The Engineers Club is proud to honor with the Desch Innovation Award the outstanding contributions of Kenneth C. Jordan and John H. Birden, researchers working at the Mound Laboratories in Miamisburg, Ohio, who in 1954 built the first radioisotope thermoelectric generator (RTG). This device would virtually eliminate then existing barriers to the use of digital equipment in space, in the deepest oceans, the highest mountains. This first RTG demonstrated the feasibility of coupling radioisotopes with thermocouple-type (thermoelectric) conversion systems and remains the basis for all radioisootopic-power thermoelectric generators.
Remarks at the Ceremony
The Joe Desch Innovation Award
The Joe Desch Innovation Award is intended to focus upon notable achievements in digital technology and novel ways to solve problems in that field. I have therefore assumed up to this point that we would be examining the originators of the devices of the information age, e.g. computers, peripherals, and the thoughts behind them.
It was a fortunate day, however, when I first followed a suggestion that I take a look at the work done down at the Miamisburg Mound Lab for ideas for this year’s award. On my first visit to the Museum on a cold Saturday morning, I was curious but did not anticipate finding anything that would help in this year’s selection process. How wrong I was.
During a tour, in one of the first display cases, I saw a small metal cylinder, a size that a person could easily hold in their hand. That modest looking device, I learned, was a nuclear battery, a generator could perform the herculean task of powering spacecraft on celestial voyages. They were called RTGs, which stood for Radioisotope Thermoelectric Generator. I began to be intrigued. And the more I learned over the ensuing weeks, the more I realized I wanted to honor this work.
But before I went any further I had to consider: how did these RTGs relate to an award for digital technology. Fortune and common sense soon answered that question. I was reading at the same time a recently released book named Red November, the story of two generations of submariners in a Navy veterans’ family. Late one night, in a chapter recounting a secret dive in 1975 in the Sea of Okhotsk, I read: “sophisticated new recording devices for the pod could monitor dozens of lines for months…the enclosure contained an electronically programmed system and a miniature plutonium 238 nuclear power source.” There was my answer.
What powered these undersea contraptions? An RTG. The obvious truth was that all these machines of the information age need some energy to work. One source of energy is of course our electrical utility system. Another is the battery for stored energy, in this case a nuclear battery. While in our own worlds we are tied to the grid most of the day, exciting things happen if you can leave the grid behind. Barriers of altitude, of depth, even temperature disappear.
That brings us to the work of the two gentlemen we honor tonight, John H. Birden and Kenneth C. Jordan. I cannot possibly do their work justice in the few minutes I have here, and I also cannot adequately explain how the inventions they designed function, but I can give you the barest of outlines.
In 1954 John Birden and Ken Jordan, working at the Mound Labs, originated the radioisotopic thermoelectric generator. This invention would generate electrical energy from radioactivity. This thermoelectricity is based on the Seebeck effect which is that a voltage — electromotive force — is created in the presence of a temperature difference between two dissimilar metals or semiconductors. This effect is reversible, and causes a continuous current in the conductors if in form a complete loop. Utilizing this, the first Space Nuclear Auxiliary Power generator, SNAP-3a, was fueled with polonium-201 was demonstrated in 1959 as part of the Atoms for Peace Program. In time the use of polonium-210 in space application proved to be impractical. The development of plutonium-238 heat sources was begun at the Mound in 1961.
Radioisotope thermoelectric generators are used when spacecraft must operate at significant distances from the sun or where the availability of sunlight and therefore the use of solar arrays is otherwise infeasible. The key advantage of radioactive power sources is their ability to operate continuously, independent of orientation and distance relative to the Sun. These systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, independent operations in the extreme conditions of space.