Great idea, some story flaws A great sci-fi idea messed up with the evil scientist concept. He told them some would die. OK, he should have said most of you. He told Abi that near death in the desert would be a walk in the park compared to this program. The outrage that participants were dying or "changing into an animal", as Abi put it, was ridiculous. Titan is minus 290 degrees, methane and ammonia. Surely Abi's medical knowledge or to be more realistic, any grade 6 graduate, would imagine that the skin, eyes, orifices in general would have to be wildly different than a human. The idea that the whole family would reunite on Titan was Rick's lie to his son or stupidity. It was pretty clear that not many humans could survive the transition. The new creatures would have to procreate.
They would not have brought families to the facility, only the soldiers, but OK, it was a nice place. Certainly after Rick and Tally turned into Titan fishies, it would be clear that they were not going to be human anymore. Did Abi think she was going to take Titan fishie home to coach scorched earth little league? Surely Rick's discomfort in the earth environment would have quickly escalated to the point he could no longer survive the blistering heat of a 70 degree afternoon and it would be clear to everyone he had to go.
They would not have sent the Titan fishies home to their families 2 days before launch. They would remain in the controlled environment and be given the memory melt as a routine shot. Makes no sense. This wasn't a training mission, it was humanity's last hope.
They would not have killed girl Titan fishie. They would clean up the mess she made of her husband and continue the mission. Species don't tend to survive without a breading pair. And in the last standoff, there was no visible change of heart. Just all of a sudden, everybody goes ahead with the mission that they were willing to die to prevent a minute earlier. So we have one lone male Titan fishie, flying around the ammonia sky, thinking, ... about the family on earth he would never see again?