CBS Washington correspondent John Dickerson immediately asked the president if he understood that astronaut Whitson had no control over her weightlessness due to the absence of gravity in space.
I do feel obligated to correct Mr. Dickerson’s suggestion here that there is no gravity in space. There is gravity in space, and in the space station at only just over 100 miles up, it is nearly as strong as the gravity for those of us sitting on Earth.
The astronauts experience the sensation of weightlessness because they are in a state perpetual state of free fall as the space station continuously falls around the curve the Earth. The station does that because the combination of speed pulling it away (centrifugal force) is in perfect balance with the force of gravity pulling it towards the Earth (centripetal force).