Rocket to Luna

“Well, a lot of other things enter into the figuring,” Ted said, “but that’ll give you a rough idea, anyway.”

Dr. Phelps still looked doubtful. “There would still seem to be a great many miles unaccounted for. After all, in fifty-six minutes...”

“Oh,” Ted exclaimed, brightening. “The Constant Speed Fallacy.”

Jack suddenly turned from the viewport, and his face did not help to disguise the disgust in his voice. “Another Academy catch phrase,” he said.

Ted felt suddenly embarrassed. Perhaps he’d said too much. Perhaps they thought he was showing off. He bit his lower lip and stared down at his shoes.

“I enjoy these catch phrases,” Merola said. “Let’s hear it, Ted.”

Ted shrugged. “I’ve talked too much already, sir.”

“Nonsense,” Dr. Gehardt said. “I find this most informative.”

“Well,” Ted said hesitantly.

“Come, come,” Dr. Phelps insisted.

“Well, we just called it The Constant Speed Fallacy at the Academy. I don’t know what you’d really call it. It just assumes that the rocket is always traveling at its top speed of 18,468 miles an hour. This isn’t so.” He stroked his jaw, searching for a comparison. “If you can imagine the rocket as a bullet fired from a rifle,” he said suddenly, “it might help. The bullet’s speed is greatest several seconds from the muzzle of the gun. The bullet travels in an orbit, just like the rocket, with an apogee and...”

“A what?” Dr. Phelps asked.

Ted smiled. “The apogee is simply the peak of the orbit, the point where the rocket — or the bullet — begins to turn back toward the ground. Our apogee will be at the Space Station.”

“I see. We will then be in the Space Station’s orbit.”

“That’s right. We’ll be another satellite, then. Like the Moon.” Ted paused and scratched his head. “Where was I?”

“You said the bullet’s speed was greatest...”

“Yes, several seconds from the gun muzzle. It reaches zero when the bullet is at the apogee — or peak — of its orbit, and it will again pick up as the bullet falls to the ground. The same is true of our rocket. We reached top speed at a height of 63.3 miles, and that’s when we cut off our power.”

“I’m beginning to understand,” Dr. Phelps said, “although it’s much more difficult than my first appendectomy.”

“We’re now in the process of losing speed,” Ted said. “Actually, we’re just coasting up to the Station, and we’re being slowed by the Earth’s gravitational pull.”

A new idea struck Dr. Gehardt. “Why, what will happen when we reach... our apogee, is it? Will we then fall back to Earth — like the bullet?”

“We would,” Merola said, “except for the fact that we start blasting again for fifteen seconds when we fall to a speed of 14,770 miles an hour. That fifteen seconds of power will bring our speed up to 15,800 miles an hour, and that’ll be the speed necessary for keeping us in the Space Station’s orbit.”

Dr. Gehardt nodded and looked at Ted again. He opened his eyes appreciatively and said, “They certainly train you well at the Academy.”

Merola grinned. “That’s why Jack is going along on the Moon trip. We’ll make good use of an Academy man.”

Ted smiled. “I wish you could make use of two Academy men,” he said.

Jack suddenly whirled from the viewport. “You’ll find plenty to keep you busy at the Space Station,” he snapped.

“Sure,” Merola said, slapping Ted on the shoulder. “Besides, there’ll be other trips to the Moon. Maybe you’ll be on the next one.”

“That would be swell,” Ted agreed, “but please don’t misunderstand me. I’d give anything to be going to the Moon with you fellows, but I’m perfectly happy with the year I’ll have at the Station.”

“That’s the boy,” Merola said. “There’s no sense in...”

Forbes suddenly stamped his way up the ladder, pulling himself up onto the deck and swinging the hatch shut behind him.

“Everything ticking?” Merola asked.

Forbes twisted the wheel tight, then lifted his blond head and grinned broadly. “Fine, just fine. Shouldn’t give us any trouble at all when we start blasting again.”

Merola glanced at his watch hastily. “And that won’t be too long now,” he said.

“You know,” Dr. Phelps intruded suddenly, “I still don’t understand that discrepancy.”

In less than a half-hour, they were flat on their backs again, fighting the tenacious power of acceleration.

It was a short ordeal to bear, though, much shorter than the initial blastoff period had been.

And in just fifteen seconds, they were at the Space Station.

None of the men spoke as they clambered into their bulky, rubberized nylon space suits. Using the buddy system, they paired off and fastened the toggles on their partners’ helmets. Ted, for one, was grateful for the darkened face plate of the helmet. He knew its real purpose was to ward off the powerful ultraviolet rays of the Sun, but at the moment it served to conceal the mixed emotions that were passing over his features.