sentences:  To sustain the crew, their minds were routinely kept active while asleep using virtual reality "neural stimulation" programs of their own choosing, but Sam's choice of a scenario where he was a police officer c. 2008 was abruptly changed to a 1973 setting by a computer glitch induced by a meteor-storm.The identity of Maya in 2035, however, is left unexplained.In a twist, Gene Hunt in 1973 turns out to be astronaut 'Major Tom' Tyler — Sam's father — in the conclusion.