Kerbal Space Program

This is not a new bug but I did not find it reported here so I decided to retest and report.

It is possible to land multiple ships at once as long as they don't get separated too much but quicksave and quickload in atmosphere below 23 km altitude (on Kerbin) will remove any other ships or pieces of debris except the active ship.

Reproduction:

- load the attached ship and put it on launchpad
- launch the ship and wait until SRBs flameout (about 1 s)
- stage to separate ships from each other
- quicksave while all ships are still flying near each other
- quickload

After quickload, separated ships can be seen flying along for a very short while and then they suddenly disappear.

output_log.txt contains the following messages (in this order):

Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Vessel Formation Ship was on-rails at 91.5 atm pressure and was destroyed.
Unpacking Formation

(note: I then aborted the KSP process so exceptions later in the log may not be related to the bug)

Estimated reason:
Active ship is put to physics mode (and protective "physics bubble" around it is created) only after nearby ships were already removed from the game by standard functionality designed to get rid of uncontrolled reentering debris.