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The Career of a Rocket Scientist

My auto-biography could be titled “I was a Teen-age Rocket Scientist” because I joined Aerojet-General in Sacramento upon graduating from the Northrop Institute of Technology at the age of 19. I started working on the Minuteman ICBM at a time when Aerojet was in competition to develop the solid rocket motors for all three stages. A couple of test failures with the first and third stage motors left Aerojet with the second stage contract. One of the courses that wasn’t offered at Northrop Institute was heat transfer, so naturally that was what Aerojet assigned me to do on Minuteman. I learned with the help of an IBM 704 computer. This picture appeared in an article in FLYING magazine on Northrop Institute.
Flanked by two of my fellow Aerojet engineers, I’m posing in front of a 100-inch diameter segmented solid rocket motor after a static test firing in 1962. This was the largest solid rocket motor in the world at the time and the forerunner of the solid boosters for the USAF Titan III and IV launch vehicles as well as those for the NASA Space Shuttle. I did heat transfer and interior ballistics (performance) analyses on these motors.

One of the reports I wrote was titled “Gas Flow in a Transverse Slot of a Segmented Solid-Propellant Motor.” In this report I showed that very high pressures could exist at the joint between the segments under certain design and operating conditions. Since the Challenger explosion in 1986, I’ve wondered if my report was ever read outside of Aerojet or if anyone at Thiokol did a similar study.

I did heat transfer and interior ballistics analysis for early designs of a 260-inch diameter motor that was the largest solid rocket motor ever built. Read its story.

The Titan III, consisting of a Titan II ICBM with two 120-inch segmented solid boosters, was intended as the launch vehicle for the USAF Dyna-Soar spacecraft (artists conception at right). Dyna-Soar was a contraction of dynamic soaring, a concept proposed by Eugen Saenger during WW II. His idea was to put a winged second stage on top of the V-2 and have the upper stage skip along the top of the atmosphere to deliver a warhead to the US mainland.

Aerojet made the liquid rocket engines for the Titan III. The mission of the Dyna-Soar was never revealed to those of us working on the project at Aerojet; speculation was that it carried a bomb, but manned recon was more likely. The Dyna-Soar program was cancelled in early 1964 but the Titan III went on to launch many unmanned recon satellites. It also sent the Viking spacecraft on its way to Mars in 1975.

Image from "America in Space" website

I expressed my feelings about the cancellation of Dyna-Soar in a parody of Edgar Allan Poe's The Raven that was published in Missiles and Rockets, a trade magazine. Click on the cover to read it.

A nuclear reactor in a rocket engine? Terrific way to heat liquid hydrogen to a high temperature and get a high exhaust velocity for better performance than a chemical rocket! This engine was being developed under the NERVA (Nuclear Engine for Rocket Vehicle Applications) project that I worked on at Aerojet. It was intended to power an upper stage that would be fired in orbit, until people started considering the political ramifications. End of that idea and my career at Aerojet. (Click on the picture to enlarge it)

I joined the Missile & Space Division of General Electric, located outside of Philadelphia, in mid-1965 to work on the Voyager project – but not the one you’re probably thinking of. Before the Voyager name was given to the outer planets missions it was an early study of a Mars orbiter and lander, but on a prodigious scale. The spacecraft we were funded by JPL to study was much bigger than the Viking spacecraft that eventually went to the Red Planet (see below); in fact, Voyager was designed to be launched by a Saturn V.

After several months of intense effort, during which I was part of the propulsion group that evaluated several liquid and solid rocket systems for the orbiter, the Saturn V-launched approach was cancelled. The Voyager team was kept together, though, and I soon found myself immersed in the new and somewhat arcane field of planetary quarantine.

What is planetary quarantine?
Bob Wolfson was the planetary quarantine manager on Voyager and one day he asked me if microbial spores could survive rocket combustion. That was a question I had no ready answer for; in fact, it took a year-long research project and a good sum of money to get the answer. But why did he ask in the first place?

To insert a spacecraft in orbit around Mars it has to be slowed down by firing a rocket engine. IF the propellant contains viable microorganisms, IF some of them survive until the rocket is fired, IF some of those survive combustion, IF they are on a trajectory that enters the Martian atmosphere, IF they survive the heat of atmospheric entry and reach the surface, and finally, IF they find a nutrient source and replicate themselves, the planet will have been contaminated to some extent. All of those IFs had probabilities associated with them, which the statisticians strung together as part of the much larger PQ model. My job was to find out the probability of surviving combustion and thus was born the Combustion Lethality Experiment.

I didn’t do it all by myself, of course. The GE project team I headed included microbiologists, a QC engineer and others, and some of us moved to Sacramento for almost a year for the testing. Aerojet built the liquid and solid rocket hardware and did the test firings, while our microbiologists figured out how to recover spores of B. subtilis var. niger from the rocket exhaust products. The equipment for doing that is shown in these pictures. The plastic model shows a valve on top of which sat a very small solid rocket motor or liquid propellant engine. It fired into the test chamber through the middle of cooling coils, which were used to reduce the amount of heat any surviving microbes would see after they left the rocket nozzle. The actual hardware is shown disassembled on the upper right and the test stand with a liquid monopropellant engine installed is shown below, ready for one of the test firings.

It took several months of testing to isolate the toxicity of the liquid propellants to the spores before firing and the effects of the exhaust gas in the test chamber afterwards from the effects of combustion. Finding the spores in the heavy particulate produced by the solid motor proved a challenge. Finally, we were ready for the actual tests with inoculated propellant. The results? Viable spores were recovered from all three types of propulsion systems: mono-propellant and bi-propellant liquid engines and solid propellant motors. The statisticians now had numbers to plug into the Voyager PQ model.

The technical challenges of the CLE were formidable – no one had previously done what we did and we had to improvise and innovate. The most challenging part of my job, however, was getting rocket scientists like myself – who thought in tolerances of thousandths of an inch – to communicate across a technical and cultural divide with microbiologists who pinned down the number of organisms to the nearest order of magnitude.

My last year at GE was spent on the Manned Orbiting Laboratory, a “black” program about which there is much information on the web that I will neither confirm nor deny due to the uncertainty of its current classification even after all these years. Suffice it to say that I found coordinating interfaces for ground support equipment less than challenging. My co-workers on MOL told me I was foolish to leave the security of a billion-dollar program to become the first employee of a start-up company without any contracts. Three weeks after I left GE the MOL program was cancelled.
Dr. Joseph Stern ran the planetary quarantine program at the Jet Propulsion Laboratory and he established Bionetics to “compete” for the Viking PQ contract that was soon to be awarded by NASA’s Langley Research Center. I put “compete” in quotes because it was a foregone conclusion that all Joe Stern had to do was leave JPL, form a company and the contract was his. Knowing that, I had no qualms about accepting his offer to become the first employee of Bionetics, moving temporarily to LA and then to our permanent location in Hampton, VA.

Within a year the core of Bionetics had been assembled in Hampton to work on Viking: Joe, myself, Bill Paik and Dick Wrobel (both ex-JPL), Fred Nayor and Maurice Landry (both ex-GE Voyager). Bob Wolfson would soon join the company. The group held together through the duration of the PQ contract that lasted until launch in 1975.

Bionetics subsequently became a large support-service contractor, running government facilities nationwide. If you’re a Bionetics employee these are the founders of your company. From left: Bill Paik, Maurice Landry, myself, Joe Stern and Dick Wrobel

We supported the NASA Langley Viking Project Office on the planetary quarantine and contamination control aspects of the mission that searched for life on the planet. To satisfy these constraints, the orbiter and lander were assembled in the cleanest facilities existing at the time, and the microbial population of the lander was reduced by meticulous cleaning and a heat sterilization cycle. A complex statistical model analyzed every mission event and every piece of hardware to assess their contributions to the probability of contaminating the planet with viable micro-organisms or organic material (The lander had a GC/MS on board.). We worked closely with team members at Martin-Marietta, who was building the hardware, and JPL as well as with NASA Langley staff to develop the structure and inputs for this model. I supervised two statisticians at Bionetics who tackled problems like the survival of microbial spores ejected from the orbiter by micrometeoroid impact en route to Mars and the consequent probability of their contaminating the planet. My first encounter with atmospheric dispersion modeling, which would later become part of my graduate studies in air pollution and the start of my consulting business, was predicting the contamination of the Viking soil sample with particulates of the lander coating eroded by the sandstorms in the Martian atmosphere. You can appreciate this problem from the picture of the surface of Mars as seen from one of the Viking landers in 1976.

My signature, along with those of other project contributors, was etched onto a plaque that was attached to the outside of the lander – long since eroded by sandstorms. A little bit of me is somewhere on the surface of Mars.

One of the life detection experiments reported an early positive result that suggested the presence of microbial organisms in the soil. Neither of the other two experiments confirmed this finding and the GC/MS did not detect any organic compounds in the soil.

More recent missions have concentrated on finding out if life could have ever existed on Mars in the past and the planetary quarantine constraints are limited to cleaning the hardware, which was not heat-sterilized after Viking.

Viking orbiter with the lander capsule below


Viking lander as it would appear on the surface of Mars


Viking lander self-portrait on the surface of Mars

EPILOGUE: I have not worked in the aerospace industry since Viking and, yes, I miss it. Looking for llife on another planet is a tough act to follow. The missions that have successfully reached Mars, in orbit and on the surface, have told us much about the planet but the mystery of past or present life remains. I personally feel that the question will not be answered until we return samples to Earth -- with all of the environmental and ethical implcations such a mission would raise -- for analysis in properly-equipped laboratories. It is regrettable that we waited 20 years to return to Mars after Viking and that the sample return mission planned in the late 1990s fell victim to the mission failures of that era. Had the mssion not been cancelled, there is a small chance I might have worked on it.

The Making of a Rocket Scientist