Joe made his face go completely expressionless. There was nothing else to do. Sally hadn't said that his chances looked bad for making the crew of the Platform when it went out to space. But Sally had ways of knowing things. She would be sure to keep informed on a matter like that, because she was wearing Joe's ring and it would have taken a great deal of discouragement to keep her from finding out good news to tell him. She didn't have any good news. So it must be bad.
Joe drank his coffee, trying to make himself believe that he'd known all along he wasn't going to make the crew. He'd started late to learn the things a crew member ought to know. He'd stopped at the most crucial part of his training to work on the gyros, which were more crucial still. He'd slept a day and a half. The platform would take off in forty–eight hours. He tried to reason carefully that it was common sense to use a man who was fully trained from the beginning for a place in the crew, rather than a latecomer like himself. But it wasn't easy to take.
Mike the midget said suddenly: "I got a hunch."
"Shoot it," said the Chief, amiably.
"I got a hunch I know what kind of sabotage will be tried next—and when," said Mike.
The others looked at him—all but Joe, who stared at the wall.
"There hasn't been one set of guys trying to smash the Platform," said Mike excitedly. "There's been four or five. Joe found a gang sabotaging the pushpots that didn't think like the gang that blackmailed Braun. And the gang that tried to kill us up at Red Canyon may be another. There could be others: fascists and commies and nationalists and crackpots of all kinds. And they all know they've got to work fast, even if they have to help each other. Get it?"
Haney growled.
"I'll buy what you've said so far," said the Chief. "Sure! Those so–and–sos will all pile in everything they got at the last minute. They'll even pull together to smash the Platform—and then double–cross each other afterward. But what'll they do, an' when?"
"This time they'll try outright violence," said Mike coldly, "instead of sneaking. They'll try something really rough. For sneaking, one time's as good as another, but for really rough stuff, there's just one time when the Platform hasn't got plenty of guys around ready to fight for it."
The Chief whistled softly.
"You mean change–shift time! Which one?"
"The first one possible," said Mike briefly. "After every shift, things will get tighter. So my guess is the next shift, if they can. And if one gang starts something, the others will have to jump right in. You see?"
That made sense. One attempt at actual violence, defeated, would create a rigidity of defense that would make others impossible. If a successful attempt at violent sabotage was to be made, the efforts of all groups would have to be timed to the first, or abandoned.
"I could—uh—set up a sort of smoke screen," said Mike. "We'll fake we're going to smash something—and let those saboteurs find it out. They'll see it as a chance to do their stuff with us to run interference for them.—Sally, does your father sure–enough trust us?"
Sally nodded.
"He doesn't talk very cordially, but he trusts you."
"Okay," said Mike. "You tell him, private, that I'm setting up something tricky. He can laugh off anything his security guys report that I'm mixed up in. Joe'll see that he gets the whole picture beforehand. But he ain't to tell anybody—not anybody—that something is getting framed up. Right?"
"I'll ask him," said Sally. "He is pretty desperate. He's sure some last–minute frantic assault on the Platform will be made. But―"
"We'll tip him in plenty of time," said Mike with authority. "In time for him to play along, but not for a leak to spoil things. Okay?"
"I'll make the bargain," Sally assured him, "if it can be made."
Mike nodded. He drained his coffee cup and slipped down from his chair.
"Come on, Chief! C'mon, Haney!"
He led them out of the room.
Joe fiddled with his spoon a moment, and then said: "The crewman I was to have subbed for if he didn't get well—he did, didn't he?"
Sally answered reluctantly: "Y–yes."
Joe said measuredly: "Well, then—that's that! I guess it will be all right for me to stick around and watch the take–off?"
Sally's eyes were misty.
"Of course it will, Joe! I'm so sorry!"
Joe grinned, but even to himself his face seemed like a mask.
"Into each life some rain must fall. Let's go out and see what's been accomplished since I went to sleep. All right?"
They went out of the Platform together. And as soon as they reached the floor of the Shed it was plain that the stage had been set for stirring events.
The top five or six levels of scaffolding had already been removed, and more of the girders and pipes were coming down in bundles on lines from giraffelike cranes. There were some new–type trucks in view, too, giants of the kind that carry ready–mixed concrete through city streets. They were pouring a doughy white paste into huge buckets that carried it aloft, where it vanished into the mouths of tubes that seemed to replace the scaffolding along the Platform's sides.
"Lining the rockets," said Sally in a subdued voice.
Joe watched. He knew about this, too. It had been controversial for a time. After the pushpots and their jatos had served as the first two stages of a multiple–rocket aggregation, the Platform carried rocket fuel as the third stage. But the Platform was a highly special ballistic problem. It would take off almost horizontally—a great advantage in fueling matters. This was practical simply because the Platform could be lifted far beyond effective air resistance, and already have considerable speed before its own rockets flared.
Moreover, it was not a space ship in the sense of needing rockets for landing purposes. It wouldn't land. Not ever. And again there was the fact that men would be riding in it. That ruled out the use of eight– and ten– and fifteen–gravity acceleration. It had to make use of a long period of relatively slow acceleration rather than a brief terrific surge of power. So its very special rockets had been designed as the answer.
They were solid–fuel rockets, though solid fuels had been long abandoned for long–range missiles. But they were entirely unlike other solid–fuel drives. The pasty white compound being hauled aloft was a self–setting refractory compound with which the rocket tubes would be lined, with the solid fuel filling the center. The tubes themselves were thin steel—absurdly thin—but wound with wire under tension to provide strength against bursting, like old–fashioned rifle cannon.
When the fuel was fired, it would be at the muzzle end of the rocket tube, and the fuel would burn forward at so many inches per second. The refractory lining would resist the rocket blast for a certain time and then crumble away. Crumbling, the refractory particles would be hurled astern and so serve as reaction mass. When the steel outer tubes were exposed, they would melt and be additional reaction mass.
In effect, as the rocket fuel was exhausted, the tubes that contained it dissolved into their own blast and added to the accelerating thrust, even as they diminished the amount of mass to be accelerated. Then the quantity of fuel burned could diminish—the tubes could grow smaller—so the rate of speed gain would remain constant. Under the highly special conditions of this particular occasion, there was a notable gain in efficiency over a liquid–fuel rocket design. For one item, the Platform would certainly have no use for fuel pumps and fuel tanks once it was in its orbit. In this way, it wouldn't have them. Their equivalent in mass would have been used to gain velocity. And when the Platform finally rode in space, it would have expended every ounce of the driving apparatus used to get it there.
Now the rocket tubes were being lined and loaded. The time to take–off was growing short indeed.