’) which we were using for the work at MTF, we did not have another vehicle to give them. NASA simply installed a metal tank in place of our stage. The main players at MTF then were Dick Schwartz running the test operations to get the A-1 test stand activated, along with Gerry Wilson, responsible for the A-2 test stand and Engineering. Yes, Dick is the same person, who along with two others and me received the ‘2019 Queen Elizabeth Prize for Engineering some 50 years later. I know you are very familiar with this prize. In 1966 we were on our way to recovery when Rockwell hired a retired Air Force Colonel, Chuck Allen to run the entire Mississippi operation for Rockwell. Chuck and Dick formed an incredible team, driving hard to recover our schedule problems. It was a great opportunity for me to work for Dick – his drive, knowhow, and management skills to get things done, formed my career for the next 50 years.

I started out in Engineering trying to figure out why we could not get through a countdown sequence to engine start without getting hung-up for one reason or another. I was redesigning both electrical and mechanical ground support systems that worked well at Downey CA headquarters, but not so well in the cryogenic environment at MTF. To get through an uneventful countdown and firing of an S-II stage, I proposed to make a monumental change in our test operations – go from a ‘sequenced-based’ vehicle countdown to a time-based countdown control process. Within weeks, the shiny new Countdown Control Console (countdown clock) was ready to go and served us well for the remainder of the program. In 1967, I switched to the Test Department as Test Conductor, and later, Chief Test Conductor, joining Dick Schwartz, my new boss. NASA had some concerns about the “Chief” part, noting that I was only 27 years old and looked like 18 and that I was a “sparkie” (an electrical guy); Test Conductors were usually mechanical or cryogenic engineers. Dick held fast for my new appointment, but NASA Huntsville asked for me to be tested first. Off I went to Rockwell’s Santa Susana mountain ‘Battleship’ facility in California. It was a hardened S-II (like) vehicle with steel tanks, hard to blow up. One of the early Rockwell S-II development test conductors met me there in case I got into trouble during critical operations such as LOX and LH2 tanking, engines start, etc. He was also tasked to evaluate my performance and declare me ready or not ready for my new appointment. Well, I made it.

Geselowitz:

And this was based where?

Fruehauf:

North American Rockwell’s Santa Susana facility near Canoga Park CA; for me to be tested to determine if I can handle my new job assignment.

Geselowitz:

The Mississippi Test Facility?

Fruehauf:

Yes, all my work would be at MTF of course.

I think I would be remiss if I failed to mention what it’s like to be a Test Conductor (TC) conducting a static firing test. Simply put – “terrifying” – every time – including a six- minute adrenalin rush. If all goes well, it would basically be a one-day affair. It would begin early in the morning, while already daylight with the project engineers running final checkout of their assigned subsystem, followed by LOX and LH2 tanking, which would consume about four hours. At this point the test stand is on high alert, with about 83,000 gallons of LOX (liquid oxygen) and about 260,000 gallons of LH2 (liquid hydrogen) in the vehicle tanks. The LH2 tank, now at -423°F was no problem for the vehicle, but tough on nearby ground support equipment. Once reaching this point, the test stand is cleared of all personnel as the test conductor (TC) initiates the Countdown Control Clock. I would usually be standing, pressing my leg to the side of my table, so no one would notice my knees shaking. To my left, another table, seating S-II key managers and usually some NASA obervers from Huntsville. This group would be my consulting team if the Countdown Clock stopped, indicating something is wrong. At ten seconds before engine start, the Countdown Clock was programmed to stop to get a “go” from participating parties before committing to the six-minute engine run. If something goes wrong after engine start, the TC is God – no time for consulting with anyone. On occasions when the wind was blowing toward Gulfport (to the east) and a static firing test was in progress, our home’s kitchen windows 42 miles away would rattle. If they rattled less than six minutes, my wife knew I was not coming home that evening. After engine shutdown, another four to five-hour effort begins to ensure the area is safe for test personnel to return to the test stand. It involves checking for possible damage to the vehicle and engines; checking for hydrogen gas leaks from damaged test stand pipes; clearing the hydrogen gas out of the vehicle LH2 tank with helium purges, etc.

Something else hardly ever discussed. The Apollo first and second stages were so large, they could not be transported by land. So, the Boeing first stage was built only about 70 miles from MTF at Boeing’s Michoud Facility. It was floated on a barge up the Pearl River and a connecting canal to MTF, a relatively short transport compared to Rockwell’s S-II, second stage. It was manufactured in Seal Beach, CA, again floated on a barge down through the Panama Canal, across the Gulf of Mexico, ending up again on the Pearl River to the test site, MTF. After the S-IC and S-II static test programs were successfully completed the stages were floated south, through the Gulf of Mexico, but this time around the Florida’s Keys, then north to Kennedy Space Center

Geselowitz:

Was the canal built only for the test stands or did it have other uses?

Fruehauf:

Only for the first and second stage test program during the Apollo era. Not to forget however that big barges used the Pearl River/canal access to bring in LOX and LH2 for the S-II and LOX and Kerosene for the Boeing S-IC. After the Apollo era it became Stennis Space Center and again serves mostly as a rocket engine related test center. As a matter of fact, the two original S-II test stands are now being used to test Shuttle engines for future NASA human space flight programs. Some months ago in 2019, to my delight, my son sent me a picture of him standing next to a Shuttle engine and asked me: “where do you think this picture was taken”? yes, you guessed it, the same test stands his father (me) was testing the S-II vehicles 52 years earlier. My son is an EMI engineer (Electromagnetic Interference) working for Aerojet at the Canoga Park CA facility.

Geselowitz:

Wow.

Fruehauf:

There were several, memorable events worth noting during my time at MTF. On one occasion, I was conducting an X-1-day meeting to see if the project managers had their systems ready for the next day’s static firing test. All the managers were in attendance, including our NASA representative. I addressed each manager around the table, asking if they had any unresolved, open issues, “squawks” we called them. There were about eight system managers, seven reported no open items – “Go” TC was their response. When I got to the last system manager, he reported seven open items (at X-1-day it should be zero, but maybe just one). I was furious! slammed my notebook on the table, jumped up, the chair crashing behind me, and said this meeting is adjourned and walked out, slamming the door behind me. At this point everything went pitch-black; I thought I was having a stroke, only to discover I had walked into the coffee closet instead of the door going to the test stand. Now terrified to see if anyone noticed – and hearing no commotion, I opened the door and found my guests killing themselves with laughter. I excused everyone and asked all to resume the meeting in a couple of hours, but it was simply impossible. We rescheduled the meeting for the next day, while the guilty manager and his crew worked 24 hours to resolve his open items. It was still hard the next day – a slight raise in my voice caused some struggling to contain themselves. This event had a life-changing effect while at MTF – people struggling to contain themselves when things got a bit edgy in meetings. Some 20 years later, my son Steve working at Rocketdyne CA, with his name Steven Fruehauf on his office door, someone comes in his office asking if he was related to Hugo Fruehauf – Steven proudly answered, saying: “he is my Dad”, to which the visitor said; “let me tell you a story about your dad”…

Another event equally funny involved Dr. Wernher von Braun when he visited MTF; I think 1967? I can’t remember where I was when I met him. I believe it was the doorway going to the S-II firing room where I was sitting. I stood up reaching out to shake his hand; he gracefully did the same. He looked at me and said in English (with a great-sounding German accent): “we would build better boosters if we had canvas blockhouses”! to which I said to him in German: “in dem fall würde ich eine neue arbeit finden” (in that case I would find a new job). He laughed and continued to ask a few questions in English – I got the message. He looked around a few minutes, then thanked me and left with his assistants. He had an incredibly charismatic personality; a smooth German accent and it was easy to see how President Kennedy bonded with him. I think their relationship made it possible to continue funding the moon program while we were at the height of the Vietnam conflict. I was stunned, remembering my earlier fascination with his appearance on Disney’s Mickey Mouse Club TV program when I was still in my teens, mid-50s. Wernher von Braun made a presentation about ‘how we will go to the moon someday’. I never dreamed in a million years that I would ever meet him in person. Watching that Disney program, sealed my love for a rocket-oriented career and that is exactly what I ended up doing.

Geselowitz:

[Laughter.]

Fruehauf:

Most always, we had Rockwell S-II representatives in the Secondary Firing Room at the Cape, in case there were any glitches with the S-II stage and especially so for Apollo-11 going to the moon. I went to the Cape as one of the S-II representatives, hitching a ride on a Rockwell-leased commercial airplane, packed with high-flyers, such as Bob Hope, Eva Gabor and a host of others like him. Not much to say about this event in Florida – the launch was picture perfect, augmenting the already US technology leadership of the world. By 1971, all the testing of the S-II vehicles was complete (I believe?) and shipped to the Cape. After a six-year stay in Mississippi, the family and I moved to California; to Rockwell’s Space Division headquarters at Seal Beach CA. It was here years earlier, where the S-II was manufactured. Dick Schwartz, already in CA by 1970, again became my boss, assigning me to head up the S-II electrical/electronic system. For some reason that I never understood, NASA became increasingly concerned about the single-string vehicle command structure, which was the case for the entire stack to my knowledge, not just S-II. I thought it was a bit late at this point of the Apollo program. Nevertheless, NASA requested to put in vehicle electrical commands redundancy wherever possible. I got to work on their request, able to design-in only two commands that could be made redundant; ‘S-II Engine Start’ and ‘S-II Interstage Release’. The Interstage was a ring designed to make a smoother separation from the SI-C first stage. It was jettisoned about 30 seconds after S-IC release and S-II engine start. While busy making redundancy modification, I discovered a potential failure mode in the S-II power system. It was corrected by several diodes placed ‘in-line’ with the cable set. Such changes required NASA reviews. Finding no problems after four days of reviewing, the fifth day NASA discovered a possible diode overheating mechanism. It required a fix while the S-II was in the Vertical Assembly Building at the Cape – usually never allowed. I almost caused a launch delay. Dick Schwartz, furious, asked me to give him three reasons why I should not be fired! Well, I survived.

We continued to have successful moon landings, concluding with Apollo-17, Dec. 1972, but with less and less public enthusiasm. To make sure everyone reading this paper knows that we landed not just one time, but six times, enabling 12 Astronauts to walk/ride on the moon… what a success story! After Apollo-17, there were four more launches with Saturn-V vehicles, not to the moon - one unmanned and three of them ‘manned’ for the “Skylab project”, May 1973. The first launch, unmanned, consisted of Saturn-V first and second stages, boosting into orbit an empty Saturn S-IVB third stage, modified to become America’s first space laboratory. Thank God, the first launch being ‘unmanned’, it came close to being the first Saturn launch catastrophe. I, with several other engineers from the late 60’s launch era were in the Secondary Firing Room at the Cape, this time however communicating with both the NASA launch crew here, but this time also with Houston, because this launch configuration was different. (By the way, in mid-73, I was already deeply involved with GPS; with a super-capable team attempting to win the GPS Development contract). It was a spectacular night launch, it lit up the sky almost to daylight level, the acoustics were much more pronounced than at daylight launches – my tears flowing. S-II engine ignition normal, all five engines at full thrust, but within minutes we noted our S-II vehicle was slow, as if an engine problem, or after first stage separation and S-II engine start, the S-II Interstage ring failed to jettison. Feverishly looking at telemetry, only to find the thrust of all engine normal, and that the S-II Interstage ring had jettisoned. Our crew’s effort to pin down how much extra weight would cause the slowdown, came up with a weight very close to that of the S-II Interstage ring, about 11,000 lb. as I remember. With the usual extra fuel on board for such occasions, we burned longer and placed the S-IVB lab into its proper orbit.

So, where is the ‘close to a catastrophe’ I mentioned? Well, during the S-II engine run, the launch crew saw pieces of metal raining down, later identified as pieces of the micrometeoroid shield torn away from the Skylab, taking out the Solar Array on one side of the Lab and jamming the full extension of the Solar Array on the other. NASA made a fatal error by requalifying the structural elements of the S-IVB Skylab by what is called “similarity”, meaning that it is still the same S-IVB, only changed to become a lab. But there was no similarity. For an Apollo mission, the S-IVB stage is normally stiff when fueled and the aluminum structure gets stronger when at cryogenic temperatures! We theorized then and believe it or not, our conclusions were verified 30 years later (will be discuss at the end). We concluded that a piece of the micrometeoroid shield impacted the S-II at the Interstage area cutting our Interstage ordnance ring and when the jettison command was activated, the Interstage separated, but only to about 300 degrees of ordnance travel, cantilevering the ring, hang down on one side within probably inches of an outboard J-2 engine, but still attached to the other side. At the next day’s NASA meeting, with maybe some 100 attendees, I was asked to explain what I think happened. As a rocket guy, I was trained to believe telemetry, unless there were alternative facts available. I said: “according to available data, the Interstage jettisoned”. Unknown to me of course – the Interstage was still connected on one side of the S-II, but came off on the other side; cantilevered, but not far enough to tear off one of the outboard engines. I was almost booed off the stage. Stepping off the stage to the side while others continued to theorize, a rather poorly-dressed gentleman leaned over to me and said; “Hugo, you are making an ass out of yourself, the Interstage is still hanging on at one side of the vehicle, but off on the other side, ‘cantilevered’… I have pictures”! Wow I said, let’s show them! Can’t do that, they are highly classified and he would not give me a peek. He continued, saying that they were taken at a classified facility with the ability to count rivets on satellites, joking a bit; (I assume he was talking about Cheyenne Mountain Colorado Springs). There it was left. Three manned launches to Skylab followed, making some fixes to the damaged lab, but over-all not much was learned from it other than the result of extended stay in space for humans. Some months later, there were concerns about S-II vehicles de-orbiting after about ten to twelve years. The concerns were valid; the de-orbiting S-IIs would be the biggest-yet piece of space junk coming down in one piece. Since two-thirds of the earth is water, deorbiting big satellites is somewhat low risk. Four S-IIs and one Skylab deorbited in the late ‘70s and early ‘80s, crashing into the sea. Why was there no concern about S-IIs de-orbiting during the Apollo days? The Apollo S-IIs were sub-orbital and did not push anything into orbit; the Saturn 3rd stage did; and the S-IIs were guaranteed to come down in the sea hours later.

About 30 years later, now about 2003, an Apollo ‘would-be’ historian named Ivin F. Blejec contacted me for information about the S-II vehicle. He sent me a huge amount of material about S-II and testing at MTF, asking me to verify certain elements of the history. How he came to accumulate all this information, he would not say. One day I asked him what he has about the first Skylab launch. He said: “you mean about the Interstage Issue”? I was shocked – he was completely aware of the whole history and said he would send me a report and a hand-drawn picture of the real photograph that the gentleman long ago talked about. He continued saying that the NASA report with the ‘picture’ became classified until 1995. He did send me the report including a hand-drown picture of the real photograph, which I now have in my possession. It was exactly what we thought then – the Interstage was attached on one side with the other side hanging down at approximately 30 degree. It must have come within inches of one of our outboard engines. Unusual engine gimballing would have surely contacted the cantilevered Interstage, followed by the biggest-yet blowup in space, with an S-II vehicle with about 260,000 gallons of LH2, oxidized by about 80,000 gallons of LOX. Our US space industry brought us great success; ‘manned’ moon landings six times and ‘manned’ trips to Skylab three times, all Apollo-related – not to forget the test pilots and astronauts who paved the way to Apollo. And with all that, we never killed an astronaut in space. Of course, in the mid-60's we had a terrible accident at the Cape, killing three astronauts during ground testing of the Apollo capsule. As for the Space Shuttle, I can’t talk about it without getting upset – fourteen astronauts dead; seven leaving for space, and seven returning from space. I would rather tell you what America has done for the world – it changed the world forever and for good! – GPS –

Geselowitz:

Well, you can do what you want. We'll include it and you can decide if you'd rather embargo it.

Fruehauf:

Okay, I would rather not get into the Shuttle disasters in this interview; I will delete any reference to it, thanks.

So, late 1972, after a host of government RFI releases (request for information), Dick Schwartz became interested in following-up a bit on what was being planned by the government. It became clear, the gov wanted inputs from industry – was a satellite-based global positioning system possible? a PNT system – Positioning, Navigation, and Time, giving the military precision targeting to avoid collateral damage. It would provide tactical superiority, since most likely strategic engagements are the thing of the past. We began to follow up on all the commotion about this and the gov people involved, such as the USAF, USN, NRL, USNO, the Aerospace Corp. near LAX, and gov thinktanks all over the country. Dick Schwartz at that time headed the Satellite Division at Seal Beach, CA, began to pull the best people from other (less important) programs and formed a 54-man “GPS Proposal Dream Team”. So, let me get into the GPS story in detail now.

Geselowitz:

That would be great. So now, let's get back to your story though, because that's really why we came.

Fruehauf:

Exactly…

Since the mid-60s, the US government had been seeking ways to ‘more accurately’ conduct tactical warfare to reduce, even eliminate collateral damage. As I see it, having been a WW-II kid in Germany, carpet bombing was then the only means to end a war when the enemy hides its military facilities within the civilian population. God forbid a return to strategic military engagements, but tactical warfare capabilities (tactical, meaning precision) will be needed to stabilize various hot spots and insurgencies on the planet. To that end, the US government’s Aerospace Corporation, supported by the USAF and a host of gov agencies, conducted tests at desert facilities (Classified, starting in 1966) that led to the conclusion that a precise Position, Navigation, and Time (PNT) capability was possible with a ‘satellite-based’ system. The test used laboratory Cesium Atomic Clocks at ground terminals and in a test aircraft, measuring signal time delays between terminals and the aircraft, precisely determining the aircraft’s location – essentially, ‘an upside-down GPS’. Other related tests in 1971 to 73 conducted by the Navy continued to be classified till 1979. Funny though, four GPS satellites (SVs) were already on orbit, a year earlier.

By the way, when the gov released the RFP (Request for Proposal), to be submitted by the interested parties, the program was called DNSDP; ‘Defense Navigation Satellite Development Program. There were four bidders; RCA, Philco-Ford, Grumman, and Rockwell International (we prevailed, won the contract late 1974). At program-win, most all involved called it; ‘Nav-Star’. During the initial satellite building process, early 1975 it became known as GPS. To learn more about the government’s involvement in developing GPS, see GPS World Magazine articles: “The History of GPS”, Part-1- May issue, 2010 and Part-2- June issue, 2010. All that was needed after the successful tests in the desert were: (1) Good government leadership – young Col. Brad Parkinson, Ph.D., USN, and later USAF– considered to be “The Father of GPS” – leading this team with a joint program office relationship (JPO), Navy’s deputy director Cdr. Bill Huston, and Maj. Gaylord Green, USAF, the government’s GPS Chief Engineer, my counterpart. (2) Defense Department funding to get things started; (3) The best aerospace company, Rockwell International, with a ‘Dream Team’ to build the satellite constellation, led by Dick Schwartz as GPS PM, (also head of Rockwell’s Satellite Division), and ‘me’, his Satellite Chief Engineer; again, Dick was my boss, going from rockets to GPS without a pause. (4) A component, the very heart of the satellite system – ‘miniature’ atomic clocks that work as good or better than laboratory devices, but must also be capable of handling electronic circuit killing space environments; a ‘monumental’ task’, since such was not available at the time of the initial RFP.

A satellite design team has PMs (Program Managers) for every critical system. Highlighting some of the critical systems: (1) The Systems Engineering PM. It begins with a very preliminary assessment of the available launch vehicle the customer plans to use (usually not changeable) and the SV design requirements. With an assessment of the SV’s expected weight, shape, and power requirements, the data is continually updated as the design begins to take shape. For the initial GPS SV launches (GPS Blk-I, II, and IIA) the USAF used 21 Atlas-F’s, originally hosting ICBM payloads. It has a ‘throw weight’ of only 1450 lb. So, to reach the GPS operational orbit of ~12,500 miles, it required both the Atlas-F, plus a 600 lb. solid rocket motor to get the SV to its final orbit.

Geselowitz:

You put it into a circular orbit?

Fruehauf:

Yes, using the 600 lb. motor

1450 lb. throw-weight, minus a 600 lb motor, leaving only 850 lb. for the GPS satellite(s) weight. Then, it was all about the right price to get gov approval for the demo to validate the concept. By the way, today it’s all about superior military capabilities and GPS satellite weight (these days ~4,000 lb.) is no longer a problem – just pick the right booster for the job. Let’s take a look at just two more PMs of about twelve that are part of the team – the Payload and Orbital Mechanics PMs. As for the Payload, the development of the satellite signal structure, involving giants in the industry such as: Robert Gold (of the “Gold-Codes” fame), orthogonal, unique codes that ID the SVs, yet all transmitting on the same frequency. James Spilker of Stanford-fame and Charles Cahn of (then) Magnavox, developers of spread spectrum ‘code division multiple access (CDMA), which is part of the signal structure. All that and more is part of the “Payload” design, which Rockwell subcontracted to (then) ITT, Nutley NJ, under the direction of Andy Codik. The Orbital Mechanics PM, Dick Meston, aided by Tom Logsdon and Denni Galvin, determining the best orbits, inclinations, eccentricity, radiation environments, Einstein’s ‘General’ and ‘Special’ Relativity adjustments of the space-borne atomic clocks, etc.

I saved the best story for last, the Atomic Clocks, the most important hardware on all GPS satellites (GPS = Clock = GPS)! It begins with basic requirements of the GPS precision clocks. First, if the military would have been able to update the SV clocks every two hours or so, using owned or leased ground stations around the globe, small, high precision, (then available) quartz (Qz) oscillators (clocks) could have been the SV timing devices. But consider the era – we were in the ‘70s, the ‘Cold War’. The GPS system would have been vulnerable to interference at foreign ground stations. However, if the SVs could update the clocks only when over the US, that huge threat would be eliminated. In this case, it would require a ‘so called’ Atomic Clock that is significantly more accurate over 24 hours, as a Qz clock would be in two hours. Since the SVs are in a 12-hour orbit, in the first 12 hours of SV revolution, the earth has also rotated 12 hours, putting the SV now over foreign territory. With the next 12 hours, the SV is again over the US. So, the gov demanded ‘CONUS’ (Continental US) clock updates during war-time scenarios. Generally, SV Atomic Clock ‘time accuracies’ remain less than 0.000,000,010 seconds (10 nanoseconds) and ‘frequency stability’ over 1-day, better than 0.000,000,000,000,010.

In 1973, one year before the RFP was issued by the gov, I began to visit every major instrument company in the US, knowing only too well that foreign products would be a ‘no-go’. HP, a global instrument giant in those days, had the best Cesium Beam and Rubidium Vapor Atomic Clocks. They usually came in a 19-inch rack-mountable package, weighing 35 or so pounds. Any attempt to work with me with a well-funded contract to make one of their instruments smaller got nowhere.

Geselowitz:

Now, this is when?

Fruehauf:

This is now 1973

Geselowitz:

’73. This is for Rockwell?

Fruehauf:

This is for Rockwell, the GPS Program

Geselowitz:

And this is still in the proposal stage?

Fruehauf:

This is all just for the proposal

Geselowitz:

And you can’t do a proposal until you know you can do the clock?

Fruehauf:

Right.

Geselowitz:

Right. Okay

I was budgeting about 50 lb. for three clocks to insure a successful ‘demo’ program. Frankly, I knew this was impossible, but the Systems Engineering PM needed a number. Out of the blue, Aerospace or NRL (don’t remember which) heard of a very small company in Munich, called Efratom, working out of their basement. The founders were Ernst Jechart and his associate Gerhard Hübner. Before forming their company, they were Rohde & Schwarz instrument designers. They designed a miniature Rubidium Vapor Atomic Oscillator, 4x4x4 inches, weighing 4 lb. and had frequency stability specs very close to that of large lab instruments – absolutely unbelievable. Thinking the world was dying to have such a product, Ernst Jechart, the main designer was told there was no market: “Wer wurde so ein gerät kaufen und für was”? (who would buy such a device and for what?). Ernst gave back his 17K DM prize in exchange for the future patent, which Rohde did. Aerospace and NRL visited Ernst in Munich and brought back two Efratom model FRK units. Almost a year later, in July 1974, without much updating other than potting the units to get more conductive rather than radiated heat transfer, NRL launched both units on Timation-I (NTS-1) satellite. One unit (as I recall) failed in about three months, the other lasted about a year, actually very impressive for a commercial unit. NRL decided not to pursue rubidium technology after the launch, focusing instead on their small Cesium Beam clocks that had been in work since the late ‘60s by three vendors. Not to forget, there was also the ‘foreign product thing’, the prohibition of using foreign hardware in US military systems.

Early 1973, a miracle happened, and unbeknownst to me, Efratom Munich received a contract from an American company in Costa Mesa CA, requiring five or so FRK units per week, the product Efratom was marketing, but with the stipulation that an Efratom, Inc. be formed in the US. With five or more units per week at a sales price of about $4 K each, it was a ‘no-brainer’ to come to the US. The units were part of an Omega Navigation sets used by Executive Jet travel to increase flying route utility. Ernst was happy to come to the US, setting up Efratom Inc. Costa Mesa CA, later in Irvine CA. Gerhard remained in Munich, managing Efratom GmbH, tending to potential European needs for this remarkable new product. Not aware of this event, I continued to struggle to find or build a small Atomic Clock for the SVs, but to no avail. It is now toward the end of 1973, when one of my design engineers said: “there is a company that just opened in Costa Mesa that sells miniature Rb clocks to an Omega Nav company; we can go visit him tomorrow”. I ignored him for a while; it seemed too good to be true – but he was persistent! We finally went and spent all day with founder Ernst Jechart, his chief engineer Werner Weidemann, and his VP of marketing, Heinz Badura, switching back and forth between English and German, discussing this great product. I kept thanking God that I was fluent in German; it was an unbelievable day for me. Just before midnight the same day, Ernst called me, angered about my visit – I had no idea what he was talking about and I told him I would come by in the morning. Geselowitz: OK. Go ahead. Fruehauf: So, at 12, midnight, that same day, I get a call, Ernst Jechart is chewing me out with every 35-syllable swear words the Germans have - (joke) Geselowitz: Right Fruehauf: As it turned out, my design engineer who introduced me to Ernst, was ‘moonlighting’ in the evenings for the Omega Nav company, trying to ‘reverse-engineer’ Efratom’s FRK in their lab. Ernst had seen him there, but my engineer was not aware of this. Rockwell, like most companies, prohibited employees working second jobs where there was a ‘conflict of interest’. I let my engineer go the next day, and the rest was history. Of course, competing companies discovered Efratom as well, but apparently due to culture and partially language-related problems, they were unable to bond with Efratom as well as we did. After learning a lot from Efratom, I formed a small Rb Clock design team consisting of Efratom, Rockwell, and Rockwell-Autonetics in an effort to redesign the FRK for space environments. We retained my initial concept of having a high precision Qz Oscillator part of the Atomic Clock, in case the atomic section were to fail. In that event, we would still be able to prove the GPS concept, but the SVs would no longer be updated just over CONUS (continental US), but required ground station clock updates every two hours or so. Now having a well-functioning Rb Atomic Clock, ~7x5x4 inches, weighing only 6 lb., I informed the Systems Engineering and Structural PMs to change my initial clock weight estimate from 50 lb. to a total weight of 18 lb. for three units. I spent the next several months in Gov labs getting expert help with performance measurements and what to expect once the Rb Clocks are on orbit. These tests were followed by verifying the Rb Clock’s ability to operate in severe radiation environments and still meet all specifications. Since we had a fully radiation hardened, ready-to-fly clock, we showcased it as part of the GPS proposal submittal, April 1974. It apparently worked; Rockwell won the GPS contract some six month later. After winning the contract, we formed a Rockwell, Autonetics, Efratom teaming relationship to produce the future clocks. For the first and second GPS launches, beginning Feb. 1978, the SVs had (3) Rb Vapor Atomic Clocks on board because NRL’s small Cs Beam Clock was not ready. Beginning with the third launch, late 1978, (2) Rb and (2) Cs was generally the configuration, all the way to 1996, the last launch of the Blk-IIA GPS SVs. Several clocks were still functioning in ‘spec’ when some satellites were deactivated, having exceeded their SV operational life time by a factor of four. By the way, beginning with GPS Blk-IIR satellite launches in 2000, a new and improved generation of clocks were flown, produced by Excelitas, Boston area, with improved 1-day stabilities by a factor of ten. (https://scpnt.stanford.edu/news/age-aerospace-tv-documentary) Now, let’s return to the foreign company, its foreign owner, and foreign hardware issue. Much was said in the military circles, that this product, no matter how much needed, cannot be the solution for GPS. Having expected this early-on, both GPS deputy director Major Green and me got to work on the problem, late 1973. Major Green focused on the gov side to make the case that we need Jechart to remain in the US, because we needed this technology and Ernst’s overall capability. I instead focused on our California Governor’s office explaining the formidable financial benefit possible if Rockwell were to win this and follow-on GPS contracts. Jechart hoped we would succeed; he wanted to be a US citizen. To our surprise, both Major Green and I succeeded – I had the honor to present the citizenship certificate to Ernst. He had lived in the US less than one year. Usually, application can be made only after five years of residence. Early Feb. 1978, Dick Schwartz, me, and some of our original PMs flew to VAFB (Vandenberg AFB) in a very old DC-3 (WW-II era) to support the first GPS launch. It would require the Atlas-F, plus our apogee-kick motor to place the satellite into a 12-hour, circular, highly inclined (almost) polar orbit. We were all gathered in the Launch Control Center – everything went well. Immediately after the launch, the DC-3 flew us back to Moffett AFB, Mountain View, CA, near a satellite control facility referred to as the “Blue Cube”. We wanted to be in the Control Center to watch instrumentation for the apogee kick motor firing (that would occur about six hours after the Atlas-F launch) to circularize the 12-hour orbit, and later, the stretch-out of the SV solar panels. It turned out to be a horrifying experience because we could not find our satellite for the first six, or so hours – we were sure it was lost. Having no other options, we did some short, very high-risk attitude control thruster bursts, and all of a sudden we had the indication the SV automatically found the sun, and subsequently the nav antenna locked-on to the earth. Except for one Atlas-F launch failure in 1981, the 7th launch, all remaining Blk-I, II, and IIA GPS launches, from 1978 to 1996 (38 satellites) were successful. We had some clock issues on orbit, but never lost a SV because of clocks. As we all know, GPS is an unbelievable success story. For the military, GPS accomplished everything they could have ever hoped for and more. For the every-day user, the commercial unencrypted, open signal changed the world. In the ‘80s, the open signal was purposely degraded, due to fears that terrorists would use GPS to do us harm. Almost 20 years later, during the Clinton administration, it started to sink in that terrorist want mass destruction, not precision, President Clinton directed the USAF GPS ground controllers that the distortion of accuracy of the open signal would now be turned off. So, while we were sleeping, the navigation and positioning accuracy went from the distorted 300 feet to an undistorted 5 to 10 ft. accuracy, now good enough to map every street on the globe. Over these 20 years, the initial GPS receivers as big as a briefcase, turned into electronic chips half the size of our little fingernail, costing less than$5 dollars. The cellphone industry, not only developed chips to make their own products smaller, but did the same for GPS receivers. Now, the two-giant technology ‘break-throughs’ are combined and indispensable. Today, there are three GPS “look-alike” systems – first GPS, early’80s; Glonass (Russia), began some 5-years later; Europe’s Galileo, with a very long development process, early 2000; and BeiDou (China), starting about 2010. Each satellite system has their own military signals, but also a common, open signal all receivers on the globe can receive – all signals on the same frequency, thanks to GPS technology visionaries. Very exciting times, but I was ready to move on after a fantastic career at Rockwell, beginning in 1965. I learned a lot working for Dick Schwartz and felt ready to go to a startup company.

After the first GPS launch in Feb. 1978, I accepted a job offer from Efratom Inc. CA as their VP. It was quite a change for me – from a huge Rockwell, to a company with $1M sales. To top all, I was working for a true genius. His work hours from about noon to midnight made it difficult for me to manage. His somewhat flamboyant life style made it difficult for me to plan R&D funds and stay on-course with business objective. In 1981, three years after leaving Rockwell, I proposed to leave unless he was willing to sell the company and I would stay with the new owner (if they decided to have me). We are now at about$4M in sales, asking Ernst how much he wanted for the company. Without hesitation, he said $15M. Wow, I responded$15M for a $4M company?? Getting the word out brought in a few contenders, but not at 15 mil. One day Ball Aerospace, Boulder CO called me indicating their interest in having a west coast company, adding to their four other companies, each with a virtual monopoly like we were. Late 1982, Ball Aero bought Efratom for the asking price of$15M and asked me if I would stay as its President. I accepted and we became Ball-Efratom Inc., Irvine, CA and Ball-Efratom GmbH, Munich Germany. There was no negotiation over price – they simply thought it was worth it; I was blown away… and it turned out they were right. Now, able to manage the business like a ‘real’ business, I continued to support GPS, but now as a more comprehensive contributor. One of my main objectives was to mil-qualify the company in order to serve a host of new atomic oscillator applications that we invented over a 15-year period without competition – when does this ever happen? The company was profitable, in spite of the usual military limitations on profit. By the 1990s, our unique ‘GPS-aided’ commercial, mil-spec, and mil-spec SAASM products for ground, air, and space platforms caught the attention of both US and NATO organizations, bringing the sales to over $75M. By the way, Ernst Jechart died in 1991, nine years after selling Efratom; he was only 54 years old. Werner Weidemann, Efratom’s Chief Engineer, who came to the US with Jechart, died in 2008 from cancer; he was only 65 years old. At the time of his death, was working with me at FEI-Zyfer, Garden Grove, CA. Jechart’s partner Gerhard Hübner, who remained in Munich, VP, Efratom GmbH, is retired and at the time of this writing is very well. Heinz Badura, who also came to the US with Jechart, is retired and at the time of this writing is also very well. In 1995, I left Ball-Efratom and again joined Dick Schwartz. Heinz Badura took over for me as President and CEO of Ball-Efratom. Dick was now CEO, Alliant-Techsystems, (ATK), Hopkins MN, a (then) recent spin-out of Minneapolis Honeywell. ATK consisted of three groups with total sales of about$1.5B. I became Group VP, Defense Systems, with about one third of ATK’s total sales. In addition to my headquarters in Hopkins, the Defense group was supported by four weapon systems production facilities, each with its own President, located throughout the US in strategic locations. We were a weapon systems developer/producer for tactical warfare, missile systems, including munitions, rocket motors, and warheads. Bringing with me GPS applications experience, previously applied to telecom and time/frequency while at Ball-Efratom, but now becoming GPS-aided weaponry. In addition, the gov had just released the new GPS military signal security infrastructure, applying to legacy L1 and L2 P(Y) crypto security, the new SAASM module (Selective Availability Anti Spoof Module). Teaming with Trimble, CA, we developed the first, small, SAASM-based NavCom receiver. We were also the first company to successfully gun-fire a GPS-aided 155mm Howitzer shell, with both the crystal oscillator clock and GPS receiver surviving the shock load. We made significant contributions to the development of IOCW (Individual, Objective, Combat Weapon) and early development of combat UAVs (Unmanned Air Vehicle), commonly referred to as ‘Drones’ now. It was my dream job ever. I returned to California, late 1997.

Having returned to California, I accepted a job offer from Odetics Inc., Anaheim, CA, as CEO of their Telecom Group. It was one of five groups, each having a CEO. Being sure that the new military SAASM technology would become popular, we did everything needed to become a (classified) ‘Secret’ Telecom facility. Sure enough, we became the sole provider of ‘so-called’ classified, mil-class GPS-aided Telecom and Time/Frequency systems for more than three years. During the late ‘90s, leading up to the “dot.com” crash, year 2000, Odetics Inc. corporate visionaries put its five CEO on a new path: "invent a new product with which each CEO would go out in an IPO." It was brilliant. Steve Strang, my Telecom Engineering Manager would continue to produce the legacy products in order to fund the development of the new, would-be IPO company. In the meanwhile, we came up with a new product called “StealthKey”. With the help from a small electronics engineering company, “Technovare”, and using the H-1B visa system, to bring in two former ‘East German’ cryptographers, from their (then) defunct’ equivalent NSA. They would help design and proto-type our IPO ‘StealthKey’ product invention. As security products go, StealthKey was in the “Network Crypto Security and Conditional Access with StealthKey” category. So, our final product? “a “Secure GPS-aided Symmetric Key Exchange System”. We were in the demo, form, fit, and FPGA planning stage when the “dot.com” crash happened. Long before the crash, Steve and I renamed our Telecom company “Zyfer Inc.” to have an appropriate name when we were ready to spin out. Long before the crash, we filed four patents, but owned by Odetics/Zyfer Inc.

• US 6,590,981 B2 – July. 8, 2003 – System and Method for Secure Cryptographic Communications
• US 7,149,308 B1 – Dec, 12, 2006 – Cryptographic Communications using in situ generated Cryptographic Keys, for Conditional Access
• US 7,120,696 B1 – Oct. 10, 2006 – Cryptographic Communications using Pseudo-Randomly Generated Cryptography Keys

The story is not all bleak, Odetics succeed in spinning out two of five companies. One made it and is still in business and one failed. It was too late for Zyfer Inc. The dot.com crisis had an enormous negative impact on our legacy business and I was asked by my boss, CEO and owner of Odetics, to look for a buyer. I contacted Martin Bloch, CEO of Frequency Electronics Inc. (FEI), Mitchel Field, NY, (and long-time friend since 1973) to determine his interest. FEI purchased Zyfer Inc. in 2003, renaming it FEI-Zyfer, and retained me as President, CEO an CTO. Martin however, was not interested in anything related to StealthKey, although it had a strong tie to mil-type security and GPS.

In 2005, I decided to go back to school for a career after retiring. I entered a Presidential and Key Executive (PKE) MBA degree program, a program like none ‘other’, at Pepperdine University, Malibu CA – all students in the class must be CEOs, Presidents, or Sr. VPs – imagine the egos in such a class. After 18 months of cruelty, I graduated in 2007, and immediately received a job offer from Pepperdine, as an Adjunct Professor, teaching graduate-level Global Economics and International Business classes, able to bring my 45 years of domestic and international business experience to the classroom. Exactly perfect, a career after retiring 45 years of stress. I turned my job over to Steve Strang in 2005 as the new President, CEO/CTO of FEI-Zyfer, Inc. CA. From then, till my retirement, late-2008, I continue working at FEI, NY as VP/CTO of special projects and continued to improve coordination between facilities.

In addition to my part-time teaching at Pepperdine, I am a Management, Scientific, and Technical Consultant (NAICS Code 5416), ‘The Hugo Fruehauf Company’ (Sole Proprietorship), specializing in GPS Design and Applications, Atomic Clocks, Precision Navigation, Time and Frequency, and Manned Space Flight. In 2019, I was awarded (along with three associates, one of the three being Dick Schwartz) the ‘Queen Elizabeth Prize for Engineering’ for the development of the Global Positioning System (GPS). http://qeprize.org/winner-2019/. In addition (not related to the QEPrize) I have been awarded Pepperdine's “The Alumni for the World”, April 2020. Celebrations and the giving of the Award is delayed to April 15, 2021 due to COVID-19.

thfc@hugofruehauf.com , hugo.fruehauf@pepperdine.edu , www.hugofruehauf.com