The Mars Imperative - Excerpt (part 1)
Engineering Marvels: Space Elevator – Six Magnetic Levitation (Maglev) elevator cars travel up and down each ribbon cable, transporting both passengers and cargo. The cars differ in many ways from traditional land-based maglev trains. Rather than riding atop a narrow horizontal rail, the elevator car is suspended alongside a vertical flat ribbon cable. The ribbon passes between two sets of magnets, on the front and back sides of the cable. This arrangement prevents the train from drifting away from the ribbon. An elevator car has to travel tens of thousands of kilometers nonstop; therefore, it is impractical for an elevator car to be self-powered. Instead, the motive force is provided by the ribbon cable.
The cables could not be made of copper for several reasons: 1) copper is far too bulky and heavy, 2) it was in short supply, and 3) too much power would dissipate along the way. Some sort of lightweight superconductor was required.
For these reasons the cable is composed primarily of BORON NITRIDE NANOTUBES (BNNTs) due to the material’s high strength-to-weight ratio, as well as thermal and radiation resistance. The outer courses of the ribbon, front and back, also contain a superconducting layer of CARBON NANOTUBES (CNTs), using BNNTs for electrical insulation. These layers act as power conduits, reaching all the way from the solar panels on the Orbital Docking Facility down to the ground. Woven transversely across the ribbon, in strips, are lightweight threads made of superconducting magnets that tap into the power source. As a result, the elevator cars need only enough internal power to maintain the onboard magnets and life support.
The ribbon magnets pulse rhythmically. Magnets in front of the car draw the car forward, while those behind push the car. Then, as the vehicle approaches its destination, the pulses reverse themselves to slow the car for docking.
— Excerpt from Encyclopedia Solaris, 2176
* * * *
Distracted by his ruminations, James was startled by the actual launch. Surprisingly, only a small jolt gave away the fact that the car was moving. At first the acceleration felt much like that of an elevator in any high-rise, gradually increasing until the G-forces topped out at 1.25. It was hardly enough to even notice while seated, and even then it lasted only for a few seconds before returning to one gee.
“You know,” James said as he scanned his surroundings, “I’m surprised at how small the car is inside. It seems a lot bigger in the holos.”
“That’s because you’re only seeing the passenger section of the car. The lower half contains cargo, loaded before we boarded. There’s two freight car containers under our feet.”
“Ah. That makes sense.” James watched the sky gradually darken through the window as the car rose.
After five minutes, the Fasten Seat Restraints sign went out, replaced by an altitude indicator.
James was surprised. “Sixty-two klicks, already?”
“Yep. This thing really moves.”
The flight attendant rose and walked in front of the holoscreen. “Ladies and gentlemen,” she announced in a melodious voice, “on behalf of ODF Nautilus, I’d like to thank you for traveling with us today. Our travel time will be approximately forty-eight hours. We will reach a top speed of two thousand, one hundred and forty-nine kilometers per hour, with an average cruising speed of sixteen hundred and thirty-eight KPH. Each of your seats contains immersive speakers, to enhance your enjoyment of the holo or audio programs of your choice during the trip. Meals will be served at your seats.
“Each seat contains a foldout table. These tables can also be tilted up to serve as personal screens for viewing holos, reading, communicating, or playing video games. Your berths are located in the upper level of the car.” She gestured to the lift on one side of the car and the spiral staircase on the other.
“If you require assistance, please press the call button in your armrest. The main viewscreen will display the view ahead of the car. For a view of the Earth receding below us, you may tune in to channel 450. We hope you enjoy your trip.” She took her seat again.
Daniel gestured at the window. “Take a look; the view’s something you’ll remember forever.” They stood and walked over to the large glassy expanse. Daniel pointed. The curvature of the Earth and most of South America were visible below. “We’re already beyond the troposphere and nearing the top of the stratosphere. The car will really start moving then.”
“Wow! And you’re right; I hardly feel a thing. This is absolutely amazing. I’d never know we were moving if I couldn’t see the ground falling away.” The altimeter on the wall now showed ninety-eight kilometers. “As fast as we’re going, it’s hard to believe it’ll take two days to get up to the ODF.”
Daniel smiled. “Yeah, we’re going fast, but this trip is almost equivalent to twice around the globe. Imagine if Jules Verne were alive today: Instead of Around the World in Eighty Days, he’d have to write Around the World Twice in Two Days.”
It was James’ turn to smile. Then he grew sober. “Um, I hate to sound like a worrywart, but isn’t it kind of dangerous to have all this glass here?” He reached out to tap the window, then thought better of it. “What if someone fell against it, or threw something at it?”
Daniel nodded. “You’d be right, if that window was made of glass. But it’s actually a sandwich consisting of layers of aluminum oxynitride—transparent aluminum—and other materials, with a three micron-thick molecular diamond scratchproof coating inside and out. The window is actually stronger than the surrounding walls are. Hit it as hard as you want with a sledgehammer and all you’ll do is hurt yourself.”
James conceded the point with a smile. “You’re determined to convince me we’ll live to reach Nautilus, aren’t you? Okay, you win: I’m convinced. But if we die, I’ll track you down in Heaven to say ‘I told you so!’”
“At least,” Daniel said with a wicked grin, “way up here we won’t have far to go to reach Heaven.”
* * * *
The two men thanked the smiling flight attendant for their dinner trays. Daniel nodded in the direction of the departing young lady. “I wonder how they always stay so cheerful on these long trips?” Then he winked at James. “She’s cute, don’t you think?”
James shrugged. “Sure, I guess.”
“You guess? Man, you’ve been out of it all evening. What is it? A girl back home or something?”
“No, no girl. My last girlfriend broke up with me a couple of weeks ago. She wasn’t crazy about me going to Mars for several years.”
Daniel grinned. “Yeah, girlfriends are funny that way.”
“How about you, Daniel? Are you leaving a string of girlfriends behind?”
“Nah. I’m in the same boat as you. Girlfriends just don’t understand why guys would prefer to go to Mars rather than stay with them.”
“Yeah, never mind that’s where the high-paying jobs and career advancement are.”
They shared a smile at that.
Daniel cocked his head at James. “So…I notice the torrent of questions seems to have stopped. Don’t tell me I’ve succeeded in answering every question you’ve ever had about living and working in space.”
James grinned. “Not exactly. This stuff’s all new to me, but I didn’t want to bug you with too many dumb questions all at once.”
“Don’t worry about it. Your questions are all perfectly reasonable. It’s not like they teach orbital mechanics and space elevator engineering in grade school. Besides, I don’t have anything better to do at the moment, anyway. It’s probably good that you get those questions out of the way now, rather than pester your supervisor on Mars with them. You wouldn’t want to get branded a yair.”
James blinked, and when no explanation was forthcoming he sighed. “Okay, I’ll bite. What’s a yair?”
“Oh, about 365 days on Earth and 687 days on Mars.” Daniel burst out laughing.
“Oh, jeez.” James rolled his eyes. “I walked right into that one.”
“Seriously, it stands for Yet Another Ignorant Rookie. It takes forever to grow out of that label, believe me. Don’t worry, I’ll let you know
if you ask a dumb question.”
“Thanks. I really appreciate your help. I don’t want to appear too ignorant when I arrive.”
“Not a problem. I was you a year ago. Fortunately I had someone to help me over the initial hurdles—Charlie Fields. I’ll have to introduce you some time; you’d like him. Lucky for you, we’ve got months to get you ‘de-yaired’ before we reach Mars.”
“Okay,” James said, “here’s one for you: Why was the security at the elevator terminal so lax? No one even checked our bags. It was a lot stricter at the airport. What if I’d been a crazy with a bomb in my duffel, looking to blow up an elevator?”
“You think the security was lax, do you?” Daniel wore an I-know-something-you-don’t-know smirk. “That’s only because you didn’t take the security engineering class I took third year. Do you remember the double set of doors we passed through when we entered the building—sort of like an elongated airlock?”
“As soon as you passed through the outer doors, you were photographed, scanned, weighed and sniffed. Your image was immediately compared against databases of known and suspected terrorists from around the world. Had your image matched, the inner and outer doors of the bomb-proof airlock would have sealed until security personnel arrived. It's a good thing you didn’t match.”
“Likewise, if the electronic sniffers had detected any chemicals associated with explosives or other chemical weapons. Or if the various sensors had detected guns, knives or other identifiable weapons on your person or in your bag.”
“Wow. I had no idea all that was going on.”
“Good. That means everything worked as designed.”
“Okay, you also said we were weighed. What’s that all about?”
“Ah. Good question. When you stepped into the airlock, you were weighed by sensors in the floor, bag and all. Then when you presented your wrist at the elevator, you were weighed again. If you and your bag had weighed at least a kilo less than at the entrance, you would have been detained on the chance that you’d left a bomb behind somewhere in the terminal.”
“And, if you’d used a restroom before reaching the elevator car, you would have been weighed again as you left the restroom and that weight compared against a statistical average bowel movement, to see if you might have left something ‘extra’ in the bathroom.”
“Wait a minute! Are you kidding me? They compare pre- and post- bowel movement weights?”
Daniel burst out laughing and continued until he couldn’t breathe and tears streamed down his face. “You-you should have seen the indignant expression on your face when you said that! It was priceless.” He took a moment to compose himself, dabbing at his eyes with a napkin. “Actually, I was kidding. They do weigh incoming passengers and their baggage, but only at the elevator car entrance when you present your pass, and that’s simply so they can monitor the total weight of cargo on each car.”
James sighed. “Smartass. Okay, you got me again. I guess that makes me a yagger—‘Yet Another Gullible Rookie.’ Still, I’m impressed with all the security measures. Remind me not to smuggle any weapons in here.”
Daniel grinned. “You might also want to keep your voice down, before someone gets the wrong idea.”
James flashed a weak smile. “Sorry. So how do you know I’m not a terrorist who cleverly managed to fool all the sensors?”
Caught in mid-swallow, Daniel sprayed synthcaf out of his nostrils and onto the remainder of his meal as he simultaneously laughed and choked. “Sorry about that.” He dabbed at the mess with his napkin.
Still smiling, he said, “I don’t, of course, but I’ve never seen anyone who looks or acts less like a terrorist than you do. You could be a choirboy, and it seems to me that a terrorist dead-set on blowing himself up along with the elevator probably isn’t going to obsess over the safety features of the car and the cable like you’ve been doing.”
“Oh,” James said in a small voice. “I guess you’re right.”
“Hey, don’t sweat it. I’m happy you’re not a terrorist!” The two men shared a grin.
James decided to change the subject. “By the way, I’ve been meaning to ask where you’re from originally. I can’t place your accent. I know you went to UMC, but your accent isn’t Spanish.”
“I’m not surprised you can’t identify it. I’m from the Kuala Lumpur metroplex and the accent is Bahasa Melayu. Of course, with all the distinct languages and dialects spoken in Malaysia before Universal, picking out a specific accent is virtually impossible for anyone but a native.”
“So why fly halfway around the world to Nautilus when ODF Olivaw is in your backyard, so to speak?”
Daniel made a raspberry sound. “Remember when I promised to let you know when you asked a dumb question? Well, that was the first.”
James’ eyebrows shot up. “Really? Why was it dumb?”
“Why did I come all this way to ride Nautilus up to orbit instead of Olivaw?” Daniel grinned. “Simple. Because this is the ODF where my ride to Mars is berthed.”
“Ouch! Okay, you got me there.” James threw up his hands. “I surrender. No more dumb questions for now. Let’s just watch a holo or something.”
* * * *
The next morning, the two enjoyed a breakfast of synthcaf, pancakes, and some sort of tropical fruit juice that James couldn’t identify. The mealtime conversation was the kind of thing you might hear in any restaurant: sports, women, the stock market, women, politics, women.
Afterward, Daniel stretched his arms over his head and cracked his knuckles with a satisfied grunt. He glanced at the altimeter. “Twenty-one thousand klicks. We’re nearly a third of the way there. So, how did you sleep last night? Any trouble?”
“Nope. Just as you said, the beds are comfortable and there’s no feeling of motion. I dropped right off. I’m sure the fact that I was exhausted from all the traveling helped.”
“Excellent! So now that you’re all rested and alert, do you have any more questions for me?”
“Nothing comes to mind at the moment. Anyway, what do you get out of all these questions? Surely you could be making better use of your time.”
Daniel shrugged. “Not at all. I’m new, too, remember? You just happen to be asking questions that fall into my bailiwick. It’s good for me to think about these things, to review them in my head in case my supervisor asks me the same things. If we were talking about geology, you’d be the expert and I’d be the yair asking the dumb questions. Heck, I don’t even know the difference between sedimentary and ignatius rocks.”
“See what I mean?” Daniel grinned amiably.
James suspected that Daniel had messed up on purpose simply to build James’ confidence. Well, it worked. I know I’m not an idiot; I’m merely fishing in someone else’s pond. Of course I don’t know the ins and outs of elevator engineering. That’s not my field.
“Well, I’m out of questions for now. Just in time to avoid sinking even lower on the ignorance scale. How about a game of chess? Maybe I can stump you at something before this trip is over.”
Daniel rubbed his hands together with a hawkish glint in his eye. “Don’t count on it, bucko. I’ll take white.”
* * * *
The following day, shortly before the car reached Nautilus, the flight attendant rose and stood in front of the screen. “Ladies and gentlemen, we will begin decelerating in three minutes. Please take your seats during the transition.” The Fasten Safety Restraints sign lit up as she returned to her seat.
James turned to the designated channel on his seat’s viewscreen. Although the elevator car was still hundreds of kilometers away from the ODF, its immense structure was already easily visible, glinting in the sunlight. James knew that there likely were ships docked at Nautilus, but at this distance they were not yet visible. Off to the right was Luna, bigger, brighter and closer than ever. (CONTINUED)