Discover why astronauts must pass medical tests, what doctors screen for, and how these exams reduce mission risk in space.

Astronaut sleep in microgravity is surprisingly complex. Here’s how NASA trains crews to rest safely, manage circadian rhythms, and adapt to spaceflight.

Learn why most planets orbit the Sun in the same direction, from protoplanetary disk physics to angular momentum and exceptions.

Learn where dwarf planets belong in the solar system, how astronomers classify them, and why they matter to planetary science.

Discover how astronauts train for confined spaces using simulators, isolation tests, teamwork drills, and emergency procedures.

Astronauts prepare for weightlessness through underwater labs, parabolic flights, simulations, and strength training that reduce risk and build adaptability.

Explore how astronauts prepare for launch pressure through centrifuge training, emergency drills, medical screening, and mindset conditioning.

Learn how the Sun, planets, and Milky Way all move together through space—and why the solar system is never truly still.