Okay.
I see how it is.
I’m not some intrepid explorer who nobly sacrificed his life to save Earth. I’m a terrified man who had to be literally dragged kicking and screaming onto the mission.
I’m a coward.
All that came to me in a flash. I sit on the stool and stare at the lab table. I went from nearly hysterical to…this. This is worse. I’m numb.
I’m a coward.
I’ve known for a while that I’m not the best hope for saving mankind. I’m just a guy with the genes to survive a coma. I made my peace with that a while ago.
But I didn’t know I was a coward.
I remember the emotions. I remember that feeling of panic. I remember it all now. Sheer, unadulterated terror. Not for Earth or humanity or the children. For myself. Utter panic.
“God damn you, Stratt,” I mumble.
What ticks me off the most is that she was right. Her plan worked perfectly. I got my memory back, and now I’m so committed to the mission I’m still going to give it my all. Plus, come on, of course I was going to give it my all. What else would I do? Let 7 billion people die to spite Stratt?
At some point, Rocky came through his tunnel to the lab. I don’t know how long he’s been there. He didn’t have to come—he could “see” everything going on from the control room with his sonar sense. Still, there he is.
“You are very sad,” he says. “Yeah.”
“I am sad also. But we not be sad for long. You are scientist. I am engineer.
Together we solve.”
I throw up my arms in frustration. “How?!”
He clicked along the tunnel to the closest point above me. “Taumoeba eat all your fuel. Therefore Taumoeba survive and breed in fuel-tank environment.”
“So?”
“Most life no can live outside its air. I die if not in Erid air. You die if not in Earth air. But Taumoeba survive when not in Adrian air. Taumoeba stronger than Erid life—stronger than Earth life.”
I crane my neck to look up at him. “True. And Astrophage are also pretty tough. They can live in vacuum and on the surface of stars.”
He tapped two claws together. “Yes yes. Astrophage and Taumoeba from same biosphere. Probably evolve from common ancestor. Adrian life is very strong.”
I sit up. “Yeah. Okay.”
“You have idea already. Not question. I know you. You have idea already.
Tell idea.”
I sigh. “Well…Venus, Threeworld, and Adrian all have a bunch of carbon dioxide. The Astrophage breeding zone in all three is where pressure is 0.02 atmospheres. So maybe I’ll start with a chamber full of pure carbon dioxide at
0.02 atmospheres and see if Taumoeba survives that. Then add in more gases one at a time to see what the problem is.”
“Understand,” says Rocky.
I get to my feet and dust off my jumpsuit. “I need you to make me a test chamber. Clear xenonite with valves so I can let air in and out. Also, I need to be able to set temperature to minus 100 degrees Celsius, minus 50 degrees Celsius, or minus 82 degrees Celsius.”
I could use my own equipment, but why not take advantage of superior material and craftsmanship?
“Yes yes. I make now. We are team. We fix this. No be sad.” He skitters down the tunnel toward the dormitory.
I check my watch. “The main thrust ends in thirty-four minutes. After that’s done, let’s use the beetles to put ourselves in centrifuge mode.”
Rocky pauses. “Dangerous.”
“Yeah, I know. But we need gravity for the lab and I don’t want to wait eleven days. I want to make good use of time.”
“Beetles arranged for thrust, not rotation.”
It’s true. Our propulsion right now is, to say the least, rudimentary. We don’t have servos or gimbals to vector our thrust. We’re like a sixteenth- century nautical ship, but we’re using beetles for sails. Actually, scratch that. The nautical ship could at least control the angle of their sails. We’re more like a paddlewheel boat with a broken rudder.
It’s not all bad, though. We have some slight attitude control by deciding how much each engine thrusts. It’s how Rocky zeroed out our rotation before. “It’s worth the risk.”
He skitters back up the tunnel to face me. “Ship will rotate off-axis. No can unspool centrifuge cables. Would tangle.”
“We’ll create the needed rotation first, then shut off beetles, then unspool cables.”
He draws back. “If ship not unspooled, force is too much for human.”
That does present a problem. I want 1 g of gravity for the lab when the ship is fully unspooled in two halves. To get that much rotational inertia with the ship in one piece means spinning it very fast. Last time we did that, I passed out in the control room and Rocky almost died saving me.
“Okay…” I say. “How about this: I’ll lay down in the storage room under the dormitory. That’s the closest to the center of ship I can get. The force will be smallest there. I’ll be okay.”
“How you operate centrifuge controls from storage room, question?” “I’ll…umm…I’ll bring the lab’s control screen down there with me. I’ll run
data and power extension cables from the lab to the storage room. Yeah. That
should work.”
“What if you unconscious and no can operate controls, question?”
“Then you cancel the rotation and I’ll wake up.”
He shimmies back and forth. “No like. Alternate plan: Wait eleven days. Get to my ship. Clean out you ship fuel tanks. Sterilize—make sure no Taumoeba. Refill with fuel from my ship. Then can use all functions of you ship again.”
I shake my head. “I don’t want to wait eleven days. I want to work now.” “Why, question? Why no wait, question?”
He’s completely right, of course. I’m risking my life and maybe the
structural integrity of the Hail Mary. But I can’t just sit around for eleven days when there’s so much work to do. How do I explain “impatience” to someone who lives seven hundred years?
“Human thing,” I say.
“Understand. Not actually understand, but…understand.”
—
The spin-up went as planned. Rocky selected Ringo to do the spinning work, leaving John and Paul offline. George is still safely aboard the ship in case I need him.
The g-forces during the spin-up were rough—I won’t lie. But I stayed awake long enough to manually deal with the centrifuge steps. I’m getting pretty good at it now. Since then, it’s been a nice, level 1 g.
Yeah, it was impatient and a little risky, but thanks to that, I’ve had seven days of hardcore science since then.
Rocky delivered on the testing apparatus as promised. As always, everything worked flawlessly. Instead of a small, annoying glass vacuum chamber, I had something resembling a large fish tank. Xenonite doesn’t care if there’s a bunch of air pressure on a large, flat panel. “Bring it on,” says xenonite.
I have, shall we say, an inexhaustible supply of Taumoeba. The Hail Mary is currently the Taumoeba party bus. All I have to do is open the fuel line that used to lead to the generator when I want more.
—
“Hey, Rocky!” I call out from the lab. “Watch me pull a Taumoeba out of a hat!”
Rocky climbs up his tunnel from the control room. “I assume that is Earth idiom.”
“Yeah. Earth has entertainment called ‘television’ and—” “Do not explain, please. You have findings, question?”
Just as well. It would take a long time to explain cartoons to an alien. “I
have some results.”
“Good good.” He hunkers down into a comfortable sitting position. “Tell findings!” He tries to hide it, but his voice is just a touch higher in pitch than normal.
I gesture to the lab apparatus. “This functions perfectly, by the way.” “Thank. Tell about findings.”
“My first experiment was Adrian’s environment. I added Taumoeba and a
slide covered in Astrophage. The Taumoeba survived and ate it all. No surprise there.”
“No surprise. Is their native environment. But proves equipment works.” “Exactly. I did more tests to learn Taumoeba’s limits. In Adrian air, they
can live from minus 180 degrees Celsius to 107 degrees Celsius. Outside that
range they die.” “Impressive range.”
“Yes. Also, they can survive in a near vacuum.”
“Like your fuel tanks.”
“Yeah, but not a total vacuum.” I frown. “They need carbon dioxide. At least a little bit of it. I made an Adrian environment but put argon in instead of carbon dioxide. The Taumoeba didn’t eat anything. They stayed dormant. Eventually they starved to death.”
“Expected,” he says. “Astrophage need carbon dioxide. Taumoeba from same ecology. Taumoeba also need carbon dioxide. How they get carbon dioxide in fuel tanks, question?”
“I had the same question!” I say. “So I did a spectrograph of my fuel-bay sludge. There’s a bunch of CO2 gas dissolved into the liquid.”
“Astrophage probably have carbon dioxide inside. Or decomposition creates carbon dioxide. Some percentage died in fuel tanks over time. Not all cells are perfect. Defects. Mutations. Some die. Those dead Astrophage put carbon dioxide in tanks.”
“Agreed.”
“Good findings,” he says. He starts climbing back down. “Wait. I have more. Much more.”
He stops. “More, question? Good.”
I lean against my lab table and pat the tank. “I made Venus in the tank. But not quite Venus. Venus’s air is 96.5 percent carbon dioxide and 3.5 percent nitrogen. I started with just the carbon dioxide. The Taumoeba were fine. Then I added the nitrogen. And the Taumoeba all died.”
He raises his carapace. “All die, question? Sudden, question?” “Yes,” I say. “In seconds. All dead.” “Nitrogen…unexpected.”
“Yeah, very unexpected!” I say. “I repeated experiment with Threeworld’s air. Carbon dioxide only: The Taumoeba were fine. I added in the sulfur dioxide: The Taumoeba were fine. I added the nitrogen: Boom! All the Taumoeba died.”
He taps a claw absently on the tunnel wall. “Very very unexpected. Nitrogen harmless to Erid life. Nitrogen required by many Erid life.”
“Same with Earth,” I say. “Earth’s air is seventy-eight percent nitrogen.” “Confusing,” he says.
He’s not alone. I’m just as baffled as he is. We’re both thinking the same
thing: If all life evolved from a single source, how can nitrogen be critical to two biospheres and toxic to a third?
Nitrogen is utterly harmless and nearly inert in its gaseous state. It’s usually content to be N2, which barely wants to react with anything. Human bodies ignore the stuff despite every breath being 78 percent nitrogen. As for Erid,
their atmosphere is mostly ammonia—a nitrogen compound. How could a
panspermia event ever seed Earth and Erid—two nitrogen-riddled planets—if a tiny amount of nitrogen kills that life?
Well, the answer to that is easy: Whatever the life-form was that caused the panspermia, it didn’t have a problem with nitrogen. Taumoeba, which evolved later, does.
Rocky’s carapace sinks. “Situation bad. Threeworld air is eight percent nitrogen.”
I sit on the lab stool and cross my arms. “Venus’s air is 3.5 percent nitrogen. Same problem.”
He sinks farther and his voice drops an octave. “Hopeless. Cannot change Threeworld air. Cannot change Venus air. Cannot change Taumoeba. Hopeless.”
“Well,” I say. “We can’t change Threeworld or Venus’s air. But maybe we can change Taumoeba.”
“How, question?”
I grab my tablet from the workbench and scroll through my notes about Eridian physiology. “Do Eridians have diseases? Sicknesses inside your bodies?”
“Some. Very, very bad.”
“How does your body kill diseases?”
“Eridian body is closed,” he explains. “Only opening happen when eat or lay egg. After opening seals, area inside made very hot inside with hot blood for long time. Kill any disease. Disease can only get into body through wound. Then is very bad. Body shut down infected area. Heat with hot blood to kill disease. If disease fast, Eridian die.”
No immune system at all. Just heat. Well, why not? The hot circulatory system of an Eridian boils water to make the muscles move. Why not use it to cook and sterilize incoming food too? And with heavy oxides—basically rocks—as skin, they don’t get many cuts or abrasions. Even their lungs don’t exchange material with the outside. If any pathogens do get in, the body seals the area off and boils it. An Eridian body is a nearly impenetrable fortress.
But a human body is more like a borderless police state.
“Humans are very different,” I say. “We get diseases all the time. We have very powerful immune systems. Also, we find cures for diseases in nature. The word is ‘antibiotics.’ ”
“No understand,” he says. “Cures for diseases in nature, question? How, question?”
“Other life on Earth evolved defenses against the same diseases. They emit chemicals that kill the disease without harming other cells. Humans eat those chemicals and they kill disease but not our human cells.”
“Amaze. Erid no have this.”
“It’s not a perfect system, though,” I say. “Antibiotics work very well at first, but then over the years, they become less and less effective. Eventually they barely work at all.”
“Why, question?”
“Diseases change. Antibiotics kill almost all the disease in the body, but some survive. By using antibiotics, humans are accidentally teaching diseases how to survive those antibiotics.”
“Ah!” Rocky says. He raises his carapace a tad. “Disease evolves defense against chemical that kills it.”
“Yes,” I say. I point at the tank. “Now think of Taumoeba as disease.
Think of nitrogen as antibiotic.”
He pauses, then raises his carapace back to its proper location. “Understand! Make environment barely deadly. Breed Taumoeba that survive. Make more deadly. Breed survivors. Repeat, repeat, repeat!”
“Yes,” I say. “We don’t need to understand why or how nitrogen kills Taumoeba. We just need to breed nitrogen-resistant Taumoeba.”
“Yes!” he says.
“Good!” I slap the top of the tank. “Make me ten of these, but smaller. Also provide a way for me to get Taumoeba samples without interrupting the experiment. Make a very accurate gas injection system—I need exact control over the nitrogen quantity in the tank.”
“Yes! I make! I make now!”
He skitters down to the dormitory.
—
I check the results of the spectrograph and shake my head. “No good. Complete failure.”
“Sad,” Rocky says.
I put my chin in my hands. “Maybe I can filter out the toxins.”
“Maybe you can concentrate on Taumoeba.” There’s a special warble that Rocky does when he’s being snarky. That warble is especially present right now.
“They’re coming along fine.” I glance over to the Taumoeba processing tanks arrayed along one side of the lab. “Nothing to do but wait. We’ve had good results. They’re already up to 0.01 percent nitrogen and surviving. The next generation might be able to go as high as 0.015.”
“This is waste of time. Also waste of my food.” “I need to know if I can eat your food.”
“Eat your own food.”
“I’ve only got a few months of real food left. You have enough aboard your ship to feed a crew of twenty-three Eridians for years. Erid life and Earth life use the same proteins. Maybe I can eat your food.”
“Why you say ‘real food,’ question? What is non-real food, question?”
I checked the readout again. Why does Eridian food have so many heavy metals in it? “Real food is food that tastes good. Food that’s fun to eat.”
“You have not-fun food, question?”
“Yeah. Coma slurry. The ship fed it to me during the trip here. I have enough to last me almost four years.”
“Eat that.”
“It tastes bad.”
“Food experience not that important.”
“Hey.” I point at him. “To humans, food experience is very important.” “Humans strange.”
I point at the spectrometer readout screen. “Why does Eridian food have
thallium in it?” “Healthy.”
“Thallium kills humans!”
“Then eat human food.”
“Ugh.” I walk over to the Taumoeba tanks. Rocky had outdone himself. I can control the nitrogen content to within one part per million. And so far, things are looking good. Sure, this generation can only handle a smidgen of nitrogen, but it’s a smidgen more than the previous generation could do.
The plan is working. Our Taumoeba are developing nitrogen resistance. Will they ever be able to handle the 3.5 percent needed for Venus? Or the
8 percent for Threeworld? Who knows? We’ll just have to wait and see.
I’m using percentages here to track the nitrogen. I can only get away with that because in all cases, Astrophage breed where the air is 0.02 atmospheres of pressure. So, since the pressure is always the same across all experiments, I can just track the percent of nitrogen.
The proper way to do it would be to track “partial pressure.” But that’s annoying. I’d just end up dividing by 0.02 atmospheres and multiplying by it again later when dealing with data.
I pat the top of Tank Three. It’s been my lucky tank. Out of twenty-three generations of Taumoeba, Tank Three made the strongest strain nine times. Pretty good, considering she’s got nine other tanks to compete with.
Yes, Tank Three is a “she.” Don’t judge me. “How long until we reach the Blip-A?” “Seventeen hours until reverse-thrust maneuver.”
“Okay, let’s spin down the centrifuge now. Just in case we run into trouble and need extra time to fix something.”
“Agree. I go to control room now. You go to storage locker and lie flat. Do not forget control panel with long extension cords.”
I glance around the lab. Everything is firmly secured. “Yeah, okay. Let’s do it.”
—
“John, Ringo, Paul off,” says Rocky. “Velocity is orbital.”
There is no “stationary” in a solar system. You’re always moving around something. In this case, Rocky reduced our cruise velocity to put us in a
stable orbit about 1 AU from Tau Ceti. That’s where he left the Blip-A.
Rocky relaxes in his control-room bulb. He clamps the boxes to their wall mounts. Now that the engines are off we’re back to zero g, and the last thing we want is for the “make ship thrust” button to be floating around unattended.
He grabs a couple of handholds and centers his carapace over the texture monitor. As always, it shows him my center monitor feed with colors represented as textures.
“You in control now.” He’s done his job. Now it’s my turn. “How long until the flash?” I ask
Rocky pulls an Eridian clock off the wall. “Next flash is three minutes, seven seconds.”
“Okay.”
Rocky’s no dope. He left his ship set up to turn on its engines for a fraction of a second every twenty minutes or so, giving us a much-needed beacon. It’s easy enough to math out where the ship should be. But gravity from other planets, inaccurate measurement of last known velocities, inaccuracies in our estimate of Tau Ceti’s gravity…they all add up to make slight errors. And a slight error on the location of something orbiting a star is a pretty big distance.
So rather than hoping we can see Taulight reflect off the ship when we get to where it should be, he just set it up to flash the engines now and then. All I have to do is watch with the Petrovascope. It’ll be an extremely bright flash.
“What is current nitrogen tolerance, question?”
“Tank Three had some survivors at 0.6 percent nitrogen today. I’m breeding them up now.”
“What spacing, question?”
It’s a conversation we’ve had dozens of times. But it’s fair for him to be curious. His species depends on it.
The “spacing,” as we’ve come to call it, is the difference in how much nitrogen each of the ten tanks receives. I don’t just do the same thing in every tank. With each new generation, I try ten new percentages of nitrogen.
“I’m being aggressive—0.05 percent increments.” “Good good,” he says.
All ten tanks are breeding Taumoeba-06 (named for the nitrogen percent it can withstand). Tank One is the control, as always. It has 0.6 percent nitrogen in the air. Taumoeba-06 should have no problem in there. If it does, it means there was a mistake in the previous batch and I have to go back to an earlier strain.
Tank Two has 0.65 percent nitrogen. Tank Three has 0.7. And so on all the way up to Tank Ten with 1.05 percent. The heartiest survivors will be the champions, and will move on to the next round. I wait a few hours just to make sure they can breed for at least two generations. Taumoeba has a ridiculously fast doubling time. Fast enough to eat all my fuel in a matter of days, as it happens.
If we get to Venus or Threeworld nitrogen percentages, I’ll do much more thorough testing.
“Flash is soon,” Rocky says. “Copy.”
I bring up the Petrovascope on the center monitor. Normally, I’d have it off to the side, but the center is the only one Rocky can “see.” As expected, there’s just background light in the Petrova frequency courtesy of Tau Ceti. I pan and tilt the camera. We deliberately positioned ourselves closer to Tau Ceti than the Blip-A should be. So I’m looking more or less directly away from the star. That should minimize the background IR and give me a good view of the flash.
“Okay. I think I have it pointed roughly toward your ship.”
Rocky concentrates on his texture monitor. “Understand. Thirty-seven seconds until flash.”
“Hey. What’s is your ship’s name, anyway?” “Blip-A.”
“No, I mean, what do you call it?”
“Ship.”
“Your ship has no name?”
“Why would ship have name, question?” I shrugged. “Ships have names.”
He points to my pilot’s seat. “What is name of you chair, question?”
“It doesn’t have a name.”
“Why does ship have name but chair no have name, question?” “Never mind. Your ship is the Blip-A.”
“That is what I said. Flash in ten seconds.” “Copy.”
Rocky and I each fall silent and stare at our respective screens. It took me a long time to notice the subtleties, but I can now tell when Rocky is paying attention to something specific. He tends to angle his carapace toward it and pivot ever so slightly back and forth. If I follow the line he’s pivoting on, that’s usually what he’s examining.
“Three…two…one…now!”
Right on cue, a few pixels on-screen blink white. “Got it,” I say.
“I not notice.”
“It was dim. We must be far away. Hang on…” I switch to the Telescope screen and pan to where the flash came from. I sweep back and forth with small movements until I catch a slight discoloration in the blackness. Taulight reflecting off the Blip-A. “Yeah, we’re pretty far away.”
“Beetles have much fuel remaining. Is okay. Tell me angle change.”
I check the readouts at the bottom of the screen. All we have to do is align the Hail Mary with the current telescope angle. “Rotate yaw plus 13.72 degrees. Rotate pitch minus 9.14 degrees.”
“Yaw plus one three mark seven two. Pitch minus nine mark one four.” He grabs the beetle controls from their holders and gets to work. By flicking on and off the beetles in sequence, he angles the ship toward the Blip-A.
I zero the telescope and zoom in to confirm. The difference between background space and the ship is so small as to be barely perceivable. But it’s there. “Angle correct.”
He focuses hard on his texture screen. “I no detect anything on-screen.” “Light difference is very very small. Need human eyes to detect. Angle is
good.”
“Understand. What is range, question?”
I switch to the Radar screen. Nothing. “Too far for my radar to see. At least ten thousand kilometers.”
“Accelerate to what velocity, question?”
“How about…three kilometers per second? Will get to the Blip-A in an hour or so.”
“Three thousand meters per second. Standard acceleration rate is acceptable, question?”
“Yes. Fifteen meters per second per second.” “Two hundred second thrust. Begin now.”
I brace for gravity.
