Paul Dabbar is the Undersecretary for Science at the Department of Energy (DOE). The Undersecretary was in Houston on November 21, 2019. He gave a presentation that morning to the attendees of SpaceCom (Houston, TX) on how the DOE is investing in space research. Paul Dabbar has a BS degree from the US Naval Academy and an MBA from Columbia University. I had an opportunity to speak to him right after his presentation.
DOE manages 17 different national laboratories around the USA. These laboratories are involved in a wide range of research regarding energy, and a portion of that research is dedicated to space and working with NASA. Currently the laboratories employ 60,000 people and do 18 billion dollars worth of research.
Undersecretary Dabbar explained to me after his speech that DOE is very interested in using nuclear energy in outer space. This is particularly true in rocket propulsion and satellites. I thought to myself, let’s face it, if we are going to colonize space, we are going to need a lot of energy. How can that be done in an atmosphere with no oxygen? Last year at SpaceCom I published an article on a company called BWXT that is doing research for NASA in the area of nuclear propulsion. You can read it here: https://houstonenergyindustrynews.com/2018/11/29/bwxt-exhibits-nuclear-thermal-propulsion-at-the-spacecom-conference/ .
An area of particular interest to DOE, as Undersecretary Dabbar explains, is the Radioactive Thermocouple. The thermocouple works off of the Seebeck Principle: When two dissimilar metals are joined at both ends, and one end is heated while the other end is cooled, a voltage potential is formed and current is generated. Mathematically that is expressed as V = S * ΔT where V is voltage, ΔT is the temperature difference between the hot and cold junctions, and S is the Seebeck coefficient which applies to the metal in question.
In refineries and petrochemical plants, the voltage generated is very small – down in the millivolt range. However, when the hot junction is nearly the temperature of the Sun, well, that is a large temperature difference. Temperature differences that large can develop large voltages; and thus, large currents. Furthermore, space is so vast, that disposing of the nuclear waste is no issue at all.
The Undersecretary closed by stating that nuclear energy in space can be used to power satellites, preheat rocket fuel for better combustion, and is currently being studied in DOE’s Krusty Project (application of the Stirling Engine in space). Nuclear power is a must because batteries and solar power simply cannot supply the needs of long term space exploration. Moreover, these innovative and efficient technologies have great application potential for the energy needs of earth.