Inside the world's first reactor that will power Earth using the same nuclear reaction as the Sun

In the heart of Provence, some of the brightest scientific minds on the planet are setting the stage for what is being called the world’s largest and most ambitious science experiment.

"We are building arguably the most complex machine ever designed," confides Laban Coblentz.

The task at hand is to demonstrate the feasibility of harnessing nuclear fusion - the same reaction powering our Sun and stars - at an industrial scale.

To do this, the world’s largest magnetic confinement chamber, or tokamak, is under construction in the south of France to generate net energy.

The International Thermonuclear Experimental Reactor (ITER) project agreement was formally signed in 2006 by the US, EU, Russia, China, India, and South Korea at the Elysée Palace in Paris.

There are now more than 30 countries collaborating on the effort to build the experimental device, projected to weigh 23,000 tonnes and withstand temperatures of up to 150 million°C when complete.

"In a way, this is like a national laboratory, a big research institute facility. But it's the convergence of the national laboratories, really, of 35 countries," Coblentz, ITER’s head of communications, told Euronews Next.

Nuclear fusion is the process by which two light atomic nuclei fuse to form a single heavier one, generating a massive release of energy.

In the case of the Sun, hydrogen atoms at its core are fused together by the sheer amount of gravitational pressure.

Meanwhile, here on Earth, two main methods are being explored to generate fusion.

"The first, you might have heard at the National Ignition Facility in the US," Coblentz explained.

"You take a very, very tiny bit - the size of a peppercorn - of two forms of hydrogen: deuterium and tritium. And you shoot lasers at them.