Nuclear fusion powers stars. Could it one day electrify Earth?

The elusive power source can’t save us from the need to cut emissions now. But a $20-billion reactor approaching completion in southern France could pave the way for the future.

Tim Luce, chief scientist of ITER, the giant experimental fusion reactor now under construction in southern France, stands in the pit that will house the donut-shaped "tokamak," in which hydrogen nuclei will be heated to hundreds of millions of degrees and fused into helium.

For seven years, Bernard Bigot oversaw the construction of a building so ambitious and challenging, and of such significance to humanity, he sometimes thought of it as a cathedral.

Rising from a 445-acre plot in southern France, an hour north of Marseille, it’s a very strange edifice indeed. Not many buildings house cavernous vacuum chambers or require sub-millimeter precision during construction. Fewer still would include a 59-foot-tall magnet powerful enough to lift an aircraft carrier, or enough superconducting niobium-tin wire to circle the equator twice.

The project that Bigot oversaw, called ITER, for the International Thermonuclear Experimental Reactor, is arguably the biggest, most complex, and, at a cost of more than $20 billion, most expensive science experiment ever devised. The consortium of 35 countries financing ITER and building its components represent more than half of the world’s population and 85 percent of global GDP. The U.S., Russia, China, and the European Union are all members.

Read This Next

Do spiders dream? A new study suggests they do.
Why monkeypox cases are still rising at such an alarming rate
Thunderstorms are moving East with climate change

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet