Re: In a rocket that doesn't reach escape velocity, eg, 200km/ h, what happens?

Hello, Robert.

Once enough speed has been imparted to an object, it will escape the 
gravitational pull of the earth.  Escape velocity is defined as the speed 
necessary to escape the earth's pull, assuming that the object has no 
thrust of its own.  In other words, if I fire a bullet straight up out of a 
gun, and that bullet leaves the barrel at 12 kilometers per second, it will 
never fall back to the earth.

Unlike a bullet, a rocket has its own thrust.  Even if it is only moving at 
one kilometer per hour, it will eventually get far enough in space 
that if you shut off the thrust, it won't fall back to earth.

Here's one more point for you to consider.  A rocket coasting in space, 
using no thrust at all, has a constant speed.  Nothing speeds it up, 
nothing slows it down.  A rocket that is continually thrusting forward, 
with unlimited fuel, is constantly accelerating.  The longer it thrusts, 
the faster it goes.  Even if the acceleration was only 1 meter per second, 
after 35 days of constant thrust the rocket would reach the speed of light.

I hope this answers your question,

Layne Johnson