I just found out from watching another Gerry Anderson YouTube video on the changes between the first and second season of Space: 1999 that Fred Freiberger was a writer/producer on the later seasons of 'Ironside' and it was after this show was canceled that he was approached by Gerry Anderson to help revamp/helm Space: 1999. So, I guess we have 'Ironside's' cancelation to blame for freeing up Freiberger to work his magic on Space: 1999.