Excerpt: 'Joe Kenmore heard the airlock close with a sickening wheeze and then a clank. In desperation he turned toward Haney. 'My God, we've been locked out!' Through the transparent domes of their space helmets, Joe could see a look of horror and disbelief pass across Haney's face. But it was true! Joe and his crew were locked out of the Space Platform. Four thousand miles below circled the Eart...