Part 3 — The Slingshot

What you're seeing

Orion arrives from Earth (left side) heading toward the Moon. As it gets close, the Moon's gravity grabs it and bends the trajectory.

The closer Orion passes, the sharper the bend. Think of it like rolling a ball past a drain — the closer to the drain, the more the ball curves toward it.

At the right distance, gravity bends the path just enough to loop around the far side of the Moon and redirect Orion back toward Earth. This is the free-return trajectory — the most elegant safety net in spaceflight.

If every engine on Orion fails after the TLI burn, the crew still comes home. The Moon does all the steering.

Artemis II: The flyby distance was chosen to be approximately 8,890 km above the Moon's surface — precisely calculated to produce the right deflection angle. This sends Orion on a path whose return trajectory lines up exactly with Earth's atmosphere. Apollo 13's crew survived because this same principle brought them home when their engines were crippled.