The federal agency has a broad mandate to protect Americans’ health and an expansive global reach. But the COVID-19 pandemic has been one of its most daunting challenges.

Recent killings by U.S. officers have sparked widespread calls for police reform and an end to systemic racism. Here’s how U.S. policing compares with other countries’ approaches.

The swift development of effective vaccines against COVID-19 was an unprecedented scientific achievement. But production challenges, vaccine nationalism, and new variants have all presented hurdles.

U.S. space exploration inspired a generation of students and innovators, but NASA’s role has diminished, and the number of global space competitors is growing.