We need more powerful nuclear engines to explore space. Plutonium-238 production is growing

Last year, Voyager 2 finally broke throughinto interstellar space, having covered more than 18 billion kilometers. This epic mission was made possible by nuclear energy, on the technology of which spacecraft operated for decades. Spacecraft similar to the Voyager pair are equipped with radioisotope thermoelectric generators (RTGs). These engines rely on the fact that as the destruction of radioactive substances heat is released. Transforming the heat generated by the decay of plutonium-238 (P-238) into electricity, the spacecraft continues to work long after the sun's rays become a dim glow.

What fly "Voyagers"

RTGs are also holding us back. If we want to send spaceships — or people — farther, faster, and more often, we cannot continue to rely on the same nuclear technology that we have used for decades. How do we expand our reach?

Our plutonium-238 reserves are almost exhausted. His first batches were made in the USA as a by-product of the creation of combat plutonium-239 during the Cold War. To continue research, NASA needs a lot more.

Oak Ridge National Laboratory has taken overthe task of its production in 2012. Producing even a few grams was a slow and manual process. But last month, scientists at Oak Ridge announced that they had finally developed a way to automate and increase the production of neptunium and aluminum pellets necessary for the production of P-238. The granules are transformed into precious P-238 in the process of pressing in aluminum tubes with subsequent irradiation in the reactor.

Making these pellets was the most problematic this process, and removing people from this equation also required a lot of experimentation. “In many nuclear jobs, you need to“ bake and watch, ”says program manager Bob Wam. “You design by putting a lot of safety factors into the design; get out; See if it works the way you expected. ” After many years of work on the automation of measurement and production, everything worked out.

Now the lab produces 50 grams of P-238 inyear, but soon plans to go up to 400 grams per year. According to forecasts, NASA's annual goal of 1.5 kilograms will be achieved within two years. The more P-238 we have, the more missions we will be able to send to deep space.

Small steps into space

NASA also explores making more efficientRTGs - Advanced Multi-Purpose RTGs, or UMRITAGs. But to make a breakthrough, you need to look for something new. Ultimately, more powerful systems will be needed. Only nuclear fission can provide such power in the short-term scenario, says David Poston of the Los Alamos National Laboratory.

Postton - the main developer of the reactor forKilopower, a prototype fission reactor that NASA successfully tested last year. He will be able to provide long missions with energy, perhaps even planetary outposts of people. “The way we put it into reality simplified everything,” says Poston. “We have had many space reactor programs over the past 30 years, but they all failed. Mostly because it turned out to be too expensive. ” Currently, Kilopower's power is 4 kilowatts, but scientists hope to overclock it to 10 kW.

Giant racing

More recently, morefuturistic ideas, including the detonation of atomic bombs in the back of the spacecraft in the so-called pulsed nuclear engine (obviously, he had a number of practical problems). But some people are still working to bring crazy ideas to life.

One of these teams works in PrincetonSatellite Systems, which seeks to generate megawatts of energy through fusion. Yes, we went from watts to kilowatts and megawatts. You are probably familiar with the synthesis - it happens in the sky every day, thanks to our sun. Synthesis produces several times more energy than fission, but it is difficult to control.

Princeton Satellite Systems is developingdirect fusion engine that uses magnetic fields to generate current in the plasma and heat it up to 1 billion degrees Celsius. The team says that, in theory, a minivan-sized car could produce, could cut the travel time between solar systems by more than half (a trip to Pluto would take four years, not nine), and more energy would remain.

“If you have energy by the time youWhen you reach your destination, you can do a lot of really cool experiments, ”says Charles Swanson, a physicist. “One of the coolest things that Cassini did is radar images of the satellite of Saturn Titan. But the radar requires a lot of energy and is limited in capabilities. The presence of megawatt power frees options. "

The company received a huge amount of funds fromNASA and the US Department of Energy, so someone believes in the success of this event. But let's be honest, success will not come soon. Thermonuclear fusion is in its earliest stages of research.

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