Watch Live: NASA to Reveal Energy Breakthrough That Can Take Humans to Mars and Power a Home for 10 Years

What NASA's Kilopower devices may look like arrayed on Mars. NASA

Updated | Keeping the lights on will be even trickier on Mars than it is on Earth, which is why NASA has been working on developing new nuclear power sources for space. That initiative is called Kilopower, and on Thursday, the agency is holding a press conference "to discuss a recent experiment involving a new power source," NASA promises. The event will be live-streamed beginning at noon Eastern time.

NASA and the Department of Energy's Nevada National Security Site have been testing the Kilopower project since November and are due to continue through March, so the press conference will likely announce early results of those tests. The tests include confirming that the system can work at full power for 28 hours straight without failing.

A form of plutonium called plutonium-238 has long been considered the only radioactive isotope capable of fueling missions, and it has driven many important spacecraft, including Voyager, Curiosity, Cassini, and New Horizons. (Other spacecraft, like the Juno mission currently orbiting Jupiter, are solar powered, but at Jupiter, a solar panel receives just four percent the amount of sunlight as it would here at Earth.)

But plutonium-238 can't be used in weapons, and so the U.S. stopped making it in the late 1980s until a small NASA/Department of Energy program produced a tiny quantity in 2015.

So NASA has been exploring new ways to take nuclear power to space safely and effectively. That's where Kilopower enters the picture, the agency's effort to develop a power system that relies on uranium-235 instead of plutonium-238. As the uranium atoms are split, they produce heat, which converter systems turn into electricity.

The project includes a few different designs, each of which would last about 10 years but be a different size and generate a different amount of power. With the Kilopower project, NASA's focus is on building more smaller reactors, rather than trying to fuel a whole mission on just one unit. Smaller power systems are also cheaper, and if one goes down others are still working.

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The approach pictured above, for example, which looks like a flattened umbrella and is designed to be used on a planet's surface, stands 13 feet tall and would produce 10 kilowatts. That's enough to continuously power two average American houses and is substantially more energy than existing plutonium-powered space systems produce.

Kilopower, a project budgeted at about $15 million, is NASA's first foray into nuclear fission power in space since the 1960s. The agency has discussed using a small, one kilowatt version to visit Saturn's moon Titan, to the small frozen objects in Pluto's neighborhood, or to land humans on Mars, but it's not yet clear how soon the Kilopower technology would be ready to take flight.

This story has been corrected to note that a small government program re-initiated plutonium production in 2015.