At the top of each width of solar panel was a spring-loaded fin running along the length of each panel that deployed perpendicular to the solar sail. The fins served two purposes. They were made of a special material that absorbed the waste heat from the solar panels and turned a portion of that heat into more electricity. They also provided radiating surfaces to get rid of the remaining waste heat from the sail. The cooling vanes rolled flat when the sail was “furled” into the rollup cylinder of the spar to essentially turn off the generation of electricity
Albert showed Wallace the updated rectangular design on his computer display. “It looks like this design will actually be better than the one with the half-moon sails. It’s heavier, but the cost is almost certain to be lower and the ship’s sails are likely to wear longer. We can also do a better job of managing the heat in the engines and cooling system because we can furl and unfurl the panels quite frequently without putting a lot of stress on them. We’ll lose some cargo capacity to the added weight, but we’ll almost certainly save money on construction and wear and tear.”
Wallace watched the three-dimensional view on Albert’s design station as it rotated slowly on the screen. “How much additional weight?”
“We think about a ton because of the motors and the increased weight of the masts. That’s an upper limit, though; it could be quite a bit less if we can keep the weight of the masts and spars down.”
“What about the cooling vanes for the solar panels?”
“That might have been the easiest part of the redesign. We have to have at least one reinforcing rod attached to each section of panel to stiffen it. We changed the material in the rods and flattened them out so that they are now the cooling vanes. The vanes use an extra cable run in the pivot rods and sit perpendicular to their solar panels so they can radiate the remaining waste heat out into space.”
Wallace nodded. “Okay, let’s run it through the trip simulators to see how things work. We need the updated figures on weight, too. Every pound we have to put into the ship is a pound of cargo we can’t carry.”
“Okay, boss. I think we’ll be okay with this design. Are you going to update Klaus on the change?”
Wallace nodded again. “Yeah, but it will be brief. The savings in costs will make him happy and I’ll try to keep him away from the loss of cargo weight. Right now I think anything that saves money on the ship’s construction will be okay with him.”
The Lunar Compact
In the year since his first meeting with the Secretary General, Aman had politicked his way across more small- to medium size nations than he cared to count, promoting his (actually the Secretary General’s) draft of a constitution for the Moon. He carried the draft with him everywhere, looking for support from the Secretary General’s list of potential signatories, checking in to other possible supporters, asking for suggestions and listening to problems. In retrospect the draft constitution seemed to hold up well under scrutiny. People took it seriously and made thoughtful suggestions, some of which made their way in to revisions. Even though he was the one pushing the draft he was somewhat amazed at how many of the nations he visited seemed to approve and were willing to back it up. The Secretary General’s plan had worked; he had agreements in principle from twenty nations. Many of them were in a group he most wanted to have on board- medium sized, not particularly aligned with any political block, and interested in a piece of the lunar action. He thought he could turn those agreements into reality, especially once the first ship made a run.
He thought he understood the reasoning behind the general reaction. From the viewpoint of the less powerful nations in the U.N. the Lunar Compact would give them a chance to wedge themselves and possibly the rest of the world into what was the nearly exclusive province of a small number of powerful nations. (One of the first suggestions he received was to call the proposed document something other than a Constitution.) It would also help to reduce the threat of open warfare between nations who wanted a piece of the lunar pie. That was the most significant of his original concerns, and it looked as though his efforts and that of the Secretary General were going to pay off.
Once Aman had started to push the Lunar Compact there was no way he could keep the agreement or the ship secret. Fortunately the current crop of spacefaring nations weren’t taking the project seriously. They thought of him as foolish and considered his personal crusade to get to the Moon a rich man’s folly, nothing to spend always-scarce national resources on. As far as Klaus and Chaz could tell no one was even trying to evaluate Wallace’s work. The potential competitors were all busy making money on their satellite businesses. In a strange way the Compact had contributed camouflage for the ship; the space nations focused on the political issues and were unconcerned about the progress of the project. They treated Aman’s objective of protecting a lunar colony as a big waste. There weren’t any colonies now; they themselves weren’t planning any, so why bother?
Nonetheless, he wasn’t entirely happy with the outcome. The draft had taken much more of his time than he had anticipated, and as usual time was money. (The push also hadn’t been much fun.) His businesses had suffered from neglect and would suffer further if he wasn’t able to get back to them soon. Aman was hoping he could get an announcement in the immediate future, partly for the sake of his businesses, but also because the first ship was nearly ready. When his drone explorers landed on the Moon, he wanted to get the Lunar Compact portrayed to the public as more than a piece of paper. Once out in the open, it should be harder for any latecomers to seize any of the planned research stations.
At least that was what he hoped. His next tasks were to get his group of nations together to establish some sort of government for the Moon, publicize the agreement, and arrange for some security to be on the Moon as soon as the civilian research station was inhabited. All of it would cost money and time. He wasn’t sucking so much of his personal wealth out of the businesses that he would lose control, but he still had to keep things moving. That was likely to change as soon as the Treble Foundation (or maybe one of his corporations?) starting shipping people up for long-term stays. He had to get things wrapped up soon or find additional sources of funding to bear some of the burden.
The Assembly Drones
The drone team entered the new control room and took a look around. The room itself wasn’t much; empty except for a series of ten workstations that looked like they belonged in a game arcade.
The operator positions were comfortable shells with some isolation from each other. Each faced a bank of monitors dedicated to the management of a single drone. Each drone needed the support of two workstations. Ten workstations controlled four drones; the last two were supervisory stations that could take control of any given drone if need be, but whose primary functions were to coordinate multi-drone activities and manage the overall workflow.
Over the next two months the drone team would actually work with simulations of the actual drones while the machines themselves were still being completed and then taken into orbit. Once the drones were up the workstations would switch out of the simulations into live operation in space.
The team’s two months would be spent learning the basics of drone handling first, and then learning how to assemble the construction space dock and the ship in the alpha version simulation. The operators would contribute their experiences in the alpha simulation to the development of beta procedures, recommending needed changes to the space dock and the ship kit. Then beta feedback would be applied to a production simulation. Wallace and company hoped that the production simulation would deal with one hundred percent of the real in-space procedures that operators would have to execute, as well as a goodly portion of any unexpected contingencies. That was probably a bit unrealistic. Somewhere, somehow, something unexpected would turn up. That would be the real test of the in-space concept and the drones themselves.
In addition to building the space dock and the ship, two of the drones would be carried on the ship to be used f
or some regular and all emergency maintenance. Some members of the ship’s crew would learn the basics of drone operation to enable them to operate the drones during voyages. For the cargo carrier, all of the human crew would work from Earth; the ship’s artificial intelligence system and the drones would be the crew for the trips to Moon orbit. The human crew would return to action when the ship dropped its passengers- a set of three stations and six mobile drones, customized for landing and exploration of the lunar environment. The mobile drones were one-way actors. They would land as a group via a rocket-powered frame and break off to start their exploration.
Each construction drone was controlled by a “mover” workstation and a “handler” workstation. Both mover and handler workstations had nine video screens, each of which covered sixty degrees of vision horizontally and sixty degrees vertically. The human controller could view a full one hundred eighty degrees of horizontal space and one hundred eighty degrees of vertical space. There were controls for forward and backward acceleration, a two-button joystick allowed the user to turn right or left; pushing the joystick forward caused the drone to nose “down” from its position, while pulling back would turn the drone “up.” Up was defined as moving into the drone’s primary headlight beams; down moved the drone into the light from two smaller headlight beams on the bottom of the drone.
There were also controls for two tether reels on opposite sides of each drone. The tethers had hooks and electromagnetic pads at the ends to fasten a drone in place, both to keep the drone relatively motionless while working and to keep a drone from escaping away into space in case of an accident.
The handler workstation had a similar visual setup with nine video screens, but the controls consisted primarily of two sets of two gloves each that the operator would use to control the motion of four manipulators on a drone. The “big” manipulators were near the top of the drone on opposite sides of the body. The two “small” manipulators were set close to one another at the front of the drone top (or “head”). Via drone an operator could grasp, move, and handle parts of the ship kit. The manipulators were first rate technology, one set enabling the operator to grasp and move large, heavy objects such as a plasma engine and the second set capable of manipulating small parts that required fine motor coordination like tools, screws and other small fasteners. Within some limits the large manipulators could also be used to pull the drone around the ship or the space dock. The two operators thus had control over two different forms of locomotion for their drone- maneuvering jets to cover distances and position a drone quickly and manipulators to pull the drone along the space dock or parts of the ship for short distances.
The drones were designed to propel themselves by jetting water steam from nozzles arrayed around the frame of the drone. Water was heated by electricity from solar panels and pure sunlight where there were no panels. The operator could control speed by releasing more or less steam through the drone’s jets, but the jets were limited to prevent an operator from overaccelerating. The two tethers, the ends of which could be fastened to the ship or the space construction dock that the ship and its parts were clamped to, also limited drone motion. The tethers ensured that the drones could not fly off uncontrolled in case of an accident or malfunction. The tethers were retractable, and proper procedure was to have at least one tether attached to the ship assembly or the space dock at all times.
In a nearly frictionless, zero gravity environment like space, it’s easy to forget that a little push will go a very long way. It’s easy to forget that objects moving in space won’t stop unless they are stopped by a force equal to and opposing the force that started them moving in the first place. Inexperienced drone drivers were very likely to use too much speed and force to get to a position, especially one at some distance from the drone’s starting point. They were also very likely to make braking mistakes by using too little or too much braking force.
For very small distances the move operator could maneuver a drone in what the team called “manual” mode. In manual mode the joystick worked just like a game joystick, slowly rotating the drone in the direction required. Once the target was in the operator’s gun sight the accelerator pedal was pushed to get the drone moving, albeit slowly because of the firm limits to acceleration built into the drones’ programming. Once the drone was moving it was necessary for the operator to brake the drone with the brake pedal; again with the force of the jets severely limited.
For larger distances, however, more force was needed to move the drone quickly, and more force was necessary to stop the drone’s motion. It was hard for operators to move the drone efficiently, and even harder to balance the braking force against the original push to stop a drone in the proper position.
The team attempted to deal with the problem in a very video game-like way, both to reduce the amount of time and fuel it took to position a drone and reduce the likelihood of collisions with the ship, the space dock, or another drone. The operator could set the drone in “automatic” mode, in which the drone handled all the calculations to start, maneuver and stop itself to get to the desired location.
The mover operator could set a target on an object by rotating the drone and setting a gun sight on the object. The operator then pressed the Calculate button on the joystick; the drone brain would calculate the distance to the object and the force vectors needed to get the drone to the object. Speed was not controlled by the operator in automatic mode; the drone calculated a speed appropriate to the distance and the availability of fuel. If the operator was satisfied with the parameters calculated by the drone, he or she pressed a button on the joystick to execute the move. The drone fired its steam jets and then fired a reversing set when the drone was within the drone manipulators’ reaching distance. In the process the tethers were automatically reeled in or out to minimize tangling and prevent the drone from coming to a halt because it ran out of tether. The process was a little cumbersome but reduced human error in positioning. To the extent possible the drones did their own “housekeeping” to maximize the efficiency of the operator. At least, that was the plan.
Drone Problems
Lucy slammed the joystick forward, causing the simulated drone to spin head over heels. As the drone wasn’t real, the only thing the slam did was cause the view on the displays to roll as if the camera was attached to a ball. She needed something to throw and there wasn’t anything available.
“Damned rotten little teapot!”
Wallace pinched his nose, trying to relieve the tension brought on by one of his cousin’s temper tantrums. He hadn’t planned on hiring his cousin even though they needed someone in the programming area. Family forces being what they were, however, he had relented and brought Lucy on board. As good as she was she had a temper, one that tended to show up in verbal abuse of whoever or whatever was the source of her frustration. He restrained himself and did his best to ask a calm, meaningful question.
“What’s wrong, Lucy? Is there something we should look at?”
“Yes, dammit! Every time I try to line something up the jets aren’t calibrated closely enough and the stupid teapot drifts past my target! Worse, the little tiny difference between the two brake jets causes the stupid drone to turn. I can’t get the drone lined up enough to pull the trigger to get the damned thing moving in the right direction!”
He looked over at Albert, who motioned him over with a pained look on his face. Wallace took the couple of steps over to Albert’s station. He whispered quietly, “Is she right?”
Albert shrugged. “She has a point. The drone sims work but it takes a lot of time to line one up on a target. If the calibration of the jets is just a little off it gets to be a real pain to line a drone up and get it moving in the right direction. Something has to be done; the drones will be out in space where we can’t just go out and replace or recalibrate pairs of jets.”
“Are you sure this isn’t something in the simulations, rather than the drones themselves?”
“The guys checked t
he simulation software. They’re pretty sure it’s a real design flaw. They checked the design of the steam jets and with no friction and no gravity it doesn’t take much of a difference to cause the drone to spin.”
“Well, what are you going to do?’ yelled Lucy. “I’m not going to spend my drone time jockeying one of the little bastards around. We need an effing solution!”
Wallace made a conciliatory motion with his hands, hoping he could quiet Lucy down a bit. “Okay, Lucy, okay. We’ll take a look at the design of the drones to see what we can do. We get the point. They’re hard to maneuver with the jets. Albert and I will get together with the drone engineers to see what can be done. We’ll review the procedures manual too; there might be something we can do to help the drone drivers guide them. Why don’t you take a break, relax a little, and try running through some manipulator scenarios at one of the handler stations?” He looked at the rest of the trainees in the drone room. “I think it’s best if everyone takes an early lunch and work at the manipulator stations when you come back. Team up and take turns running the scenarios. And if anyone has any ideas to improve handling of the drones, feel free to share them with Albert or me.”
Fixing the Drones
“Okay, Albert, let’s hear it. Can we fix the drone design?”
Albert nodded. “Yeah, Wallace, it can be done. We’ve run a couple of designs through the simulators and the best one works really well. The only problem is that none of the workable designs are modifications. It’s actually a brand new drone. At least half, maybe more of the original design is being replaced.”
Solar Sailer Page 5