Page 179 of Project Hail Mary

“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 shipshouldbe. 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 anextremelybright 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 theBlip-Ashould 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 theBlip-A.”

“That is what I said. Flash in ten seconds.”