I won't argue if anybody says that I think about Toobworld topics way too much. Here's one that actually came to me in a dream and woke me up.....
Barbara Bain was born in 1931, and her character of Cinnamon Carter on 'Mission Impossible' would have been the same age. 'Space: 1999' was set in "the future", and the birth date for her character of Dr. Helena Russell was established on the series as being 1957, which made her 42 at the time of the lunar explosion at the nuclear dump. Had Dr. Helena Russell been the same age as Ms. Bain, she would have been 44 in 1999 (like me).
Here's the Toobworld Central hypothesis - in 1957, Cold War femme fatale Cinnamon Carter gave birth to a daughter out of wedlock. The baby was named Helena, but we don't know what family name she was given. It may be that Cinnamon gave the child up for adoption because her life as a spy made it impossible for her to be a mother as well. But I think Helena was raised by her birth father, a prominent physician.
Helena's last name of Russell was her married name - she had been married to Lee Russell, an astronaut who was missing and presumed dead on the Astro 7 mission to Jupiter.
As to the identity of Helena's father, the lover of Cinnamon Carter? In the script for the episode "Bringers Of Wonder [Part One]", we learned that Helena's father died of a massive coronary while she was a first year intern. As she remembered it, she "was there in the house when happened. I haven't lost many patients, but the first one had to be my father."
(I suppose the temptation would have been to suggest that Cinnamon's IMF partner Rollin Hand could have been the father. But Rollin didn't join the team until shortly before we met him on 'Mission Impossible' in 1966, and before that he wasn't even known as Rollin Hand. Two years before, in April of 1964, he defected to the United States to offer his services to the government. His name was Major Ivan Kochenko and the story of his defection can be found in the 'Twilight Zone' episode "The Jeopardy Room". At least, that's the premise Toobworld Central supports.) My only regret is that Cinnamon Carter's return to the small screen on 'Diagnosis Murder' took place in 1997. She seemed somewhat frail and careworn in the episode "Discards"; and had it taken place in 1999 we might have suggested that her condition was due to the death of her daughter Helena in the lunar explosion.
(In case you didn't know, the lunar explosion of the nuclear waste dumps which kicks off the series 'Space: 1999' was the only thing that actually happened on that show. Everything else - the Moon breaking free of its orbit and the adventures of Moonbase Alpha while hurtling thorugh space - was part of the coma dream playing out in the mind of Commander Koenig, who barely survived the blast. Sadly, Dr. Russell was not one of those who survived.
Incidentally, her character has been described as dour and humourless in the first season of 'Space: 1999', but she became more playful in the second season. I think the change can be ascribed to the type of medications given to Koenig while he was comatose; it altered the landscape of his dream world.)