They were rocket-trails from target-seeking missiles which had reached the area of the north magnetic pole by herculean effort and were aimed at the radar-detected little ship by the heavy planes that carried them.
From the surface of the Earth, it would have seemed that monstrous columns of foaming white appeared and rose with incredible swiftness toward the heavens. They reached on, up and up and up, seeming to draw closer together as they became smaller in the distance, until all eight of them seemed to merge into a single point of infinite whiteness in the sunshine above the world's blanket of air.
But nothing happened. Nothing. The ship did not accelerate as fast as the rockets, but it had started first and it kept up longer. It went scuttling away to emptiness and the bottoms of the towers of rocket-smoke drifted away and away over the barren landscape all covered with ice and snow.
When Earth looked like a huge round ball that did not even seem very near, with a night side that was like a curious black chasm among the stars, the atmosphere of tension inside the ship diminished. Keller completed his wiring of a ship-to-ground transmitter. He stood up, brushed off his hands and beamed.
The little ship continued on. Its temperature remained constant. The air in it smelled of growing green stuff. It was moist. It was warm. Keller turned a knob and a tiny, beeping noise could be heard. Dials pointed, precisely.
"We couldn't go on our true course earlier," Burke told Sandy, "because we had to get out beyond the Van Allen bands of cosmic particles in orbit around the world. Pretty deadly stuff, that radiation! In theory, though, all we have to do now is swing onto our proper course and follow those beepings home. We ought to be in harmless emptiness here. Do you want to call Washington?"
She stared.
"We need help to navigate—or astrogate," said Burke. "Call them, Sandy. I'll get on the wire when a general answers."
Sandy went jerkily to the transmitter just connected. She began to speak steadily, "Calling Earth! Calling Earth! The spaceship you just shot all those rockets at is calling! Calling Earth!"
It grew monotonous, but eventually a suspicious voice demanded further identification.