premise: A person in full astronaut suit and gear trains in an underwater lab as a scuba diver assists. hypothesis: An astronaut working with an alien to repair a satellite.
contradiction: An scuba diver would not be considered an alien. A satellite is in space, not underwater.|contradiction: A person cannot be training in an underwater lab and repairing a satellite simultaneously.|contradiction: The astronaut cannot be working with a scuba diver who is also an alien as it is almost impossible that both can be the same.