"A spaceship,” suggested Greg.
Russ nodded. “That's the only answer."
The two men looked at one another.
"That's something we can get hold of,” said Greg.
He walked to the ship controls and lowered himself into the pilot's chair. A hand came out and hauled back a lever.
The Invincible moved.
From the engine rooms came the whine of the gigantic power plant as it built up and maintained the gravity concentration center suddenly created in front of the ship.
Russ, standing beside Greg at the control panel, looked out into space and marveled. They were flashing through space, their speed building up at a breath-taking rate, yet they had no real propulsion power. The discovery of the gravity concentrator had outdated such a method of driving a spaceship. Instead, they were falling, hurtling downward into the yawning maw of an artificial gravity field. And such a method made for speed, terrible speed.
Jupiter seemed to leap at them. It became a great crimson and yellow ball that filled almost half the vision plate.