14 Lookout
JPL, Pasadena · Monday, 11 March – Monday, 9 September 2030.
Ray Delgado had the Lookout fault-protection document printed and bound, because he said he couldn’t think about software on a screen. On the Monday after Tianxun went silent he had it open on the project conference table and was going down it with a green felt-tip.
“Safe mode on loss of Sun.” A line through it. “Autonomous target reacquisition.” A line. “Onboard star-pattern search.” He drew that one out slowly. “Star tracker gets an attitude from the ground. It doesn’t go hunting.”
Dana had the last Tianxun packets on her laptop, the housekeeping the Chinese had posted to the shared feed on Saturday. Every channel nominal to the final frame.
“Nobody’s shown AUTO did anything,” she said. “The last packet says no faults. It could have been the range. It could have been the pass itself.”
“Could have.”
“So if it was the pass, stripping the software doesn’t buy you anything.”
“I can’t take the range out.” He turned a page. “I can’t take out whatever was on the far side. That part I can take out.” He crossed out another line. “Mm.”
Lookout was eight weeks into cruise. Over March and April his team sent up patch after patch, and each one left the spacecraft a little stupider: no onboard targeting, no onboard navigation, no recovery it could start on its own. If it lost the Sun it would sit and wait for a person. By May it could hold an attitude it was told to hold and fire what it was told to fire, and that was all.
The interview was on the second Thursday in April, in a conference room in Building 180 that somebody had cleared of its whiteboard. Two people from counterintelligence, a man in his fifties and a woman maybe fifteen years younger, both in suits that had been through airports. They thanked her for her time twice before anyone sat down.
“Vienna,” the man said. “The thirteenth of November. The lunch break.”
“Yes.”
“You gave a folded sheet of paper to Dr. Lin Wen of the Chinese delegation.”
There was no point asking how they knew. “My Hubble baseline,” she said. “The photometry.”
“Only that?”
“My notes on it.”
It was true as far as it went. The woman waited. Dana didn’t add anything.
They asked about the hotel bar and Dr. Kessler, and she told them the truth, which was that she’d told him nothing and he’d known it. They asked whether anyone had asked her to pass the sheet. Nobody had. They asked why, and she said Lin had asked the only good question in the room, and they let that sit without comment. The woman closed the folder.
“One other thing, while we’re here,” she said, standing. “The Goddard business. How Dr. Raman came to have the Surveyor frames. That one’s straightforward. We traced it, ticket and all.”
“Traced it to whom?”
“That’s outside this inquiry.” She smiled. “Thanks again.”
By four the badge office had swapped her badge for one with a different stripe, and her clearance was suspended pending review. She could still work. She couldn’t open the vault on the third floor or read anything that lived in it, and half of what she needed lived in it.
Glen carried her papers. He’d go in, pull what she asked for, read out the parts that weren’t marked and summarize the parts that were in a way that didn’t technically count. He didn’t complain. On the third or fourth trip he set a folder on her desk and stood there.
“What’s this about, Dana?”
“The Hubble data. They want to know why the program had one name on it.”
He thought about that and seemed to find it reasonable. “Should have put the branch on it,” he said, and went back down the hall.
The letter came on the sixth of June. The inquiry was closed. The information at issue had been found to be substantially available from an open source, namely the last sentence of section 4 of the Purple Mountain preprint of June 2029; anyone who read it would know to look at the night side. That sentence had been “brought to the inquiry’s attention through liaison channels (UK).” Her clearance was restored.
She went through the British delegation in her head, the four or five faces she could put to it, and couldn’t make any of them want to do her a favor.
On the eleventh of June the Lookout floor was eight consoles and a wall display in a room that had last flown a comet mission. Delgado stood behind the navigation console with a banana, peeling it in sections.
A solid motor had no throttle. Once it was lit it burned until it was done. The igniter command had gone up forty minutes earlier with the light-time on it, and now the Doppler was coming down and the navigator was reading it.
“Ignition. Chamber pressure’s nominal.” Then, after a while: “Tail-off.”
Delgado ate the last of the banana.
“Burnout. Residual’s under a meter per second.” The navigator leaned back. “Fifty thousand kilometers and change. Off the Earth line, where you wanted it.”
That was for Dana. She’d asked for the side view last October, and Delgado had moved the hold point for her without asking why.
The first image took eleven minutes to come down. It was mostly black. In the middle sat Anvil, nine pixels long at 240 m a pixel, the day side a smear of gray and the night side nothing at all. The imaging lead, a woman with her hair up in a pencil, stretched the display until the noise floor came up in a gray grain across the whole frame.
“There’s something on the night side.”
Off the dark face, along the line toward Earth, sat a row of faint points. Separate points, side by side, standing off the shadow edge in a row.
“It’s a brush,” the navigator said.
Nobody improved on it. The imaging lead dropped a cursor at each end. “Five pixels. Call it twelve hundred meters. Rooted right at the far face, or inside a kilometer of it.”
“Sunlit tips,” Dana said. “The rest of it’s in the shadow. Those are the ends sticking out into the light.”
“The ends of what?”
“The columns. What Tianxun saw on the far side.”
The navigator shook his head. “Tianxun saw a hollow on the leading face. Fresh, they said. Somebody dug something out of it. This is the debris. You blow material out, it comes off along the axis, it sits there.”
“In a line?” the imaging lead said. “For three months? It’d be a fan by now. It’d be gone. Debris doesn’t hold a row.” She zoomed in until the points were blocks. “That’s spaced. That’s a structure.”
“You’ve got five pixels.”
“Five pixels that line up.”
Delgado had come around to stand by the wall. “What’s it made of?”
Dana had been doing it on the back of the burn timeline while they argued, and she said it out loud before she’d finished checking it. “If those are the spheres Tianxun saw, a few meters across, iron-nickel, solid, that’s a couple of hundred tonnes each. The mass I can’t account for is about 2.5 × 10¹² kilograms, and the dimming’s hardly moved since last summer.” She looked at the number. “About ten million of them.”
The navigator laughed once. “Ten million. In five pixels.”
“In columns a kilometer long, across most of the far face. It fits.” She checked the volume again and it still fitted. “That’s the missing mass. Near enough.”
“Or it’s a few hundred big ones,” the imaging lead said, “and they’re nothing like Tianxun’s.”
“Then where’s the rest of the mass?”
Nobody had an answer to that. The imaging lead was still looking at the points. The navigator had his arms folded and was looking at Dana, not at the wall.
“Then it’s been building,” Delgado said. “The whole time it’s been sitting there. Since it stopped.”
“Since before the movers,” Dana said. “It’s been dimming since I started looking.”
Someone at the back console, a young telecom engineer, said, “Is that what Green Bank’s hearing?”
The carrier near 31.7 GHz had turned up in May, narrowband, steady to a few hertz, coming from the object’s position. Green Bank had put the recordings on its public server, and half the radio astronomers in the world had pulled them and found nothing that could carry a message.
“Green Bank’s hearing a tone,” Delgado said. “Nobody can read it. Don’t put it in the log next to this.” He looked at the wall a while longer. “Get me the next frame. And the one after that. Every one we can fit through the pipe.”
The imaging lead had already queued them. The second image came down with the same nine pixels and the same row of points, in the same place.
The consultation met in Vienna in the third week of July, in the same room with the same chair. Dana’s badge had the right stripe again. Lookout’s frames were on the shared feed now, every one, which was Delgado’s idea and Washington’s grudging permission. The brush was on every screen in the building.
At the morning break Lin Wen found her by the coffee urns and handed her a sheet, unfolded, as if there were nothing to hide in it.
| Feature: 4 px, cols 2210–2213, single row | |
| Plate scale: 2.4 µrad/px | |
| Range to target at row 1840: 1,051.7 km | |
| Linear extent at target range: 10.1 m | |
| Row integration: 0.20 ms | |
| Apparent transverse rate: 50 ± 2 km/s | |
| (if feature at target range) | |
| Not consistent with charged-particle track in | |
| adjacent rows or in dark frames | |
“Officially,” Lin said, “it is a cosmic ray.”
Dana knew the number. She’d done it on the sixth of March in the hotel, with a worse range and the same four pixels. She uncapped a pen and wrote under Lin’s last line, 50.4. 6 March, VIE., and handed the sheet back.
Lin read it and put it in her folder, and went back to her delegation.
On Monday the ninth of September the frame from 15:20 UTC came down like the two thousand before it, and the imaging lead stopped scrolling.
“Ray.”
Off the tips of the brush, on the sunward side, sat points that hadn’t been there in the morning frame. Not many. Separate, faint, a pixel or two off the row and spread along it. She blinked the two frames against each other, and the new points moved and the brush didn’t.
They counted them three times. Forty-one.
The navigator took them through the next three frames and fitted what he could. “They’re drifting. Sunward. A few tenths of a meter per second.” He sat back. “That’s nothing. That’s a walk. At that rate they don’t go anywhere.”
“On their own,” Dana said.
Delgado was already on the phone to Planetary Defense in Washington. It took him under five minutes, and Dana heard him say forty-one twice and no, I’m not rounding.
By noon Pasadena time it was a conference call. PDCO had the chair. The White House Situation Room was on the bridge, and somewhere in the list of names on the line was the man with the legal pad. Dana knew him by his first question, which was who exactly was in the room in Pasadena.
She told them what she could. “Forty-one objects have come off the end of the brush. From brightness and Tianxun’s reprocessed frames, each is about 3.85 m across, the same as the spheres in the columns. If they’re going somewhere in months, they have to push the whole way, the way the movers did, and brake at the end.”
“Going somewhere like where,” someone said from Washington.
Delgado answered before she could. “From L5 you don’t come straight at us. You slow down, you fall in toward the Sun, you’re on a faster orbit and you catch Earth up from behind.” He paused. “You’d come in out of the evening sky, low in the west after sunset, where nobody’s looking.”
“Are they coming here?” a voice asked. Somebody at the Situation Room end, a woman, quick.
“I don’t know,” Dana said.
“That’s not an answer.”
“Three frames. Forty-one points. I don’t have an orbit. I have a direction.”
The man with the legal pad spoke for the second time. “How long?”
Delgado looked at Dana and she shook her head, and he said it himself. “If they’re pushing. About seven months.”
After a moment PDCO moved on to who would brief whom by when, and Dana muted herself and turned back to the console.
The 19:40 UTC frame was coming down, row by row. Anvil, nine pixels. The brush along the Earth line, a pixel longer than in June. And off its tips, a little farther sunward than an hour before, forty-one points.