by OMAR FINK
All the hands had gone down and the questioners were now silent, so Ed continued, “Please remember we have included all the details in our written report, which is available to everybody in the room.”
He paused momentarily, then continued again, “Once we have a cable long enough and strong enough, we need to turn our attention to the climbers. A climber is a payload transport that has the ability to winch itself up the ribbon cable. The major issues with climbers is how much weight the cable will sustain and how we’ll get power to the climber. My company, Tethers, has a preliminary climber design but it has yet to be actually built and tested. It uses electric motors and friction wheels to climb the ribbon cable. It’s not practical for the climber to carry massive batteries or fuel tanks, but at the same time, once this issue is solved, it becomes an advantage over lift rockets. The climber will be supplied power by beaming lasers to photo-voltaic, or solar panels that convert light to electric energy. We are also investigating the possibility of using the carbon nanotubes in the ribbon cable to provide electrical conduits. We don’t know yet if this will work, but the solar panel solution is ready to go today.”
Ed shuffled some papers around on the table in front of him, found what he was looking for and held it up for everybody to see. He said, “Here is a mock-up of a scheduling time table for climber activity. The ribbon cable will only hold so much weight at one time and this limits the size of the climbers and the number of them that can be on the cable at the same time. But the weight of the climbers will change quite a bit during their voyage, which by the way, should take around seven days. This is assuming speeds of around two hundred kilometers per hour. Back to the time table. Each climber will weigh less as it climbs higher, reaching zero weight as it approaches the platform at the geo-synchronous altitude. This allows us to add new climber payloads at the bottom as the ones already on the ribbon cable reach higher positions and weigh less.”
Ed put the papers back down on the table and continued, “When a climber reaches the geo-synch platform, it can either stop and offload its cargo, or if it continues on up the ribbon cable, once it passes the equilibrium point at the platform, the force applied to it is upward or outward from an orbital point of view. The farther out the far end of the cable the climber goes, the more force is applied to it. By allowing the climber to progress to a desired point and then releasing it, we can actually “throw” the payloads out to Mars and beyond to the asteroid belt. In normal freight lifting operations, it would make sense for the climbers to unload at the platform and then crawl back down the cable to reload once they reach the ground. For our application, it makes more sense to use one way traffic only. This allows us to put only upward bound climbers on the cable, instead of sharing the cable capacity with empty climbers returning to Earth. The climbers can be designed to become part of the habitats under construction when they arrive at the construction location. We will use the outer portion of the cable to throw them into the correct trajectory to reach that location.”
Ed paused and somebody asked, “How many cables will it take and how much will it cost?”
Ed replied, “We don’t have finite answers to those questions yet. However, we can make some pretty good ballpark estimates. The reason why we don’t have hard numbers yet is because we don’t yet know how strong we can make the ribbon cables. We are fairly confident that we can begin with a load of around one hundred tons per cable. We think we can improve on that number as we go, but won’t know how far until we actually get some elevators into operation. If we can ramp up the ribbon strength substantially, it will decrease the total number of space elevators we’ll need in the end. If we can’t, we’ll need to build more. Our current estimates show we’ll need about one thousand elevators and that will cost somewhere in the neighborhood of ten trillion dollars.”
At this point, Andy Watson rose and interrupted, “I know you all have some questions, but let’s take a quick break and get some more coffee in here, and we’ll let Ed answer as many questions as you have.
+42 days, JOHANNESBURG, SOUTH AFRICA
Delize Naidu stepped out of the Aikido dojo onto the sidewalk and glanced up into the sky darkening at dusk. A dark skinned male followed her gaze and asked, “Watcha lookin’ for D?”
Delize turned her head to see who spoke and replied, “Hey Sibo, just lookin’ for that comet thing everybody talking about.” She pointed at a speck of light near the horizon, “You think that’s it?”
Sibo looked at the sky where she pointed but shook his head, “I dunno, that’s for sure. I just know what they say on the TV news. That French reporter was saying it broke into pieces and it’s gonna come back here in ten years, but they don’t know yet if that will be bad or not.”
Delize looked back at Sibo, “Yeah, I saw him. Gitane something, right? He said they don’t know what’s gonna happen, but he seemed worried.”
Sibo sighed and looked back at Delize, “Ten years is a long time. All those smart people they got working on stuff like this should be able to come up with something to do, right?” Then his face brightened up, and he added, “Oh hey, congrats on passing your Shodan test last month. I missed it but heard you did great.”
Delize smiled back at him and answered, “Thank you Sibo. I was nervous, but once we started, it all seemed automatic, just like practice. I dunno. They tell us there is a harmony to things and Aikido is just the way of finding the harmony and moving with it. That’s actually how it seemed while I was taking the test. All I had to was find the harmony and follow it and everything else seemed to disappear. It seemed easy at the time.” She shook her head.
Sibo asked, “How long did it take for you to get to Shodan?”
Delize answered, “A little more than three years, going three times a week. Now that I have that first degree black belt, I get to start working on the next level.” She sighed.
Sibo said, “You should be proud. I’ve been coming here for five years and haven’t reached Shodan yet. But then, I only come twice a week. Anyway, you done good, girl.” He looked back at the light in the sky.
Delize followed his line of sight, “If my son was here, he could tell us if that’s the comet. He’s only sixteen, but he loves the stars and stuff. He’d probably say it’s just Venus, though.” She laughed.
Sibo laughed back, “Well, see ya later D. I gotta get home.”
Delize replied, “See ya Sibo.” and turned and walked toward her car.
+43 days, GENEVA, SWITZERLAND
The image of Eileen Gillespie on the video screen shifted and shuffled some papers in front of her, then cleared her throat. She began, “My team has been working on the logistics of moving people, on medical screening and treatment, and on education. Let’s take them in that order. We’ll need to move eight billion people from points all over the planet, to the elevator base stations near the equator. This will probably take place over a seven to eight year timetable, depending on how long it takes to build the first elevators. Using the numbers provided by the elevator team, we need to plan for moving somewhere near one hundred million people per month to the base of many hundreds of elevators. These are ballpark numbers of course, based on best guesses at the moment, and they are subject to change. The only things we know for sure are that we have less than ten years and no more than eight billion people.”
Eileen squirmed in her seat again and continued, “These numbers further break down to over one hundred thousand people per month per base site and that means around five thousand people per day per site. Of course, this is not a starting point, but a peak volume estimate. In order to maintain a steady state stream of people always ready to get on an elevator climber, we’ll need to create a queue of several days backlog that can be managed to create a smooth flow. All the infrastructure needed to do this already exists but it will have to be committed to the purpose and mobilized on time. In addition to transportation, we need to consider housing, food, and medical care.”
Eileen picked up a stack
of papers and moved it to the side. She continued, “Since we also need to consider medical care, let’s talk about that. Everybody who is involved in this migration will at times be in small enclosed spaces with other people for days at a time. Before moving into this environment, we need to perform at least a basic medical screening to prevent outbreaks of contagious disease. It also makes sense to know who are the most fragile people being transported and put into strange new environments. We can also use this opportunity to do some basic immunization. Since we’ve already established the need for a queuing process, we should integrate the medical screening and care with that.”
Eileen moved some more papers and adjusted her seating position. She said, “At first glance, education doesn’t seem to play a role in the migration, but it does. A certain percentage of humanity is functionally illiterate. It will be difficult to rapidly integrate uneducated people into a strange new living environment where it’s simply not possible to step outside the nearest air-lock and survive. This basic education process will have to be done. The only point of contention is whether to do it on the ground or do it out in space after the move up the elevator.”
Eileen gathered together all her stacks of paper and moved a little closer to the camera supplying her image. She spoke, “What we are proposing is a comprehensive staging process that spans several months and integrates all of these functions. We need to move and stage and queue people. We need to screen them medically and apply remedies as needed. We need to screen for educational needs and then also supply education as needed. A person who needs no health care attention and is already fully educated can breeze through the screening and staging in a few days and get on an elevator climber to take them up into space. Anybody who needs more attention can be diverted into a clinic or hospital or school of some sort. Large amounts of this process will need to be automated and made into self service functions.”
Eileen added, “And finally, we were asked to supply cost estimates. There are many different ways to address the issues we’ve looked at in my team. And the base assumptions are all essentially guesses. But to finance the entire package as we’ve laid it out will probably cost in the range of twenty-five to thirty-five trillion dollars spread out over ten years.”
+43 days, JAIPUR, INDIA
Nabith Mehra used a push pin to attach a sheet of paper to the bulletin board in the kitchen and announced to no one in particular, “Here is the family chore chart.”
His mother turned from her task preparing food for dinner, “That’s very nice, Nabith.”
Nabith responded, “You said I must step up and take my place in keeping the family on the path of righteousness and dharma. I started with the things you and auntie and gammy already do most days, then added all the other things that must be done and started assigning tasks according to who is capable of doing what.” He smiled.
His mother smiled back at him and wiped her hands on her apron. She walked over and began to scrutinize his chart. She pointed at several items and murmured to herself, “Mmm-hm” several times. Then she turned to Nabith who was watching her intently, “That’s good Nabith. Now begins the task of getting everybody to stick to their assignments. That’s usually not as easy as just telling them what to do. I can help you with that.”
Nabith smiled at his mother, “I also have a plan for tutoring all of the kids in math. Since I am good with math, I can do that myself, but eventually we’ll also need a plan to tutor them in other subjects where I am not so good.”
His mother replied, “That’s excellent.”
Nabith continued, “But I don’t know how to plan our budget and spending. I’m going to need some help from you with that. Oh, I can set up a spreadsheet okay, but I don’t know what the numbers are that need to go into it. Once I have the spreadsheet designed, it will make it easier for you to know how our budget is working.”
His mother said, “That’s a good idea. Let me know when you want to work on it and I’ll bring my checkbook and the bills, and we can do it.” She smiled at Nabith.
Nabith smiled back, “You said following Dharma and the path of righteousness is important. That is really just other words for the idea of ethics, or what is the right thing to do. I’m convinced we should be able to set up a matrix, like in linear algebra, that will help us to determine what is the right thing to do when we’re not sure. But I will need a lot of help with that because the words people use to describe ethics are confusing. It’s probably the same thing with the word Dharma.” He looked at his mother curiously.
His mother smiled again, “Indeed. Nabith, you are wise beyond your age of thirteen, but if anybody can do that it is likely to be you. This will be a long term project and I advise against expecting any quick results because you are correct about the confusing language and it will take some effort to sort it all out. But I will help you with this. It is another good idea.” She beamed at her son.
+44 days, GENEVA, SWITZERLAND
Andy Watson finished the last bite of his scone and washed it down with a drink from his mug. Then he rose and addressed the group, “This morning, we’re starting early with the report from Marco and his team on building space habitats. After that, we’ll be served a full breakfast buffet and then resume our breakout teams as needed. By now, Marco should not need any introduction.” He waved in the direction of Marco, “Marco, the floor is yours.”
Marco remained seated, but spread his arms out wide like he was greeting an old friend and with a broad smile spoke loudly, “Good morning! If Andy won’t introduce me, I guess I’ll have to do it myself. My name is Marcello Lagorio. Please call me Marco. I am a consultant for Space Habitat Engineering, a company that designs habitat dwellings for humans to live in space. Let’s begin by defining what we’re talking about. Once we build enough space elevators to migrate eight billion human beings off the planet and out into space, we’ll need somewhere for them to live. It doesn’t make sense to go back down into a gravity well after we’ve spent so much time and effort climbing up out of one. That rules out any planets like Mars or even most moons. There are two primary requirements that must be met first. We need a contained atmosphere to breathe. We need gravity for our bodies to stay healthy in the long term. Many years of studying design options and engineering calculations show us that the best way to meet these requirements is to use a rotating wheel design.”
Marco put his hands out palm down on the table and a serious look took over his face, “Imagine a giant wheel, about five kilometers in diameter and several hundred or maybe even a thousand meters wide. The rotation of the wheel provides a form of artificial gravity. We need at least one third of normal gravity for healthy living and there is little point in creating any more than normal gravity or one G. We can control how much downward force we create against the floor by varying the rotation speed of the wheel. We will spin it at a rate to create one G at the outer edge. We can build floors upward from the outer edge until we reach the level where one third G downward force exists, and we should stop there. For a wheel with these dimensions, that tells us we can build a little over three hundred floors up from the bottom or outer edge. The width is likely to be tapered but using an average width, we can calculate the amount of living space we are building inside the wheel. Assigning an ample amount of space for each individual living in the wheel, we can support a population of around ten million people. Assuming these dimensions are fixed for all the habitat wheels we build, we will need eight hundred wheels to house eight billion people. Of course, I’d imagine we’ll start out smaller than that and build up to larger sizes.”
Marco paused, then continued, “The construction of these habitat wheels will need to begin before the first elevator goes live, so people have someplace to live when they get out into space. This means the first wheels will need to be very close to the top of the space elevators, although we can throw the climber shuttles out to the wheel position. We should consider pushing each wheel into a trajectory that will take it out tow
ard the asteroid belt because that is where the richest building materials will be found. And don’t forget we’ll need volatiles for life support and fuel needs. We can always have a few habitat wheels near Earth to offload the elevators, but as each one fills up, it should be sent off to the asteroid belt and the building of a new one can begin. We might find it necessary to over populate each wheel at first, then allow them to build more living space as they move into the asteroid belt. I’m not sure about this, but any way we do it will need a detailed time line for construction planning. The first construction materials will have to come almost totally from the Moon base. It’s just too expensive to lift raw materials on the elevators, which would also be taking up mass capacity we need for people.”
Marco let out a big sigh, leaned back in his chair and clasped his hands behind his head for a brief moment, then undid those actions, unclasping his hands and leaning back toward the table. He placed his hands on the table with his fingers rolled up, “We can do this.” He sighed again and nodded his head in agreement with himself. “We can do this. But it will take a maximum effort and a massive amount of money.” Marco sighed again and looked worried.
