Re: Should NASA turn Voyager I back around?
Posted: Sat Jun 29, 2013 2:36 pmjohn9blue wrote:the awesome thing about satellites is that they keep going when they run out of gas
Only when they are actually in space. A significant number of them do experience small amounts of atmospheric drag.
Even above the Kármán line, significant atmospheric effects such as auroras still occur. Meteors begin to glow in this region though the larger ones may not burn up until they penetrate more deeply. The various layers of Earth's ionosphere, important to HF radio propagation, begin below 100 km and extend beyond 500 km. By comparison, the International Space Station and Space Shuttle typically orbit at 350–400 km, within the F-layer of the ionosphere where they encounter enough atmospheric drag to require reboosts every few months. Depending on solar activity, satellites can experience noticeable atmospheric drag at altitudes as high as 700–800 km.