The remaining time passed quickly. The sun receded.[pg 244] The Planeteers corrected course. Rip sent in his recommendations for promotions, and looked over the last nuclear crater to see why the blast had started the asteroid spinning.
The reason could only be guessed. The blast probably had opened a fault in the crystal, allowing the explosion to escape partially in the wrong direction.
Once the course was corrected, Rip calculated the position for the final nuclear charge. When the asteroid reached the correct position relative to earth, the charge would not only change its course but slow its speed somewhat. The asteroid would go around the earth in a series of ever-tightening ellipses, using Terra's gravity, plus rocket fuel, to slow it down to the right orbital speed.
When it reached the proper position, tubes of rocket fuel would change the course again, putting it into an orbit around the earth close to the space platform. It wasn't practical to take the thorium rock in for a landing. They would lose control and the asteroid would flame to earth like the greatest meteor ever to hit the planet.
Putting the asteroid into an orbit around earth was actually the most delicate part of the whole trip, but Rip wasn't worried. He had the facilities of Terra base within easy reach by communicator. He dictated his data and let them do the mathematics on the giant electronic computers.
He and his men rode the gray planet past the[pg 245] moon, so close they could almost see the Planeteer Lunar base, circled Terra in a series of ellipses, and finally blasted the asteroid into its final orbit within sight of the space platform.
Landing craft and snapper-boats swarmed to meet them and within an hour after their arrival the Planeteers were surrounded by spacemen, cadets from the platform, and officers and men wearing Planeteer black.
A cadet approached Rip and looked at him with awe. "Sir, I don't know how you ever did it!"
And Rip, his eyes on the great curve of earth, answered casually, "There's one thing every space-chick has to learn if he's going to be a Planeteer. There's always a way to do anything. To be a Planeteer you have to be able to figure out the way."
A new voice said, "Now that's real wisdom!"