"Can't they get out?"
"Oh yes, if the skipper loses his nerve. Otherwise not."
Olga clenched her fists. "Why must you do that? It isn't human."
Joe fixed her with a sardonic eye. "Sister, if they can't stand that, what chance have they got in space?"
"Why go out in space? Isn't the earth big enough?"
Joe turned his attention back to Perry. "You can't make a man permanently contented in a nice, pretty, upholstered civilization. We've got to, that's all. There's something out there to be seen, and we're gonna have a look." Perry nodded. Olga held her peace. "But these babies here are what we're working on. Messenger rockets." He indicated a number of metal bodies roughly cylindroconical in shape. "These are rejected models but they look a lot like ones we've tried. One like this fellow got into a permanent orbit, we think. At least the data showed it making nearly five kilometers when it left."
Olga's lips moved. "That doesn't seem fast; three hundred kilometers per hour."
"Not three hundred; eighteen thousand. It was going five kilometers per second. That ain't enough though. We need a speed of eleven point three kilometers per second to break out of the earth's field entirely."
"That applies to shots rather than rockets, doesn't it?"
"That's right. You know something about ballistics, don't you, bud ? Any speed at all will do as long as our accelerating force is greater than gravitational force. The distances are enormous though. Without pretty heavy acceleration you'd grow old waiting to get there."
"Not from here to the moon, surely."
"Oh, no. That's no distance. But if we get there, we'll establish a base there and try some long hops. In a thin gravity field like the moon's we ought to be able to take off for any planet in the system."
"How much acceleration do you figure on using?"
"Two g's is about all that's healthy. I've taken that for ten hours in the centrifuge, but then I'm husky. It's uncomfortable though, and it made me sick to my stomach at first. Of course we can take as high as six or seven g's for a short time in a good corset and braces and a water cushion. I pass out at about five and half."
"What's a 'g'?" Olga whispered to Perry.
"Force of gravity at earth seal level. At two g's you'd feel twice as heavy as you do now."
"Now see this baby," continued Joe, indicating a silver grey torpedo-like body about ten feet long. "We've sent off eight like it towards old Luna. Her pay load is a lot of magnesium ribbon to make a flare. One of 'em got across, at least Flagstaff reported a spark in Mare Imbrium. Pick it up." Perry stooped over and prepared to heave. It came up lightly and he almost fell over backwards. "Light, ain't it? It's a tungsten aluminum alloy, lighter than potassium. Inert, too."
"I should think it would be porous," Perry commented.
"It is, but it's got a mirror surface inside about two molecules thick that would stop the breath of scandal. The only hard metal in it otherwise is the jets themselves."
"Look here," put in Olga, "If you've got a little one across, why not build a bigger one and ride it over?"
"Well, you see all this little fellow has to do is to climb up to the change over point—that's where the attraction of the moon and the earth are equal—then fall down. To get to the moon and back means to climb up, then climb down to the moon, using rocket fuel to break your fall, then climb up again and climb back down to earth again, four stages. We can't do that yet. But we do think that we are well on the way to building one that will do two of those stages; go up, swing in an orbit around the moon, then climb back down to earth again. That's what Vivian, the girl you saw in the lobby, is working on. She's going to ride the ground tests on some new fuel."
"What do the ground tests amount to?"
"They are the nearest thing to flight conditions we can manage on the ground. This stuff has been laboratory tested, and fired in ground jets, and a rocket designed for it which should be strong enough and light enough to do the trick. Today it is tested in a dummy rocket with a full control panel and full size jets, but the whole framework is tied down solid. The rocket reaction produces stress and strain instead of acceleration. We measure the stresses by instrument. If it all checks out the way it should, we'll try the real rocket in flight."
Olga interrupted. "If you've made all those preliminary tests, what can you learn by running a rocket that is tied down? You already have the data on what it will do."
Joe shook his head. "No, not quite. We know what we think it ought to do, but we knew that when the equations of synthesis were for it. But this stuff is all new. Suppose it does something different? We've got to know before a ship leaves the ground."
Perry put in a word. "Why is this girl Vivian running the tests? Isn't it a man's job?"
"It's her right to. She's the molecular synthesist who designed the fuel. This is as far as she can take it though, as she's not a rocket pilot."
A siren howled mournfully from outside the building. Joe moved toward the door. "Come along if you want to see it." They followed him back through the corridor, through the entrance hall and up a spiral staircase which gave into a small observation room. On the side toward the field was a wide shallow window of amber glass. Several persons who were lined up along this window made room for them. Joe spoke to one of the spectators. "How soon do they start?"
"Any minute now. There goes Vivian." Perry looked down and saw a small figure, bunchy in coveralls, climb a ladder to a manhole in the top of a stubby metal shape. The figure hesitated halfway in and turned its helmeted head toward the building. Perry thought he could detect the flash of a smile. An arm waved and the figure disappeared. The manhole cover closed into place from the inside, made a quarter turn and stopped. For a moment all was still in the room and nothing moved on the field. Perry could hear Olga's quick breathing at his ear. Then a little burst of violet flame showed from the stern of the test rocket. Somebody said "There she goes!" and the tension relaxed. The flame shot out again, lightened in color and became a blinding white as solid to the eye as white-hot metal. It fanned a trifle and made a myriad little green sparks where it licked the desert soil. A buzz of conversation spread around the room. "Pretty neat, what?"—"Yeah, she's got it this time."—"Watch it fade. That'ud be clean kinetic in vacuo."—Then charged, the main jet darkened, turned purple and quit. Smaller jets around the waist of the craft lighted one after another, and a nose jet blazed out for an instant. More comment came from around them.—"Pretty as a picture, one-two-three."—"Yeah, but I still like precession. Those fractional controls are too complicated."—"It looks nice though, doesn't it."—The smaller jets cut out and the stern jet cut in again, passing quickly from violet to white. It held steady for several minutes, then trembled and Perry thought that he detected a faint shadow on the under side. The whole flame turned a deep purple and split into two parts. He heard a shout of "Down!" and someone jerked savagely at his arm, unbalancing him. He fell across Olga as a white glare like photographer's flashlight temporarily blinded him. A dumb rumble, a short grinding shock, and then silence. He stumbled to his knees and blinked his eyes. Joe was beside him, already rising. They hurried to the window. Before him still lay the rocket but it had lurched awkwardly toward them and a split had opened for several feet near the stern jet. A cloud of yellowish oily smoke partially obscured the scene. Joe turned and hurried down the stairs. The other spectators were gone. Perry had not noticed when or how. He stared again at the sight, trying to interpret it, when Olga's voice sounded beside him.