“Gee, with so many of those things orbiting earth every minute of the day, it seems that space ships are always in danger of hitting one of them,” Patch remarked. “That is a very real danger,” Captain Eaton said, “especially for us, since we usually cruise in that area above earth called the ‘satellite zone.’ For this reason, every person on pilot duty is responsible for knowing the position of every satellite within dangerous range of the _Carefree_. This requires constant study and figuring of orbit paths. It really is the biggest job the pilot has to do, because generally the _Carefree_ is on automatic pilot and runs itself, you might say.” “What are some of these smaller satellites?” Garry asked. “Well, there, there, and there are some of the observation satellites called ‘Tiros.’ They are used to photograph part of the earth for different reasons. Some of the reasons are prediction of weather, mapping, and for military purposes to see that the countries of the world do not start arming themselves for aggression.” “The Tiros moons were first put into orbit in the 1960’s, weren’t they?” Garry asked. Captain Eaton nodded. “Also these, Garry—the Transit satellites, which are used for navigation, both in space and on earth. This odd-looking little moon over here is one I’m sure you’ve heard about. It is WAS, which means weather-alteration satellite. Know what it does?” “Sure,” Garry replied. “It’s used to seed storm clouds with chemicals. If the seeding works, hurricanes and tornadoes can be broken up before they cause damage. I believe they were first put into orbit in the late 1960’s.” “Very good,” the captain complimented. “Of course there are many other kinds of man-made moons, some too technical to explain. But, in spite of their great number and complexity, each has its use, and they are a tribute to man’s great achievements in the world of science. One of our big jobs aboard the _Carefree_ is to see that they remain in orbit, doing their duty for the people of earth. If we should ever change their orbit, for instance by colliding with one of them, we not only would destroy their usefulness but we would, in all likelihood, destroy the _Carefree_ as well.” Garry did not even want to think about the possibility of such a disaster. After the visit to the observatory, the captain asked the boys if they would care to try out the swimming pool. “Hey, would we!” Garry and Patch said together. A few minutes later, as they were heading down the corridor toward the gym, they passed Mr. Klecker walking along stiffly—in full dress of course—and carrying a stack of books. “Hello, gentlemen,” the tall man greeted them cordially, and the boys returned his greeting. As he passed, Patch whispered to Garry, “Bet those books are about the circus.” Garry smiled and nodded.