Just as the title asks,
How far away can, say, a satellite be and still be in "orbit" ?
How about for a given velocity?
Fun FactsFun Facts
200 miles (320 km) up is about the minimum to avoid atmospheric interference. The Hubble space telescope orbits at an altitude of 380 miles (600 km) or so.
potentially helpful numbers
mass of Earth = 5.97219 × 1024 kilograms
mass of the Moon = 7.34767309 × 1022 kilograms
distance (earth, moon) = 238,900 miles (384,400 km)