Robert Heinlein - Destination Moon

Rosy light flashed through the eastern port, followed at once by dazzling sunlight. Traub yelped, "What happened?"

Barnes himself had been startled but he strove to control his voice and answered, "Sunrise. We're up that high." He went on, "Doc-how's the power plant?"

"Readings normal," Corley replied in tongue-clogged tones. "How long -- to go?"

Barnes looked at his board. "More than three minutes."

Corley did not answer, three minutes seemed too long to bear. Presently Traub said, "Look at the sky!" Corley forced his head over and looked. Despite harsh sunlight the sky was black and spangled with stars.

At three minutes and fifty seconds the jets cut off. Like the first time, the cutoff was mushy, slow. The terrible weight left them gradually. But it left them completely. Rocket and crew were all in a free orbit "falling" upward toward the Moon. Relative to each other and to ship they had no weight.

Barnes felt that retching, frightening "falling elevator" feeling characteristic of no weight, but, expecting it, he steeled himself. "Power, plant," he snapped, "report!"

"Power plant okay," Corley replied weakly. "Notice the cutoff?"

"Later," decided Barnes. "Co-pilot, my track seems high."

"My display tracks on," wheezed Bowles, " -- or a hair high."

"Mannie!"

No answer. Barnes repeated, "Mannie? Answer, man-are you all right?"

Traub's voice was weak. "I think I'm dying. This thing is falling-oh, God, make it stop!"

"Snap out of it!"

"Are we going to crash?"

"No, no! We're all right."

"All right,' the man says,'~ Traub muttered, then added, "I don't care if we do."

Barnes called out, "Doc, get those pills. Mannie needs one bad." He stopped to control a retch. "I could use one myself."

"Me, too," agreed Bowles. "I haven't been this seasick since I was -- " He caught himself, then went on. " -- since I was a midshipman."

Coriey loosened his straps and pulled himself out from his couch. Weightless, he floated free and turned slowly over, like a diver in slow motion. Traub turned his face away and groaned. --

"Stop it, Mannie," ordered Barnes. "Try to raise White Sands. I want a series of time-altitude readings."

"I can't-I'm sick."

"Do it!"

Corley floated near a stanchion, grabbed it, and pulled himself to a cupboard. He located the pill bottle and hastily gulped a pill. He then moved to Traub's couch, pulling himself along. "Here, Traub-take this. You'll feel better."

"What is it?"

"Some stuff called Dramamine. It's for seasickness."

Traub put a pill in his mouth. "I can't swallow."

"Better try." Traub got it down, clamped his jaw to keep it down. Corley pulled himself to Barnes. "Need one, Jim?"

Barnes started to answer, turned his head away, and threw up in his handkerchief. Tears streaming from his eyes, he accepted the pill. Bowles called out, "Doc -- hurry up!" His voice cut off; presently he added, "Too late."

"Sorry." Corley moved over to Bowles. "Criminy, you're a mess!"

"Gimme that pill and no comments."

Traub was saying in a steadier voice, "Spaceship Luna, calling White Sands. Come in White Sands."

At last an answer came back, "White Sands to Spaceship-go ahead."

"Give us a series of radar checks, time, distance, and bearing."

A new voice cut in, "White Sands to Spaceship-we have been tracking you, but the figures are not reasonable. What is your destination?"

Traub glanced at Barnes, then answered, "Luna, to White Sands-destination: Moon."

"Repeat? Repeat?"

"Our destination is the Moon!".

There was a silence. The same voice replied, "Destination: Moon' -- Good luck, Spaceship .Luna!"

Bowles spoke up suddenly. "Hey! Come look!" He had unstrapped and was floating by the sunward port.

"Later," Barnes answered. "I need this tracking report first."

"Well, come look until they call back. This is once in a lifetime."

Corley joined Bowles. Barnes hesitated; he wanted very badly to see, but he was ashamed to leave Traub working. "Wait," he called out. "I'll turn ship and we can all see."

Mounted at the centerline of the ship was a flywheel. Barnes studied his orientation readings, then clutched the ship to the flywheel. Slowly the ship turned, without affecting its motion along its course. "How's that?"

"Wrong way!"

"Sorry." Barnes tried again; the stars marched past in the opposite direction; Earth swung into view. He caught sight of it and almost forgot to check the swing.

Power had cut off a trifle more than eight hundred miles up. The Luna had gone free at seven miles per second; in the last few minutes they had been steadily coasting upwards and were now three thousand miles above Southern California. Below-opposite them, from their viewpoint-was darkness. The seaboard cities stretched across the port likeChristmas lights. East of them, sunrise cut across the Grand Canyon and shone on Lake Mead. Further east the prairies were in daylight, dun and green 'broken by blinding cloud. The plains dropped away into curved skyline.

So fast were they rising that the picture was moving, shrinking, and the globe drew into itself as a ball. Barnes watched from across the compartment. "Can you see all right, Mannie?" he asked. --

"Yeah,", answered Traub. "Yeah," he repeated softly~ "Say, that's real, isn't it?"

Barnes said, "Hey, Red, Doc-heads down. You're not transparent."

Traub looked at Barnes. "Go ahead, skipper."

"No, I'll stick with you."

"Don't be a chump. I'll look later."

"Well -- " Barnes grinned suddenly. "Thanks, Mannie." He gave a shove and moved across to the port.

Mannie continued to stare. Later the radio claimed his attention. "White Sands, calling Spaceship-ready with radar report."

The first reports, plus a further series continued as long as White Sands and Muroc were able to track them, confirmed Barnes' suspicion. They were tracking "high," ahead of their predicted positions and at speeds greater than those called for by Hastings' finicky calculations. The difference was small; on the autopilot displays it was hardly the thickness of a line between the calculated path and the true path.

But the difference would increase.

"Escape speeds" for rockets are very critical Hastings had calculated the classical hundred-hour orbit and the Luna had been aimedjo reach the place where the Moon would be four days later. But initial speed is critical. A difference of less than one percent in ship speed at cutoff can halve-or double-the transit time from Earth to Moon. The Luna was running -- very slightly ahead of schedule-but when it reached the orbit of the Moon, the Moon would not be there.

Doctor Corley tugged at his thinning hair. "Sure, the cutoff was mushy, but I-was expecting it and I noted the mass readings. It's not enough to account for the boost. Here-take a look."

Corley was hunched at the log desk, a little shelf built wto the space between the acceleration bunks. He was strapped to a stool fixed to the deck in front of it. Barnes floated at his shoulder; he took the calculation and scanned it. "I don't follow you," Barnes said presently; "your expended mass is considerably higher than Hastings calculated."

"You're looking at the wrong figure," Corley pointed out. "You forgot the mass of water you used up in that -- test. Subtract that from the total mass expended to get the effective figure for blast off-this figure here. Then you apply that -- " Corley hesitated, his expression changed from annoyance to dismay. "Oh, my God!"

-- -- "Huh? What is it, Doc? Found the mistake?"

"Oh, how could I be so stupid!" Corley started frenzied figuring.

"What have you found?" Corley did not answer; Barnes grabbed his arm. "What's up?"

"Huh? Don't bother me."

"I'll bother you with a baseball bat. What have you found?"