Mars' orbital speed is not constant, as its orbit is slightly elliptical. However, we can give you an average orbital speed.

The average orbital speed of Mars is approximately 24.1 kilometers per second (15 miles per second).

Here are some other ways to express this:

* 86,760 kilometers per hour (54,000 miles per hour)

* 23.93 kilometers per second (14.88 miles per second) at its perihelion (closest point to the Sun)

* 21.94 kilometers per second (13.63 miles per second) at its aphelion (farthest point from the Sun)