 Why do the astronouts have to wait to talk to White Sands?
There, high in the emptiness of space, Space Station One swung in its orbit. Once every two hours, the artificial satellite looped completely around the planet, watching what went on below. 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. Why, I wouldn't let you get into an airplane, much less land on Earth in a rocket! The terrible pressure of a rocket landing would increase her effective body weight to nearly half a ton; an adult human being couldn't take that sort of punishment for long, much less the tiny life that was growing within her. And then, only half an hour ago, a meteor had hit the radar room. The self-sealing walls had closed the tiny hole quickly, but even in that short time, a lot of air had gone whistling out into the vacuum of space. "Something wrong, doctor?" "Incubator," he said, without taking his eyes off the clock. But as soon as we get within radio range of White Sands, I'll ask them to send up an emergency rocket with an incubator. 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.
 They have to wait until they are in the right place in orbit to send a signal
 Some of their communication systems are down  They have to wait until they are in the right place in orbit to send a signal  It takes a couple of hours for a signal to get to Earth  They are waiting on a response from the base so they have more information