The planet with an orbital speed of approximately 30 kilometers per second is Earth.

Here's why:

* Earth's orbital speed varies slightly throughout its orbit, but it averages around 29.78 km/s. This is close enough to 30 km/s to be considered a reasonable approximation.

* Other planets have different orbital speeds: For example, Mercury, being closer to the Sun, orbits much faster, while Mars, farther away, orbits slower.

Let me know if you'd like to know the orbital speeds of other planets!