Horizontal velocity does not prevent an object from falling or keep it in the air any longer








However, since the earth is not flat, a very large horizontal velocity would allow an object to travel so far horizontally that it would fall over the horizon, and stay in the air longer.


With enough horizontal velocity, an object would keep missing the earth and fall forever, never hitting the ground unless something took away its horizontal velocity.  This is how objects are put into orbit.













Air friction takes horizontal velocity away from objects, so if  you want something to orbit, you need to get out of the atmosphere.


Satellites are sent into space because there is no air friction there to rob them of their horizontal velocity, not because gravity is weaker.


If you took away the moon’s horizontal velocity, it would fall straight to earth.  But since there is no friction in space, it will not loose its horizontal velocity, and it will orbit forever.


Spaceships in orbit do not have to fire their engines to remain in orbit, they simply fall – around the earth.


The closer a satellite is to earth, the faster it will orbit.


John Glenn was the first American to orbit the earth.  It took his ship 88 minutes to complete one orbit.  He orbited at an altitude between 100 and  160 miles up, at a  velocity of 17,000 mi/hr.


By contrast, the moon orbits at an altitude of 240,000 miles at a velocity of  2,300 mi/hr and takes 27.3 days to complete one orbit.


Geosynchronous orbit occurs when a satellite takes exactly one day to orbit the earth.  This can only occur if the satellite is at an altitude of 35,786 km (22,241 miles) and traveling at a velocity of 7,000 mi/hr.