The Gateway Trip

MISSION PULSAR

The first big science bonus was paid to a man named Chou Yengbo, and he might not have earned it if he hadn’t happened to have taken a few elementary science courses before he discovered that even a college degree couldn’t get you a decent job, those days, in Shensi Province. When Chou’s ship came out of the faster-than-light drive, Chou had no trouble figuring out which objects the Heechee had set the controls for.

Actually there were three objects in view. They were weird. The first was wholly unlike anything Chou had ever seen before, even in the holograms of his astronomy course. It wasn’t quite like anything any other human being had ever seen before, either, except in imagination. The object was an irregular, cone-shaped splash of light, and even on the viewscreen its colors hurt his eyes.

What the thing looked like was a searchlight beam fanning out through patches of mist. When Chou looked more carefully, magnifying the image, he saw that there was another beam like it, sketchier and fainter and fanning out in the opposite direction. And between the two points of the cones formed by those beams, the third object was something almost too tiny to see.

When he put the magnification up to max, he saw that that something was a puny-looking, unhealthily colored little star.

It was much too small to be a normal star. That limited the possibilities; even so, it took Chou some time to realize that he was in the presence of a pulsar. Then those Astronomy 101 lessons came back to him. It was Subrahmanyan Chandrasekhar, back in the middle of the twentieth century, who had calculated the genesis of neutron stars. His model was simple. A large star, Chandrasekhar said, uses up its hydrogen fuel and then collapses. It throws off most of the outer sections of itself as a supernova. What is left falls in toward the star’s center, at almost the speed of light, compressing most of the star’s mass into a volume smaller than a planet—smaller, in fact, than some mountains. This particular sort of collapse can only happen to big stars, Chandrasekhar calculated. They had to be 1. 4 times as massive as Earth’s Sun, at least, and so that number was called Chandrasekhar’s Limit.

After that supernova explosion and collapse has happened, the object that remains—star heavy, asteroid sized—is a “neutron star.” It has been crushed together so violently by its own immense gravitation that the electrons of its atoms are driven into its protons, creating the chargeless particles called neutrons. Its substance is so dense that a cubic inch of it weighs two million tons or so; it is like compressing the hugest of Earth’s old supertankers into something the size of a coin. Things do not leave a neutron star easily; with that immense, concentrated mass pulling things down to its surface, escape velocity becomes something like 120,000 miles a second. More than that: its rotational energy has been “compressed,” too. The blue-white giant star that used to turn on its axis once a week is now a superheavy asteroid-sized thing that whirls around many times a second.

Chou knew there were observations that he had to make—magnetic, X-ray, infrared, and many others. The magnetometer readings were the most important. Neutron stars have superfluid cores and so, as they rotate, they generate intense magnetic fields—just like the Earth. Not really just like the Earth, though, because the neutron star’s magnetic field, too, is compressed. It is one trillion times stronger than the Earth’s. And as it spins it generates radiation. The radiation can’t simply flow out from all parts of the star at once—the lines of magnetic force confine it. It can only escape at the neutron star’s north and south magnetic poles.

The magnetic poles of any object aren’t necessarily in the same place as its poles of rotation. (The Earth’s north magnetic pole is hundreds of miles away from the point where the meridians of longitude meet.) So all the neutron star’s radiated energy pours out in a beam, around and around, pointing a little, or sometimes a lot, away from its true rotational poles.

So that was the explanation of the thing Chou was seeing. The cones were the two polar beams from the star that lay between them, north and south, fanning out from its poles. Of course, Chou couldn’t see the beams themselves. What he saw were the places where they illuminated tenuous clouds of gas and dust as they spread out.

The important thing to Chou was that no Earthly astronomer had ever seen them that way. The only way anyone on Earth ever could see the beam from a neutron star was by the chance of being somewhere along the rim of the conical shape the beams described as they rotated. And then what they saw was a high-speed flicker, so fast and regular that the first observer to spot one thought it was the signal from an alien intelligence. They called the signal an “LGM” (for Little Green Men) until they figured out what was causing that sort of stellar behavior.

Then they called the things “pulsars.”

Chou got a four-hundred-thousand-dollar science bonus for what he had discovered. He wasn’t greedy. He took it and returned to Earth, where he found a new career lecturing to women’s clubs and college audiences on what it was like to be a Heechee prospector. He was a great success, because he was one of the first of the breed to return to Earth alive.

Later returnees were less fortunate. For instance, there was: MISSION HALO

In some ways Mission Halo was the saddest and most beautiful of all. The mission had been written off as lost, but that turned out to be wrong. The ship wasn’t lost. Only its crew was.

The ship was an unarmored Three. When it came back its arrival was a surprise to everyone. The ship had been gone over three years. It was a certainty that nobody could have survived so long a trip. In fact, no one had. When the hatch crews on Gateway got the ports open, recoiling from the stench inside, they discovered that Jan Mariekiewicz, Rolph Stret, and Lech Szelikowjtz had left a record of their experiences. It was read with compassion by the other prospectors, and with rejoicing by astronomers.

“When we reached two hundred days without turnaround,” Stret had written in his diary, “we knew we were out of luck. We drew straws. I won. Maybe I should say I lost, but, anyway, Jan and Lech took their little suicide pills, and I put their bodies in the freezer.

“Turnaround came finally at 271 days. I knew for sure that I wasn’t going to make it either, not even with only me alive in the ship. So I’ve tried rigging everything on automatic. I hope it works. If the ship gets back, please pass on our messages.”

As it happened, the messages the crew left never got delivered. There was no one to deliver them to. The messages were all addressed to other Gateway prospectors who had been part of the same shipment up from Central Europe, and that batch wasn’t one of the lucky ones. Every one of them had been lost in their own ships.

But the pictures the ship brought back belonged to the whole world. Stret’s jury-rigging had worked. The ship had stopped at its destination. The instruments had thoroughly mapped everything in sight. Then the ship’s return had been triggered automatically, while Stret’s corpse lay bloating under the controls.

The record showed that their ship had been outside the Milky Way galaxy entirely.

It brought back the first pictures ever seen of our galaxy from outside. It showed a couple of fairly nearby stars and one great, distant globular cluster—the stars and clusters of the spherical halo that surrounds our galaxy—but most of all it showed our Milky Way galaxy itself, from core to farthest spiral wisp, with its great, familiar octopus arms: the Perseus arm, the Cygnus arm, the Sagittarius-Carina arm (with our own little Orion arm, the small spur that held the Earth, nearby), as well as the large, distant arm that Earthly astronomers had never seen before. They called it simply “Far Arm” at first, but then it was renamed the Stret-Mariekiewicz-Szelikowitz arm to honor the dead discoverers. And in the center of it all was the great bellying octopus-body mass of core stars, laced with gas and dust clouds, showing the beginnings of the new growing spiral structures that might in another hundred million years become new arms themselves.

They also showed the effects of a structure more interesting still, but not in enough detail to be recognized just then—not until some other events had taught human beings what to look for in the core. All the same, they were beautiful pictures.

Since no one returned from Mission Halo alive, there wasn’t even a science bonus due, but the Gateway Corporation voted a special exception to the rules. Five million dollars was voted for the heirs of Mariekiewicz, Szelikowitz, and Stret.

It was a generous gesture but, as it turned out, a very inexpensive one. The award went unclaimed. Like so many Gateway prospectors, the three who had manned the ship had no families that anyone could find, and so the Gateway Corporation’s bursar quietly, and philosophically, returned the cash to the Corporation’s general funds.

The first, best, and brightest hope of any exploration crew was to find a really nice planet with really nice treasures on it. Ultimately some of them did, of course, but it took a while. For a good many orbits after the systematic exploration program began the crews went out and came back with nothing but pictures and hard-luck stories—when they came back at all.

But some of the things they had seen were wonderful. Volya Shadchuk took a One into the heart of a planetary nebula, green-tinged with the radiation from oxygen atoms, and collected fifty thousand dollars. Bill Merrian saw a recurring nova system, red giant’s gases being sucked onto a white dwarf; luckily not enough matter had accreted while he was there to blow off in a noval explosion, but he got the fifty thousand and ten percent more for “danger bonus.” And then there were the Grantlands.

There were five of the Grantlands—two brothers, their wives, and the eldest son of one of the couples. They reached a globular cluster—ten thousand old stars, mostly red, mostly sliding toward the sunset at the lower right side of the Hertzspung-Russell diagram as they aged. The cluster was in the galactic halo and, of course, the trip was a long one. None of them survived. The trip took 314 days, and all of them were alive at the time of arrival (but existing on scant rations). They took their pictures. The last of them, the young second wife of one of the brothers, died thirty-three days into the return trip; but the pictures they had taken survived.

The three Schoen sisters were no luckier. They didn’t come back at all, either. Again, their ship did, but thoroughly racked and scorched, and of course their bodies inside were barely recognizable.

But they, too, had taken a few pictures before they died. They had been in a reflection nebula—after analysis it was determined that it was the Great Nebula in Orion, actually visible to the naked eye from Earth. (American Indians called it “the smoking star.”) The Schoen sisters must have known they were in trouble as soon as they came out of drive, because they weren’t really in space anymore. Oh, it was close to a vacuum—as people on Earth measure a vacuum—but there were as many as three hundred atoms to the cubic centimeter, hundreds of times as many as there should have been in interstellar space.

Still, they looked around, and they started their cameras—just barely. They didn’t have much time.

There are four bright young stars in the Orion Nebula, the so-called Trapezium; it is in such nebulae that gas clouds fall together and are born as stars. Astronomers conjectured that the Heechee knew this, and the reason the ship had been set to go there was that Heechee astronomers had been interested in studying the conditions that lead to star formation.

But the Heechee had set that program half a million years before. A lot had happened in those half million years. There was now a fifth body, an “almost” star, in the Orion Nebula, formed after the Heechee had taken their last look at the area. The new body was called the Becklin-Neugebauer object; it was in its early hydrogen-burning stage, less than a hundred thousand years old. And it seemed that the Schoen sisters had the bad luck to come almost inside it.

MISSION NAKED BLACK HOLE

The crew was William Sakyetsu, Marianna Morse, Hal M'Buna, Richard Smith, and Irma Malatesta. All of them had been out before—Malatesta had done it five times—but luck hadn’t favored any of their ventures. None of them had yet made a big enough score to pay their Gateway bills.

So for their mission they were careful to choose an armored Five with a record of success. The previous crew in that ship had earned a “nova” science bonus in it, managing to come close enough to a recurring nova to get some good pictures, though not so close that they didn’t live through the experience. They had collected a total of seven and a half million dollars in bonus money and had gone back to Earth, rejoicing. But before they left they gave their ship a name. They called it Victory.

When Sakyetsu and the others in his crew got to their destination they looked for the planet—or the star, or the Heechee artifact, or the object of any interesting sort—that might have been its target.

They were disappointed. There wasn’t anything like that to be found anywhere around. There were stars in sight, sure. But the nearest of them was nearly eight light-years away. By all indications they had landed themselves in one of the most boringly empty regions of interstellar space in the galaxy. They could not find even a nearby gas cloud.

They didn’t give up. They were experienced prospectors. They spent a week checking out every possibility. First, they made sure they hadn’t missed a nearby star: with interferometry they could measure the apparent diameter of some of the brighter stars; by spectral analysis they could determine their types; combining the two gave them an estimate of distance.

Their first impression had been right. It was a pretty empty patch of sky they had landed in.

There was, to be sure, one really spectacular object in view—the word Marianna used was “glorious"—a globular cluster, with thousands of bright stars interweaving their orbits in a volume a few hundred light-years across. It was certainly spectacular. It dominated the sky. It was much nearer to them than any such object had ever been to a human eye before. But it was still at least a thousand light-years away.

A globular cluster is an inspiring sight. It was a long way from Sakyetsu and his ship Victory, but by the standards of Earthly astronomers that was nothing at all. Globular clusters live on the outer fringe of the galaxy. There aren’t any in the crowded spiral-arm regions like the neighborhood of Earth. There are almost none less than twenty thousand light-years from Earth, and here was one a twentieth as far—and thus, by the law of inverse squares, four hundred times as bright. It was not an unusually large specimen, as globular clusters go; the big ones run upward of a million stars, and this one was nowhere near that. It was big enough to be exciting to look at, all the same.

But it was neither big enough nor near enough for Victory’s instruments to reveal any more than Earth’s own orbiting observatories, with their far more powerful mirrors and optical systems, had seen long ago.

So there was very little chance that the instruments on Victory could earn them any kind of decent bonus. Still, those instruments were all they had. So the crew doggedly put them to work. They photographed the cluster in red light, blue light, ultraviolet light, and several bands of the infrared. They measured its radio flux in a thousand frequencies, and its gamma rays and X-rays. And then, one sleeping period, while only Hal M'Buna was awake at the instruments, he saw the thing that made the trip worthwhile.

His shout woke everybody up. “Something’s eating the cluster!”

Marianna Morse was the first to get to the screens with him, but the whole crew flocked to see. The fuzzy circle of the cluster wasn’t a circle anymore. An arc had been taken out of its lower rim. It looked like a cookie a child had bitten into.

But it wasn’t a bite.

As they watched, they could see the differences. The stars of the cluster weren’t disappearing. They were just, slowly, moving out of the way of—something.

“My God,” Marianna whispered. “We’re in orbit around a black hole.”

Then they cursed the week they had wasted, because they knew what that meant. Big money! A black hole. One of the rarest objects (and, therefore, one of the most highly rewarded in science bonuses) in the observable universe—because black holes are, intrinsically, unobservable.

A black hole isn’t “black,” in the sense that a dinner jacket or the ink on a piece of paper is black. A black hole is a lot blacker than that. No human being has ever seen real blackness, because blackness is the absence of all light. It can’t be seen. There is nothing to see. The blackest dye reflects a little light; a black hole reflects nothing at all. If you tried to illuminate it with the brightest searchlight in the universe—if you concentrated all the light of a quasar on it in a single beam—you would still see nothing. The tremendous gravitational force of the black hole would suck all that light in and it would never come out again. It can’t.

It is a matter of escape velocity. The escape velocity from the Earth is seven miles a second; from a neutron star as much as 120,000 miles per second. But the escape velocity from a black hole is greater than the speed of light. The light doesn’t “fall back” (as a rock thrown up from Earth at less than escape velocity will fall back to the ground). What happens to the light rays is that they are bent by the gravitational pull. The radiation simply circles the black hole, spiraling endlessly, never getting free.

And when a black hole passes in front of, say, a globular cluster, it doesn’t hide the cluster. It simply bends the cluster’s light around it.

If Victory’s crew had wasted seven days, they still had five days’ worth of supplies left before they had to start back to Gateway. They used them all. They took readings on the black hole even when they couldn’t see it . . . and when at last they got back to Gateway they found that one, just one, of their pictures had paid off.

They shared a five-hundred-thousand-dollar bonus simply for the pictures of the globular cluster. But the one picture that they hadn’t even noticed when they took it—a split-second frame, taken automatically when no one happened to be watching the screen—showed what happened when the black hole occluded a bright B-4 star, a few hundred light-years away. That star hadn’t moved up or down. By chance it had passed almost exactly behind the black hole. Its light had spread to surround the hole, like a halo; and that gave them a measure of the hole’s size.

And then, long after they were back in Gateway, the research teams that studied their results awarded them another half a million, and the information that they were very lucky.

Marianna Morse had wondered about that: Why had the Heechee used an armored Five to visit this harmless object? Answer: It hadn’t always been harmless.

Most black holes are not safe to visit. They pull in gases in accretion rings, and the acceleration of the gases as they fall produces a hell of radiation. Once this one had, but that was a long time ago. Now it had eaten all the gases in its neighborhood. There was nothing left to fall and so generate the synchrotron flux of energy that might fry even an armored Five if it lingered too long nearby.

And so the crew of Victory, without knowing it at the time, had had an unexpected stroke of luck. They arrived at the neighborhood of their black hole after its lethal feeding frenzy had ended, and so they had come back alive.

In its first twenty years the Gateway Corporation handed out more than two hundred astronomical science bonuses, for a total of nearly one billion dollars. It paid off on double stars and supernova shells; it paid off on at least the first examples of every type of star there was.

There are nine members of the catalogue of star types, and they are easily remembered by the mnemonic “Pretty Woman, Oh, Be A Fine Girl, Kiss Me,” which runs the gamut from youngest to longest-living stars. The stellar classes from A down to the dim, small, cool Ms didn’t earn any special science bonuses unless there was something truly remarkable about them, because they were too common. The vast majority of stars were dim, small, and cool. Contrariwise, the Os and Bs were hot young stars, and they always got bonuses because they were so few. But the Gateway Corporation awarded double bonuses on the P and W classes: P for gas clouds just condensing into stars, W for the hot, frightening Wolf-Rayet type. These were new stars, often immense ones, that could not be approached safely within billions of miles.

All those lucky prospectors collected science bonuses. So did the ones who happened to find themselves near known objects, at least if they were the first to claim the rewards. Wolfgang Arretov was the first to arrive near the Sirius system, and Earthly astronomers were delighted. The stars Sirius A and B (“Bessel’s satellite”) had been studied intensively for centuries, because the primary star is so bright in Earthly skies.

Arretov’s data confirmed their deductions: Sirius A at 2. 3 solar masses, B only about one—but a white dwarf with a surface temperature over twenty thousand degrees. Arretov got half a million for letting the astronomers know they had been right all along. Later, Sally Kissendorf got a hundred thousand for the first good pictures of the tiny (well—three solar masses, which is not real tiny; but just about invisible next to its huge primary) companion of Zeta Aurigae. She would have gotten more if the companion had happened to flare while she was nearby, but that might not have been worth her while, since it was very likely she could not have survived the experience. Matt Polofsky’s picture of little Cygnus A only got him fifty thousand dollars, though—red dwarf stars simply weren’t that interesting. Even well-studied nearby ones. And Rachel Morgenstern, with her husband and their three grown children, shared half a million for the Delta Cepheid shots. Cepheids aren’t all that rare, but the Morgensterns happened to be there just when the star’s surface layers were losing transparency through compression.

And then there were all the missions that wound up in Oort clouds.

Oort clouds are masses of comets that orbit a star very far out—the Oort in Earth’s system doesn’t get going until you’re half a light-year from the Sun. There are lots of comets in your average Oort cloud. Trillions of them. They generally mass as much as the aggregate of a star’s planets, and almost every star has an Oort.

They seemed to fascinate the Heechee.

In Gateway’s first twenty years of operation, no fewer than eighty-five missions wound up in an Oort cloud and returned to tell of it.

That was a big disappointment to the prospectors involved, because the GatewayCorporation stopped paying bonuses for Oort data after the tenth such mission. So those prospectors who came back from an Oort complained a lot. They couldn’t understand why the Heechee had targeted so many missions to the dumb things.

And, naturally, they had no idea how lucky they really were, because it was a long time before anyone found out that, for an astonishing reason, most Oort missions never got back to the Gateway asteroid at all.

That billion dollars in astronomical science bonuses was welcome enough to the prospectors who got a share of it. But, really, it was chicken feed. What the Gateway Corporation was formed for was profit. The prospectors had come to the asteroid for the same reason, and big profit didn’t come from taking instrument readings on something millions of miles away. The big bucks came from finding a planet, and landing on it—and bringing back something that made money.

Neither the Gateway Corporation nor the individual prospectors had much choice about that. Making a profit was the basic rule of survival, and neither the prospectors nor the Corporation made the rules. Those rules were made by the nature of the world they came from.