Almost every station on the factory floor of Commonwealth Fusion Systems’ northeast Massachusetts headquarters was bustling on a steamy Friday morning in June. Hard-hatted workers ferried along the components for the company’s first fusion reactor, including giant slabs of magnets that will eventually be joined together in a doughnut-shaped reactor called a tokamak. Construction crews were expanding the facility to make more space for the company, which is racing to be the first private enterprise to prove that nuclear fusion can be a viable source of energy.
And SPARC, the demonstration-scale version of CFS’s larger-scale reactor prototype, was starting to look complete. CFS hasn’t yet claimed to have produced more energy from a fusion reaction than it put in, a milestone that has long eluded public and private fusion efforts. Nevertheless, it says SPARC is on track to start up next year, and the company is confident it will work as planned.
Investors are once again betting big that CFS’s aggressive vision will pan out. On Thursday, the company announced its latest fundraising round — an eye-popping $1 billion. It has now raised a total of $4 billion since it was spun out of the Massachusetts Institute of Technology in 2018.
