We did some tests on him. We don't know that he won't get sick in space"But he's our command module pilot," said Jim. "He has to go. Fred and I worked with him in the simulator" "I know," said the doctor."I'm sorry Jim went to the mission controllers ofice. His boss was at his desk"The doctor says that Ken Mattingly can't fly with us," said Jim. "What does this mean?" "What does it mean? You know the answer to that question. We have a big problem answered his boss. "But he has to go said Jim."There are only two days before Apollo 13 leaves. We can't go without Ken. "Ken can't go," said his boss Jack Swigert will have to be the command module pilot.'' Jim thought about Jack Swigert. He didn't know Jack as well as Ken. "Jack Swigert is a good pilot, said the mission controller."He can fly the command module, and he's ready.