There was an eruption of rocket fumes from the side of the Platform. Something went foaming away toward Earth. It dwindled with incredible rapidity. Then Joe said:
"Chief, I think we'd better go down and meet that rocket. We'll learn to handle these wagons on the way. I think we're going to have a fight on our hands. Whoever's in that rocket isn't coming up just to shake hands with us."
He steadied the small red vehicle and pointed it for Earth. He added:
"I'm firing a six-two solid-fuel job, Chief. Counting three. Three—two—one."
His mount vanished in rocket fumes. But after six seconds at two gravities acceleration the rocket burned out. The Chief had fired a matching rocket. They were miles apart, but speeding Earthward on very nearly identical courses.
The Platform grew smaller. That was their only proof of motion.
A very, very long time passed. The Chief fired his steering rockets to bring him closer to Joe. It did not work. He had to aim for Joe and fire a blast to move noticeably nearer. Presently he would have to blast again to keep from passing.
Joe made calculations in his head. He worried. He and the Chief were speeding Earthward—away from the Platform—at more than four miles a minute, but it was not enough. The manned rocket was accelerating at a great deal more than that rate. And if the Platform's enemies down on Earth had sent a manned rocket up to destroy the Platform, the man in it would have ways of defending himself. He would expect guided missiles—but he probably wouldn't expect to be attacked by space wagons.
Joe said suddenly:
"Chief! I'm going to burn a twelve-two. We've got to match velocities coming back. Join me? Three—two—one."