Tech Billionaires’ Craziest Inventions—And Which Ones Might Actually Save the World (4 of 6)

Bill Gates’s next-gen mini nuclear reactors

Bill Gates co-founded TerraPower, which is building a sodium-cooled fast nuclear reactor called Natrium. The design pairs a smaller, advanced reactor with a molten-salt energy storage system, so the plant can ramp power output up and down to complement wind and solar.

In June 2024, construction began on the first Natrium demonstration plant near Kemmerer, Wyoming. This is the first advanced reactor project in the U.S. to move from design into actual construction. Gates has framed it as a potential tool for decarbonizing the grid while providing reliable baseload power in former coal communities.

Sergey Brin’s giant “airship of the future”

Another Google co-founder, Sergey Brin, is reviving the concept of airships as low-emission cargo and disaster-relief platforms in his LTA (Lighter Than Air) project. Its first baby, “Pathfinder 1,” is a 124-meter helium airship built at NASA’s Moffett Field. In late 2024, LTA confirmed the aircraft’s first free flight at Moffett Field. In May 2025, the airship made its first public flight over the San Francisco Bay Area, showcasing a future where large cargo airships deliver supplies to remote or disaster-stricken regions, using less fuel than conventional aircraft.