AN ASTRONAUT IN AN ORBITING SPACECRAFT IS WEIGHTLESS
WRONG!!
WEIGHT is the force with which we are pulled toward the Earth (or whatever the nearest planet is). If an
astronaut and the spacecraft are near the Earth (in orbit) they are pulled towards it (see "centrifugal force") so they have weight.
The astronaut and spacecraft are both "falling" towards the earth together (like a person in a lift if the cable broke), so the astronaut has no force relative to the
spacecraft, so he(she) floats around in it.
The reason the spacecraft and astronaut do not hit the Earth is that they were given a sideways speed which is just right so that as they fall towards the Earth they keep missing it forever!