Escape Velocity Calculator

What It Does

The Escape Velocity Calculator computes the minimum velocity required to escape the gravitational influence of a central body from a given altitude, using v_esc = √(2μ/r). It also computes the hyperbolic excess velocity (v∞) needed to reach a target arrival velocity, which is the natural input for interplanetary trajectory design. Central body presets cover Earth, Moon, Mars, Venus, Mercury, Sun, and Jupiter.

Key Features

• Escape velocity from any altitude above any supported central body
• Hyperbolic excess velocity (v∞) computation for interplanetary trajectories
• Delta-V from circular orbit to escape (the actually-relevant number)
• Central body presets plus custom μ for asteroids and moons

Why It Matters

Escape velocity is the boundary between bound and unbound orbits and the starting point for every interplanetary mission. A spacecraft leaving LEO needs about 11.2 km/s to escape Earth — but only about 3.2 km/s above its current circular speed, which is what actually drives the propulsion sizing. Confusing these two numbers causes some of the most common back-of-envelope errors in early mission planning. The calculator separates them clearly so you trade against the right one.

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