The problem could be made vastly more complicated. The Galileo was riding with the earth and the moon in their yearly journey around the sun at a speed of about 19 miles per second or approximately 70,000 miles per hour as seen from outer space. In addition, the earth-moon line was sweeping around the earth once each month as it followed the moon—but Joe the Robot had compensated for that when he set them on a course to where the moon would be rather than where it was.

There were also the complicated motions of the sun and its planets with reference to the giddily whirling ‘fixed' stars, speeds which could be nearly anything you wanted, depending on which types of stars you selected for your reference points, but all of which speeds are measured in many miles per second.

But Joe cared nothing for these matters. His cam and his many circuits told him how to get them from the earth to the moon; he knew how to do that and Doctor Einstein's notions of relativity worried him not. The mass of machinery and wiring which made up his being did not have worry built into it. It was, however, capable of combining the data that came to it to show that the Galileo was now moving somewhat more than 3300 miles per hour along an imaginary line which joined earth to the point where the moon would be when they arrived.

Morrie could check this figure by radar observations for distance, plus a little arithmetic. If the positions as observed did not match what Joe computed them to be, Morrie could feed Joe the corrections and Joe would accept them and work them into his future calculations as placidly and as automatically as a well-behaved stomach changes starch into sugar.

"Thirty-three hundred miles per hour," said Art. "That's not so much. The V-2 rockets in the war made more than that. Let's open her up wide and see what she'll do. How about it, Doc?"

"Sure," agreed Ross, "we've got a clear road and plenty of room. Let's bust some space."

Cargraves sighed. "See here," he answered, "I did not try to keep you darned young speed demons from risking your necks in that pile of bailing wire you call an automobile, even when I jeopardized my own life by keeping quiet. But I'm going to run this rocket my way. I'm in no hurry."

"Okay, okay, just a suggestion," Ross assured him. He was quiet for a moment, then added, "But there's one thing that bothers me..."

"What?"

"Well, if I've read it once, I've read it a thousand times, that you have to go seven miles per second to get away from the earth. Yet here we are going only 3300 miles per hour."

"We're moving, aren't we?"

"Yeah, but-"

"As a matter of fact we are going to build up a lot more speed before we start to coast. We'll make the first part of the trip much faster than the last part. But suppose we just held our present speed—how long would it take to get to the moon?"

Ross did a little fast mental arithmetic concerning the distance of the moon from the earth, rounding the figure off to 240,000 miles. "About three days."

"What's wrong with that? Never mind," Cargraves went on. "I'm not trying to be a smart-Aleck. The misconception is one of the oldest in the book, and it keeps showing up again, every time some non-technical man decides to do a feature story on the future of space travel. It comes from mixing up shooting with rocketry. If you wanted to fire a shot at the moon, the way Jules Verne proposed, it would have to go seven miles per second when it left the gun or it would fall back. But with a rocket you could make the crossing at a slow walk if you had enough power and enough fuel to keep on driving just hard enough to keep from falling back. Of course it would raise Cain with your mass-ratio. But we're doing something of that sort right now. We've got tower to spare; I don't see why we should knock ourselves out with higher acceleration than we have to just to get there a little sooner. The moon will wait. It's waited a long time.

"Anyhow," he added, "no matter what you say and no matter how many physics textbooks are written and studied, people still keep mixing up gunnery and rocketry. It reminds me of that other old chestnut—about how a rocket can't work out in empty space, because it wouldn't have anything to push on."

"Go ahead and laugh!" Cargraves continued, seeing their expressions, "It strikes you as funny as a The-World-Is-Flat theory. But I heard an aeronautical engineer, as late as 1943, say just that."

"No! Not really!"

"I certainly did. He was a man with twenty-five years of professional experience and he had worked for both Wright Field and the Navy. But he said that in it. Next year the Nazis were bombing London with V-2s. Yet according to him it couldn't be done!"

"I'd think any man who had ever felt the kick of a shotgun would understand how a rocket works," Ross commented.

"It doesn't work out that way. Mostly it has no effect on his brain cells; it just gives him a sore shoulder." He started to lift himself out of his semi-reclining position in his pilot's chair. "Come on. Let's eat. Wow! My foot's gone to sleep. I want to stock up and then get some sleep. Breakfast wasn't much good for me—too many people staring down our necks."

"Sleep?" said Art. "Did you say ‘sleep'? I can't sleep; I'm too excited. I don't suppose I'll sleep the whole trip."

"Suit yourself. Me, I'm going to soak up shut-eye just as soon as we've eaten. There's nothing to see now, and won't be until we go into free fall. You've had better views of the moon through a telescope."

"It's not the same thing," Art pointed out.

"No, it's not," Cargraves conceded. "Just the same, I intend to reach the moon rested up instead of worn out. Morrie, where did you stow the can openers?"

"I-" Morrie stopped and a look of utter consternation came over his face. "I think I left them behind. I put them down on the sink shelf and then some female reporter started asking me some fool question and-"

"Yeah, I saw," Ross interrupted him. "You were practically rolling over and playing dead for her. It was cute."

Cargraves whistled tunelessly. "I hope that we find out that we haven't left behind anything really indispensable. Never mind the can openers, Morrie. The way I feel I could open a can with my bare teeth."

"Oh, you won't have to do that, Doc," Morrie said eagerly. "I've got a knife with a gadget for-" He was feeling in his pocket as he talked. His expression changed abruptly and he withdrew his hand. "Here are the can openers, Doc."

Ross looked at him innocently. "Did you get her address, Morrie?"

Supper, or late breakfast, as the case may be, was a simple meal, eaten from ration cans. Thereafter Cargraves got out his bedding roll and spread it on the bulkhead- now a deck -which separated the pilot compartment from the hold. Morrie decided to sleep in his co-pilot's chair. It, with its arm rests, head support, and foot rest, was not unlike an extremely well-padded barber's chair for the purpose, one which had been opened to a semi-reclining position. Cargraves let him try it, cautioning him only to lock his controls before going to sleep.

About an hour later Morrie climbed down and spread his roll beside Cargraves. Art and Ross slept on their acceleration hammocks, which were very well adapted to the purpose, as long as the occupant was not strapped down.

Despite the muted roar of the jet, despite the excitement of being in space, they all were asleep in a few minutes. They were dead tired and needed it.

During the ‘night' Joe the Robot slowly reduced the drive of the jet as the pull of the earth grew less.

Art was first to awaken. He had trouble finding himself for a moment or two and almost fell from his hammock on to the two sleepers below before he recollected his surroundings. When he did it brought him wide awake with a start. Space! He was out in space! -- Headed for the moon!