The Stars That Beckon

by Kevin J Simington

  36

  Six days later, they had been in high-altitude orbit around the planet for two days, and the ship was abuzz with a mixture of excitement and anxiety. The excitement was due to the obvious beauty of the planet and its suitability for human settlement. It was temperate and lush with vegetation. There were two small polar ice caps and two continents on almost opposite sides of the globe, separated by oceans that encompassed 78 percent of the planet. Earth-like photosynthesis appeared to be in operation and the atmosphere was perfect for humans. In short, it appeared to be a paradise.

  Except for one thing. It had been previously occupied. At least, they hoped the occupation was previous and not current. The planet was encircled by an artificial ring in the shape of a giant cylindrical “hula hoop” that orbited about 250 kilometres directly above the equator. During the final three days of the ship’s approach, Genesis had bombarded the planet with friendly “We come in peace” messages, transmitted on every available bandwidth and in multiple languages, but had received no reply. Neither had scans been able to pick up any electromagnetic radiation from either the ring or the planet itself. The planet seemed entirely dead in terms of sentient life. High-resolution images of the planet’s surface revealed nearly 60 small cities or towns, spread over both continents, but without any sign of current intelligent habitation.

  The “hoop,” as it was now called by the colonists, was the subject of much speculation, as were the cities below it. Who had lived there? And where were they now? Endless theories abounded: Perhaps they had all been wiped out by a plague. Or, maybe they had transcended to a higher dimension. Perhaps they were in hiding, underground, and were waiting for the right moment to attack. No one knew.

  As Genesis drew closer, the ship’s high-resolution cameras revealed that the hoop was not perfectly uniform, but bulged out into spherical balls, evenly distributed around the hoop, like a string of pearls. There were 12 of these spheres, leading to speculation that the builders used a base 12 mathematical system. The spheres were about 200 metres in diameter, and the tubular hoop that linked them was 50 metres in diameter. From the vantage point of Genesis’s much higher orbit, the entire structure appeared to be made of a dull, black substance that gave off no emissions itself and did not reflect radar or other scanning emissions from the ship. It looked dull, black and dead, except for the perfectly geosynchronous orbit that the entire structure maintained.

  Although all kinds of theories abounded concerning the nature and purpose of the hoop, everyone was in agreement about one thing: the builders were clearly thousands of years more technologically advanced than the Genesis colonists were.

  The council had been meeting every day to discuss the latest findings from scans of the planet’s surface. The continents had been mapped, and animal life had been identified, including herds of animals of various sizes apparently grazing in areas of grassland. The colonists had been invited to suggest names for the new planet, and dozens had been contributed. Most were rejected, including Ringworld (already taken by Larry Niven’s work of fiction) and Hoopworld (too childish). A short list had been generated and had been published on the data terminals: Acquis, Aquatica, (both because it had more ocean than Earth), New Hope, Nova, and Prime. Voting had been open for 24 hours and was scheduled to close at 0900, after breakfast on the morning of their third day in orbit.

  Melody was bouncing with excitement at breakfast, as she had suggested Prime, because of her love of prime numbers. “Do you think mine will win?” she asked, as she scoffed down what passed for porridge.

  “Eat slowly, and don’t talk with your mouth full,” said Jaz, wiping a piece of Melody’s projectile porridge from her own left eyebrow.

  “I’ve been telling everyone to vote for mine! And Grizzle let me put signs on the loading bay walls: ‘Vote for Prime’.”

  “She’s very persuasive,” said Grizzle, bashfully.

  “Yes, I know,” said Zac. “She stuck one on my cabin door as well.”

  “How long to go until it’s announced?” asked Melody.

  “Ten minutes. Eat your breakfast,” said Jaz.

  “So, Keo, how’s your ‘There’s no such thing as aliens’ philosophy going?” asked Martinez.

  “Fine, thank you,” answered Keo.

  “Oh, come on! We’re staring at technology that’s way beyond anything humans are capable of!”

  “Humans 3,000 years ago, yes. But we don’t know what has happened in the three millennia while we were trapped in the black hole. It is entirely possible that humans who survived in our solar system could have advanced to this level by now.”

  “So, where are they?” asked Martinez.

  “Where are your aliens?” countered Keo. “The same mystery confronts both theories. All we can do is reserve judgment and wait to see what further investigation uncovers.”

  “Well, my money is on aliens.”

  “If they are aliens,” contributed Kit, “they must be remarkably similar to us in size, shape and architectural preferences. I mean, the pictures we’ve seen of their cities don’t exactly scream out ‘aliens live here,’ do they?”

  Others had commented on this, as well. The same basic architectural shapes seemed to be in evidence in most buildings, arranged in orderly rows, separated by what could only be sealed streets of some kind. From their perspective, high above the planet, it all looked very normal. What was puzzling, however, was the extremely understated simplicity of the cities. No skyscrapers, no elevated freeways, and no obvious technological marvels. No buildings over two stories high, and no towers, antennas or transmitters to be seen anywhere. And the cities were all very small. In fact, they were towns rather than cities. The incongruence with the obviously advanced technology of the orbital hoop was stark. And puzzling.

  “Ladies and gentlemen, can I have your attention please.” Captain Christensen’s face appeared on the screens on all the living decks. “It is now 0900. The voting for naming the planet has now finished, and the results are in. I can tell you that there were two clear front-runners: Prime and Nova.”

  Melody squeezed Jaz’s hand and started whispering, “Please, please, please, please, please ...”

  “The most popular name, by a clear margin, is ... Nova!”

  There was a mixture of cheers and clapping and disappointed moans all over the dining room. Melody moaned, “No! I thought I was going to win!”

  Captain Christensen continued, “Nova, which means ‘new’, is now the official name of the planet. Of course, we aren’t yet calling it our home until we ensure that it is entirely vacant. We will continue our investigation of the planet from a safe distance until we are convinced that it poses no threat to us. Thank you for your patience while we do so. I am also happy to announce the result of the poll to name Nova’s two moons. Overwhelmingly, you voted for Big Boy and Little Boy. Thank you for your participation. I will continue to post regular updates on your data screens regarding our exploration of the planet.”

  Melody looked mildly glum. “I wanted to call it Prime! It’s not fair!”

  “Actually, it’s very fair,” said Zac. “It’s called democracy.”

  “But Prime is a much better name for a planet!”

  “Sounds more like a piece of steak, if you ask me,” mumbled Grizzle.

  “Hey, whose side are you on?”

  “I’m just sayin’, Possum, I’m just sayin’.”

  37

  By Orbit Day 4, they had gleaned all the information they could get from their high-altitude orbit, and it was decided to send one of the shuttles for a closer inspection of the hoop. As the shuttle pilot with the most flight hours logged throughout her career, Kit was the obvious choice, which meant that Zac got to go as co-pilot. As they emerged from the shuttle bay into clear space, Kit thumbed the comm, “Shuttle one is clear and free. Commencing burn to lower orbit.” The voice of Lance Catrell came back through the cabin speakers, “Copy that, Kit. Fly safe.”

  “OK,” Kit told Zac. �
�It’s time for a physics lesson. How much do you know about orbital velocities?”

  “Probably about as much as you know about the origin of Egyptian hieroglyphics.”

  “That’s what I thought. OK, pay attention, because this is important. That thing down there is a planet.”

  “OK. Got it so far.”

  “Planets are massive.”

  “Yep. Still with you.”

  “And massive things have lots of gravity. This planet is trying to pull us down. The only way to avoid that is to have enough lateral velocity that the centripetal force of your circular path around the planet exactly cancels out the planet’s gravitational pull on you. When you achieve precisely the right velocity, you are neither falling towards the planet, nor shooting out into space. You have achieved orbital velocity. With me so far?”

  “Yep. Clear as crystal.”

  “If a spacecraft in a stable orbit fired up its engine and kept increasing its velocity, it would break out of orbit and shoot out into space. On the other hand, if it slowed itself down by firing its engine forwards, using it as a brake, it would lose its orbit and start plummeting towards the planet. Still with me?”

  “Uh-huh.”

  “Now, the thing about orbits is, the closer you want to orbit a planet, the faster you have to go, because gravity is stronger as you get closer. Back on Earth, a spacecraft in a high-altitude orbit of 35,000 kilometres would only need to be travelling at about 3 kilometres per second. A spacecraft in a low-altitude orbit of only 200 kilometres would need to be travelling at about 7 kilometres per second for the centripetal force of its velocity to overcome the much greater gravity at that proximity to the Earth. So, the lower the orbit, the higher the velocity you need to avoid falling toward the planet. Got it?”

  “Yep, I can handle all that so far.”

  “Good. Now, here’s the tricky bit. The hoop we are flying down towards is at a very low altitude of 250 kilometres above the planet’s surface. A normal spacecraft orbiting at that height, around a planet that is 6 percent more massive than Earth, would need to have an orbital velocity of about 7.4 kilometres per second. But the hoop doesn’t have anywhere near that velocity. It’s in equatorial geosynchronous orbit around the planet, which means that each sphere on the hoop is stationary over a set point on the planet’s surface and rotates in synch with it. To achieve that, the hoop is only rotating at about 1 kilometre per second.”

  “So how does it stay up?”

  “Well here’s the really cool part. It actually doesn’t need to rotate at all to stay up. It could be completely stationary, and it would still just hang there.”

  “But how ...?”

  “Because it is a solid hoop that encircles the entire planet. At every point around the hoop, the planet is trying to pull it down, but the downward force of gravity at each point on the hoop is cancelled by the downward force of gravity acting on a point exactly opposite it on the other side of the planet. The planet is trying to pull the hoop down, but it can’t because its own gravity is holding the whole thing in place by pulling it down from every direction simultaneously.”

  “Wow! That really is cool!”

  “Yeh it is. But what isn’t cool, is what we’re going to have to do to get a close look at the hoop. If we try to match its orbital velocity, we will plummet straight past it and crash into the planet. That’s because we aren’t a solid ring, encircling an entire planet We’re just a teeny-weeny shuttle, so we need to have a much faster orbital velocity at that low altitude. We can certainly orbit at the same altitude as the hoop, but we will be whizzing past it at an additional 6 kilometres per second.”

  “So how are we going to ...?”

  “Here’s what we’re going to do. I’m going to start with a standard low-altitude orbit, about 300 metres above the surface of the hoop, which means we will be 225 metres above the spheres. We will be racing past it at 6 kilometres per second. After we’ve stabilised at that orbit and had a bit of a look at it, I am going to do some fancy-pants flying.”

  “OK ...” said Zac uncertainly. “Am I going to like this?”

  “Sure. You’ll love it. I’m going to exactly match the hoop’s orbit so that we are hovering stationary just underneath it.”

  “But I thought you said we couldn’t ...”

  “And I’m going to do that by constantly firing our main engine at a very precise angle and a very precise thrust, so that our loss of orbital velocity is constantly compensated for by upward thrust. We will be like a hummingbird hovering in front of a flower, beating its wings like crazy but staying perfectly still.”

  “Wow! OK. I get it. That’s pretty cool. When did you learn to do that?”

  “I haven’t yet.”

  A little more than 20 minutes later, Kit cut her engine, thumbed her comm and said, “Shuttle 1 to Genesis, we’re in stable orbit 300 metres above the hoop. Are you getting the video feed?”

  “Roger, Kit. It’s a good feed. Clear and sharp.”

  “Cool. We’re just gonna park here for a while and watch the world go by.”

  “Copy that.”

  They looked through the front screen at the hoop, which looked dull, black and completely smooth.

  “It doesn’t seem to be moving,” said Zac, squinting through the front window.

  “That’s because our speed differentials are so great. We are currently flying over the top of the hoop at over 22,000 kilometres per hour. At that speed there could be a pink elephant sitting on the hoop and it would flash by so fast we wouldn’t even see it.”

  “What about the spheres? They’re 200 metres in diameter. We should be able to see them, shouldn’t we?”

  “OK, let’s watch and see. There are 12 spheres, each about 3,500 kilometres apart. At this speed, one will go past every 7 minutes, 42 seconds. I inserted us into orbit about 600 kilometres from the next sphere. We should be passing it within the next 40 seconds. Watch carefully!”

  Zac stared at the hoop directly in front of the shuttle. Nothing changed. And then, suddenly, there was the briefest of flashes, the barest suggestion of an anomaly in the perfectly smooth hoop, and it was gone before his eyes could register it.

  “Good grief! That was fast!”

  “Yep. Ten times the speed of a bullet. That’s why we have to slow down a bit, because we’re not gonna see anything at this speed.” She flicked the comm. “Genesis, we’re gonna change the tempo and do a bit of slow dancing now.”

  “Copy that. Be careful, Kit.”

  “Always.” She fired some manoeuvering thrusters, pivoted the shuttle around and then started firing their main engine in short bursts, to retard their velocity. “We’ll be flying backwards from this point on,” she said, staring into the monitors showing the video feeds from the rear-facing cameras.

  “What do you want me to do?” asked Zac.

  “You got any chocolate?”

  “Um ...”

  “Any chewing gum?”

  “Er ...”

  “Can you play the mandolin?”

  “The ... um ...?”

  “In that case, just sit there and shut up for a few minutes.”

  He glanced across at her and said, “Do you always stick your tongue out when you’re concentrating?”

  “Only when we’re about to crash and burn and die because some idiot is talking to me and ruining my concentration.”

  “OK. Shutting up now.”

  It took a lot longer than a few minutes. In fact, it took nearly 20 minutes, but finally the shuttle had become a hummingbird, perfectly stationary underneath the hoop while its engine roared continually behind it. Kit edged closer to it until she was a mere 20 metres away. The hoop was indeed perfectly smooth, at least at this point. Looking to left and right along its length, they could not see any perturbations; no lumps or bumps or bits sticking out of it.

  “Let’s mosey along a bit further and find the next sphere. It should be about 5 kilometres ahead.” The hoop remained perfectly smooth as t
hey moved along it, a black dull tube 50 metres in diameter. The next sphere became visible in the distance, a perfect sphere, 200 metres in diameter, with the hoop seeming to pass directly through its middle. At last, they came up to the sphere and Kit froze the shuttle’s movement at the point where the hoop and the sphere met.

  “Are you getting this video feed, Genesis?”

  “We sure are, Kit. Keep it coming.”

  “I’m gonna swing out and around the sphere now.”

  “Roger that. Be careful, Kit. Nice and easy.”

  “I’m always nice. But I’m not easy.”

  Lance chuckled. “Copy.”

  Slowly the shuttle swung out and around the huge sphere, with Kit furiously working the thrusters and main engine, her tongue working equally furiously at the side of her mouth. The middle third of the sphere had horizontal rows of rectangular windows extending around its entire circumference. Nothing could be seen through the windows, which seemed to be made either of a darkened glass or some kind of one-way viewing material. The top and bottom thirds of the sphere were completely smooth.

  Kit said to Zac, “Let’s have a look underneath.” Slowly they slipped downwards and under the smooth surface of the sphere. “Bingo! Here’s something, at last,” she said. At the very base of the sphere, there appeared to be a giant set of hangar doors. Kit couldn’t decide whether they opened outwards (downwards) or slid open within the shell of the sphere.

  “It looks like access for shuttles,” said Zac.

  “Sure does.”

  “But how do we get them open?”

  “Precisely! That is the question.”

  She thumbed her comm. “Genesis, I’m pinging the sphere with every frequency we’ve got. Are you reading any response on your scanners?”

  “Nothing, Kit. It’s as dead as a tomb.”

  “I’m gonna push a magnetic grapple cable across to it and see what happens.”