https://www.nasa.gov/mission_pages/station/research/benefits...Sounds like in most cases the satellites don't have any propulsion of their own, and are "ejected" onto their orbit from the ISS. Put simply, they get thrown out.
I'm sure some checks are done of the orbital mechanics to avoid any risk of a later collission, but keep in mind that the ISS makes frequent course corrections to stay in orbit, and at this low of an orbit drag is also a factor, so simply being a smaller craft will cause different forces to push you onto a different path.
Obviously this means you have very little choice in your orbit, but for many small satellites this isn't a concern.
EDIT: To answer your "use it as a garage" point, the answer is that it's way too impractical. In orbital mechanics, drifting apart from something is far easier than getting closer to it, and space is really, really big. Plus keep in mind that you need to not only be in the same place at the same time, but you also need to be moving at the same speed (relative velocities in LEO can quickly reach the order of kilometers per second).
Sounds like in most cases the satellites don't have any propulsion of their own, and are "ejected" onto their orbit from the ISS. Put simply, they get thrown out.
I'm sure some checks are done of the orbital mechanics to avoid any risk of a later collission, but keep in mind that the ISS makes frequent course corrections to stay in orbit, and at this low of an orbit drag is also a factor, so simply being a smaller craft will cause different forces to push you onto a different path.
Obviously this means you have very little choice in your orbit, but for many small satellites this isn't a concern.
EDIT: To answer your "use it as a garage" point, the answer is that it's way too impractical. In orbital mechanics, drifting apart from something is far easier than getting closer to it, and space is really, really big. Plus keep in mind that you need to not only be in the same place at the same time, but you also need to be moving at the same speed (relative velocities in LEO can quickly reach the order of kilometers per second).