Analog SFF, June 2011 (8 page)

"I know. I walked around for a bit."

"How far did you get?"

"Half past Saturn before I turned around. Any farther and I would have been late."

She pulled the Jetta onto the shoulder near each telescope to share some of its background. Near one dish, bikes leaned against a trailer: the mark of grad students at work. She took Marcus inside the cramped maintenance trailer for a peek at the equipment—and at the quarter-inch steel walls shielding the dish from the electronics.

Back in her car, as she started to describe the first eighty-five-footer, the Science Center's white diesel tour bus lumbered past. “This is part of a three-telescope interferometer. An interferometer—"

"Synthesizes data from multiple instruments into one image. The composite has the resolution of an instrument the size of the separation between instruments. Same principle as synthetic aperture radar.” He grinned. “I'm an engineer, and I come prepared."

Valerie knew the former. She had hoped for the latter—and that he would be open-minded. Only then did it occur to her to ask how open-minded
she
was.

It was not the time to second-guess herself. And anyway, he would get much the same message from many of the staff. All the more important that she get him to lunch on time. . . .

"Let's skip to the main event,” she said. Because the
big
dish will knock your socks off.

When she next parked, Marcus, his eyes round, rushed from the car. Everyone did. She gave him time to take it all in: the world's largest birdbath, atop an intricate lattice pyramid, above a round trolley base with sixteen enormous wheels. In addition to a standalone trailer, a built-in shielded room high above the ground held many of the onsite controls. The instrument arm, jutting out from and over the dish, made the telescope that much more impressive.

"The Green Bank Telescope,” she began, pointing up at the enormous paraboloid dish. “Completed in 2000, the GBT replaced the smaller big telescope that collapsed under its own weight from metal fatigue in 1988. The dish's signal-collecting surface measures one hundred meters by one hundred ten meters—longer in both dimensions than a football field. Only that's not
a
surface, but 2,004 small aluminum surfaces. Automation tilts and warps each panel in real time as the structure moves, to compensate for sagging, thermal gradients, and wind."

"
Damn
, that's big. What happens if lightning strikes?"

"It happens about four times a year, without incident. The GBT weighs more than sixteen million pounds, about the same as nineteen loaded and fueled jumbo jets. When lightning does strike, that's a lot of metal, with all its metal wheels firmly pressed against the well-grounded steel track. The track is lots of metal too: a circle sixty-four meters in diameter."

She resumed her script. “When tipped such that the instrument arm reaches its highest position, the GBT stands taller than the Statue of Liberty. This is the world's largest fully steerable radio telescope."

Hand to his forehead, shading his eyes, Marcus countered, “Surely Arecibo is bigger."

Because everyone knew the observatory at Arecibo, Puerto Rico. Filmmakers loved it. The first time she remembered seeing the Arecibo dish was in some old James Bond flick.
Goldeneye
, maybe.

Arecibo's dish was
three
hundred meters across, its aluminum panels suspended over a mesh of steel cables to form a single surface: way too massive to move. To aim the Arecibo telescope—to the extent it could be aimed—you positioned its suspended instrumentation module using the cables that spanned the dish. None of which mattered. If she failed, Arecibo would face the same problems as Green Bank.

Valerie limited herself to, “Bigger, but not fully steerable.” She pointed at the GBT's base, where the mammoth wheels engaged the circular steel track. “As opposed to
our
big scope. This whole structure can rotate up to forty degrees a minute, versus one-fourth degree per minute needed to keep pace with Earth's rotation. The dish can tip up and down at as much as twenty degrees per minute. That instrument turret at the end of the arm holds up to eight independent instrument modules, each—"

"Back up,” Marcus said. “Those tipping and turning rates. You're telling me that the GBT can track planets, asteroids, even close-orbiting satellites. Stars and galaxies only move with the Earth's rotation.” She must have looked surprised because he added, “Remember who I work for?"

"Right. And sorry."

"Except asteroids and most planets don't emit radio waves. In the middle of the quiet zone, where my cell phone has no service and NRAO won't even permit digital cameras up close, I can't believe the observatory is pumping out radar pulses so you can read the echoes."

He was quick, which was promising, and he seemed engaged in what she'd had to show him. But around the eyes she saw a touch of . . . something. Suspicion? Was she that transparent, or was it something else?

"You're correct,” she said. “Arecibo transmits and Green Bank reads the faint echoes. We
could
transmit ourselves"—she pointed up at the instrumentation arm—"by replacing one of the receiver modules with a transmitter, but that would hardly be radio quiet. My work involves the radar mapping of Titan, and we partner with Arecibo to do it."

"Titan? Just how sensitive
is
this scope?"

"If there were a cell phone on Titan, with the GBT I could listen to the call.” Barring other complications, and that topic was coming. “We need to move along, Marcus. The weekly science lunch is not to be missed."

Especially because
you
are on deck.

Patrick Burkhalter toted his cafeteria tray to the residence hall's second floor, where he found the social lounge half filled. Many of his colleagues were already seated and eating. Others surrounded Valerie Clayburn and her guest, meal trays in hand, intercepted before they could find a table. With maybe eight thousand people in the entire county, everyone welcomed new faces. But visitors and outsiders comprised very different categories, and after eight years here Patrick remained an outsider.

"Hey,” he offered as he took an empty seat. Tamara Miller glanced his way, nodded, and went back to her conversation with Liam Harris. Something about intergalactic dust.

Patrick went to work on his country-fried steak, mashed potatoes, and gravy. His choices would do nothing for his waistline or his cholesterol, but who did he have to impress?

Or to live for?
That
was a thought depressing enough to make him set down his fork.

Their guest got perhaps two minutes with his lunch before Valerie began tapping her water glass with a butter knife. “Hi, everyone. We have a visitor, as you may have noticed."

Not to mention that she had put out the word to make sure the tech staff all came today. Would she get the outcome for which she so obviously schemed? In Patrick's experience, manipulating scientists and engineers worked about as well as herding cats.

"Hello,” the chorus rang out raggedly, from around the collection of short, narrow tables arrayed in a U.

Valerie said, “Our visitor, Marcus Judson, works at NASA Goddard on the demonstration powersat project. I'm hoping he'll tell us about it."

Patrick refocused on his lunch while others murmured their encouragement.

Judson kept his response short, and Patrick approved.
You didn't know you were today's featured attraction, did you?

"So what do you think, folks?” Valerie prompted. “How will powersats affect us here?"

And the games began.

"A powersat is a huge noise generator,” Aaron Friedman said. “And because it's sky-based, that's noise from which we can't hide."

"The power beam is focused.” Judson slid away his tray, the meal all but untouched, clearly perceptive enough to see what was coming. “The downlink won't come anywhere near here."

"Doesn't matter,” Aaron persisted. “Well, aiming will help, but not enough. The satellite shapes the beam with phased-array techniques, right? So there are unavoidable side lobes to the main beam. That's basic math. Even sixty dB down, there'll be a lot of noise."

Engineers and astronomers set aside lunches to argue about phased arrays: their pointing accuracy and failure modes, the frequency distributions apt to show up within the noise, and whether sixty decibels was the expected attenuation for a side lobe. Of course even sixty dB down from one gigawatt left a kilowatt of noise.

Judson kept thanking people for their comments. Mostly he let the staff argue among themselves, jotting notes on paper napkins—and looking ticked off.

This was not a mugging, exactly. More like an intervention, or maybe an inquisition. When Patrick tried to catch Valerie's eye, she looked away.

Patrick knew all about inquisitions by the tech staff. That had been his introduction to Green Bank, too, if for a different reason. Judson would go home with only bad memories to show for the day. Whereas he . . .

He still bore the scars. Patrick was more than qualified to coordinate routine maintenance and teach visiting astronomers to operate the gear, so it hadn't been
entirely
a pity appointment. More like an
I'll owe you one
arrangement between execs at the apex of Big Science.

After the Jules Verne probe went missing, JPL wanted Patrick
gone
. NASA did, too, but even more, they wanted to put a halt to the embarrassing publicity. No matter what anyone suspected, they could only prove that he had cut procedural corners to upload an emergency maneuver. That the distant probe went silent days later could have been pure coincidence.

And so Patrick had made clear what would keep him from giving interviews and suing for wrongful termination. He required ongoing access to a big dish—somewhere.

Without
too
much torture of the English language, Green Bank was somewhere.

And so he went in one not-so-easy step from the principal investigator of a major interplanetary probe to lowly observatory staffer. Training and maintenance offered plenty of opportunity to use radio telescopes without grant applications sure to be rejected.

He used the big dishes every chance he could get.

After the divorce—no
way
would Anna move here from Pasadena—what else did he have to do?

He had sworn to Anna that things would turn out all right. That maybe this had happened for a good reason. He would not have trusted him, either, especially given how little he had been able to explain, but it still hurt that
she
hadn't. More than anything, he missed the kids. He wondered if Rob and Clarissa would ever understand, or forgive him for the divorce.

When Patrick tuned back to the present, Judson remained in the hot seat. Only the objections varied: from powersats, miles across, getting in the way of observations, to the heat they would reradiate as infrared, to minutiae of RF interference. Some people argued for the joy of arguing. Par for the course here, but Judson could not know that.

Along the way, an admin slipped into the lounge and handed Valerie a folded sheet of paper. Another joy of life in the quiet zone: runners instead of cell phones. Valerie grimaced at whatever she found written, dashed off her own note, and handed it to Judson, then rushed off.

By the time the hyperbole reached, “Powersats will mean the end of astronomy until"—yeah, right!—"someone builds an observatory on the far side of the moon,” Patrick had had enough.

"There's more to life than astronomy,” he snorted. Too bad Valerie had left. If anyone needed the reminder, she did. But for Simon, she might never go home. “And life takes power, people. Lots and lots of power."

Turning, Tamara gave Patrick an
Et tu, Brute
stare, but from across the room a couple of engineers nodded.

"We learned to live with DirecTV,” Ernesto Perez conceded.

To which someone snapped, “Yeah, by giving up listening on those frequencies."

Rekindling the debate, from which it took the tech director noisily sliding back her chair to bring a halt.

At least, Marcus thought, tucking his notes from the lunch into his shirt pocket, one secret of the Universe had been revealed. Town meetings were
not
the worst way to spend a day.

If he had correctly parsed Valerie's scrawl, she was retrieving a sick kid from school and going home for the rest of the afternoon. One scribble might have said “single mom,” to explain her disappearance. It was too bad about her son, but Marcus was happy to make a quick getaway.

Only driving home, as much as he tried to enjoy the Appalachian scenery, he couldn't. Ellen's recent rebuke kept nagging at him:
Have you considered the possibility someone else might know something?

If he could get past Valerie bushwhacking him, she had given him a lot to ponder.

Wednesday, April 19

Marcus poked at a telecom console, setting parameters for the upcoming conference call, and thinking: all meetings are not created equal.
He
was in a mundane conference room at Goddard, deep within suburban Maryland, but this call was out of this world.

Whatever grief the week might bring him, the progress review reminded him why everything else was worth it.

Landscape undulated over the conference table, sliding past as a distant camera swiveled on its post. Somewhere behind the camera, the full moon was about to set; Phoebe's hills and structures cast long, knife-edged shadows. To his right, in the tourist-bot preserve, the Grand Chasm gaped: a vast, inky blackness. The dazzling “star” just above the eerily close horizon was The Space Place, almost two hundred miles ahead of Phoebe in its orbit.

Ellen limped into the telecom room, bearing Starbucks. Despite physical therapy, her leg still bothered her. She set a cardboard cup on the table beside him.

"Thanks,” he said, concentrating on the final link left to configure. “That said, you have no respect for tradition."

She laughed. “Okay, who confirmed for today's session?"

He gestured at the holo. “The usual folks on the far end, though Darlene Stryker is at the powersat. She'll call in from there."