Patients are like spacecraft that you are attempting to manoeuvre into permanent orbit around Planet Practice.
Approach too quickly and they will crash and burn.
Too slow and they will swing past, simply accelerating towards their next destination.
Too many and they will bump into each other, with potentially disastrous results.
If you judge it just right – angle of approach, altitude, velocity – then they will arrive at a safe height above your planet and circle above for many years, occasionally descending to land and transact business before fly missions and return to orbit.

A successful encounter will prompt a signal from the spacecraft to others of the same ilk, saying “this is a safe place”.

If you are unsuccessful, the signal will be one of warning.
You are mission control.
Make sure your team are well-trained and experienced pilots and navigators, caring for a beautiful blue and green Gaia, encircled by glistening craft.