Most rocket launches are watched on the way up. Engines ignite, the vehicle climbs through the atmosphere, and its stages separate as it heads toward space.

But for reusable rockets and spacecraft, reaching space is only one part of the mission. They must also find a way back to Earth.

The return is far more complicated than simply falling from the sky. The vehicle has to reduce its speed, survive the heat of re-entry, and remain stable as it descends. 

Depending on its design, it may then use engines, parachutes, or wings to complete the landing. That journey begins by establishing a controlled path back toward the planet.

A spacecraft remains in orbit not because it has escaped Earth’s gravity, but because it is moving sideways fast enough to keep falling around the planet. To come home, it must first slow down.

The spacecraft performs a deorbit burn by firing its engines against its direction of travel. This slows it enough to lower its orbit and enter the upper atmosphere, where drag further reduces its speed.

Reusable rocket boosters follow a different path because they usually separate from the vehicle before reaching orbit. 

After separation, a booster may perform a boost-back burn to reverse part of its trajectory and head toward land. Alternatively, it can continue downrange toward a landing platform at sea.

The booster then fires its engines again during its descent. These burns help control its speed and position it for the final approach.

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