Flying in space is a hugely misunderstood phenomenon. When asked why astronauts float around their spacecraft, most people reply that there is no gravity in space. The truth is that gravity reigns throughout the universe.
If you give a football a good kick or throw a tennis ball across a room, then what you are doing is no different to what NASA did to the Apollo 11 spacecraft. All were given a short push then left to coast on a long flight path known as a ballistic trajectory. Ignoring air resistance, the path taken by these objects depends to a large extent on the gravity field through which they travel.
Another example of a ballistic trajectory is when something is let go from a height. Imagine a lift cage in which the cable breaks. (Not something you would want to experience in real life but it serves to illustrate the point.) For the few seconds that the lift descends in freefall, all the people and objects in the lift appear to float like astronauts. Indeed, the comparison is exact. Astronauts float around only because they are falling. There is a great deal of truth in the line from the movie ‘Toy Story’ after Buzz Lightyear flies around the room; “That’s not flying. It’s falling, with style!”
