· POETRY ·
J Andrew Clark
Bill the Cat
· FICTION ·
· SWAG ·
S L I N G S H I P S A M T H E
A S T E R O I D M A N
A Novel Excerpt
"Sam," said the slingship, "I regret to inform you that asteroid 13247 is far from its predicted position."
Sam Clark was bicycling on the beach by Santa Barbara when the ship's computer spoke. He didn't stop pedaling. The Santa Ynez mountains were on the north side of the bicycle path, and the Pacific Ocean on the south side. "Don't give me that," he said to the blue skies. "We aren't due to pass 13247 for six more days." He maneuvered the bicycle through the throngs of tourists and watched the pretty girls.
Six days to asteroid 13247, where he would turn a sharp corner, then twelve days to asteroid 624, Hektor, where he had a job waiting. Hektor is a double asteroid orbiting in the forward Trojan position 60° ahead of Jupiter. Hektor A and Hektor B have collided several times, exposing corium. All you have to do is sift through the surface rubble for it.
"Sam, asteroid 13247A is far from its predicted position, much nearer to us than expected. It has just now come into range of my detectors. The iron companion 13247B is not detectable at all."
Sam sighed and stopped pedaling the exercycle; the Santa Barbara beach scene disappeared, and he was alone in his slingship 560 million miles from Earth. "Okay, I'll be right there." He folded the exercycle back into its slot. There was a lot of room in the old Mercedes motor home, even with the mag drive and the life support capsule installed. He went up front to the driver's compartment and looked out the windshield.
The Mercedes was a custom bi-mobile with dual controls. The left-hand driver's seat had a standard steering wheel, folded away for now, and controls for driving on-planet; the right-hand seat had the magnetic drive controls. He sat down in the right hand seat. He hadn't looked out at the stars for several days and it took him a minute to find the Milky Way; then he saw Jupiter and Saturn and had his bearings.
"Okay, show me 13247," he said.
"Yes, Sam." The starfield moved as the ship rotated a few degrees. A blinking red circle appeared around one of the points of light. The motor home windshield was a quadrillion-pixel nanotube view plate. Sam usually had it set to "transparent," or watched movies on it, but Fling could also detect incoming photons and process them any way Sam requested. The ship's computer studied Sam's head position and his eye motion and knew where he was looking and projected information for Sam.
"Okay, I see it," he said. "Give me a good look at it." The point of light brightened and grew until it filled a quarter of the windshield. It was a battered chunk of pitted black rock shaped like a charred potato.
A potato. After nearly three months on slingship rations, Sam was seeing food everywhere.
A chart appeared showing the astral specs for binary asteroid 13247: a carbonaceous chondrite 11 miles long accompanied by a mile-wide lump of solid nickel/iron. Its eccentric orbit was an anomaly, but that was the reason Sam had chosen it: there were no other asteroids to use in the emptiness of the 4:3 Kirkwood Gap.
Sam was an orbital mugger: he was going to rob 13247 of some of its orbital momentum, transferring it with his magnetic drive, and sling himself directly into Hektor Control's big ground-based mag drive.
But 13247 was here six days too early. Sam looked at the charcoal-black lump slowly rotating in the starry night. He didn't see the iron companion -- 13247 was a binary-maybe it was behind the big carb.
"Closest approach is five hours away," said Fling. Sam buckled himself into the mag driver's seat. "We'll have to recalculate the transaction," he said. "How the heck did we get here six days too soon, anyway?"
"We won't be able to make a transaction of momentum," the ship said.
"What? We won't be close enough? How can that be?" One of the advantages of the mag drive is that it works over long distances. The further you are from your interacting mass, the more power it takes, of course, but since you can tap the mass for orbital energy, you just take that much more. The only real constraints are the size and strength of your ship's corium structure. "How far are we going to miss?"
"At our closest approach we will be 50,000 miles from 13247," Fling said. "But Sam, the binary companion is not in any detectable orbit."
Sam blinked. "It's gone?" The mag drive worked only on magnetic materials or magnetic fields. "The iron is gone?"
"It is not detectable with our radar equipment."
"Then how am I going to turn the corner here? How am I going to get to Hektor?"
"You can use the solid fuel motor."
"You're so helpful," Sam said. The solid fuel motor was his last-resort parachute. No matter where he was in the solar system, he could use the solid fuel motor to get back to Earth orbit. Or to just about anywhere else, as long as he aimed carefully and there was something magnetic to snag onto at the destination. Mars was a bustling operation these days; he could boost to Phobos Station with the solid fuel motor and let them catch him in their mag drive.
At Earth orbit he could use the big magnetic field of the planet itself to kill his velocity. But at Earth orbit there were plenty of catchers. Official police catchers, and if they caught Sam he'd spend at least ten years in the Lunar prison mines. But at least he'd be alive.
"How could we make such a big mistake, anyway?" he said. "Are you sure this is the right rock?"
"Spectroscope of this carb matches that of 13247 A," Fling said. "However its vector and velocity are much different than listed in the ephemeris." The ephemeris was the directory of orbital motions of all charted bodies in the solar system.
"We updated the ephemeris before we left Interamnia," Sam said. "How much can a solar system change in three months?"
"I conjecture that 13247 has interacted with another asteroid, and lost the iron companion."
"Okay, so we can't swing to Hektor off this rock. What's the next rock we'll encounter?"
"I warned you against this path, Sam. I told you how dangerous it was."
"Yeah, skip the recriminations. I was the one who decided." Usually in the Belt you have plenty of rocks to sling yourself along with. When the asteroids are thick you can move right along, swinging like a kid on monkeybars. But Sam wanted extra-fast transit -- he wanted to get from asteroid 704 Interamnia to 624 Hektor in time to get the job. He'd accelerated to 100 miles per second and cut a big chord inward almost to the orbit of Mars, and the only other interaction remaining on the schedule was at 13247 to bend his orbit high above the ecliptic. He was crossing the big 4:3 Kirkwood gap, which Jupiter's gravity had long since swept clean -- for a hundred million miles the only available asteroids were Thule, which was far out of position, and 13247.
It had been a big risk to take this cometary orbit. Usually your computer can plan an orbit so that if something goes wrong on your planned interaction, you'll encounter another rock fairly soon afterward.
Sam didn't know a goddam thing about orbital mechanics. Sam had asked "How can I get to Hektor?" and Fling had displayed a map showing an optimax orbit. 219 days. "I've got to get there faster than that." 31 weeks, over 7 months. No way.
Fling had displayed a new orbit. "Faster, I have to get there in just a couple of months," Sam said. Eventually Fling displayed a cometary orbit chording far inward of Mars' orbit (although Mars was far from that area right now) that decelerated to 50 miles per second at 13247, and then decelerated to zero at Hektor. You could shed any amount of speed at a big iron like Hektor (not to mention Earth) but you could gain only so much speed away from an iron before you were out of range of your mag drive. 13247 was Sam's last acceleration, and a course change. But now the iron wasn't there.
"So what's our back-up rock?"
"That's what I was trying to tell you. We don't have one."
"Fling, there are 32,000 charted asteroids in the inner Belt, and 2,000 in the outer belt between Uranus and Neptune. Surely we'll approach one sooner or later."
"Yes, we will approach asteroid 2060 Charon in two hundred and eighty four years."
Sam stared at 13247. It looked like he was done. He'd have to use the solid fuel booster. Where should he go?
He didn't want to go to Earth. Nor Mars. There wasn't any work for him. There was work at Hektor.
A solid fuel motor cost about ten million dollars plus installation and is a use-once, throw-away rocket. If Sam used it simply to maneuver between two rocks...then he'd be without his parachute. And he frankly didn't have an extra ten million dollars right at that moment. And if he didn't have a usable booster when he got to Hektor, he wouldn't be able to do the splinter-jockey work. Only a fool launches on a mag-drive trip without a solid booster backup.
The closest approach to 13247 was five hours away -- about 1,800,000 miles at Fling's speed of 100 miles per second. Add the asteroid's vector and it's more like 2,000,000 miles, which was the outside range for Fling's radar for an object that size. Those carbonaceous chondrites have very low albedo on radar wavelengths, too. Maybe the iron was really out there, but too far away for Fling's radar to find. "Let's talk to Hektor," Sam said. "How far out of now are they?"
"We are thirty six million miles from Hektor. Speed-of-light time lag is 387 seconds, round-trip."
Every human-occupied asteroid is at the center of its own bubble of Now. Earth's moon is about at the outer edge of Earth's Now -- it is possible to have a phone conversation between Luna City and New York, but the 3-second lag is highly annoying. In the Belt, a 3-second lag is stripped-naked intimacy. Sam was 6 minutes and 27 seconds out of now with Hektor.
He could hear the big dish antenna cranking around to aim at Hektor. He'd had the antenna focussed on Earth, of course. Where else in the solar system would you point an antenna, given a choice?
He was 500 million miles from Earth, 90 minutes out of Earth's now, so conversation was impossible. But he could watch the Earth channels.
"Focussed on Hektor Station," Fling said. Space is a lonely place and not just because you're alone. On Earth you can be alone and still talk to people on the phone. Even on the moon you can phone other people and yak about things. Distances in the Belt were too far. Sam was trapped in his own solitary Now.
"Okay. Start message: Hello, Hektor, this is Sam Clark -- I'm six weeks away from arriving. I'm your new splinter jockey. I've encountered 13247 A 'way out of position, and I can't find 13247 B. Can you locate the iron companion for me? Thanks."
It would be at least six and a half minutes before they could answer. Meanwhile, what was Sam going to do if Hektor couldn't help? Was there no choice except using the solid fuel booster?
"Look, why can't we use the mag drive on the carb?" Sam gestured at the carbonaceous chondrite.
"Carbs don't have magnetic moment."
"Surely they have some. Let's get in close to that carb and use a giant pulse of energy at closest approach and see if we can grab enough momentum to sling us to Hektor. Heck, we only need, what--" I looked at the charts-- "a delta V of 1.2..."
The ship said, "Our closest approach will be no less than 50,000 miles, much too far away."
"Well, use all attitude jets to alter the orbit. Use the mag drive against the solar field if you can. Jam us in on a near collision course with that carb and we'll use whatever it's got."
"It won't work, Sam. You need iron, not a carb."
"Do you have an assay report for 13247?"
"So it could be anything. It can't hurt to try. Maybe we can swing into an orbit toward some other iron. Anything is better than using up the booster."
The radio spoke: "Roger, Sam, this is Hektor Control. Stand by." It was a computer voice; on Hektor it was two o'clock in the morning.
Fling said, "They're uploading their file on 13247. The most recent entry is two years ago."
So there would be no news from Hektor.
"Operator Timmins speaking," the Hektor Control voice said. "We have no report of any change in 13247's orbit." Then the voice became more personal: "Hey Sam, how are you, I remember you now. This is Phil Timmins, I was a sulfuroid collector on Io for a while, remember? I hung out at the Caverns Bar, I played pool with you a couple of times. You were the tall guy."
That's what they always remembered about Sam. He was only 6'1" but most guys in orbit are small. When NASA has several candidates for a job who are all about equal, they'll tend to take the smallest one. Small spacemen who don't eat much. There's nothing NASA hates like boosting your body fat into orbit. NASA employees were fed a strict and regimented diet. Usually on a big asteroid there was a black market source of food; somebody growing cabbages or something. Back on Interamnia there was a guy who kept a hen alive for two years and got five eggs a week out of her.
"The job's open until somebody gets here," Timmins continued, "but there are a couple of other guys en route for it, Sam. I've got to have somebody to run the retriever bucket, and fast. But, you know, the attrition is still fairly high out here, and there may be some more openings.
"Oh, and are you still an outlaw? Not that the company cares, but I'm curious. The company paid off my bounty and I'm not an outlaw any more."
"Yeah, I'm still an outlaw, Phil," Sam said sourly. "See you when I get there. Go back to bed. Over."
The escape velocity of the Sun is 384 miles per second. That's the local speed limit, because anything going that fast will never come back again. At a hundred miles per second Sam wouldn't leave the solar system forever if the close approach to 13247 failed. But he'd be on a long, long orbit...
"Let's aim close to the carbonaceous chondrite and pulse the hell out of the mag drive. Maybe there's something in there we can use to help us make the turn. If it doesn't work, we'll use the solid fuel rocket and go back to Earth."
Once the rocket started there was no stopping it; when you achieved your required velocity for a Hohmann orbit to your destination, you released the rocket and it zoomed on ahead of you. Sam wanted to postpone that, if possible.
"Sam, that is possibly an overload power demand."
"That's the way I want to do it."
There was a long pause, but eventually Fling said, "Yes, Sam."
There were still four hours to go. Sam said, "I'm going to go bicycling for a while. Tell me when we're half an hour from closest approach."
Sam left the driver's seat and went back and pulled out the bicycle again. He had four hours to kill and he might as well do it on the beach in Santa Barbara. The full-sense illusion stopped if he stopped pedaling. It was a good incentive to keep pedaling, and you need that in micro-G.
Sam liked to keep the ship's artificial gravity around 1/10 G. It used more power, and most of the space rats Sam knew preferred a much lower G -- just enough to keep the crumbs on the floor.
But your body still gets mushy in that kind of gravity field. Sam had always been vain about staying strong. You never know when you might need strength to save your life. Such as at Hektor. He sat on the exercycle and started pedaling, and the mountainous skyline of Santa Barbara was once again outlined against the electric blue sky and throngs of people surrounded him, many of them beautiful young women in the daring beach costumes of the 2010s.
The job on Hektor was going to be the worst kind of work. Hektor was two big rocks a hundred miles thick in close orbit around each other. Hektor A and Hektor B collided about a hundred thousand years ago and the dust has almost settled. The two big rocks are in such close orbit that they still brush against each other and rubble is pinched and squirted into wild flailing orbits. It's dangerous, and the mining company will hire a spaceman whether he's an outlaw or not.
The job? Sifting rocks. After the big slow-speed collision, all the tumbling rocks gradually drifted back into two clumps again under the mild gravitational pull. Ores that had been at the center of the asteroid were thoroughly intermixed, and some of the rocks buried near the surface were chunks of pure corium.
Sam pedaled and steered out onto Stearns' Wharf and pedaled in circles and looked at the Channel Islands thirty miles south across the Pacific Ocean. He liked to watch the ocean from here, but if he stopped, the scene vanished. Sam had been in the asteroid belt for nearly twenty years -- ever since the beginning of the corium boom. He went out with Frankie Helix's gang in the early days and came back to Earth with tons of corium, and Sam's share was a two hundred million dollars. He was 19 years old. He bought the biggest, most luxurious Mercedes motor home ever built and put in a corium floorboard as a mag drive frame. He spaceproofed it, installed a life support system and strapped on an emergency solid-fuel chemical rocket, and went into space again. He was going to become the youngest trillionaire in history.
Well, that was the plan. Now Sam was 38 and things hadn't gone as he had planned. There were half a million people in the Solar System living off-planet now, and the inner Belt was played out. Oh, there was lots of ore still there, but it was all charted and owned and reduced to routine.
Sam had been lucky the job at Interamnia lasted as long as it did, but then NASA finally arrived, and then Frankie Helix got killed, and things weren't the same, and the old gang drifted away, and then there Sam was, an outlaw, hanging around in an official NASA base and although they weren't about to do anything to him, nobody was going to hire him, either, not unless it was some exceptionally stinky job. Like the one on Hektor.
Which Sam was desperate enough to take, by now.
He'd been on Interamnia two months ago on the other side of the sun when he heard about the Hektor job. Interamnia is one of the largest asteroids near the outer edge of the main belt, about 286,000,000 miles from the sun. The slow, easy way to get to Hektor was to decelerate and drop outward from the sun, encountering rocks and working his way toward the destination in Jupiter's orbit.
The fast slingship method is to speed up and cut chords.
The fastest way would be to skim as close as possible to the sun. But that required tremendous speed and energy. Instead Sam traveled in fast, tight orbits, slinging from rock to rock, gaining speed and heading further inward toward the Sun, until there weren't any more rocks to sling off of. He never got closer to the sun than the orbit of Mars, but he was able to get his speed up to a hundred miles per second. At 13247 he was supposed to change his vector up from the ecliptic and slow down by 25 miles per second, then one more interaction before arriving at Hektor.
Slinging. That's how the old Voyager space probes were able to get to Saturn, Uranus and Neptune last century. They used a gravitational slingshot at Jupiter to get to Saturn, and used Saturn to get to Uranus, and Uranus to get to Neptune. The asteroids are far too gravitationally feeble for that kind of slinging; but you can do the same thing electromagnetically if you have a corium-powered mag drive.
Sam pedaled to Ledbetter beach and watched surfers riding the waves. The hologram was a recording of one day on three miles of the Santa Barbara beach trail from East Beach two miles to Ledbetter Beach, from dawn to dusk on July 4, 2010. Sam was still discovering new parts of the sights and sounds on the bikepath. It was a classic recording that couldn't be duplicated now that Santa Barbara was submerged due to global warming.
Sometimes he pedaled with the exercycle set for dawn when nobody was there, because the system wouldn't let him ride "through" people and he couldn't steer off the path. He could go slowly and steer around the people and other bicycles, and that's what he did a lot because it almost was not like being alone in the depths of space.
"Sam, it is time to prepare for the momentum transaction," said Fling.
Sam stopped pedaling and he was alone in the depths of space again. He went back to the driver's seat and buckled in again. "We're 400,000 miles from 12347," Fling said. A little further than the distance from Earth to the Moon. The asteroid still filled the windshield as it had before, but the detail was much clearer now. "Its rotational rate differs from the value in the ephemeris, which was one rotation every 11 hours and 42 minutes. It now rotates only once every 16 days."
"How could that happen?"
"I don't know, Sam."
"Have you found the missing iron companion?"
"Well, let's start. I'm strapped in. Switch to transparent mode." The big asteroid vanished from the windshield and Sam searched for it and then said, "Okay, okay, show it to me," and a red circle appeared around one bright dot among the ten thousand stars. "Okay, I got it." It slowly expanded as Sam watched. The hiss of the attitude jets was a barely audible background noise.
"Our closest approach will be about 2,000 miles, at which time we will engage the magnetic drive at the maximum possible power to slow us down and redirect our flight path. If there is anything there for the magnetic drive to interact with, which is doubtful."
"Okay, I know," Sam said. "But I've got to make the try. You want me to give the signal to activate the mag drive when we're at closest approach?"
"Our time through the optimal interaction zone is 1/3 of a second. Please allow our automatic proximity detectors to activate the drive. Your reaction time may not be accurate enough to--"
Asteroid 12347 was getting bigger and bigger and Slingship Sam swooped in close and a huge programmed pulse of energy was activated. Billions of joules poured out from the corium frame of the mag drive, reaching out for other magnetic material. He'd set it for the greatest sensitivity, because carbs are nothing but carbon and nitrogen and water and silicates. The ship passed the asteroid in the blink of an eye and a tearing, wrenching acceleration slammed Sam against his safety web, at least ten gravities and Sam heard a giant zapping sound and then he blacked out.
He woke in darkness floating in zero gravity. He saw 12347 moving slowly away. Very slowly. "Fling? What's going on?"
There was no answer. He listened and heard no attitude jets, no subtle whir from the life support system. Dead silence. The only light in the ship came from the stars and asteroid 12347. Sam unstrapped himself and felt around for the emergency power control. The floor felt different under his hands as he groped under the dashboard. What was going on?
He found the control and flipped the switch; a thunking sound came from the rear of the motor home, and then the lights flickered and came on dimly. The life support system's ventilators resumed moving fresh air. Sam didn't notice. He was staring at the floor of the motor home, which was bulged up everywhere, as though it had turned gooey and then expanded into hills and valleys. "What the heck happened? Fling! Are you back yet?"
There was no reply. "God damn it." He touched the windshield manual control patches and turned off the windshield display except for a 12 inch by 12 inch square. The annoying hum of the emergency generator relaxed its intensity a small amount. Sam was able to bring a list of powered systems into view and he clicked off all communications and housekeeping systems, plumbing control, attitude control...as he clicked off each system, the lights began to brighten and then Fling said, "Systems are now being monitored and optimized."
"Fling! What happened?"
"Asteroid 21347 apparently contained large amounts of highly magnetic material. The energy transfer overloaded the corium drive plate to the point that it reverted to iron. We are now in a derelict orbit around 12347."
"So we're going to have to use the solid fuel rocket after all, nuts."
"Sam, without the mag drive, how can we stop at our destination?"
Sam stared at the active area of the windshield. Of course. Even if they used the solid fuel motor, there now was no way of decelerating at Earth, or Mars, or Hektor, or wherever they decided to go.
Sam was stuck in space.
To Be Continued . . .