Orbital velocity equals escape velocity divided by the square root of two.
For a moment he lay there, rigid, and his eyes stared at death walking up the slope but did not see it.
Then, in a crazy blur of motion, he brought his wrench around, closed it on a nut at one side, and turned.
The right hand air tank unscrewed easily. He held it in his hands, a three foot cylinder, blind while calculation raced through his head. What would the centrifugal and Coriolis forces be? It was the roughest sort of estimate. He had neither time nor data, but—
Lundgard was taking it easy, stopping to examine each patch of shadow thrown by some gaunt crag, each meteor scar where a man might hide. It would take him several minutes to reach the hilltop.
Bo clutched the loosened tank in his arms, throwing one leg around it to make sure, and faced away from Lundgard. He hefted himself, as if his body were a machine he must use. Then, carefully, he jumped off the top of the hill.
It was birdlike, dreamlike, thus to soar noiseless over iron desolation. The sun fell behind him. A spearhead pinnacle clawed after his feet. The Southern Cross flamed in his eyes.
Downward—get rid of that downward component of velocity. He twisted the tank, pointing it toward the surface, and cautiously opened the blow valve with his free hand. Only a moment's exhaust, everything gauged by eye. Did he have an orbit now?
The ground dropped sharply off to infinity, and he saw stars under the keel of the world. He was still going out, away. Maybe he had miscalculated his jump, exceeded escape velocity after all, and was headed for a long cold spin toward Jupiter. It would take all his compressed air to correct such a mistake.
Sweat prickled in his armpits. He locked his teeth and refused to open the valve again.
It was like endless falling, but he couldn't yet be sure if the fall was toward the asteroid or the stars. The rock spun past him. Another face came into view. Yes, by all idiot gods, its gravity was pulling him around!
He skimmed low over the bleakness of it, seeing darkness and starlit death sliding beneath him. Another crag loomed suddenly in his path, and he wondered in a harsh clutch of fear if he was going to crash. Then it ghosted by, a foot from his flying body. He thought he could almost sense the chill of it.
He was a moon now, a satellite skimming low above the airless surface of his own midget world. The fracture plain where Lundgard had shot at him went by, and he braced himself. Up around the tiny planet, and there was the hill he had left, stark against Sagittarius. He saw Lundgard, standing on its heights and looking the way he had gone. Carefully, he aimed the tank and gave himself another small blast to correct his path. There was no noise to betray him, the asteroid was a grave where all sound was long buried and frozen.
He flattened, holding his body parallel to the tank in his arms. One hand still gripped the wrench, the other reached to open the blow valve wide.
The surge almost tore him loose. He had a careening lunatic moment of flight in which the roar of escaping gas boiled through his armor and he clung like a troll to a runaway witch's broom. The sun was blinding on one side of him.
He struck Lundgard with an impact of velocity and inertia which sent him spinning down the hill. Bo hit the ground, recoiled, and sprang after his enemy. Lundgard was still rolling. As Bo approached, he came to a halt, lifted his rifle dazedly, and had it knocked loose with a single blow of the wrench.
Lundgard crawled to his feet while Bo picked up the rifle and threw it off the asteroid. "Why did you do that?"
"I don't know," said Bo. "I should just shoot you down, but I want you to surrender."
Lundgard drew his wrench. "No," he said.
"All right," said Bo. "It won't take long."
When he got up to theSirius, using a tank Lundgard would never need, Valeria had armed herself with a kitchen knife. "It wouldn't have done much good," he said when he came through the airlock. She fell into his arms, sobbing, and he tried to comfort her. "It's all over. All taken care of. We can go home now."
He himself was badly in need of consolation. The inquiry on Earth would clear him, of course, but he would always have to live with the memory of a man stretched dead under a wintery sky. He went aft and replaced the links. When he came back, Valeria had recovered herself, but as she watched his methodical preparations and listened to what he had to tell, there was that in her eyes which he hardly dared believe.
Not him. Not a big dumb slob like him.