Destination Moon

"Doctor Corley!"

Corley looked around vaguely, as if awakening in a strange place. "Eh? Yes, Ma

"Doctor Hastings calling."

"Oh, fine," Corley acknowledged. "Slide out of there and let me take it."

They changed places with effort, bothered by weightlessness. Traub felt a touch on his arm. "What is it, Ma

He turned; Barnes and Bowles had waked -- up and loosed themselves. "Howdy, Skipper. It's Doctor Hastings."

"Good!"

"Uh, Admiral-got something for you." Traub hauled out the code dispatch.

Bowles stared at it. Barnes remarked, "Race results?"

Bowles did not answer. He shoved himself toward the forward bulkhead, as far away as possible. He then took a thin book from an i

Hastings' report was short but not sweet. They would reach the Moon's orbit where 'pla

Barnes whistled. "Hot pilot Barnes, they call me."

Corley said, "It's no joke."

"I wasn't laughing, Doe," Barnes answered, "but there is no use crying. It will be tragic soon enough."

Traub broke in. "Hey-what do you mean?"

"He means," Bowles said bluntly, "that we are headed out and aren't coming back."

"On out? And out-out into outer space? Where the stars are?"

"That's about it." -- "Not that," Corley interrupted, "I'd estimate that we would reach our farthest point somewhere around the orbit of Mars."

Traub sighed. "So it's Mars, now? That's not so bad, is it? I mean -- they say people live on Mars, don't they? All those canals and things? We can get another load of water and come back."

"Don't kid yourself, Ma

"A bachelor? Who said I was?"

"Aren't you?"

"Me? I'm a very domestic type guy. Four kids-and married -- fourteen years."

Corley looked stricken. "Ma

Barnes said, "Ma

Corley raised his voice. "Please! Everybody! I -- didn't say we weren't going to get back. I said -- "

"But you -- "

"Shut up, Red! I said this orbit is no good. We've got to vector west, toward the Moon. And we've got to do it at -- " He glanced at a clock. "Good grief! Seven minutes from now."

Barnes jerked his head ar~ind. "Acceleration stations, everybody! Stand by to maneuver!"

VII

The most treacherous maneuver known to space flight is a jet landing on an airless planet. Even today, it commands the highest pay, the most skilled pilots -- Farquharson, Ibid., III: 418

For forty hours they fell toward the Moon. The maneuver had worked; one could see, even with naked eye, that they were closing with the Moon. The four took turns at the radio, ate and slept and talked and stared out at the glittering sky. Bciwles and Traub discovered a common passion for chess and played off the "First A

Some two hundred thousand miles out the Luna slid past the,null point between Earth and Moon, and began to shape her final orbit. It became evident that the correction vector had somewhat overcompensated and that they were swinging toward the Moon's western limb -- "western" as seen from Earth: the Luna's orbit would intersect her namesake somewhere on the neveryet-seen far side-or it was possible that the ship would skim the far side at high speed, come around sharply and head back toward Earth.

Two principal styles of landing were possible-Type A, in which a ship heads in vertically, braking on her jets to a landing in one maneuver, and Type B, in which a ship is first slowed to a circular orbit, then stopped dead, then backed to a landing when she drops from the point of rest. --

"Type A, Jim-it's simplest."

Barnes shook his head. "No, Doc. Simple on paper only. Too risky." If they corrected course to head straight in (Type A), their speed at instant of braking would be a mile and a half a second and an error of one second would land them 8000 feet above-or below! -- the surface. --

Barnes went on, "How about a modified 'A'?" Modified Type A called for intentionally blasting too soon, then cutting the jets when the radar track showed that the ship hovered, allowing it to fall from rest, then blasting again as necessary, perhaps two or three times.

"Confound it, Jim, a modified 'A' is so damned wasteful."

"I'd like to get us down without wrecking us."

"And I would like us to get home, too. This ship was' figured for a total change of twelve and a half miles per second. Our margin is paper thin."

"Just the same, I'd like to set the autopilot to kick her a couple of seconds early."

"We can't afford it and that's that."

"Land her yourself, then. I'm not Superman."

"Now, Jim -- "

"Sorry." Barnes looked at the calculations. "But why Type A? Why not Type B?"

"But Jim, Type B is probably ruled out. It calls for decelerating at point of closest approach and, as things stand now, 'closest approach' may be contact."

"Crash, you mean. But don't be so damned conventional; you can vector into a circular orbit from any position."

"But that wastes reaction -- mass, too."

"Crashing from a sloppy Type A wastes more than reaction mass," Barnes retorted. "Get to work on a 'B'; I won't risk an 'A."

Corley looked stubborn. Barnes went on, "There's a bonus with Type B, Doe-two bonuses."

"Don't be silly. Done perfectly, it takes as much reaction mass as Type A; done sloppily, it takes more."

"I won't be sloppy. Here's your bonus: Type A lands us on this face, but Type B lets us swing around the Moon and photograph the back side before we land. How does that appeal to your scientific soul?"

Corley looked tempted. "I thought about that, but we've got too little margin. It takes a mile and a half of motion to get down to the Moon, the same to get up-three miles. For the trip back I have to save enough mass to slow from seven miles a second to five before we dip into the atmosphere. We used up seven to blast off-it all adds up to twelve. Look at the figures; what's left?"

Barnes did so and shrugged. "Looks like a slightly fat zero."

"A few seconds of margin at most You could waste it on the transitions in a Type B landing."

"Now the second bonus, Doe," Barnes said slowly. "The Type B gives you a chance to change your mind after you get into a circular orbit; the straight-in job commits you beyond any help."

Corley looked shocked. "Jim, you mean go back to Earth without landing?"

Barnes lowered his voice. "Wait, Doc. I'd land on the Moon if I had enough in tanks to get down-and not worry about getting up again. I'm a bachelor. But there's Ma

Corley pulled at his scalp lock. "He should have told us."

"If he had, we wouldn't have taken off."

"Confound it, things would have been all right if I hadn't suggested that you test the engine."

"Nonsense! If I hadn't scared those babies off with a blast, they probably would have wrecked the ship."

"You can't be sure."

"A man can't be sure of anything. How about Traub?"