CanX-6 as well as other satellites stay in orbit for a set
amount of time. Earth's gravitational pull is always pulling on
this constantly slowly bringing it down closer towards earth.
Eventually it becomes so low that is will burn up in the atmosphere
since it is no longer has the shielding from the payload that
brought it up into space in the first place. The higher the orbit
the longer that it will stay in orbit. For instance a cubesat
(nanosatellite-this is one to my knowledge) at a 1000 km above
Earth will stay in orbit for roughly 2000 years. However if you go
to just a few 100 km above Earth then it can deobit in a matter of
weeks. Company's are currently working on projects to make them
deorbit sooner with many different devices (i.e. :tether's,
propulsion etc.) as well as make them stay in orbit/transfer to
different orbits with mutliple technologies. I hope this helps with
the question and sorry if I went to indepth. The bottom line is it
is constantly deorbiting and only large satellites really use
propulsion to keep them up (i.e. the space station) but the orbit
and mass play heavily into it.
I know this because this is what I do at work.
