NASA says it has completed testing on a new nuclear fission power system for deep space missions – and the results went extremely well.
The system is called Kilopower, and it involves using the heat generated by uranium to produce power. It’s a $20 million project that’s been billed as a way to support human missions to the Moon, Mars, and beyond.
At a conference at the NASA Glenn Research Center in Ohio, engineers from the $20 million project revealed results of the tests, conducted earlier this year in the Nevada desert. And they said their prototype, called KRUSTY (Kilopower Reactor Using Stirling Technology), exceeded all of their expectations.
“I’m really glad to be able to report back to you that the test went great,” Marc Gibson, the lead engineer on Kilopower, said at the event.
Kilopower is a technology that uses heat generated by the nuclear fission of uranium to produce power. It could theoretically supply constant power for hundreds of years, with no need to rely on consumables or the Sun.
At the core of the reactor is an enriched uranium core, encased in a reflector made from beryllium oxide. A rod of boron carbide starts the fission reaction in the uranium, producing heat that’s transported by pipes to the power generators, known as Stirling converters.
On top of the reactor is a large circular radiator, which emits the excess heat from the reactor. In total, a finished reactor would measure about 2 meters (6.5 feet) tall.
To prove it worked, engineers built a smaller KRUSTY prototype and ran it at temperatures of hundreds of degrees, putting it through its paces to see just how useful it could really be. On March 21 they concluded their testing, which included a demonstration that lasted for 28 hours. And things went pretty well.
Running at up to 800°C (1,470°F), the team found that the reactor exceeded pretty much all of their expectations. It produced up to 1 kilowatt of power, but the team noted this was easily scalable up to 10 kilowatts with their existing system. Future designs for the Moon and Mars could reach 40 kilowatts.
“Kilopower is ingenious in its design,” James Reuter, acting associate administrator of NASA’s Space Technology Mission Directorate, said at the conference. “The aim is to solve key technological challenges that will enable more ambitious human science missions in the future.”
This was the first time a new nuclear reactor of any sort had been tested in the US for 40 years, let alone one designed for space. So the fact the test was a success will be pretty welcome news for people dreaming of ideas for future missions.
Kilopower, in theory, opens up a lot of doors. Some deep space missions already use a source of nuclear fuel, radioisotope thermonuclear generators (RTGs), which rely on the decay of plutonium-238. But they are limited to a maximum power of about 1 kilowatt.
“We start where the RTG stops,” Gibson noted in the conference. “One kilowatt is our lowest level, and you can go up to megawatts of power.”
Another benefit of Kilopower over RTGs is that the latter constantly run, and cannot be turned off once the process begins. The former, however, could be started at any time during a mission, and its power output is completely scalable too.
It was noted that as the reactor isn’t turned on until it reaches space, Kilopower also has an added layer of safety prior to launch, allaying some nuclear-related concerns.
“If there was a 15-year mission to the Kuiper Belt, we don’t have to start the reactor up until we get there,” added Gibson.
With the completion of this test, the team said they no longer had any need for further ground demonstrations. Now they’re seeking approval to actually test the Kilopower system in space, something that will be looked at over the next 18 months.
With NASA continually looking to broaden its horizons, be it the Moon or Mars, a source of power like this is pretty desirable. It’s fairly cheap, easy, and provides more juice than other sources like solar power. If we want to conduct prolonged stays on other worlds, we may well need something like Kilopower to make that a reality.