Obviously, we can make rockets go very fast, but what is a reasonable top speed? Assume that a rocket is fired from rest at a space station in deep space, where gravity is negligible. If the rocket ejects gas at a relative speed of 2000 m/s and you want the rocket’s speed eventually to be 1.00×10⁻³ c, where c is the speed of light in a vacuum, what fraction of the initial mass of the rocket and fuel is not fuel?
