This makes me want to build model rockets again..
If you need FOSS app for design & simulate model rockets -- use OpenRocket.[0,1,2]
There are many tutorials on YouTube.[3,4,5,6,7]
[0] http://openrocket.info
[1] https://github.com/openrocket/openrocket
[2] https://sourceforge.net/projects/openrocket
[3] https://www.youtube.com/watch?v=JCU8QRVkdYQ
[4] https://www.youtube.com/watch?v=1pp-mVTBd14
[5] https://www.youtube.com/channel/UCIUaeJ7GV_WPTp26NIkg4rg
[6] http://www.youtube.com/watch?v=egHbZUEr_Co
[7] https://www.youtube.com/channel/UCeWSz41c1ic4pBmUIiZQsTQ
This makes me want to build model rockets again..