With NASA starting to get serious about sending astronauts into deep space, beyond low Earth orbit, with bases on the moon and eventually expeditions to Mars, the space agency is developing a technology called kilopower to give them enough power to operate. Kilopower is a small-scale Nuclear Reactor capable of delivering one to ten kilowatts of energy. As a means of comparison, the typical American private home uses five kilowatts of power.

What is kilopower?

Hitherto, American space satellites or crewed spacecraft have either used fuel cells, solar power or a version of nuclear power called an RTG or Radioisotope Thermoelectric Generator that uses the decay of plutonium-238 to generate electricity.

However, planned space missions are going to need far more power than these technologies can create.

Kilopower is a small-scale nuclear reactor that uses uranium-235 as fuel. Sodium heat pipes transfer heat from the fuel core, the size of a roll of paper towels, to Stirling engines to convert into electricity. A kilopower unit would be able to operate without a great deal of attention or maintenance for Ten Years.

NASA and the Energy Department recently conducted a 28-hour experiment with a kilopower unit that involved startup, a ramp up to full power, a period of steady operation, and then reactor shutdown. The trial included a number of failure modes to determine how the unit would behave during accidents and other equipment malfunctions.

The next step will be to conduct a flight demonstration mission as early as 2020.

What about earthly applications?

Naturally, the question occurs, are there earthly applications for the Kilowatt unit, or as NASA calls it KRUSTY or Kilopower Reactor Using Stirling Technology? A spokesman for the Los Alamos National Laboratory suggested that the military might use the technology for remote bases that are off the grid.

Civilian uses include things such as remote mining operations.

Unfortunately, hooking up arrays of KRUSTY units putting power out on the grid, not to mention having one as a home unit are not in the cards, at least for a long time. The idea of a backyard nuclear reactor that not only provides enough power to run a house and puts out excess electricity to the grid is a beguiling one.

Such an arrangement would secure a home or a small business against a great many disasters such as hurricanes that take down the grid for extended periods. However, safety and regulatory concerns are likely to foreclose such an application ever becoming a reality. The word “nuclear” elicits scary scenarios that include Three Mile Island, Chernobyl, and Fukushima,