"That's our minimum flight speed," Lewis told him shortly.
"I know that. What I meant was whether you could try something like a stall or some other fancy maneuver that would pull your speed temporarily lower."
"Wouldn't gain us enough, I'm afraid," Betsy said, sounding thoughtful. "Besides which, wing sections aren't designed for fancy maneuvers." She seemed to sigh. "We've got a new problem, folks. The shuttle's backwards drift, Aaron, was not the collar slipping. It was the last two supports bending, apparently under slightly unequal thrusts from the shuttle's engines."
Lewis growled an obscenity Greenburg had never heard him use. "What happens if they break? Does the collar fall off the shuttle?"
"The book says yes—but exactly when it goes depends on how fast the hydraulic fluid drains out. My guess is it would hold on long enough to turn the shuttle nose down before dropping off and crashing somewhere in the greater Fort Worth area."
"Followed immediately by the shuttle," Greenburg growled. His next task was clear—too clear. "All right, say no more. Tom, there should be a supply locker just forward of here. See if there's any rope or cable in it, would you?"
"What do you want that for?" Betsy asked, her tone edging toward suspicious.
"A safety harness. I'm going to go inside the bay and see if there's any way to get that forward clamp connected. Tom?"
"Yeah, there's some rope here. Just a second—I have to untangle it."
"Hold it, Tom," Betsy said. "Aaron, you're not going in there. You're a pilot, not a mechanic, remember? We'll wait for some professionals from the ground to handle this."
"Wait how long?" he shot back, apprehension putting snap into his tone. "Rayburn can't keep firing his engines all day; and even if he could you have no guarantee the thrusts from all three turbofans would stay properly balanced. Do you?"
There was a short silence, during which Greenburg was startled by something snaking abruptly across his chest. It was Lewis, perhaps sensing the outcome of the argument, starting to tie Greenburg's safety line around him. "No," Betsy finally answered his question. "Rayburn's on-board can't give us those numbers any more, and the support stress indicators aren't really sensitive enough."
"Which means chances are good the shuttle's going to continue putting stresses on the clamps—variable stresses, yet. They're bound to fatigue eventually under that kind of treatment."
"Mr. Greenburg—Aaron—look, the program's almost finished running." Whitney, putting in his two cents again. "Once it's done we can have people up here in fifteen minutes—"
"No; only once we've found the problem and made sure the other wing sections don't have it. Who knows how long that'll take?" A tug on the rope coming off the chest of the makeshift harness Lewis had tied around him and a slap on the back told him it was time. Gripping the edges of the opening, he raised a foot, seeking purchase on the curved wall. Lewis's cupped hands caught the foot, steadied it. Greenburg started to shift his weight... and paused. He was still, after all, under Betsy's authority. "Bets? Do I have permission to go?"
"All right. But listen: you've got one shot at the clamp, and whether it reaches or not you're coming straight out afterward. Understand? No one's ever been in a docking bay during flight before, and you're not equipped for unexpected problems."
"Gotcha. Here goes."
Greenburg had spent the past couple of minutes studying the curving bay wall, planning just how he was going to do this maneuver. Now, as he shifted his weight and pushed off of Lewis's hands, he discovered he hadn't planned things quite well enough. Pushing himself more or less vertically through the narrow opening, he twisted his body around as his torso cleared, coming down in a sitting position with his back to the shuttle. But he'd forgotten about the oxygen tank on the back of his belt, and the extra weight was enough to ruin his precarious balance and to send him sliding gracelessly down the curving metal on his butt.
He didn't slide far; Lewis, belaying the line, made sure of that. Getting his legs back around underneath him, Greenburg checked his footing and nodded back toward the opening. "Okay, I'm essentially down. Let me have some slack." Moving carefully, he stepped down into the teardrop-shaped well under the shuttle and walked to the nosewheel.
The forward clamp was designed to slide out of the wall as the landing gear was lowered, locating the tow bar by means of two short-range transponders installed in the gear. Earlier, up on the flight deck, Greenburg had confirmed the clamp operation had been begun but not completed; now, on closer study, the problem looked like it might be obvious.
"The shuttle's not only angled into the bay wrong, but it's also rotated a few degrees on its axis," he reported to the others. "I think maybe that the clamp's wrist rotated as far as it could to try and match, and when it couldn't get lined up apparently decided to quit and wait for instructions."
"The telltales say it is fully extended, though," Henson insisted.
"Well... maybe it's the sensors that got scrambled."
"Assume you're right," Betsy said. "Any way to fix it?"
"I don't know." Greenburg studied the clamp and landing gear, acutely aware of the vibrating shuttle above him—and of the vast distances beyond it. But even if the shuttle fell out and my rope broke I'd be all right, he told himself firmly. Standing in the cutout well that gave the shuttle's nosewheel room to descend, he was a good two meters below the rim of the bay's outer opening. There was a fair amount of eddy-generated wind turbulence plucking at his jumpsuit and adding a wind-chill to the frigid air—but it would take a lot of turbulence to force him up that slope and out. At least, he thought so.... "Why don't you try backing the clamp arm up and letting it take another run at the tow bar?"
"We'll have to wait for Peter's program to finish," Henson said. "The computer handles that."
"Oh... right." Greenburg hadn't thought of that. "How much longer?"
"It's almost—it's done," Whitney said.
"Where's the problem?" Betsy asked. Even with the turbofan engines droning in his ears Greenburg could hear the twin emotions of anticipation and dread in her voice.
"There doesn't seem to be one."
"That's ridiculous," Greenburg said. "Something made the shuttle crash."
"Well, the program can't find it. Look, it seems to me I felt the Skyport bounce a little just before the crash—"
"Clear air turbulence," Betsy said. "That shouldn't have been a problem; the guidance program is supposed to be able to handle small perturbations like that."
"Let's forget about the 'how' of it for now," a new voice broke in—Carl Young's, Greenburg tentatively identified it through the noise. "The point is that we can start bringing shuttles back up again. Greenburg, is there anything you can suggest we bring up from the ground to secure the shuttle with?"
"Uh... hell, I don't know. Something to use to get the passengers off would certainly be handy. And if this clamp arm won't rotate any further we might need an interfacing of some kind—maybe an extra clamp-and-wrist piece to extend our clamp's rotational range."
"I've already ordered some spare ski lift track from the ground—it should be coming up aboard the first shuttle, along with men to handle it. The clamp-and-wrist section we may be able to remove from one of the other bays; other people will be coming up to try that. What I meant was, can you see anything from there that we didn't already know about?"
"Not really." Greenburg was starting to feel a little foolish as his brave descent into the bay began to look more and more unnecessary. With the guidance system coming up clean, shuttleloads of experts would be here in minutes. So much for the value of impulsive heroics, he thought acridly; but at least it hadn't wasted too much time. He'd always been much better as a team player, anyway. "Hold on tight, Tom; I'm coming up," he called, getting a grip on his safety line.