Alpha Centauri: The Return (T-Space Alpha Centauri Book 3)

by Alastair Mayer

  The Xinglong and Tianlong moved deeper into the system, observing everything. They surveyed the giant planet Aegir, found decades earlier as one of the early nearby exoplanet discoveries. It had several moons, which was hardly surprising. But Aegir was just another gas giant. There was nothing remarkable about it.

  They observed several asteroids nearly large enough to be considered dwarf planets. There were probably more, but that wasn’t what they came for.

  And then, there it was, well within the inner asteroid belt, at a distance from the star that would put it between Venus and Earth if were orbiting Sol. Since Epsilon Eridani was slightly dimmer than Sol, this put it in the outer part of the not-too-hot, not-too-cold so-called Goldilocks zone. A bright blue and white marble of a planet, with green and a lot of brown too. It was Earth-like, more than could be said for any other planet in Earth’s solar system.

  The planet, second out from its sun, had a single large moon about half the size of Earth’s. As they approached, telescopic observation showed clouds and continents on the planet. It looked startlingly like Earth, perhaps with more land and less ocean. It would be drier, like a larger, partially terraformed Mars. Like Mars and Earth, its poles had sizable ice-caps.

  Lee watched the planet beneath them as they orbited. It was smaller than Earth, but larger than Mars. The scientists worked to refine their physical estimates. Observations of its moon’s orbit and its size had given them a good first approximation, but they’d need better numbers to safely perform a landing and, more importantly, a launch back to space.

  The comparison with a partially terraformed Mars seemed apt. Ocean covered about half the surface, but instead of a single large continent as Mars might have, there were nine or ten scattered smaller ones. One larger landmass was either splitting in two or the result of a recent collision, hence the imprecise number. The geologists would figure it out. There seemed to be large deserts in the interiors of many of the continents, and the large ice-caps suggested that the planet was cooler, perhaps in an ice age. If the star was young, that would change as it slowly warmed—but the planet would also be cooling from the initial heat of its formation.

  What intrigued Lee were several large island arcs and near-circular bays. The signs of an early heavy bombardment had not yet been completely obscured by tectonic activity and erosion. And yet the green areas and the oxygen in the atmosphere made it clear that life was well-established on the planet. Perhaps whatever had triggered the leap from simple to complex life on Earth had happened much earlier here. Lee had watched plenty of sci-fi movies in his youth, and he was itching to see what kinds of alien creatures might roam the surface. But that was on the inside. Outwardly he radiated the placid calm expected of a commander.

  ∞ ∞ ∞

  From high orbit, near the planet’s moon, the astronomers surveyed the planet and made their calculations. The mass was almost exactly two-thirds—0.66—that of Earth, with a radius of 0.9 Earth. That meant its average density was somewhat lower—not surprising considering its smaller size, the core would have compressed less—with a surface gravity a mere 0.82 standard, giving an acceleration of only 8.03 meters per second squared. Lift-off from the surface should be easy, and the landing crew would all walk with a spring in their step.

  The atmosphere was very close to Earth’s nitrogen-oxygen ratio, with a trace of carbon-dioxide but a lesser amount of water vapor. The latter was no doubt due to the cooler temperatures and smaller ocean surface area.

  The two ships approached the planet and settled into a low orbit around it. Part of the survey procedure was to explore with drones and small robotic landers before committing a ship.

  Captain Lee signaled the Tianlong Huā. “Prepare an aerial drone for deployment.”

  “Very good, sir. Target?”

  “I will let you know. For now, just prep the drone and launch it to keep station with us.” The drone, a remotely piloted aircraft similar to military surveillance drones, but with additional sensors, was fitted into a deorbit capsule that would be sent into its own orbit near the two ships, then commanded to do a reentry burn to the chosen target area. The crew prepping it would be running final checks on its systems and sensors, much like preparing a satellite for launch.

  ∞ ∞ ∞

  Three hours later, the drone, in its capsule, floated a safe five kilometers away from the ships as the formation came up on the burn point to bring it down over one of Epsilon Eridani II’s large continents, which had showed signs of large animal herds on the Xinglong’s observation telescope.

  Right now, a smaller scope was trained on the capsule, its view relayed to a screen on Captain Lee’s console.

  “System status?” he asked.

  “Everything is correct. Approaching burn point in thirty seconds.”

  “Commence burn on the mark.”

  “Yes sir. Transferring control.” The technician touched an icon on his screen which allowed the capsule’s computer to initiate the burn and control the entry sequence.

  “Burn commencing in three...two...one...now.”

  On Lee’s screen, the rocket nozzle at the base of the capsule flared to life, momentarily washing out the image until the compensator stopped down the brightness. The scope tracked it as it fell behind the formation, then began descending into the atmosphere as it lost orbital velocity. In a minute, it was too small to make out, and the burn had stopped. The computer controlling the scope knew its trajectory, however, and soon a bright orange streak showed as the capsule burned into the thicker atmosphere below. In another minute, the upper aeroshell would blow off, be dragged away by a small parachute, and leave the drone aircraft sitting on the heat-shield forming the lower part of the capsule.

  “Aeroshell jettisoned,” the technician reported.

  Another screen, showing the view from the drone’s primary camera, lit up now that the view was no longer impeded. They saw blue sky and a few distant clouds above the edge of the heat shield.

  “Motor systems are good. Coming up to speed.” The drone was preparing to fly under its own power.

  “Jettison maneuver initiated.” This was the tricky part. The drone had to separate from the heat shield and fly away from it, but in the entry configuration, it was in the shield’s wake. To eject the shield, clamps were released and the heat shield tilted at an angle to the airflow, allowing the slipstream to get under the drone’s wings. This introduced unavoidable turbulence, which the drone had to quickly power through and clear any erratic motion from the discarded heat shield.

  The crew watched the monitors as the drone ejected its heat shield and came to flying speed, then soared away under its own power. A brief cheer came from the crew, quickly stifled with a few guilty glances at the captain.

  Lee Shing smiled, then starting clapping. The crew relaxed and joined in the applause.

  ∞ ∞ ∞

  The drone had power for several hours of flight. It cruised in a standard pattern, surveying the ground with optics and radar and sniffing the air with its chemical sensors.

  While the drone pilot concentrated on his flying, Chief Scientist Shufeng Bai and Captain Lee watched the images being relayed back.

  “Look there, a group of flying creatures.”

  “Bring the drone closer,” ordered Lee. “Let us get a look.”

  “They are avoiding the drone, but look,” Wu froze a frame and enlarged it. “Two wings, two legs, a beak—”

  “—and feathers. Are those birds?”

  “How is that possible if this system is only a billion years old? That’s not enough time for complex life to evolve.”

  “Perhaps the age estimates are wrong. We saw animal herds with the main telescope. The star does have low metallicity, perhaps it really is old.”

  The drone pilot was still watching the live feed, now flying it low over the br
oad open plain they had targeted as a landing area. A herd of large animals grazed there, disturbingly familiar looking animals, with shaggy hair or fur. “I do not know about birds, but those,” he pointed to the screen, “could be cousins to elephants.”

  Chapter 3: Preparing for Landing

  Orbiting Epsilon Eridani II

  “The planet is smaller than Earth and has a lower escape velocity,” Chen, the First Officer, reported to Captain Lee. “We have a wide choice of landing sites.”

  “Very good. See if you can get the scientists to agree on three or four. I will make the final decision from those.” Lee knew there’d be no way for the scientists to all agree on one spot. He doubted even all the geologists or biologists would agree with each other. Personally, he’d prefer the place most likely to have a wide variety of alien life, but the safety of the ship was his overriding concern. Not so much for safety per se, but he couldn’t complete his mission without an intact ship, nor did he want to get into a position where the Tianlong had to rescue them. That would cause a great loss of face.

  “Shì de xiānshēng.” Yes, sir.

  The Chinese ships bore some similarities to the Xīng Huā and the American USS Robert A Heinlein which had flown on the Alpha Centauri mission. They were built according to a large aerospike single-stage-to-orbit design. Like the Centauri ships, the fusion reactor was built into the hull, but it was a lighter, more-efficient model. The Chinese weren’t so stupid as to reveal their best technology on an international expedition. Unlike those ships, but similar to the landers on that mission, the warp field generator pods—based on original Chinese designs but incorporating the American secret to overcoming Finazzi quantum warp instability—attached to a ring which could be separated from the ship. There was no need to bring the mass of those down to the planet then lift it back to orbit. Instead of the separate, fission-powered refueling modules intended for the Centauri landers, the Xinglong Huā—and the Tianlong Huā if it was decided to land that ship too—would refuel itself using the on-board fusion reactor to synthesize propellants from the local atmosphere and water. It simplified the overall mission, although at the expense of some payload capacity taken by the weight of the fusion reactor.

  ∞ ∞ ∞

  They decided to land on the largest continent, near the mountain range that marked where two smaller plates were colliding. Since the geologists hadn’t detected any signs of a rift valley, they were pretty sure that’s what was going on. The uplifted mountains would give them some insight into the strata making up the crust in that area, and hopefully tell them something meaningful about the history of the planet.

  The biologists were happy with that too. There were several different ecological niches, from plains to alpine to the nearby ocean. If they were lucky, they might also find fossils, which could help them determine the history of life on the planet.

  The landing spot was near the coast. Instead of a manned ultralight such as the Centauri mission had taken along, they had a larger number of remotely piloted drone craft with robotic sampling systems. They wouldn’t be able to closely examine any large creatures with the drones, the noise would scare them off, but there should be something near the landing area.

  The science crew, which had been split between the two ships for the voyage out, transferred to the Xinglong for the landing.

  ∞ ∞ ∞

  “Xinglong is ready to undock.”

  “Proceed,” said Captain Lee.

  “Commencing undock,” the pilot announced.

  Lee felt as much as heard the ka-chunk of the docking latches retracting from the support arms connecting the ship to its warp ring

  “Unlatched. Retracting.”

  The three support arms—spokes in a wheel—connecting the ring to the ship began to fold at elbow joints midway along their length, pulling the arms away from the ship. Lee heard muffled sounds as the power couplings pulled free, then silence. He watched a pair of screens linked to external cameras as the arms slowly folded away from the ship, leaving plenty of clearance for the Xinglong to pull free of the warp ring’s embrace.

  “Full retraction. Ring is free, still on external guidance.”

  Just as with the similar American design, the warp ring had its own guidance and orbital maneuvering systems, which were currently slaved to controls aboard the Xinglong. It wouldn’t do for some glitch to cause it to move on its own until the ship was well clear.

  “Very well,” Lee acknowledged. “Disengage and withdraw to five hundred meters. Rate one.”

  “Five hundred meters, yes sir. Proceeding at one meter per second.”

  There was a quiet thump of the maneuvering thrusters firing briefly, and the Xinglong slowly drew away from the warp ring.

  Lee watched the numbers count up on his console’s range display. “At fifty meters,” he said, “go to rate two.”

  “Rate two at fifty, yes sir.” They were just coming up on forty.

  “Going to rate two in three, two, one, now.” The pilot nudged his control stick again and with another gentle thump, the ship accelerated to two meters per second.

  On the forward view screen, the warp ring was still maintaining its position, with the Tianlong standing off a thousand meters away.

  “Transfer ring control to internal, and advise Tianlong of same,” Lee ordered. The warp ring would now maintain its position in orbit on its own, unless overridden for some reason by the Tianlong. The plan was for the warp ring to assume an orbit which made rendezvous with it easy when the Xinglong launched back to space from the planet’s surface. Meanwhile, the Tianlong would assume an orbit that let it do a more detailed survey of the planet’s surface, yet still bring it into communications range of the landing site at regular intervals. To that end, the warp ring also mounted a communications and data relay system. Despite that, there would still be times each day when the two ships were out of communication with each other, but the Science Directorate had been unwilling to swap out their instruments for mere communication satellites.

  The Xinglong reached the desired five hundred meters from the warp ring, and the pilot fired a short thruster burst to stop their relative motion. “Five hundred meters, rate zero.”

  “Thank you, Pilot Cheng,” Lee said. “Navigation, position relative to landing site?”

  “Sixteen thousand, two hundred kilometers up-range. To reenter on this orbit, we have approximately fifteen minutes until burn.”

  “I think we can be ready by then,” Lee said. They could wait another orbit, or several, if they had to, but that would mean some additional maneuvering. It would also mean they would land later in the day, and Lee preferred to land shortly after local sunrise, to maximize the amount of daylight they had to settle in, and to minimize any crosswinds that might pick up during the day.

  Lee donned his communications headset and switched to the ship-to-ship channel. “Tianlong, this is Xinglong. Captain Lee speaking.”

  “This is Tianlong, please go ahead. This is Captain Zhing responding.”

  “Captain Zhing, Xinglong will commence deorbit burn in fifteen minutes for landing on this orbit. You have command in space here until we return. Please try not to go anywhere without us.”

  “Acknowledged, Captain Lee. We would not presume to go anywhere without your inspired leadership.”

  Lee smiled at this. It was all formal, hyper-polite bullshit, of course, although he was sure Zhing Yuan would stick to the mission profile. They’d known each other a long time, and he’d been his backup for the Centauri mission. “Roger that,” he said, in colloquial English, which of course he was fluent in, as was Zhing Yuan. As also, he realized, was a good portion of the crew. He switched to Russian. “Khorosho. You have orders if something happens to us. Don’t be hero. Return to Earth first priority. Uvidimsya, be seeing you.”

  “Da, uvidimsya
. Good luck. Zhù nǐ hǎo yùn.”

  Chapter 4: Grainger

  Lunar Interstellar Quarantine Facility, a week after return

  “Doctor Grainger! How’s the spleen?” George Darwin said as he rose to greet the newcomer to the facility.

  “Envious that you got to go to Alpha Centauri while I was recovering from that stupid fall. I should have been on that expedition.” He said it good-naturedly enough, but Darwin knew there had to be an element of truth there. Grainger had been the original pick for lead exobiologist for the Centauri mission, until a training accident had put him in hospital.

  “In which case, it would be you here behind the quarantine and me out there,” Darwin said.

  “Small consolation, and it won’t last. At least I’ve got first dibs on the specimens you brought back. Rumor has it they’re remarkably terrestrial? What did DNA analysis show?”

  “Unfortunately, our sequencer was on the Xīng Huā, which as you no doubt heard disappeared as we were approaching the system.”

  “I did. It hit an asteroid or comet fragment while in warp, yes? At least it was over quickly.”

  “Officially, yes.”

  Grainger raised his eyebrows. “And unofficially?”

  Darwin looked around. There was nobody else in the area, and he was pretty sure Drake had already reported it. “There’s a possibility the explosion was faked, and that the Chinese returned in secret so they could reverse-engineer the warp drive.”

  Grainger just stared at Darwin for a moment, then muttered. “Well, well, well. Bloody politics.” He shook his head as in disgust. “So no DNA analysis. But then why terrestrial?”