Which factor is not needed when calculating the velocity of a satellite orbiting a planet

When calculating the velocity of a satellite orbiting a planet, the factor that is **not needed** is the mass of the satellite itself.

The orbital velocity can be determined using the formula:

\[ v = \sqrt{\frac{GM}{r}} \]

where:
- \( v \) is the orbital velocity,
- \( G \) is the gravitational constant,
- \( M \) is the mass of the planet being orbited, and
- \( r \) is the distance from the center of the planet to the satellite (which includes the planet's radius plus the altitude of the satellite).

As you can see, the mass of the satellite does not appear in the equation, so it does not affect the calculation of its orbital velocity.