Energy Secretary Jennifer Granholm is expected to announce a major step forward in nuclear fusion energy on Tuesday.
Why it matters: Decades of effort have gone into fusion energy, which promises almost limitless carbon-free power — without the dangerous waste from traditional fission reactors.
NASA's Orion spacecraft is back on Earth after its flight around the Moon.
Why it matters: The uncrewed capsule's splashdown in the Pacific brings the space agency's first Artemis mission to a successful end, testing out some of the technology needed to one day send people to the surface of the Moon.
