The director-general of ITER, Bernard Bigot, died on May 14 at the age of 72. The head of the ITER organization was a chemist by training who took over when the project was facing massive criticism for cost increases and delays. Observers say that he transformed it from aglomeration of interests into a more coherent scientific project.

He was an international diplomat, he knew how to deal with the various governments, and he was technically and politically savvy, according to William Madia. Bigot is one of the great leaders in turn-of-the-21st-century science, according to Steven Cowley.

Bigot was ill for a while. The international ITER organization announced his death.

Nuclear fusion can be harnessed as a source of power. ITER will use magnetic fields to trap a superhot plasma of deuterium and tritium so their nuclei can fusion to produce helium and release energy. ITER wants to prove that a tokamak can produce 10 times more energy than is needed.

The experiment has been more expensive than anticipated. In 2006 the European Union, China, India, Japan, Russia, South Korea, and United States agreed to build the giant machine, which was projected to cost about $6.5 billion and start running in 2020. ITER won't run with both deuterium and tritium and try to achieve its key energy goal until at least 2035. The US contribution alone is projected to cost between $4.7 billion and $6.5 billion, according to the ITER organization.

ITER's survival was threatened a decade ago by cost increases. The appropriations committee tried to kill the U.S. ITER program. Bigot was brought in by the ITER board after a bad management review. Cowley, who led the United Kingdom Atomic Energy Authority from 2009 to 2015, says that Bigot was instrumental in bringing the project to France.

Bigot turned ITER around despite some expectations. Observers say that his signal achievement was to transform what member nations were treating as a boondoggle for their domestic industries into a real science project. Cowley says that prior to Bigot's arrival, an industrial stimulation program was in place. Madia says Bigot brought a commitment to set hard goals and timelines.

On 10 May, ITER announced that workers had fitted the first section of the massive toroidal vacuum chamber into place, and that the first stage of the project is now more than 75% complete. Cowley says Bigot turned around a poor work culture and turned it into something that people were proud of. The project faces challenges. France's Nuclear Safety Authority put a hold on work at the ITER site until workers resolve safety issues.

Madia says Bigot was like Jimmy Stewart, the 20th century American movie star known for his folksy decency.

It is going to be difficult to find a replacement for Bigot. He says that ITER will survive without Bigot.

Cowley says it is a shame that the man who probably gave the most to the project won't be there.