Orbital Speed and Parking Orbits

Understanding Orbital Speed

Orbital speed is the speed at which a satellite must travel to maintain a stable orbit around a celestial body, like Earth. This speed depends on the altitude of the satellite's orbit.

For a circular orbit, the orbital speed $v$ can be calculated using the formula:

$$v = \sqrt{\frac{GM}{r}}$$

• $G$ is the gravitational constant $(6.674 \times 10^{-11} \text{Nm}^2/\text{kg}^2)$
• $M$ is the mass of the Earth $(5.972 \times 10^{24} \text{kg})$
• $r$ is the distance from the center of the Earth to the satellite

Parking Orbits

A parking orbit is a temporary orbit used by spacecraft before moving to a higher orbit or to another destination. It is often circular and allows for adjustments and checks before proceeding.

Geostationary Orbits

A geostationary orbit is a specific type of parking orbit where a satellite appears to be stationary relative to an observer on Earth. This is achieved by matching the Earth's rotational period.

• Located approximately 35,786 km above the equator.
• Orbital period is 24 hours, matching Earth's rotation.
• Used for communication, weather monitoring, and broadcasting.

Worked Example