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Introduction To "Race To The Pole"

The previous science speculation chapter, "Beanstalks", discussed various possible mechanical technologies, such as towers, beanstalks, and skyhooks, to place things in the sky without having them in orbit around the Earth. There is another technique for hanging things in the sky, and I have the patent on it—U.S. Patent 5,183,225 "Statite: Spacecraft That Utilizes Light Pressure and Method of Use", filed 9 January 1989, issued 2 February 1993. The unique concept described in the patent is to attach a television broadcast or weather surveillance spacecraft to a large highly reflective lightsail, and place the spacecraft over the polar regions of the Earth with the sail tilted so the light pressure from the sunlight reflecting off the lightsail is exactly equal and opposite to the gravity pull of the Earth. With the gravity pull nullified, the spacecraft will just hover over the polar region, while the Earth spins around underneath it. Since the spacecraft is not in orbit around the Earth, it is technically not a satellite, so I coined the generic term "statite" or "-stat" to describe any sort of non-orbiting spacecraft.

  

To a person standing on the Earth, the statite will be seen to rotate around the pole once a 24 hour day. If the statite is stationed close to the pole, the circle it makes is small, and more people in that hemisphere can observe the spacecraft for the whole day without it dipping below the horizon. The angle between the Sun and the sail becomes smaller the closer the statite gets to the pole, however, decreasing the light pressure force, so the hovering altitude of the spacecraft increases. In the wintertime, when the North Pole is always on the shadowed side of the Earth, it is easy to have the spacecraft hover directly over the North Pole as a polesitter. It is harder to do in the summertime, when the North Pole is in constant sunshine, but a detailed analysis that takes into account not only the gravitational attraction of the Earth, but the gravitational attraction of the Sun, and the centrifugal force due to the once per year rotation of the spacecraft around the Sun, shows that it is possible to have the spacecraft hover over the sunlit North Pole, provided it is more than 250 Earth radii away.

  

I originally had the idea for the polesitter back in 1979 when I was working for the Hughes Aircraft Company. But when I worked out the equations and put numbers into them, I found that even for lightsails with very low mass-to-area ratios, the minimum altitude at which the sail would hover was thirty to one hundred Earth radii, many times the six Earth radii altitude of the communication satellites in geosynchronous orbit. The round trip communications time delay from the ground up to the spacecraft and back again was many seconds, obviously much too long for the polesitter to be used as a communications satellite, one of the primary business lines of Hughes, so I dropped the idea. The polesitter concept was revived in 1986 as a possible method of providing continuous surveillance of the polar regions as an early warning system for ballistic missile defense. The concept was kept secret for a few years while the Hughes Defense Systems people tried to interest the Department of Defense in the concept. But with the end of the Cold War in 1989, the idea was declassified. Hughes didn't want to patent it, since they felt that geosynchronous satellites were adequate. I, however, didn't want to make the same mistake that Arthur Clarke did, when he didn't obtain a patent on his geosynchronous orbit communication satellite idea, so I obtained the rights when I left Hughes in 1987 and filed the patent. So far, I haven't made any money. But with the increased use of direct broadcast television spacecraft, weather surveillance spacecraft, and data link spacecraft, all of which are not bothered by a few seconds time delay, plus the increased crowding of the satellites along the geosynchronous orbital arc, I hope that before the seventeen-year life of the patent runs out on 2 February 2010, that the fictional story that follows becomes reality, and I can collect some royalties.

 

A science fact article describing the statite concept, "Polesitters", was published in Analog Science Fiction/Science Fact, Volume 110, No. 13, pages 88-94 in the December 1990 issue. This is the first time this story has seen print. 

 

 

 

The race to the South Pole was on!!!

The video news reporters had a field day making comparisons of this modern-day race in 2011 with the first race to the South Pole between Amundsen and Scott exactly one hundred years earlier. This time, however, it was "Andy" Hawke against "Scotty" MacPherson. But, instead of risking their lives by pulling their sleds to the pole across the barren ice of Antarctica, they were risking their fortunes by sailing their videostats to the pole across the barren vacuum of space.

Andy was more experienced and better financed. His first Polestat had already claimed the prime position over the North Pole a little over a year ago. Dubbed the Hovering Hawke by the press, it was a powerful multichannel broadcast satellite hung under a kilometers-wide square light sail. It hovered stationary in space over the North Pole by balancing out the combined gravity forces of the Earth and Sun with light pressure from the Sun. Now the enormous revenues from the sale of broadcasting services to Canada, Alaska, Russia, northern China, northern Europe, and the Scandinavian countries were financing Andy's entry into the race for the South Pole.

Scotty was a young impetuous "Johnny-Come-Lately" from Australia whose entry was still on the ground. The only "race" going on was the racing stream of promises and public pronouncements coming from his constantly moving mouth. Still the race made news and Scotty had no trouble finding video cameras to talk into.

"Now, in this room you can see the ultrathin film being laid between the front and back support webs," said Scotty into the video camera, an eager gleam showing up in his light blue eyes. The cam'er moved his camera's point-of-view away from the animated face under the mop of red-brown hair and zoomed through the thick glass window into the large airless room. Hanging from the tall ceiling at one end was a complex apparatus shuttling spools of fine wire back and forth, weaving a ten-meter-wide web of wires that arched down to join a similar web coming down from a duplicate weaving apparatus at the other end of the room.

Just where the two wide webs joined together was a glowing furnace. From the furnace misted a fine spray of molten aluminum onto a long, rapidly rotating metal cylinder. The liquid aluminum instantly froze into an ultra thin metal film which was pulled off the bottom of the metal cylinder and sandwiched between the two wire webs. The wire and film sandwich was welded into a single wide belt by electrical current passing between two highly polished rollers, and then the belt was wound up into a long roll.

"The aluminum film is so thin you can see through it," said Scotty. "That's why we have to make it in a vacuum chamber. If air ever got to it, the oxygen would disintegrate it." He held up a small glass container containing a section of wire mesh with a shiny thin film of metal stretched over it. He put the container up to his eye and the video camera looked through the film at the dim image of his eye on the other side.

"Doesn't that defeat the purpose of the film?" asked the video reporter conducting the interview. "The way I understand it, the force needed to levitate your Heliostat is supposed to come from the sunlight bouncing off the film. If it's transparent, you won't get any lift."

"But the thinner you make the film, the lighter it is, so the easier it is for the sunlight to lift it," replied Scotty. "When you go through the numbers, it turns out the optimum thickness is when about forty percent of the light goes through the film and sixty percent reflects off." He stopped and pointed into the room. "That roll you see being made is the twelfth and last one. As soon as it's installed in its vacuum canister and attached to the spacecraft, we'll be ready to launch." He turned away from the camera and started to walk off. "Now, let me show you the spacecraft itself."

Scotty led the video reporter and the cam'er through a corridor into a large hangar-like building. In the center of the room was a tall cylindrical structure. Surrounding the central cylinder were eleven canisters, with space for a twelfth.

"The Heliostat has twelve long blades like a helicopter," said Scotty. "There are six blades on the top that will rotate in one direction and six on the bottom that will go in the other direction. We shoot the whole thing straight up in the air using a rocket, and once it gets to the proper position, we unfurl the light reflecting blades like unrolling a window shade. The whole process takes only a few hours, even though the blades are twenty kilometers long."

The reporter interrupted. "Then the sunlight reflecting off the blades provides an upward light pressure force that counteracts the downward gravity force of the Earth, just like the Polestat Andy Hawke has over the North Pole."

Scotty looked slightly annoyed at the mention of Andy and his Polestat. "It isn't just the Earth gravity," reminded Scotty. "There is also the gravity force of the Sun and the centrifugal force of the motion around the Sun. The control problem of keeping the Heliostat balanced over the pole is very tricky, especially during the summer season of that hemisphere when the polar axis is over on the sunlit side of the Earth. That's why 'pole-sitters' have to be placed so far away from the Earth. If they get any closer than 250 Earth radii, they become unstable during the summer." Scotty then took them up on a lift to view the top of the towering spacecraft.

"This is the transmitting end that will point at the Earth," said Scotty. "Around the circumference are the rolled up 'petals' of the big transmitting dish. It's over a hundred meters in diameter. In the center you can see the microwave feed horns. If you look carefully, you will notice that each one is shaped like the continent they are going to serve, except they are reversed, right to left. After the microwaves bounce off the dish they produce a beam that just fits the continent, with no microwave energy wasted heating up the oceans around them."

"That one must be for the lower part of South America," said the reporter, looking at the monitor while the cameraman zoomed in on each of the feed horns in turn. "But it stops about halfway through Brazil."

"My Heliostat is designed to serve those that are not well served by the geostationary satellites that hang over the equator," replied Scotty. "Anybody south of the Tropic of Capricorn has problems getting good reception from those equatorial satellites unless they live on the top of a mountain. Either something is in the way, or the path through the atmosphere is so long that by the time the microwaves fight their way through the air and clouds, they are so attenuated you have to buy a big expensive dish to get a decent signal. With my Heliostat hanging over the South Pole, you just point a small dish at the South Pole and sit back and enjoy any one of the dozen programs available from 'MacVision, Limited' broadcast services."

"If you get there first," reminded the reporter. "Don't forget there's a race on."

Scotty didn't like being reminded of the race. The polar explorer Robert Scott had prepared poorly for his rushed dash to the South Pole. When he got there, he found that Roald Admundsen had beat him by a month. Discouraged and exhausted, Scott had died on his way back, trapped in a blizzard only eleven miles from his base camp. Scotty too was rushed, and had stretched the resources of his company to the limits to get his Heliostat built.

"I will get there first," said Scotty confidently. "I'm so sure of it, that none of the millions of receiving dishes I've sold has a clock drive on it. If you get the 'pole position' in this race, your ground receiver dishes can be fixed. The broadcast station that gets there second has to be placed off the polar axis, where it will rotate once a day around the pole. The receiving dishes then have to rotate once a day to track it. If Andy Hawke is so confident he's going to be the first one to the South Pole, then why do his dishes have 24-hour clock drives?"

"You seem to be taking an awful risk," said the reporter. "Andy's Polestat spacecraft is already launched and on its way."

"That square-rigged klunker that Andy uses is heavy and slow," said Scotty. "It takes forever to deploy . . . and needs humans around to take care of hangups. He may have launched already, but he had to start with the help of the manned station in GEO. It will take him forever to fly that thing from GEO down to the South Pole. When he arrives, he will find my Heliostat already there."

Suddenly a loud klaxon blurted out a warning. Scotty frowned and started running back across the hanger toward the corridor leading to the winding room they had just left.

"What's happened?" panted the reporter as he and the cam'er caught up with him.

"The winding mechanism must have jammed in the middle of a roll," said Scotty as he ran through the corridor.

When they got to the winding room, the workers had gotten things under control. The weaving machines that manufactured the wire mesh webbing were now motionless and the spray of metal from the still glowing furnace had been turned off, but the floor of the room was stacked high with a slowly slumping pile of silvery metal ribbon. The cam'er panned his video camera over the mess as the video news reporter unctuously intoned what he was sure would be heard and seen all over the world on the evening news that day.

"And so the challenge of the brave Aussie engineer-entrepreneur to the mighty American conglomerate of Andrew Hawke looks like it has suffered a serious setback. A setback that is almost sure to cost 'Scotty' MacPherson first place in the 'Race to the Pole'."

 

"How long will it take us to get the blade room back into running order, Jane?" Scotty asked one of the engineers sitting around the conference table.

"Fortunately the web weavers weren't damaged," replied Jane. "However, one of the welder rollers developed scratches when a loose wire wound up around it, and it needs to be repolished. It's being flown to Germany right now—in your private jet."

"Germany!" said Scotty, eyes turning icy blue under a fierce frown. "Why isn't it being polished here?"

Jane, sure of herself, stared back at Scotty unafraid. "The tolerances on those rollers are beyond any conceivable manufacturing standard. They are a matched set, and the scratched roller is going to be repolished on the same machine that originally made them—by the same man. Let's hope the machine hasn't changed significantly in the past nine months."

"How many days?" said Scotty with a resigned tone.

"Minimum of three," said Jane. "The setup alone takes over six hours—and I insisted that the machinist work standard hours and get plenty of sleep. We can't afford another mistake."

"Three days!" said Scotty. "There goes the last of our margin." He sat there shaking his head, his brain whirling with alternative plans. Suddenly he brightened. "If we get everything else ready to go, then put on the last blade canister while the Heliostat is sitting on the launch pad, then we can still win! It only takes fourteen hours for our pop-up rocket to put the Heliostat in place, and Andrew's Polestat has four more days of flying before it gets there."

"I'm afraid I have additional bad news," said a quiet voice from the back of the room.

"What now, Chin-Lee?" said Scotty, lips pursed.

The skinny young man pushed his glasses up on his nose and his prominent adam's apple bobbed as he swallowed twice in order to delay having to speak.

"I have been monitoring the trajectory of the sail of our competitor. There is something unusual happening. The actual trajectory is consistently ahead of my predictions. The only way I can make my computer model make sense is to assume that the total mass of the spacecraft plus sail is constantly becoming less with time. I don't understand it."

"I'm afraid I do!" said Scotty, face now very grim. "Andy's engineers just filed a patent for a new type of plastic-backed metal film. After about a week in space, with the Sun's ultraviolet shining on it, the heavy plastic backing evaporates, leaving just the light-weight film. I didn't think he would have the new technology ready for this flight, but evidently he did. What's his projected arrival time at the pole?"

"Thirty-two hours," said Chin-Lee, almost apologetically.

"Less than three days . . . that does it," said Scotty, dejectedly. "Andy is going to get the stationary position above the South Pole and we're going to have to stand off a few degrees and rotate around the pole."

There was a polite cough from Scotty's left. It came from the company Treasurer, William Baker.

"What is it, William?" said Scotty.

"May I remind you that the nearly two million receiver units that you have already sold do not have provisions for rotation," said William.

"A simple polar mount and a 24-hour clock is all that's needed," said Scotty. "How much could that possibly cost? A few dollars at most."

"Thirteen dollars and seventy-two cents," replied William, looking at a small piece of paper. "Then there is the not so minor matter of installation, all over the outback in Australia and New Zealand, the savannas of South Africa and the mountains and jungles of Madagascar and South America. It's going to take over one hundred million dollars."

"But everything I've got is invested in the Heliostat!" said Scotty, alarmed. "I don't have an extra hundred million!"

"I know," said William, grimly. "But unless the hundred million is found, the receiver dishes will be worthless—and so will the Heliostat—and so will MacVision, Limited."

Scotty's face fell, and those around the boardroom table became pensive as bankruptcy for MacVision, Ltd., and redundancy for them all became almost palpable in its imminence. The minutes ticked on as Scotty's eyes stared blankly at the grain in the table in front of him. His body started to slump forward. William, concerned, reached over to grab his shoulder. Scotty shrugged him off.

"Go away," he said. "I'm thinking."

Suddenly he straightened up. "We'll fly with ten blades instead of twelve!" he said. "It'll cost us seventeen percent in lifting power, but that's only ten percent in hovering altitude." He looked around the table.

"Jane, tell the guys in Germany to forget the roller. We're going without it." He started to turn away, then turned back. "And remind them to send my plane back."

"Chin-Lee, I want constant updates on the position of Andy's Polestat and the estimated time of arrival over the South Pole."

"Rod, strip blade nine from the Heliostat to balance missing blade twelve. Then get the Heliostat out to the launch pad. We'll launch whenever you're ready. Keep the same launch trajectory—head from Woomera to the South Pole axis, then go straight up along the polar axis to 275 Earth radii and deploy the blades."

He stood up. "Everybody get a move on. This is a race!"

 

Later, after a successful launch, there was a telephone call for Scotty in the launch control room as he monitored the trajectory of his rocket.

"Back off!" said the grim ruddy face of Andrew Hawke over the videophone.

"Not on your life!" said Scotty. "I'm on the pole and I'm going to stay there."

"You fool!" yelled Andy. "You're going to cause a collision and both our systems will come falling out of the sky."

"I'm not budging," said Scotty, grimly. "My rocket is right on the polar axis and if your klunky square-rig is in the way it's going to get a hole torn in it."

"Sir!" said Rod from a nearby console. Scotty turned to look.

"It's from a camera in the nose cone of the rocket," said Rod, pointing at his screen. The image showed a large square sail directly above. It grew noticeably. Scotty blinked involuntarily as the enlarging image of the sail filled half the screen. When his eyes reopened the sail was gone.

"Did we hit?" asked Scotty.

The answer came from the videophone.

"No," said Andy Hawke. "Fortunately for you, your rocket passed a few hundred meters in front of the leading edge of my sail. If it had been otherwise, I would be on my phone to my lawyers instead of talking to you."

Andy looked away for a moment, then returned to the videophone with a broad smile on his face. "My engineers inform me that my Polestat is now positioned directly over the South Pole. We initiated broadcast over all our channels instantly upon arrival. We are on the air and you aren't." He paused, then added in a gloating tone. "You've lost, Mr. MacPherson. Move your whirligig aside." The videophone went blank.

Scotty sat there in a daze, trying to think of what he could do next to save his company from bankruptcy—but no ideas came. Rod's voice came drifting over from the nearby console. "Apogee reached . . . Deploy blades . . . Deploy antenna . . . Commence broadcasting . . ." The twelve seconds for the round trip delay time seemed to pass interminably. "Signals received!" said Rod cheerfully. "Loud and clear!" A weak cheer went up in the control room. Scotty cocked his head, then turned to look at Rod.

"Loud and clear?" he repeated. "With two missing blades the Heliostat stable position has to be above Andy's Polestat position. That huge metal sail should be blocking our signals."

"I believe I have the answer, Mr. MacPherson," said Chin-Lee. Scotty rushed to Chin-Lee's console. On his screen was the image of the South Polar sky as seen from a powerful telescope on the roof of the control center. Superimposed on the familiar southern constellations were two new stars, one above the other—and one of them was his star. They were very close together, but definitely separated one from the other.

"Although the Polestat of Mr. Hawke will block our signals over most of the Antarctic continent," said Chin-Lee. "It is not big enough to block the broadcast signals from our Heliostat to us here in Australia or the other continental regions in the Southern Hemisphere of Earth."

Fortunately, the two spacecraft used different frequency bands. Scotty would let Andy have the few customers in the frozen wasteland of Antarctica. They both could have a position over the pole.

There was a buzzing from the videophone and he went to answer it. It was Andrew Hawke again.

"My engineers inform me that the race to the pole had two winners," said Andy. "In fact, a large number of broadcast statites could be put over the South Pole without interfering with each other."

"Yes, I guess we both won, Andy," said Scotty, trying to be conciliatory.

"Not quite," said Andy, superciliously. "My Polestat is, in fact, closer than your wounded windmill, thus providing stronger signals and better service. I'm sure everyone will acknowledge that I won the race to the South Pole." He smiled smugly, then continued in a condescending tone. "I really must thank you for showing my engineers what should have been obvious. Service is already getting saturated in the Northern Polar regions. I was going to launch a large replacement Polestat for my North Pole station, but now I will just put up another Polestat underneath, and still collect revenue from the old one."

"Not if I put a Heliostat there first," replied Scotty.

"You stay away from my North Pole!" shouted Andy over the videophone.

"Care to race?" challenged Scotty as he blanked the screen on Andy's livid face.

 

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