Actually the so called knockoff came straight from the original NASA files that were in the National Library. Since NASA is a public domain organisation, the files were not flagged as confidential. Russians were able to take copies of those files pretty easily. When NASA found out what was going on they made slight changes to the original files, e.g. the tiles that protect the vehicle during re-entry were left with with the early versions. You can find more about this on the internet but here's a link https://www.nbcnews.com/id/wbna18686550
duckdodgers4 t1_j4xjgb3 wrote
Reply to comment by dbx999 in Does anyone have information about Russian space SHUTTLES? just saw a post with a picture of it, didn’t know they existed! by freeastronaut2100
Actually the so called knockoff came straight from the original NASA files that were in the National Library. Since NASA is a public domain organisation, the files were not flagged as confidential. Russians were able to take copies of those files pretty easily. When NASA found out what was going on they made slight changes to the original files, e.g. the tiles that protect the vehicle during re-entry were left with with the early versions. You can find more about this on the internet but here's a link https://www.nbcnews.com/id/wbna18686550