CHAPTER 12
Proxima b
The cool air inside the monitoring station was a welcome respite from the heat outside. While the Proximan weather was typically mild this time of year, the local political heat was almost unbearable. For some time, the locals had gotten more and more worked up over the Terrans’ presence there, and since the Emissary had left, many of the better-known faces like Rain and Max were gone with it. The climate was tumultuous at best.
The station, a sleek structure of some version of local concrete, metal girders, steel panels, and glass, was nestled in the midst of the alien landscape of Proxima Centauri b on the highest peak of the area the Fintidierians had set aside for the visitors from Earth. Roy Burbank adjusted his glasses and sat in front of the array of screens, the glow illuminating his determined face. Rain’s instructions had been clear. She had found the original signal from Proxima back on Earth, a task that had changed the course of human history. Roy respected her brilliance and intuition, and he diligently tracked the Luyten signal now, waiting for any changes or additional information. He also kept watch on the Emissary. He made certain that there was a weekly upload of information beamed across space to the ship that was now nearly two thirds of a light-year away.
Roy Burbank missed seeing the superbright spacecraft passing overhead on occasion. Where there had been two, the Samaritan and the Emissary, now there was only the Samaritan, and it was often doing deeper solar system missions and not in any low Finti orbit. He missed some of the team who had gone on the eighteen-year one-way trip to Luyten’s Star. A few he didn’t really know, but he missed Rain and Max the most. They were his friends. They had been the couple that he and Chloe could invite over for dinner or cards or to shoot the breeze and hang out. But Rain and Max had been gone now for almost a year. Roy had sort of come to the conclusion that he’d never see them again. But then again, he’d once thought that about his wife and daughter, and that ended up working out pretty well. But that outcome had been completely out of his hands. Perhaps, he pondered, so was everything else. Things would work out. They would have to. He put it out of his mind. If it were meant to be that he’d see his friends again, then he’d see them and that was that. Or it was at least how he decided to compartmentalize the subject. He kept it in the same regard as all of the other craziness that was going on around the planet. Somehow, it would work itself out.
Work had even been more of a thing he had to do rather than a thing he wanted to do. For the first couple of months, he’d gone in day after day to maintain the dish array and the communications equipment linking them to the Samaritan. And he managed an uplink in the direction of the Emissary with daily bursts of news and data. He also maintained the communications link between Proxima b and Earth (or Sol 3 as some of the Fintidierians called it). But over time, his enthusiasm waned and now he forced himself to check everything at least once a week. Roy had plenty of other things on his to-do list as he was one of the most senior and competent hands-on engineers planetside. There was always something in need of being repaired, updated, tweaked, and the like.
He looked up from the tablet he was currently working with and out the window at the large ten-meter-diameter dish as it turned toward the Sol system. There had been something in the signal that he’d been seeing for months that didn’t make any sense. Sure, the data stream from Earth was there, but there was something else: an increase in the noise floor sometimes, and then sometimes a decrease in the signal strength occurred, as if something were blocking the signal.
His fingers danced over the keyboard virtually projected in front of him by his contact lenses, pulling up the daily data logs. The hum of the high-performance threaded multiprocessor computers whirring behind him in the large rack was comforting; the steady tone from the cooling fans had always worked better than sedatives for his nerves. This was his element. It was where he was at home—building, doing, engineering. He jumped slightly as he heard a soft background noise in the stillness of the station, like one of the local versions of a cat scurrying across the floor. Those damned things were everywhere and so far, he had yet been able to get close enough to pet one. The Radio Astronomy and Communications Ground Station was calm, and everything was running in order, well, accept for maybe that damned cat. He’d have to make sure they hadn’t found a way into the place through a vent or loose panel or something.
But today, something was different. More than just the increase in the noise floor across the radio spectrum and more than a loss of signal, there was something else. As he scanned the spectrum, the large dish locked on to the signals from Earth, and the artificial intelligence and machine-learning algorithms homed in on the known signals and sources and began logging and demodulating them. But there was something unusual in the spectrum that was now well above the noise-floor background and was clearly a new source. Roy’s eyes focused on the anomaly as he watched the waterfall of the RF, microwave, and terahertz spectrum pass by. A new signal, its source from the direction of Earth…but not. It was not at any frequency it should be if it were coming from Earth. Roy’s heart raced.
“This can’t be right,” he whispered, recalibrating the instruments and running a diagnostic. The signal persisted, clear and strong. “Three-hundred-seventy four-point-seven gigahertz? What the hell?”
The modulated wave patterns and frequency suggested advanced technology for sure, but who used 374.7 gigahertz? Roy was certain that it was not a stray signal or a reflection, but something purposeful. He analyzed the data further and then had a thought.
“Uh, Nigel, you see this signal here?” he asked his AI as he highlighted the signal in the spectrum analyzer waterfall.
“Certainly, Roy. What would you like to know?” Nigel replied.
“If this were the Samaritan at top speed traveling toward us, what would the frequency be at the transmitter?” Roy rubbed his chin, realizing he hadn’t shaved in a couple of days. Chloe usually reminded him of such things, or maybe she had and he was too distracted with all the repair jobs to pay attention.
“Assuming the Samaritan was traveling at approximately zero-point-nine-seven-c, the pre-blue-shifted frequency would be forty-six-point-three gigahertz. And it would be using a Binary Phase Shift Keying—BPSK—modulation scheme.”
“Hmm. Okay then, demodulate it,” Roy suggested. “Assume around that forty-six gigahertz to be the base frequency.”
“I’m sorry, Roy, that didn’t work,” Nigel responded.
Roy thought it over in more detail. BPSK was a digital modulation technique that had been used in communication systems for more than a century and was the workhorse of long-range space communications. It represents binary data (0s and 1s) by shifting the phase of a carrier signal (RF, microwave, terahertz, optical, etc.). In BPSK, a phase shift of 180 degrees or π radians was typically used to encode one binary state, while no phase shift represented the other state.
The problem was that any transmitter moving relative to the receiver would have a so-called Doppler shift, which wasn’t really a shift because Doppler has to do with sound. The red or blue shift in electromagnetic signals worked the same but that incorrect term continued to be used.
“We don’t have the right transmitter frequency, Nigel,” Roy said.
“Ah, yes of course, if the Doppler shift due to the high velocity is not properly accounted for, then it can result in a carrier frequency offset at the receiver,” Nigel agreed. Roy sometimes got annoyed at how the AI would overexplain things to him. “Without the correct Doppler shift correction, the demodulation of a BPSK signal at interstellar spacecraft velocities may become impossible, and the received signal will prove impossible to be accurately demodulated.”
“Haha! No kidding,” Roy scoffed. “We need the transmitter frequency.”
“Yes, I could start running all the base frequencies at once and demodulate the signal with each Doppler shift filter,” Nigel suggested.
“Uh, hold on…” Roy bit at his lower lip, thinking about that course of action. “How long would that take, Nigel?”
“Uncertain. But there could be a very large range of frequencies from single-digit gigahertz up to a terahertz, with likely accuracy needed down to two decimal points,” Nigel explained.
“That’s like, uh, a million possible choices?”
“Correct, Roy.”
“Okay, hold on. Let’s try something else.” Roy held up his hand as if telling someone to stop. After realizing nobody was there to see his hand gesture, he briefly laughed inwardly at himself. “Open me a channel to the Samaritan. Who’s the CHENG now that Mastrano left on the Emissary?”
“That would be Bob Roca, Roy.”
“Okay, get him on the line.”
“Hold one minute, Roy,” Nigel said.
Roy sat impatiently for a couple of moments, looking at the signal in the spectrum analyzer, whose screen literally looked like a waterfall. A blue background rolled from top to the bottom. The horizontal axis from left to right was low-frequency RF to terahertz. On the right half of the screen were two bright white lines (white being maximum measured signal strength) zigging and zagging back and forth, creating two irregular randomly moving tracks as they fell down the screen.
“Roca here.” An audio channel opened almost startling Roy.
“CHENG, this is Roy Burbank down at the ground station,” Roy said.
“What can I do you for, Roy? Haven’t heard from you in a bit.”
“Yeah, it’s been a minute. Hey, man, listen, I’m detecting a radio signal coming from Earth that is blue shifted all the way up to three-seventy-four-point-seven gigahertz. I think it’s a ship.”
“No shit?” Roca questioned. Roy wasn’t sure from his tone if he didn’t believe him or was more surprised at there being possibly another ship.
“No shit,” Roy retorted. “It looks like it’s BPSK modulated, but we don’t know the base frequency. I could have the AI run it, but it would take days. I was thinking of a quicker route.”
“I’m listening.”
“Well, I was thinking, if they have a Samara Drive, then you could point the optical telescope on the Samaritan at it and measure the optical spectrum up there. We know the Samara Drive physics. The ultraviolet light beam has a specific wavelength. You get me the color measured here and I can calculate how much it is blue shifted and therefore how fast the ship is going.”
“Ah! I see. Then you can reverse calculate from the speed of the ship, the measured three-seventy-four-point-seven gigahertz signal, and apply special relativistic corrections to determine what frequency the ship is using,” Roca replied. “Got it. Okay, shoot me the coordinates.”
“Uh, just point the thing at Sol,” Roy suggested, trying not to sound condescending.
“Oh, yeah, duh,” Roca laughed. “I’ll shoot you the spectrum in minute. Anything else?”
“Naw, that’ll do it,” Roy said.
“Alrighty, then. Samaritan out.” The channel closed.
“Nigel, as soon as the spectrum gets here, run those numbers for me, okay?”
“Copy that, Roy.”
Several minutes passed and then Roy’s inbox dinged at him. He looked and could see it was the information from the Samaritan. Roca had come through. Roy opened the file making a tossing motion with his hand. The file opened virtually in front of him.
“Nigel?”
“Yes, I am working it.”
“Good, let me watch.”
“Sure, it is on your VR field of view now.”
Roy watched as the AI expanded the multispectral image that had been taken, looking in the direction of the Sol system. The image turned into a spectral graph with the horizontal axis being wavelength short to long left to right. Then another graph appeared that looked like a single big peak with smaller sidelobes near it, looking like a sombrero centered right at 221.1 nanometers. That was the known ultraviolet spectrum of the Samara Drive measured with zero relative velocity between the ship and the sensor.
“As you can see here, Roy,” Nigel interjected. “The stationary Samara Drive spectrum is centered at two-twenty-one-point nanometers. And here in the spectrum from the Samaritan looking back at Earth, we see known spectra from Sol and the other planets in the system. Filtering that out, we see here a spectrum centered at four-point-nine-five nanometers that looks exactly like a Samara Drive spectrum.”
“Boom!” Roy slapped his hands on the tabletop so hard that the one old-school keyboard there bounced upward. “There you go, using special relativity the speed of the spacecraft must be…”
“Zero point nine nine nine times the speed of light!” Nigel exclaimed.
“Holy shit, that thing is fast!”
“Yes, it is, faster than the Samaritan for sure,” Roca said.
“So, now we know the speed. What frequency are they broadcasting?” Roy pulled the 374.7 gigahertz signal back up on his screen.
“The base frequency is eight-point-three-eight gigahertz. Applying it to the BPSK demodulation correction now,” Nigel said, and an audio signal started playing over the speakers of Roy’s tablet.
“…left Sol system approximately eighteen months ago and should arrive in the Proxima system in four Earth years. This is the interstellar ship Pioneer. We are a privately funded effort to aid in the relief to the people and civilization of Proxima b. Our crew complement consists of one hundred and eighty women between the ages of eighteen and forty-six, twenty-two men, and various livestock samples. We are bringing modern scientific and engineering equipment and the latest research information on the genetics issues of the Fintidierian people. Our ship implements an updated Samara Drive pushing us faster than ever before. We accelerated from Mars and then left the Sol system approximately…”
“Nigel, what was the date stamp on that message?” Roy asked. If they were receiving this message that was sent eighteen months after departure and they were now receiving that signal at Proxima, then they were getting close. In fact, they were probably already decelerating.
“It would appear that the signal was sent Proxima relative forty-one months ago,” Nigel replied.
“Estimated arrival?”
“Six months to a year.”
* * *
“Unbelievable.” Captain Sam Crosby furrowed his brow as he leaned back in the command chair of the Samaritan. “Well, this is certainly unexpected. A private ship? Full of women volunteers and experts? That’s quite the twist, isn’t it? And they plan on doing what exactly?”
“You’re telling me, Captain!” Roy Burbank nodded as he adjusted the shades of the ground station conference room. The evening Proximan sunlight was casting strange glares across the screen. “The Samaritan and Emissary missions were supposed to be the initial contact with the Fintidierians. Now we have another player in the mix, and they’re bringing a whole lot of unknowns with them…and new female blood.”
“Yes, but new blood under no particular command structure here.” Jesus tapped his fingers nervously on the Fintidierian ashlike wooden table. “It’s a delicate situation, no doubt. We need to consider the implications carefully. Who is the legal authority over them?”
“We’ve got to think of the best way to approach this,” Cosby replied. “If they were merchant space farers then they’d be under my jurisdiction. Private citizens, well, I guess that becomes a diplomatic issue for the Fintidierians.”
“Oh, they’re gonna love that!” Roy muttered.
“Agreed,” Jesus added. “But you are right, Captain. This is an immigration issue for the Fintidierians. We can offer some form of assistance, security, diplomacy, maybe, but this is a situation of migrants showing up on the Fintidierian border with no visas or passports.”
“Well, we do have an uncomfortable decision to make here, gentlemen,” Crosby started. “Do we keep it under wraps for now? I mean, we’re not even sure what the Fintidierians’ reaction will be.”
“That’s the crux of it, Captain. We’ve come a long way, and the Fintidierians have been more cooperative than we could have hoped,” Roy said. “Right up until things went to hell and they kidnapped me and became violent toward us. Things are calmer now, but…”
“We don’t want to jeopardize the progress we’ve made,” Jesus agreed and then leaned forward toward the screen Captain Crosby was displayed on. “On the other hand, we can’t keep something like this secret forever. The Fintidierians are likely to find out sooner or later. Secrets always have a way of leaking in my experience. And you say we have six months to a year until they are in the system?”
“That’s right,” Roy agreed.
“True, true, but right now only a few in my crew and you two know of it.” Crosby made a gesture with his left hand as if to include the crew of his ship. “We should inform the Fintidierian leadership, but we need to do it carefully. We can’t afford any misunderstandings or panic. And we can take our time as to when we do it. We don’t have to rush and do it this week, even. We can take a month or more to think this through. We should take the time to think this through carefully. I mean, what if the Fintidierians want us to intercept them and turn them away? What then?”
“Fortunately, the Fintidierians don’t use gigahertz signals yet. They’re still down in the hundreds of megahertz. They are a long way from software-defined radios.” Roy exhaled slowly. “They aren’t likely to detect the signal. But what about any Earth transmissions directly to them? Are there amateurs broadcasting about the Pioneer?”
“Good point.” Jesus shook his head negatively in frustration. “We’d better tell them before they find out and realize we were keeping it from them. Oh man, what a mess this is.”
“Very well, we tell them. We tell them sometime soon, perhaps in the next couple of weeks.” Crosby grunted. “Damnit. I’d rather have time to think these things through in more detail.”
“What of the Pioneer?” Roy asked.
“What about it?” Jesus shrugged.
“I mean, uh, do I communicate with them?” Roy held both hands palms up. “I mean, they won’t get the signal for months to a year, but when do we start communicating with them?”
“Oh, that.” Crosby nodded in understanding. “No rush. I guess, let’s wait until Ambassador Jesus there has a chance to write up a protocol for interacting with the Fintidierian immigration officials and then we send it.”
“Ah, good idea, Captain. You could have been a politician.” Jesus laughed.
“Careful, Ambassador, some would take that as fighting words,” Crosby said with a smile. “I wouldn’t wish your job on a yeoman.”