I think that if whoever owns the Space1999 trademark is unhappy, let them complain, otherwise let it rest. This is a trademark issue not a copyright issue. Also, AFAIK, trademarks expire a lot sooner than copyright, so Space1999 may not even be a live trademark any more. There is a searchable database of US registered trademarks, live and dead, so you can check if you're really interested. (I'm not.)