Mr. Shannon had to put out his hands and feet at the last minute to keep from crashing into the wall of the freighter. Then he pulled himself down to the ground with his safety line. When they saw that their father was unhurt, Sue and Steve began walking toward the ship with careful steps. They heard their dad exclaim, “Mr. Ballinger!” as he walked over to one of the men from the _Pole Star_. “John Shannon!” the man said. It turned out that Mr. Ballinger was the president of the American Space Supply Company and was Mr. Shannon’s boss. Mr. Ballinger explained that the _Pole Star_ was heading for Mars when there was an explosion in the rocket tubes. By landing on Sierra the captain thought there was a better chance of their being found than if they had just kept drifting in space, because all ships knew the path of “The Flying Mountain.” No one had been hurt in the landing and the _Pole Star_ had enough fuel to get the freighter back to Earth. “I don’t know whether I should fire you people or not for risking my good freighter just to save an old codger like me!” the friendly Mr. Ballinger joked. “We almost didn’t,” Steve’s dad reminded him and explained how Sue’s outburst had decided the problem. “You’ve certainly got some smart ones there, John,” Mr. Ballinger said, smiling at Sue and Steve. “Your son has already proved himself a hero before and now it’s Sue. Yes, sir, I sure wish I had a pair like them!” But the twins scarcely heard him. They were thinking that, in spite of the great fun they had had on all their space adventures, how wonderful it was going to be to see Mom again and set foot on the grandest planet in all the Solar System—Earth! _CASTAWAYS IN SPACE_ The two of them had just shoved the supply case against the chute door when the space ship gave an unexpected burst of rocket power, knocking Skip Miller against the release lever. The escape door shot up and a big square of black space opened before the boys’ eyes. Glen Hartzell was stunned to see his friend go spinning down the incline and follow the supply case toward the open door. Automatically, Glen stretched his lean body full length trying to grasp Skip’s space suit before he escaped. But his momentum sent him skidding down the slope and the next thing he knew he was out in space, too. A week ago Glen wouldn’t have cared whether he faced death or not. He and Skip had just made the scorned fraternity of “Wockies,” washed-out cadets. His failure had cut like a knife. He had wanted to pilot ships through the depths of space more than anything else in the world. Instead, he and Skip had been assigned to ground crews on Mars. That, at least, had been their destination until Skip’s elbow unexpectedly made them castaways in space. Glen’s first thought was directed to Skip, who looked like a toy balloon as he drifted through the vacuum. “Skip!” he called over his space suit radio. “Do you hear me, Skip?”