[OSX] KSP Very slow to launch craft or go to tracking station on my large save game

[Void_Pointer]

Hi guys. I am experiencing impossibly slow load times on this save in KSP 1.7.3 on macOS.

I actually took a break from KSP for about a year and I believe I was on 1.4.3 or 1.5 or something.  I loaded up steam today on my new macbook pro and updated KSP to 1.7.3.

My only mod that is installed is KER.  I am posting this to unmodded forum because even with KER uninstalled I get the same behavior.

Sandbox mode or a new game are fine. But this save, with many ships in it and quite an advanced career game is UNBEARABLE to load.  It takes 20 minutes to load the tracking station scene.. and launching a new craft or switching to a craft form the tracking station takes 30-60 minutes!!

I did not have this problem with this savegame on previous KSP versions.

My system specs:

KSP 1.7.3 with Making History DLC
macOS 10.14.6 (Mojave) 
MacBookPro 15" 2019 Model - 32GB RAM, 1TB SSD, 8 core i9 2.4 GHz.

Here is a link to the save file (zipped)

#### Note: on my previous KSP version before the update to 1.7.3 (I think I was on 1.4 or 1.5.. it worked fine!!)

Edited October 5, 2019 by Void_Pointer
Added some formatting