What is meant by escape velocity?

• A. The maximum speed of a spacecraft in orbit
• B. The speed required to leave a celestial body's gravity
• C. The speed of light in a vacuum
• D. The average speed of objects in low Earth orbit

Answer: (B)

Escape velocity is defined as the minimum speed an object must reach in order to break free from the gravitational influence of a celestial body without any additional propulsion. This velocity is crucial for spacecraft that need to leave the surface of a planet or moon and enter outer space. It varies depending on the mass and radius of the celestial body; for instance, Earth’s escape velocity is approximately 11.2 kilometers per second.

This concept is essential in astrodynamics and helps determine the energy needed for space missions. Understanding escape velocity allows engineers and scientists to design spacecraft that can achieve the necessary speed to enter space and overcome a planet’s gravitational pull, thus ensuring successful launches and missions into space.