Complex sentence: Though she co-authored 26 scientific papers, The practice in 1960 would have been not to list the female contributors as formal co-authors, so that she was listed as an author in a peer-reviewed NASA report is significant.
Split into simpler sentences: Though she co-authored 26 scientific papers, the practice in 1960 was to not list the female contributors as formal co-authors. Thus, the fact that she was listed as an author in a peer-reviewed NASA report is significant.