 Why can't Lieutenant Britton go back to Earth?
Outside its bright steel hull was the silence of the interplanetary vacuum; inside, in the hospital ward, Lieutenant Alice Britton clutched at the sheets of her bed in pain, then relaxed as it faded away. "Lieutenant Britton, it is my personal opinion that you need your head examined, and not by a general practitioner, either! It will be at least three hours before they can get a ship up here. Major Banes was in the Communications Center a full five minutes before the coastline of California appeared on the curved horizon of the globe beneath them.
 The G-forces the body is subjected to during space travel would affect the fetus.
 There are no ships available to go to Earth at this time.  There is no one else trained to replace her as Chief Radar Technician on the space station.  The replacement Radar Technician was killed in a car wreck on his way to White Sands. A new technician will have to be trained.  The G-forces the body is subjected to during space travel would affect the fetus.