Another reporter’s hand went up. “I’m Samuel Loo, U.S. correspondent for Taiwan Science. It took roughly three days for Apollo 11 to get from Earth orbit to the Moon. Are you saying your ships will get people to the Moon in less than a day?”
Danny was beginning to thank his stars for the long briefing Chaz had given him. “That’s right, Sam, we think eighteen to twenty hours from earth orbit to lunar orbit. And we won’t leave anything like boosters behind when the ship returns.” He stopped for a moment to come up with a good way to communicate his next thought. “I have to correct that. The ship will leave things behind, but those will be the deliverables that will do the work on the surface of the Moon.
“Concerning your question, speed has never really been an issue in getting to the Moon. It’s always been about the expense. Our solar lightships are going to do their jobs not just quickly, but cost effectively. The biggest problem of getting to the Moon has been solved not by us but by the people who have made inexpensive trips to Earth orbit possible. That’s always been the big cost. We’re going to go faster, but it’s more about cost, reusability, and reliability for us. The Moon isn’t going to be our big payoff, either. The real payoff will come when we begin to make trips into interplanetary space, where the continual acceleration of our ships will greatly reduce cost and trip time compared to chemical rockets, making human travel to Venus, Mercury, and perhaps even Mars truly practical. Next question?”
Another hand went up. “Tom Stoneman, of SpaceToday.com. We’ve heard rumors that your ship is actually going to be flown by an artificial intelligence. Is that right?”
Danny nodded. “That’s correct. On this first flight, control will be shared between our people here in the control room and the ship’s onboard manager. My people will handle departure and the return to our orbital ship dock. The rest of the trip will be managed by an artificial intelligence that was named Alvin by the software developers. Alvin’s tasks will include deceleration turnover and insertion into lunar orbit. Alving will also be executing some detailed mapping as the ship orbits around the Moon. On this trip, the ship will stay in lunar orbit for two weeks. The timing of the Edison’s stay will enable us to obtain sunlit visuals of both sides of the Moon. If all goes well, Alvin will handle all aspects of the next voyage of the Edison.
“Alvin is also capable of running the maintenance drones on board the ship. It’s our thought that operation of this cargo carrier will be under complete control of the ship’s brain, even to the extent of managing emergency repairs. Between Alvin and our maintenance drones, we hope that any problems with our ships can be repaired in space and without human intervention.”
A hand in the cluster of politicians went up. “I am Serafina Delgado, representing Mexico. As signatories to your Lunar Compact, will there be any benefit to us as you begin interplanetary space travel?”
This was another question that Danny wanted to answer in exactly the right way. He smiled. “That depends. As a signatory, we hope you will take advantage of the intent of the Compact and give serious consideration to sending not just scientists, but other skilled workers as well to the Moon to help establish human habitats there. If you’ll forgive a theft of an old company saying, we would also like you to consider buying a piece of our rock. Your country and the others that have joined the Compact will be given priority as you help us build places for the first space settlers to live and work. The Compact contains rules for establishing ownership of portions of the Moon’s surface, so the legal wrangling over who owns the Moon can be kept to a minimum. Right now, the U.N. treaty says no one owns any part of the Moon. That might be workable when no one’s there. It becomes less practical when there are permanent research stations, and ever more impractical if there is some value to controlling property on the Moon.
“We believe your participation will benefit both your nations and our project by showing your citizens what you have obtained for their tax dollars. It will also enable the development of a group of skilled citizens in space. Their discoveries will contribute to the welfare of your people, and these citizens of your countries will be in great demand as space becomes the next frontier for all of humanity.”
Ms. Delgado asked another question. “Can you be more specific about benefits? The major space powers think there is no rationale, other than scientific curiosity, for establishment of permanent habitations on the Moon.”
Danny knew his briefing had been superficial but he decided to try an answer anyway. “We believe that merely addressing the challenge of survival on the Moon will be of enormous value to humanity over the long run. I understand your concern, though. The dollars needed to fund a Moon colony are immediate, while the scientific benefits are in the future, at best.
“Our intention is to establish the Moon as a waystation on humanity’s journey to the other planets of the solar system. The Moon has all of the materials necessary to build ships that can journey to the planets. Beyond availability of materials, energy is much cheaper than on Earth. In the short run solar energy is available in greater quantity than on Earth. In the long run the Moon has a greater supply of deuterium and tritium, isotopes of hydrogen that will be used to fuel fusion powered space ships. Perhaps even more important, the cost of building and operating spaceships will be considerably reduced if we don’t have to bring fabricated parts up from the bottom of Earth’s gravity well. If we can build and fuel ships on the Moon, getting to the planets will be much more cost effective. The cost of a colony on the Moon will be high, but it may be quite small compared to trying to build and fly ships from the Earth’s surface. And if we’re going to Venus or Mars anyway, why not do it cost effectively?”
A number of hands went up. Danny knew he was already out of his depth and it would be a good time to hand the session over to Chaz. He smiled again and held up his own hand.
“I really think it’s time for me to get back to the things I know well and leave questions about planets and spaceships to people who understand these things. My good friend and director of my space unit, Dr. Delsun will take over now. Thank you for attending our announcement.”
Maiden Voyage
Kevin looked at the screens over Arturo’s shoulder. They were both nervous; even though the scaled down test ship had worked well they were scaling up a lot, with more weight, more stress on the sails, and more heat to dissipate. If this worked, though, the world was going to be a different place. Space would change the world.
This launch wasn’t like the tests in another way. They had an audience. Danny Smith was in the group that Dr. Delsun had brought in. And Kevin noticed the tall blond that Danny had with him. She was as much a notable as the man himself. There were a few other people in the group that Kevin didn’t recognize. He steeled himself and headed to the back of the room to greet and meet.
He returned to stand next to Arturo, a little dazed by the rare air and the tall blond. Kevin pulled himself together and spoke quietly to his chief engineer.
“How does it look?” he asked.
Arturo scanned the screens and cracked his knuckles. The knuckle-cracking was the tell that Arturo was nervous. He took a surreptitious glance at the visitors before answering. Suzette stood behind the other workstation, looking over Robbie’s shoulder.
“Everything looks good. All green; no marginals. Mark One looks good; power to environmental and control systems optimal.”
Mark One was the first of a series of control points along the sail masts, indicating how much of each sail had been unfurled and was active. At Mark One the solar fabric rolled out far enough to provide power to the ship. It was the minimum position of the sails as long as the ship required power. The sail area exposed to the sun at Mark One was just enough to run the ship’s systems without starting the drive motors.
Kevin took a deep breath. “Okay, then. Arturo, unlock from the frame. Robbie, push her off with maneuvering jets on Arturo’s mark.”
Almost immediately, Arturo announced, “She’s unloc
ked from the frame. All locks open.”
Robbie responded, “Jets on at Five, Four, Three, Two, One, Execute.”
Everyone looked at the exterior views of Edison on the central screen. A half dozen views of various parts of the ship were displayed, with rotation of two views every thirty seconds. The views came from cameras on the assembly dock. Robbie turned the small control wheel of the maneuvering jets and pushed buttons. The ship moved ever-so-slightly away from the space dock, continuing to drift after the jets were shut down. Once the inboard sail of the ship was a few meters away from the frame, Robbie announced, “Ship clear of frame.”
Kevin spoke into the air. “Alvin, how are you doing?”
A disembodied voice filled the control room. “Everything is A-OK, Kev.”
Kevin wasn’t a fan of the short form of his name, but Alvin stuck with it. Alvin would handle navigation and engineering on the voyage. It was a test not only of the ship, but of Alvin as well. Although Alvin had flown the scale model, that one was never intended to venture out away from the Earth. Alvin was going to take this trip to the Moon and back.
With a little luck the people in the control room on Earth would have little to do during the trip. Their visitors would get bored and decide to check in once in a while as the ship completed its first voyage. The human team on Earth would monitor only the first few hours as Edison’s early acceleration widened her orbit. Alvin would handle most of the remainder of the trip, including insertion into orbit around the Moon.
Assuming all went well on this no-cargo “dry run” the human team would exert greater control during the next run, when three fairly expensive automated research stations and four mobile drones would be the cargo. People would be observing and involved as Edison’s cargo was separated and the cargo components landed on the Moon’s surface.
“Okay, Alvin. We’re going to get moving.” He turned to Robbie. “You’ve got the con, Robbie. Unfurl the sails to Mark Two. Ship’s engines on ten seconds after sails at Mark Two.”
They all watched as the next portion of the black solar panels unrolled to form more sail area in each of the four quadrants of the sail array. The process was both slow and tense; some of the sticking points in the first system tests were failures of the small sail motors. Those problems had been solved for weeks, but the team still remembered the frustrations.
“Engines One and Four up and running at low power,” announced Arturo. “Fuel consumption matched. Sail ring controls wiggled and operating smoothly. Acceleration at zero point five meters per second-second.”
Alvin’s voice came on over the speakers. “Confirmed. Moving slow but sure.”
Kevin rubbed his hands together and smiled. The rub was his nervous tell. “Okay. Unfurl the sails to Mark 4. Let’s get her moving.”
Arturo smiled. “Aye, Captain.” He hit the command sequence to unroll more sail, watching the motor positions on the masts and the slight increase in fuel consumption. Now everyone was smiling.
Arturo announced, “All systems nominal. Engines Two and Three online. Acceleration at one meter per second-second.”
Alvin came on the PA system. “Navigation program up and running. Recalculating trajectory to compensate for launch conditions.”
Next came the big question. “How’s the heat in the propulsion system?”
Alvin responded, “Heat looks good, in nominal range. Looks like I’m not going to get toasted.”
Kevin smiled, although the ‘toasted’ comment made him nervous with management present. “Okay, guys. Check stress readings as acceleration and steering take effect. Let’s see how she does now that she’s at full power. Alvin, start pulse cycle. One hour of thrust for one hour of drift. We’ll take it easy this trip.”
“Aye Aye, Captain.”
“Robbie, Suzette, any concerns on trajectory?”
Robbie responded, “Nope. We’re off a little bit but barely worth the course correction. Probably should wait until we get to the planned orbital ellipse to make a correction.”
Suzette nodded. “Agreed. Trajectory is well within the error envelope at the moment. The recalc hardly changed on launch.”
Alvin interrupted the silence after the ship went to full power. “Isn’t this where people break out the champagne or something?”
There was a bit of laughter throughout the room. Kevin kept his smile. “Not yet, Alvin. Not until you get back from the Moon. Then the party will begin.”
To the Moon and Back
So far the plan had gone flawlessly. The trip to lunar orbit had gone quickly and the two-week-long stay above the Moon was over.
The human crew had been inactive during most of the trip, with the exception of the turnover of the ship to begin the midcourse deceleration that slowed the ship enough to ensure that it would be trapped in a lunar orbit. They watched Alvin do his thing for a few seconds, as he made sure that the torque of the rotating ship’s hull was properly balanced. The sails stayed pointed toward the Sun while the hull rotated in its gimbals to point the ship’s engines opposite the outbound direction of travel, beginning the task of reducing the ship’s speed as it neared lunar orbit.
There had been a small audience for the turnover. Danny Smith and Dr. Delsun, along with the tall blond that was Danny’s executive assistant. Kevin couldn’t help sneaking a peak at Charity. He wondered whether the beautiful young woman was more than just an assistant to Danny. But that wasn’t any of his business. Besides, he had to focus.
The turnover had been a big deal for his team, even though it hadn’t brought out any of the press. They had press out for the first turnover on the way out, but as usual the topic focus of even the interested journalists was only a few seconds long.
The team was still excited about this final turnover. After breaking out of its lunar orbit, Alvin now had to reverse the process to make sure that Edison made orbit around Earth. Even more than the first turnover, this course change demonstrated the versatility of Edison’s maneuvering system. It was going to be fun to watch; Alvin had cameras on the ship’s primary control module that would see the change in orientation as the hull rotated with the sail ring gimbals.
Along with the owner and his people, however, the team were the only ones interested. Of course, things might change as the ship came back to dock in Earth orbit.
Suzette, Lucy, and Robbie had started working with Alvin to develop an observation plan that took advantage of Edison’s ability to maneuver under acceleration shortly after he was awake and fully programmed. There had been refinements in the plan and mods of Alvin’s programming as issues arose. Once Edison reached the transition into lunar orbit Alvin and the computational people began work to execute the plan, collecting new mapping and spectrographic data on Edison’s first cruise to update information required to find possible sites for human-inhabited research stations. The stay near the Moon only lasted two weeks, but there were enough orbits and enough time to enable Edison’s video systems to record a map of the entire lunar surface in daylight.
In many ways a comprehensive orbital exploration plan for the Moon is hard to produce. To start, the ship had to orbit in a north-south direction because of the importance of the Moon’s poles as possible locations for human habitats, locations where water ice in permanent shadow and energy in the form of nearly constant sunlight were close to one another. Furthermore, the orbits couldn’t be due north and south; there had to be some angle to pick up a wider view of the area around the poles in “daylight”.
Then there was the problem of highly variable gravity. The Moon’s gravity changes significantly from place to place due to patches of dense material in some regions of the Moon. In particular some of the large meteor impact basins, which in theory should have a somewhat lower than average gravity, have higher gravity due to the higher density of the material in and under the basins. These areas, ‘mascons’ for short (for mass concentrations), cause Low Lunar Orbits (LLOs; about sixty kilometers altitude) to be unstable for satellites at
tempting constant velocity transits, orbits that don’t require power. Alvin had to use information from previous lunar expeditions to help him account for changes in Edison’s altitude as it passed over the dense impact basins. Fortunately for the purpose of polar exploration there are a small number of orbital paths at extreme angles to the Moon’s equator that are fairly stable over the long term. Alvin used this information to establish orbits that were stable during the stay of the moon ship in orbit around the Moon. This minimized the use of fuel while giving Edison an excellent view of the poles for her instrument package.
Another important aspect of the exploration plan was the long-term operation of the ship on nearly constant velocity (often called “frozen”) orbits with some portion of the orbit in the dark. While the “blackout” period of Edison’s orbit was small because of its roughly north-south orientation, there were times when the ship ran on batteries. During the daylight phase the ship had to recharge its batteries, as well as use its plasma engines to compensate for any loss of orbital altitude due to mascons along her orbital trajectory. This meant that the ship’s systems had to change state fairly frequently, from charging and acceleration on the daylight side of the Moon to battery supported, constant velocity operation on the night side. While some testing of the expected lunar circumstances were done in Earth orbit, the first trip to the Moon was the real test of the reliability of the ship’s systems where little help was available.
Lightship Page 29