We've spent hours carefully writing our puzzles to make sure they are challenging but accessible to people of all ages and ...

This crossword is inspired by the August 2025 special digital issue of Scientific American. Play “On the Fly” here.

Shubhanshu Shukla and his fellow astronauts, including veteran Peggy Whitson, have successfully reached the International Space Station as part of the Axiom-4 mission.