Escape velocity
Escape velocity was the minimum velocity needed for a celestial body or other object to escape the gravitional attraction of another body.

This was one of the physical characteristics listed in a celestial body's file. It was measured in kilometer per seconds. ()

After an encounter with a black star in 2267 that sent the  back in time to 1969, warp engines became non-operational so Montgomery Scott overrode the automatic helm setting to hold the ship in orbit of Earth on impulse . However, they were too low in the atmosphere to retain orbit but they did have sufficient impulse power to achieve escape velocity, though obtaining altitude was sluggish. ()

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Physics
Astronomy