The Past Through Tomorrow

by Robert A. Heinlein

  “It’s a nuisance to have a bunch of ground-lubbers on board, sir.”

  “Yes, it is, but we have to give those boys a chance to eat, or they couldn’t work when we got there. Now I want to decelerate starting about ten o’clock, ship’s time. What’s our eight o’clock speed and co-ordinates?”

  The Navigator slipped a notebook out of his tunic. “Three hundred fifty-eight miles per second; course is right ascension fifteen hours, eight minutes, twenty-seven seconds, declination minus seven degrees, three minutes; solar distance one hundred and ninety-two million four hundred eighty thousand miles. Our radial position is twelve degrees above course, and almost dead on course in R.A. Do you want Sol’s co-ordinates?”

  “No, not now.” The captain bent over the calculator, frowned and chewed the tip of his tongue as he worked the controls. “I want you to kill the acceleration about one million miles inside Eighty-eight’s orbit. I hate to waste the fuel, but the belt is full of junk and this damned rock is so small that we will probably have to run a search curve. Use twenty hours on deceleration and commence changing course to port after eight hours. Use normal asymptotic approach. You should have her in a circular trajectory abreast of Eighty-eight, and paralleling her orbit by six o’clock tomorrow morning. I shall want to be called at three.”

  “Aye aye, sir.”

  “Let me see your figures when you get ‘em. I’ll send up the order book later.”

  The transport accelerated on schedule. Shortly after three the Captain entered the control room and blinked his eyes at the darkness. The sun was still concealed by the hull of the transport and the midnight blackness was broken only by the dim blue glow of the instrument dials, and the crack of light from under the chart hood. The Navigator turned at the familiar tread.

  “Good morning, Captain.”

  “Morning, Blackie. In sight yet?”

  “Not yet. We’ve picked out half a dozen rocks, but none of them checked.”

  “Any of them close?”

  “Not uncomfortably. We’ve overtaken a little sand from time to time.”

  “That can’t hurt us—not on a stern chase like this. If pilots would only realize that the asteroids flow in fixed directions at computable speeds nobody would come to grief out here.” He stopped to light a cigarette. “People talk about space being dangerous. Sure, it used to be; but I don’t know of a case in the past twenty years that couldn’t be charged up to some fool’s recklessness.”

  “You’re right, Skipper. By the way, there’s coffee under the chart hood.”

  “Thanks; I had a cup down below.” He walked over by the lookouts at stereoscopes and radar tanks and peered up at the star-flecked blackness. Three cigarettes later the lookout nearest him called out.

  “Light ho!”

  “Where away?”

  His mate read the exterior dials of the stereoscope. “Plus point two, abaft one point three, slight drift astern.” He shifted to radar and added, “Range seven nine oh four three.”

  “Does that check?”

  “Could be, Captain. What is her disk?” came the Navigator’s muffled voice from under the hood. The first lookout hurriedly twisted the knobs of his instrument, but the Captain nudged him aside.

  “I’ll do this, son.” He fitted his face to the double eye guards and surveyed a little silvery sphere, a tiny moon. Carefully he brought two illuminated cross-hairs up until they were exactly tangent to the upper and lower limbs of the disk. “Mark!”

  The reading was noted and passed to the Navigator, who shortly ducked out from under the hood.

  “That’s our baby, Captain.”

  “Good.”

  “Shall I make a visual triangulation?”

  “Let the watch officer do that. You go down and get some sleep. I’ll ease her over until we get close enough to use the optical range finder.”

  “Thanks, I will.”

  Within a few minutes the word had spread around the ship that Eighty-eight had been sighted. Libby crowded into the starboard troop deck with a throng of excited mess mates and attempted to make out their future home from the view port. McCoy poured cold water on their excitement.

  “By the time that rock shows up big enough to tell anything about it with your naked eye we’ll all be at our grounding stations. She’s only about a hundred miles thick, yuh know.”

  And so it was. Many hours later the ship’s announcer shouted:

  “All hands! Man your grounding stations. Close all air-tight doors. Stand by to cut blowers on signal.”

  McCoy forced them to lie down throughout the ensuing two hours. Short shocks of rocket blasts alternated with nauseating weightlessness. Then the blowers stopped and check valves clicked into their seats. The ship dropped free for a few moments—a final quick blast—five seconds of falling, and a short, light, grinding bump. A single bugle note came over the announcer, and the blowers took up their hum.

  McCoy floated lightly to his feet and poised, swaying, on his toes. “All out, troops—this is the end of the line.”

  A short chunky lad, a little younger than most of them, awkwardly emulated him, and bounded toward the door, shouting as he went, “Come on, fellows! Let’s go outside and explore!”

  The Master-at-Arms squelched him. “Not so fast, kid. Aside from the fact that there is no air out there, go right ahead. You’ll freeze to death, burn to death, and explode like a ripe tomato. Squad leader, detail six men to break out spacesuits. The rest of you stay here and stand by.”

  The working party returned shortly loaded down with a couple of dozen bulky packages. Libby let go the four he carried and watched them float gently to the deck. McCoy unzipped the envelope from one suit, and lectured them about it.

  “This is a standard service type, general issue, Mark IV, Modification 2.” He grasped the suit by the shoulders and shook it out so that it hung like a suit of long winter underwear with the helmet lolling helplessly between the shoulders of the garment. “It’s self-sustaining for eight hours, having an oxygen supply for that period. It also has a nitrogen trim tank and a carbon-dioxide-water-vapor cartridge filter.”

  He droned on, repeating practically verbatim the description and instructions given in training regulations. McCoy knew these suits like his tongue knew the roof of his mouth; the knowledge had meant his life on more than one occasion.

  “The suit is woven from glass fibre laminated with non-volatile asbesto-cellutite. The resulting fabric is flexible, very durable; and will turn all rays normal to solar space outside the orbit of Mercury. It is worn over your regular clothing, but notice the wire-braced accordion pleats at the major joints. They are so designed as to keep the internal volume of the suit nearly constant when the arms or legs are bent. Otherwise the gas pressure inside would tend to keep the suit blown up in an erect position, and movement while wearing the suit would be very fatiguing.

  “The helmet is moulded from a transparent silicone, leaded and polarized against too great ray penetration. It may be equipped with external visors of any needed type. Orders are to wear not less than a number-two amber on this body. In addition, a lead plate covers the cranium and extends on down the back of the suit, completely covering the spinal column.

  “The suit is equipped with two-way telephony. If your radio quits, as these have a habit of doing, you can talk by putting your helmets in contact. Any questions?”

  “How do you eat and drink during the eight hours?”

  “You don’t stay in ‘em any eight hours. You can carry sugar balls in a gadget in the helmet, but you boys will always eat at the base. As for water, there’s a nipple in the helmet near your mouth which you can reach by turning your head to the left. It’s hooked to a built-in canteen. But don’t drink any more water when you’re wearing a suit than you have to. These suits ain’t got any plumbing.”

  Suits were passed out to each lad, and McCoy illustrated how to don one. A suit was spread supine on the deck, the front zipper that stretched from neck to crotch w
as spread wide and one sat down inside this opening, whereupon the lower part was drawn on like long stockings. Then a wiggle into each sleeve and the heavy flexible gauntlets were smoothed and patted into place. Finally an awkward backward stretch of the neck with shoulders hunched enabled the helmet to be placed over the head.

  Libby followed the motions of McCoy and stood up in his suit. He examined the zipper which controlled the suit’s only opening. It was backed by two soft gaskets which would be pressed together by the zipper and sealed by internal air pressure. Inside the helmet a composition mouthpiece for exhalation led to the filter.

  McCoy bustled around, inspecting them, tightening a belt here and there, instructing them in the use of the external controls. Satisfied, he reported to the conning room that his section had received basic instruction and was ready to disembark. Permission was received to take them out for thirty minutes acclimatization.

  Six at a time, he escorted them through the air lock, and out on the surface of the planetoid. Libby blinked his eyes at the unaccustomed luster of sunshine on rock. Although the sun lay more than two hundred million miles away and bathed the little planet with radiation only one fifth as strong as that lavished on mother Earth, nevertheless the lack of atmosphere resulted in a glare that made him squint. He was glad to have the protection of his amber visor. Overhead the sun, shrunk to penny size, shone down from a dead black sky in which unwinking stars crowded each other and the very sun itself.

  The voice of a mess mate sounded in Libby’s earphones, “Jeepers! That horizon looks close. I’ll bet it ain’t more’n a mile away.”

  Libby looked out over the flat bare plain and subconsciously considered the matter. “It’s less,” he commented, “than a third of a mile away.”

  “What the hell do you know about it, Pinkie? And who asked you, anyhow?”

  Libby answered defensively, “As a matter of fact, it’s one thousand six hundred and seventy feet, figuring that my eyes are five feet three inches above ground level.”

  “Nuts. Pinkie, you are always trying to show off how much you think you know.”

  “Why, I am not,” Libby protested. “If this body is a hundred miles thick and as round as it looks: why, naturally the horizon has to be just that far away.”

  “Says who?”

  McCoy interrupted.

  “Pipe down! Libby is a lot nearer right than you were.”

  “He is exactly right,” put in a strange voice. “I had to look it up for the navigator before I left control.”

  “Is that so?”—McCoy’s voice again—“If the Chief Quartermaster says you’re right, Libby, you’re right. How did you know?”

  Libby flushed miserably. “I—I don’t know. That’s the only way it could be.”

  The gunner’s mate and the quartermaster stared at him but dropped the subject.

  By the end of the ‘day’ (ship’s time, for Eighty-eight had a period of eight hours and thirteen minutes), work was well under way. The transport had grounded close by a low range of hills. The Captain selected a little bowl-shaped depression in the hills, some thousand feet long and half as broad, in which to establish a permanent camp. This was to be roofed over, sealed, and an atmosphere provided.

  In the hill between the ship and the valley, quarters were to be excavated; dormitories, mess hall, officers’ quarters, sick bay, recreation room, offices, store rooms, and so forth. A tunnel must be bored through the hill, connecting the sites of these rooms, and connecting with a ten foot airtight metal tube sealed to the ship’s portside air-lock. Both the tube and tunnel were to be equipped with a continuous conveyor belt for passengers and freight.

  Libby found himself assigned to the roofing detail. He helped a metal-smith struggle over the hill with a portable atomic heater, difficult to handle because of a mass of eight hundred pounds, but weighing here only sixteen pounds. The rest of the roofing detail were breaking out and preparing to move by hand the enormous translucent tent which was to be the ‘sky’ of the little valley.

  The metalsmith located a landmark on the inner slope of the valley, set up his heater, and commenced cutting a deep horizontal groove or step in the rock. He kept it always at the same level by following a chalk mark drawn along the rock wall. Libby enquired how the job had been surveyed so quickly.

  “Easy,” he was answered, “two of the quartermasters went ahead with a transit, leveled it just fifty feet above the valley floor, and clamped a searchlight to it. Then one of ‘em ran like hell around the rim, making chalk marks at the height at which the beam struck.”

  “Is this roof going to be just fifty feet high?”

  “No, it will average maybe a hundred. It bellies up in the middle from the air pressure.”

  “Earth normal?”

  “Half Earth normal.”

  Libby concentrated for an instant, then looked puzzled. “But look— This valley is a thousand feet long and better than five hundred wide. At half of fifteen pounds per square inch, and allowing for the arch of the roof, that’s a load of one and an eighth billion pounds. What fabric can take that kind of a load?”

  “Cobwebs.”

  “Cobwebs?”

  “Yeah, cobwebs. Strongest stuff in the world, stronger than the best steel. Synthetic spider silk. This gauge we’re using for the roof has a tensile strength of four thousand pounds a running inch.”

  Libby hesitated a second, then replied, “I see. With a rim about eighteen hundred thousand inches around, the maximum pull at the point of anchoring would be about six hundred and twenty-five pounds per inch. Plenty safe margin.”

  The metalsmith leaned on his tool and nodded. “Something like that. You’re pretty quick at arithmetic, aren’t you, bud?”

  Libby looked startled. “I just like to get things straight.”

  They worked rapidly around the slope, cutting a clean smooth groove to which the ‘cobweb’ could be anchored and sealed. The white-hot lava spewed out of the discharge vent and ran slowly down the hillside. A brown vapor boiled off the surface of the molten rock, arose a few feet and sublimed almost at once in the vacuum to white powder which settled to the ground. The metalsmith pointed to the powder.

  “That stuff ‘ud cause silicosis if we let it stay there, and breathed it later.”

  “What do you do about it?”

  “Just clean it out with the blowers of the air conditioning plant.”

  Libby took this opening to ask another question. “Mister—?”

  “Johnson’s my name. No mister necessary.”

  “Well, Johnson, where do we get the air for this whole valley, not to mention the tunnels? I figure we must need twenty-five million cubic feet or more. Do we manufacture it?”

  “Naw, that’s too much trouble. We brought it with us.”

  “On the transport?”

  “Uh huh, at fifty atmospheres.”

  Libby considered this. “I see—that way it would go into a space eighty feet on a side.”

  “Matter of fact it’s in three specially constructed holds—giant air bottles. This transport carried air to Ganymede. I was in her then—a recruit, but in the air gang even then.”

  In three weeks the permanent camp was ready for occupancy and the transport cleared of its cargo. The storerooms bulged with tools and supplies. Captain Doyle had moved his administrative offices underground, signed over his command to his first officer, and given him permission to proceed on ‘duty assigned’—in this case; return to Terra with a skeleton crew.

  Libby watched them take off from a vantage point on the hillside. An overpowering homesickness took possession of him. Would he ever go home? He honestly believed at the time that he would swap the rest of his life for thirty minutes each with his mother and with Betty.

  He started down the hill toward the tunnel lock. At least the transport carried letters to them, and with any luck the chaplain would be by soon with letters from Earth. But tomorrow and the days after that would be no fun. He had enjoyed being in the air g
ang, but tomorrow he went back to his squad. He did not relish that—the boys in his squad were all right, he guessed, but he just could not seem to fit in.

  This company of the C.C.C. started on its bigger job; to pock-mark Eighty-eight with rocket tubes so that Captain Doyle could push this hundred-mile marble out of her orbit and herd her in to a new orbit between Earth and Mars, to be used as a space station—a refuge for ships in distress, a haven for life boats, a fueling stop, a naval outpost.

  Libby was assigned to a heater in pit H-16. It was his business to carve out carefully calculated emplacements in which the blasting crew then set off the minute charges which accomplished the major part of the excavating. Two squads were assigned to H-16, under the general supervision of an elderly marine gunner. The gunner sat on the edge of the pit, handling the plans, and occasionally making calculations on a circular slide rule which hung from a lanyard around his neck.

  Libby had just completed a tricky piece of cutting for a three-stage blast, and was waiting for the blasters, when his phones picked up the gunner’s instructions concerning the size of the charge. He pressed his transmitter button.

  “Mr. Larsen! You’ve made a mistake!”

  “Who said that?”

  “This is Libby. You’ve made a mistake in the charge. If you set off that charge, you’ll blow this pit right out of the ground, and us with it.”

  Marine Gunner Larsen spun the dials on his slide rule before replying, “You’re all het up over nothing, son. That charge is correct.”

  “No, I’m not, sir,” Libby persisted, “you’ve multiplied where you should have divided.”

  “Have you had any experience at this sort of work?”

  “No, sir.”

  Larsen addressed his next remark to the blasters. “Set the charge.”

  They started to comply. Libby gulped, and wiped his lips with his tongue. He knew what he had to do, but he was afraid. Two clumsy stiff-legged jumps placed him beside the blasters. He pushed between them and tore the electrodes from the detonator. A shadow passed over him as he worked, and Larsen floated down beside him. A hand grasped his arm.