I Rip Foster rider den gråa planeten av Harold L. Goodwin (aka Blake Savage) 1952 använder rymdkryssaren Scorpius metan för bränsle. Kaptenen, som inte tycker om planeterare (läs Marines), detaljer Foster's män rensar ut de (radioaktiva) kolförlusterna som finns kvar i cruiserens avgasrör.
"Foster, the designation SCN means Space Cruiser, Nuclear. This ship is powered by a nuclear reactor. In other words, an atomic pile. You've heard of one?"
Rip controlled his voice, but his red hair stood on end with anger. O'Brine was being deliberately insulting. This was stuff any new Planeteer recruit knew. "I've heard, sir."
"Fine. It's more than I had expected. Well, Foster, a nuclear reactor produces heat. Great heat. We use that heat to turn a chemical called methane into its component parts. Methane is known as marsh gas, Foster. I wouldn't expect a Planeteer to know that. It is composed of carbon and hydrogen. When we pump it into the heat coils of the reactor, it breaks down and creates a gas that burns and drives[pg 034] us through space. But that isn't all it does."
The gases go through tubes," O'Brine went on. "A little nuclear material also leaks into the tubes. The tubes get coated with carbon, Foster. They also get coated with nuclear fuel. We use thorium. Thorium is radioactive. I won't give you a lecture on radioactivity, Foster. But thorium mostly gives off the kind of radiation known as alpha particles. Alpha is not dangerous unless breathed or eaten. It won't go through clothes or skin. But when mixed with fine carbon, thorium alpha contamination makes a mess. It's a dirty mess, Foster. So dirty that I don't want my spacemen to fool with it.
"I want you to take care of it instead," O'Brine said. "You and your men. The deputy commander will assign you to a squadroom. Settle in, then draw equipment from the supply room and get going. When I want to talk to you again, I'll call for you. Now blast off, Lieutenant, and rake that radiation.[pg 035] Rake it clean."
Rip forced a bright and friendly smile. "Yes, sir," he said sweetly. "We'll rake it so clean you can see your face in it, sir." He paused, then added politely, "If you don't mind looking at your face, sir—to see how clean the tubes are, I mean."