The satellite glided through deep space like a solitary night bird, its keen electronic sensors picking up signs of the coming storm as they were swept toward it on the solar wind.
The Solar and Heliospheric Observatory — or SOHO — was a joint space probe conceived by NASA and the European Space Agency in the 1990’s for gathering a wealth of scientific information about the sun and its atmospheric emissions. In early March 1996, fourteen months after its liftoff from Cape Canaveral aboard the upper stage of an Atlas IIAS (Atlas/Centaur) launch vehicle, the satellite was injected into a counterclockwise halo orbit around the sun at what is known as the L1 Lagrangian point — named after the eighteenth-century French astronomer Joseph-Louis Lagrange, who theorized there were calculable distances at which a small object in space could remain in fixed orbital positions between two larger bodies exerting strong gravitational pulls upon it.
The mathematical formulations must be precise. Should an object in the middle of this interplanetary tug of war wander from its position by more than a few degrees, the delicate equilibrium becomes upset and its orbit will rapidly degrade.
In SOHO’s case the L1 point equaled four times the distance from our world to the moon, with any significant deviation from that point certain to result in an uncontrolled plunge toward either the earth or sun. One complication the observatory’s development team had to address, however, was that their preferred orbital position for SOHO was slightly
The team’s solution to both these problems was to equip SOHO with an onboard propulsion system for periodic orbital adjustments, knowing this imposed an inherent limitation on its mission life. For once it exhausted the hydrazine fuel that powered its thrusters, SOHO would slip from its desired Lagrangian station and go tumbling off through space beyond recovery.
Original projections were that the billion-dollar spacecraft would be able to conduct its observations and experiments for from two to five years before the propellent reserves went dry and its mission reached an end.
Six years later and counting, it was still plugging away.
Some things are still built to last, and every so often they last longer than expected.
In March 2002, SOHO’s SWAN and MDI/SOI instruments, two of a dozen scientific devices in its payload module, sniffed the astrophysical equivalent of what American prairie farmers once would have called a locust wind.
An acronym for Solar Wind Anisotropies, SWAN is an ultraviolet survey of the dispersed hydrogen cloud around our planetary system that can detect glowing hot spots in space caused by fluctuations of solar radiation. To the SWAN’s wide-angle eye, which charts the full sky around the sun three times each week, a surge in the emissions striking these areas will cause them to light up like flashes from warning beacons even if the surge originates beyond the sun’s visible face, outside the range of earthbound telescopes.
MDI/SOI — short for Michelson Doppler Imager/Solar Oscillations Investigation — is more direct in its approach, measuring wave motions that vibrate through the convective layer of the sun. Depending on their amplitude, deviations from the wavelengths commonly registered by MDI/ SOI can put scientists on the lookout for helioseismological events that are roughly analogous to earthquakes and may be indicators of impending solar flare activity.
Relayed to earth by its telemetry arrays in near-real time, SOHO’s information about the flurry of concurrent beacon flashes and solar tremors did not take long to create a stir of excitement in its command-and-control center in Maryland.
Two men in particular got the headline-making jump on the rest of the pack.
Nimec ate the last bit of his turkey sandwich and set the empty plate onto a cafeteria tray beside him. Then he lifted his demitasse off the table and sipped.
“Well?” Megan said. “I await your verdict.”
“Mmm-mm,” he said.
“I may be a princess,” she said. “But I’m known for my benevolence, truthfulness, and good taste.”
He grunted. “About arranging for that helicopter…”
She made a preemptive gesture. “After we’ve had our coffee.”
He sat with the steaming espresso in his hand, watching her drink from her cup. It contained a double something-or-other with caffeine, flavored syrup, and a light head of froth.
Several minutes passed in silence that way.
“Okay, Pete,” she said at last, dabbing her upper lip with a napkin. “The chopper aside, what’s on your mind?”
“That line sounds very familiar,” he said.
She nodded. “It does. It also got a straight answer out of me.”
He looked at her without comment.
“Come on,” she said. “I didn’t miss your backpacker’s travel guide remarks about hearing how people find spiritual cleansing, harmony, and oneness among the king penguins. Or your question about whether I’ve joined that righteous crowd. Or most of all your long looks. Something’s bothering you. I think we should get it out in the open.”
Nimec kept looking at her, then finally expelled a breath.
“You told me you came to Antarctica because the boss asked,” he said. “Or at least you implied that. But I hear you volunteered.”
Megan lowered her cup into its saucer, waited as someone came moving past on his way from the service counter to another table.
“It seems you’ve been hearing a lot of things,” she said when he’d gone.
“Not from you,” he said. “That’s the problem. We never consulted about your reassignment.”
“You’re being unfair. I let you know a month beforehand.”
“After the decision was already made.”
“Pete—”
“I’d just like you to tell me why I wasn’t advised sooner,” he said. “All the years we’ve worked together, depended on each other, you never left me hanging. And then you did.”
“Pete, I’m sorry. Honestly. I didn’t realize that was how you felt.”
“Then tell me. Straight answer.”
Their eyes met. And held.
“It’s sort of complicated,” she said. “Gord wanting me here is the truth, but he’s the one to give you his reasons. As for myself, there were personal issues.”
“They involve Bob Lang?”
“Yes,” she said. “I preferred not to share them at the time.”
He nodded. Their eyes remained locked.
“And now?”
“I’d still rather not.”
“You change your mind, I’ll be ready to listen.”
“I know, Pete,” she said. “And thank you.”
He nodded again and sat there quietly finishing his espresso.
She reached out, touched his arm.
“Are we okay, Pete? Settled, I mean.”
“Settled.”
They were silent another minute, her hand still on his arm, squeezing it gently.
“All right,” he said then. “Coffee’s done. We should discuss the helicopter.”
She nodded, reached down into the kangaroo pocket of her bib-alls, and extracted a connected Palm computer.
“All the luxuries of home,” he commented.
Megan slipped the computer’s stylus out of its silo and tapped its “on” button.
“We try to be with it,” she said with a shrug. “Now hush, I need to jot out an e-mail. We’re presently short-
