There was no shortage of threats facing Apollo astronauts on missions to the Moon. Like radiation. Specifically, the dense radiation environment of the Van Allen belts that surround our planet.

What are the Van Allen belts? Learn how these giant rings of charged particles cause problems for astronauts and satellites.

No one knew how long the beefed-up radiation belts might persist. Some feared that the increased radiation might last until 1967-1968, when NASA hoped to carry out the first Apollo expedition to ...

The Apollo program encountered many difficulties on its trip to the Moon, ranging from mechanical to astrophysics. The issue of the Van Allen belt and its radioactivity was a particularly serious ...

The Apollo astronauts passed through the belts in less than four hours total for the trip. "It's not much more serious than getting a chest x-ray," said Plait. The Claim: Multiple-angle shadows in ...

At age 42, Lovell was the world's most traveled astronaut when he joined the Apollo 13 mission, with three missions and 572 spaceflight hours under his belt. Lovell participated in Apollo 8 ...